103 research outputs found

    Environment sensing in spring-dispersed seeds of a winter annual Arabidopsis influences the regulation of dormancy to align germination potential with seasonal changes

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    Seed dormancy cycling plays a crucial role in the lifecycle timing of many plants. Little is known of how the seeds respond to the soil seed bank environment following dispersal in spring into the short-term seed bank before seedling emergence in autumn. Seeds of the winter annual Arabidopsis ecotype Cvi were buried in field soils in spring and recovered monthly until autumn and their molecular eco-physiological responses were recorded. DOG1 expression is initially low and then increases as dormancy increases. MFT expression is negatively correlated with germination potential. Abscisic acid (ABA) and gibberellin (GA) signalling responds rapidly following burial and adjusts to the seasonal change in soil temperature. Collectively these changes align germination potential with the optimum climate space for seedling emergence. Seeds naturally dispersed to the soil in spring enter a shallow dormancy cycle dominated by spatial sensing that adjusts germination potential to the maximum when soil environment is most favourable for germination and seedling emergence upon soil disturbance. This behaviour differs subtly from that of seeds overwintered in the soil seed bank to spread the period of potential germination in the seed population (existing seed bank and newly dispersed). As soil temperature declines in autumn, deep dormancy is re-imposed as seeds become part of the persistent seed bank

    Probing the Gravitational Wave Signature from Cosmic Phase Transitions at Different Scales

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    We present a new signature by which to one could potentially discriminate between a spectrum of gravitational radiation generated by a self-ordering scalar field vs that of inflation, specifically a comparison of the magnitude of a flat spectrum at frequencies probed by future direct detection experiments to the magnitude of a possible polarization signal in the Cosmic Microwave Background (CMB) radiation. In the process we clarify several issues related to the proper calculation of such modes, focusing on the effect of post-horizon-crossing evolution.Comment: 4 pages, Phys. Rev D version (revised in response to referee's comments

    The impact of the resident duty hour regulations on surgical patients’ perceptions of care

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    Implementation of the 2003 Accreditation Council for Graduate Medical Education (ACGME) resident duty-hour regulations and access to publicly reported patient satisfaction measures have challenged administrators and clinicians to balance resident’s educational experience, patient care quality, and patients’ satisfaction and perceptions. A pre-post retrospective study design investigated association between implementation of ACGME regulations and patient satisfaction/perceptions using multinomial logistic regressions. The sample consisted of all surgical inpatients (July 2001 – June 2005), who responded to surveys at an academic medical center. Patients gave lower ratings for physician interactions (patient-physician interaction time, clinical updates, and courtesy) following the implementation of post-duty hour regulations. While the odds of patients rating “below good” post-implementation for physician survey questions (i.e., related to time spent, kept informed, and friendliness/ courtesy) were higher (i.e., 1.25 to 1.3) as compared to odds of rating “very good”, the overall rating of quality care improved post-implementation. This difference could be due to increased interaction of patients with other hospital personnel. To improve patient satisfactions and in turn their perceptions, initiatives such as workload balancing, hand-off protocols, patient communication, and interactive training for care providers are recommended. Finally, residency programs and institutions need to develop strategies for implementation of current and future ACGME duty hour regulations so as to balance patient safety, patient perceptions, and resident well-being

    Monocyte dysregulation and systemic inflammation during pediatric falciparum malaria

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    BACKGROUND: Inflammation and monocytes are thought to be important to human malaria pathogenesis. However, the relationship of inflammation and various monocyte functions to acute malaria, recovery from acute malaria, and asymptomatic parasitemia in endemic populations is poorly understood. METHODS: We evaluated plasma cytokine levels, monocyte subsets, monocyte functional responses, and monocyte inflammatory transcriptional profiles of 1- to 10-year-old Kenyan children at the time of presentation with acute uncomplicated malaria and at recovery 6 weeks later; these results were compared with analogous data from asymptomatic children and adults in the same community. RESULTS: Acute malaria was marked by elevated levels of proinflammatory and regulatory cytokines and expansion of the inflammatory intermediate monocyte subset that returned to levels of healthy asymptomatic children 6 weeks later. Monocytes displayed activated phenotypes during acute malaria, with changes in surface expression of markers important to innate and adaptive immunity. Functionally, acute malaria monocytes and monocytes from asymptomatic infected children had impaired phagocytosis of P. falciparum-infected erythrocytes relative to asymptomatic children with no blood-stage infection. Monocytes from both acute malaria and recovery time points displayed strong and equivalent cytokine responsiveness to innate immune agonists that were independent of infection status. Monocyte transcriptional profiles revealed regulated and balanced proinflammatory and antiinflammatory and altered phagocytosis gene expression patterns distinct from malaria-naive monocytes. CONCLUSION: These observations provide insights into monocyte functions and the innate immune response during uncomplicated malaria and suggest that asymptomatic parasitemia in children is not clinically benign. FUNDING: Support for this work was provided by NIH/National Institute of Allergy and Infectious Diseases (R01AI095192-05), the Burroughs Wellcome Fund/American Society of Tropical Medicine and Hygiene, and the Rainbow Babies & Children\u27s Foundation

