3,103 research outputs found

    Late metal-silicate separation on the IAB parent asteroid: Constraints from combined W and Pt isotopes and thermal modelling

    Full text link
    The short-lived 182^{182}Hf-182^{182}W decay system is a powerful chronometer for constraining the timing of metal-silicate separation and core formation in planetesimals and planets. Neutron capture effects on W isotopes, however, significantly hamper the application of this tool. In order to correct for neutron capture effects, Pt isotopes have emerged as a reliable in-situ neutron dosimeter. This study applies this method to IAB iron meteorites, in order to constrain the timing of metal segregation on the IAB parent body. The ϔ182\epsilon^{182}W values obtained for the IAB iron meteorites range from -3.61 ±\pm 0.10 to -2.73 ±\pm 0.09. Correlating ϔi\epsilon^{\mathrm{i}}Pt with 182^{182}W data yields a pre-neutron capture 182^{182}W of -2.90 ±\pm 0.06. This corresponds to a metal-silicate separation age of 6.0 ±\pm 0.8 Ma after CAI for the IAB parent body, and is interpreted to represent a body-wide melting event. Later, between 10 and 14 Ma after CAI, an impact led to a catastrophic break-up and subsequent reassembly of the parent body. Thermal models of the interior evolution that are consistent with these estimates suggest that the IAB parent body underwent metal-silicate separation as a result of internal heating by short-lived radionuclides and accreted at around 1.4 ±\pm 0.1 Ma after CAIs with a radius of greater than 60 km.Comment: 11 pages, 8 figures, 2 tables; open access article under the CC BY-NC-ND license (see http://creativecommons.org/licenses/by-nc-nd/4.0/

    Effects of omega-3 polyunsaturated fatty acid supplementation on cognitive functioning in youth at ultra-high risk for psychosis: secondary analysis of the NEURAPRO randomised controlled trial

    Full text link
    BACKGROUND: Cognitive impairments are well-established features of psychotic disorders and are present when individuals are at ultra-high risk for psychosis. However, few interventions target cognitive functioning in this population. AIMS: To investigate whether omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation improves cognitive functioning among individuals at ultra-high risk for psychosis. METHOD: Data (N = 225) from an international, multi-site, randomised controlled trial (NEURAPRO) were analysed. Participants were given omega-3 supplementation (eicosapentaenoic acid and docosahexaenoic acid) or placebo over 6 months. Cognitive functioning was assessed with the Brief Assessment of Cognition in Schizophrenia (BACS). Mixed two-way analyses of variance were computed to compare the change in cognitive performance between omega-3 supplementation and placebo over 6 months. An additional biomarker analysis explored whether change in erythrocyte n-3 PUFA levels predicted change in cognitive performance. RESULTS: The placebo group showed a modest greater improvement over time than the omega-3 supplementation group for motor speed (ηp_{p}2^{2} = 0.09) and BACS composite score (ηp_{p}2^{2} = 0.21). After repeating the analyses without individuals who transitioned, motor speed was no longer significant (ηp_{p}2^{2} = 0.02), but the composite score remained significant (ηp_{p}2^{2} = 0.02). Change in erythrocyte n-3 PUFA levels did not predict change in cognitive performance over 6 months. CONCLUSIONS: We found no evidence to support the use of omega-3 supplementation to improve cognitive functioning in ultra-high risk individuals. The biomarker analysis suggests that this finding is unlikely to be attributed to poor adherence or consumption of non-trial n-3 PUFAs

    Exploring the use of Fitbit consumer activity trackers to support active lifestyles in adults with Type 2 Diabetes : a mixed methods study