    Study protocol for a randomised controlled trial assessing the clinical and cost-effectiveness of the Journeying through Dementia (JtD) intervention compared to usual care

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    Introduction Services are being encouraged to provide postdiagnostic treatment to those with dementia but the availability of evidence-based interventions following diagnosis has not kept pace with increase in demand. To address this need, the Journeying through Dementia (JtD) intervention was created. A randomised controlled trial (RCT), based on a pilot study, is in progress. Methods and analysis The RCT is a pragmatic, two-arm, parallel group trial designed to test the clinical and cost-effectiveness of JtD compared with usual care. Recruitment will be through NHS services, third sector organisations and Join Dementia Research. The sample size is 486 randomised (243 to usual care and 243 to the intervention usual care). Participants can choose to ask a friend or relative (supporter) to become involved in the study. The primary outcome measure for participants is Dementia-Related Quality of Life (DEMQOL), collected at baseline and at 8 months’ postrandomisation. Secondary outcome measures will be collected from participants and supporters at those visits. Participants will also be followed up at 12 months’ postrandomisation with a reduced set of measures. A process evaluation will be conducted through qualitative and fidelity substudies. Analyses will compare the two arms of the trial on an intention to treat as allocated basis. The primary analyses will compare the mean DEMQOL scores of the participants at 8 months between the two study arms. A cost-effectiveness analysis will consider the incremental cost per Quality Adjusted Life Years of the intervention compared with usual care. Qualitative and fidelity substudies will be analysed through framework analysis and fidelity assessment tools respectively. Ethics and dissemination REC and HRA approval were obtained. A Data Monitoring and Ethics Committee has been constituted. Dissemination will be via publications, conferences and social media. Intervention materials will be made open access. Trial registration number ISRCTN17993825

    The Effectiveness of Alcohol Screening and Brief Intervention in Emergency Departments: A Multicentre Pragmatic Cluster Randomized Controlled Trial

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    BACKGROUND: Alcohol misuse is common in people attending emergency departments (EDs) and there is some evidence of efficacy of alcohol screening and brief interventions (SBI). This study investigated the effectiveness of SBI approaches of different intensities delivered by ED staff in nine typical EDs in England: the SIPS ED trial. METHODS AND FINDINGS: Pragmatic multicentre cluster randomized controlled trial of SBI for hazardous and harmful drinkers presenting to ED. Nine EDs were randomized to three conditions: a patient information leaflet (PIL), 5 minutes of brief advice (BA), and referral to an alcohol health worker who provided 20 minutes of brief lifestyle counseling (BLC). The primary outcome measure was the Alcohol Use Disorders Identification Test (AUDIT) status at 6 months. Of 5899 patients aged 18 or more presenting to EDs, 3737 (63·3%) were eligible to participate and 1497 (40·1%) screened positive for hazardous or harmful drinking, of whom 1204 (80·4%) gave consent to participate in the trial. Follow up rates were 72% (n?=?863) at six, and 67% (n?=?810) at 12 months. There was no evidence of any differences between intervention conditions for AUDIT status or any other outcome measures at months 6 or 12 in an intention to treat analysis. At month 6, compared to the PIL group, the odds ratio of being AUDIT negative for brief advice was 1·103 (95% CI 0·328 to 3·715). The odds ratio comparing BLC to PIL was 1·247 (95% CI 0·315 to 4·939). A per protocol analysis confirmed these findings. CONCLUSIONS: SBI is difficult to implement in typical EDs. The results do not support widespread implementation of alcohol SBI in ED beyond screening followed by simple clinical feedback and alcohol information, which is likely to be easier and less expensive to implement than more complex interventions

    Assessing fidelity of a community based psychosocial intervention for people with mild dementia within a large randomised controlled trial