    Get PDF
    Background: People with type 2 diabetes are less active than those without the condition. Physical activity promotion within diabetes health care is limited. This project explored the use of Fitbit activity trackers (Fitbit, San Francisco, CA, USA) to support active lifestyles in adults with type 2 diabetes through a mixed-methods study. Methods: Two stages were conducted. In stage 1, adults with type 2 diabetes used a Fitbit Charge 4 (Fitbit, San Francisco, CA, USA) for 4 weeks. Fitbit and self-reported physical activity data was examined through quantitative analysis. Qualitative analysis was conducted to explore the experiences of participants. In stage 2, health professionals were interviewed to examine their views on using Fitbit activity trackers within type 2 diabetes care. Results: Adults with type 2 diabetes were recruited for stage 1 and adult health care and fitness professionals were recruited for stage 2. Stage 1 participants’ self-reported increases in physical activity (mean weekly minutes of walking increased from 358.75 to 507.50 min, p = 0.046) and a decrease in sedentary behaviour (mean daily hours of sedentary behaviour decreased from 10.65 to 10.05 h, p = 0.575). Fitbit activity data ranges identified individuals who led inactive and sedentary lifestyles below levels recommended and in need of physical activity support to reduce the risk to their health. During interviews, participants stated that the Fitbit activity tracker motivated them to be more active. Stage 2 participants intimated that Fitbit activity trackers could improve the promotion of physical activity within type 2 diabetes care. Interventions involving the Fitbit premium service, community prescription and combined use of Fitbits with physical activity behaviour change models were recommended by stage 2 participants. Conclusion: This study found that there is future scope for using Fitbit activity trackers to support active lifestyles in adults diagnosed with type 2 diabetes

    Quality prescribing for Benzodiazepines and z-drugs: guide for improvement 2024 to 2027

    Get PDF
    Benzodiazepines and z-drugs are indicated for a variety of conditions including the short-term relief of severe insomnia and some anxiety disorders. People can quickly become tolerant to the therapeutic effects of benzodiazepines and z-drugs, rendering them ineffective. Nonetheless chronic use is common, exposing people to avoidable adverse drug effects and harms, and associated increased mortality risks with their use.This guide is primarily intended to support healthcare professionals and others in the appropriate prescribing of benzodiazepines and z-drugs; supporting and enabling proactive person-centred reviews, and continuation, reduction and stopping of these medicines where appropriate.An important principle in improving the care of individuals on benzodiazepine and z-drugs is to consider the role of the individual in shared decision-making and adopt a person-centred approach when discussing treatment options available. The 7-Steps medication review process allows a person-centred approach to both the initiation and review of existing treatment, centred around the needs of the individual

    Quality prescribing for antidepressants: guide for improvement 2024 to 2027

    Get PDF
    The prescribing of antidepressants continues to increase in Scotland, with many people receiving antidepressants for two years or more. This may be appropriate for some individuals, but it is important that ongoing treatment is reviewed regularly and that the risks and benefits of treatment are discussed. Treatment goals should be agreed with individuals, both at the time of initiation and when reviewing medication, and treatment plans should take a holistic approach to management and support. These should include discussions of non-pharmacological and wider community support options where these are available and indicated.This prescribing advice is primarily intended to support and encourage the appropriate use of antidepressants for mental health and physical conditions, as part of the wider treatment options available. It supports appropriate initiation of antidepressants, regular and proactive reviews, reduction and stopping of treatment where it is ineffective or where treatment courses have been completed. Regular person-centred reviews can optimise the care of those receiving antidepressants and minimise avoidable medicine-related harm. These reviews can also support and enable appropriate continuation of antidepressant treatment where this is required, using the 7-Steps person-centred review approach

    An open label pilot trial of low‐dose lithium for young people at ultra‐high risk for psychosis

    Get PDF
    Aim: Lithium, even at low doses, appears to offer neuroprotection against a wide variety of insults. In this controlled pilot, we examined the safety (i.e., side‐effect profile) of lithium in a sample of young people identified at ultra‐high risk (UHR) for psychosis. The secondary aim was to explore whether lithium provided a signal of clinical efficacy in reducing transition to psychosis compared with treatment as usual (TAU). Methods: Young people attending the PACE clinic at Orygen, Melbourne, were prescribed a fixed dose (450 mg) of lithium (n = 25) or received TAU (n = 78). The primary outcome examined side‐effects, with transition to psychosis, functioning and measures of psychopathology assessed as secondary outcomes. Results: Participants in both groups were functionally compromised (lithium group GAF = 56.6; monitoring group GAF = 56.9). Side‐effect assessment indicated that lithium was well‐tolerated. 64% (n = 16) of participants in the lithium group were lithium‐adherent to week 12. Few cases transitioned to psychosis across the study period; lithium group 4% (n = 1); monitoring group 7.7% (n = 6). There was no difference in time to transition to psychosis between the groups. No group differences were observed in other functioning and symptom domains, although all outcomes improved over time. Conclusions: With a side‐effect profile either comparable to, or better than UHR antipsychotic trials, lithium might be explored for further research with UHR young people. A definitive larger trial is needed to determine the efficacy of lithium in this cohort

    Effects of omega-3 polyunsaturated fatty acid supplementation on cognitive functioning in youth at ultra-high risk for psychosis: secondary analysis of the NEURAPRO randomised controlled trial.

    Get PDF
    BACKGROUND Cognitive impairments are well-established features of psychotic disorders and are present when individuals are at ultra-high risk for psychosis. However, few interventions target cognitive functioning in this population. AIMS To investigate whether omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation improves cognitive functioning among individuals at ultra-high risk for psychosis. METHOD Data (N = 225) from an international, multi-site, randomised controlled trial (NEURAPRO) were analysed. Participants were given omega-3 supplementation (eicosapentaenoic acid and docosahexaenoic acid) or placebo over 6 months. Cognitive functioning was assessed with the Brief Assessment of Cognition in Schizophrenia (BACS). Mixed two-way analyses of variance were computed to compare the change in cognitive performance between omega-3 supplementation and placebo over 6 months. An additional biomarker analysis explored whether change in erythrocyte n-3 PUFA levels predicted change in cognitive performance. RESULTS The placebo group showed a modest greater improvement over time than the omega-3 supplementation group for motor speed (ηp2 = 0.09) and BACS composite score (ηp2 = 0.21). After repeating the analyses without individuals who transitioned, motor speed was no longer significant (ηp2 = 0.02), but the composite score remained significant (ηp2 = 0.02). Change in erythrocyte n-3 PUFA levels did not predict change in cognitive performance over 6 months. CONCLUSIONS We found no evidence to support the use of omega-3 supplementation to improve cognitive functioning in ultra-high risk individuals. The biomarker analysis suggests that this finding is unlikely to be attributed to poor adherence or consumption of non-trial n-3 PUFAs

    Evidence that complement and coagulation proteins are mediating the clinical response to omega-3 fatty acids: A mass spectrometry-based investigation in subjects at clinical high-risk for psychosis.

    Get PDF
    Preliminary evidence indicates beneficial effects of omega-3 polyunsaturated fatty acids (PUFAs) in early psychosis. The present study investigates the molecular mechanism of omega-3 PUFA-associated therapeutic effects in clinical high-risk (CHR) participants. Plasma samples of 126 CHR psychosis participants at baseline and 6-months follow-up were included. Plasma protein levels were quantified using mass spectrometry and erythrocyte omega-3 PUFA levels were quantified using gas chromatography. We examined the relationship between change in polyunsaturated PUFAs (between baseline and 6-month follow-up) and follow-up plasma proteins. Using mediation analysis, we investigated whether plasma proteins mediated the relationship between change in omega-3 PUFAs and clinical outcomes. A 6-months change in omega-3 PUFAs was associated with 24 plasma proteins at follow-up. Pathway analysis revealed the complement and coagulation pathway as the main biological pathway to be associated with change in omega-3 PUFAs. Moreover, complement and coagulation pathway proteins significantly mediated the relationship between change in omega-3 PUFAs and clinical outcome at follow-up. The inflammatory protein complement C5 and protein S100A9 negatively mediated the relationship between change in omega-3 PUFAs and positive symptom severity, while C5 positively mediated the relationship between change in omega-3 and functional outcome. The relationship between change in omega-3 PUFAs and cognition was positively mediated through coagulation factor V and complement protein C1QB. Our findings provide evidence for a longitudinal association of omega-3 PUFAs with complement and coagulation protein changes in the blood. Further, the results suggest that an increase in omega-3 PUFAs decreases symptom severity and improves cognition in the CHR state through modulating effects of complement and coagulation proteins
    • 

    corecore