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    Abstract: Background: Understanding intervention delivery as intended, particularly in complex interventions, should be underpinned by good quality fidelity assessment. We present the findings from a fidelity assessment embedded as part of a trial of a complex community-based psychosocial intervention, Journeying through Dementia (JtD). The intervention was designed to equip individuals with the knowledge and skills to successfully self-manage, maintain independence, and live well with dementia and involves both group and individual sessions. The methodological challenges of developing a conceptual framework for fidelity assessment and creating and applying purposely designed measures derived from this framework are discussed to inform future studies. Methods: A conceptual fidelity framework was created out of core components of the intervention (including the intervention manual and training for delivery), associated trial protocols and pre-defined fidelity standards and criteria against which intervention delivery and receipt could be measured. Fidelity data collection tools were designed and piloted for reliability and usability. Data collection in four selected sites (fidelity sites) was via non-participatory observations of the group aspect of the intervention, attendance registers and interventionist (facilitator and supervisor) self-report. Results: Interventionists from all four fidelity sites attended intervention training. The majority of group participants at the four sites (71%) received the therapeutic dose of 10 out of 16 sessions. Weekly group meeting attendance (including at ‘out of venue’ sessions) was excellent at 80%. Additionally, all but one individual session was attended by the participants who completed the intervention. It proved feasible to create tools derived from the fidelity framework to assess in-venue group aspects of this complex intervention. Results of fidelity assessment of the observed groups were good with substantial inter-rater reliability between researchers KAPPA 0.68 95% CI (0.58–0.78). Self-report by interventionists concurred with researcher assessments. Conclusions: There was good fidelity to training and delivery of the group aspect of the intervention at four sites. However, the methodological challenges of assessing all aspects of this complex intervention could not be overcome due to practicalities, assessment methods and ethical considerations. Questions remain regarding how we can assess fidelity in community-based complex interventions without impacting upon intervention or trial delivery. Trial registration: ISRCTN17993825

    The Journeying through Dementia psychosocial intervention versus usual care study: a two-arm, phase 3, superiority randomised controlled trial

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    Background There is an urgent clinical need for evidence based psychosocial interventions for people with mild dementia. We aimed to determine clinical and cost-effectiveness of Journeying through Dementia (JtD), an intervention designed to promote wellbeing and independence in people with mild dementia. Methods We conducted a phase 3, two-arm parallel group, superiority, individually randomised controlled trial. Thirteen NHS sites across England recruited community-dwelling people with mild dementia and Mini-Mental State Examination score of ≥18. Centralised randomisation (1:1) was conducted for participants to receive JtD plus usual care or usual care (control), stratified by site. The JtD Intervention comprised 12 group and four one-to-one sessions, delivered in the community at each site. The primary endpoint was Dementia Related Quality of Life (DEMQOL), eight-months postrandomisation. Only outcome assessors were blinded. Analysis was by intention-to-treat. Costeffectiveness analysis reported cost per quality adjusted life year (QALY) from a UK NHS and social care perspective. Findings In total 480 people were randomised to intervention (241) or control (239) arms. Intervention adherence was very good. Mean DEMQOL scores at eight months were intervention arm 93·3 (SD 13·0, n=191) and control 91·9 (SD 14·6, n=197). Difference in means was 0·9 (95% CI -1·2 to 3·0) after adjustment for covariates, lower than that identified as clinically meaningful. Incremental cost per QALY ranged from £88K to -£205K, indicating that JtD was not cost-effective. Unrelated serious adverse events were experienced by 17% (40/241) of intervention and 15% (35/239) of control participants. Interpretation In common with other recently reported studies the JtD intervention was not provenly effective. However, this complex trial successfully recruited and retained people with dementia without necessarily involving carers, and people with dementia they were actively involved as participants and study advisors throughout. Further research into methods of measuring small, meaningful changes in this population is needed. Questions remain regarding how services can match the complex, diverse and individual needs of people with mild dementia, and how interventions to meet such needs can be delivered at scale

    Incorporation of uranium into hematite during crystallization from ferrihydrite

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    Ferrihydrite was exposed to U(VI)-containing cement leachate (pH 10.5) and aged to induce crystallization of hematite. A combination of chemical extractions, TEM, and XAS techniques provided the first evidence that adsorbed U(VI) (≈3000 ppm) was incorporated into hematite during ferrihydrite aggregation and the early stages of crystallization, with continued uptake occurring during hematite ripening. Analysis of EXAFS and XANES data indicated that the U(VI) was incorporated into a distorted, octahedrally coordinated site replacing Fe(III). Fitting of the EXAFS showed the uranyl bonds lengthened from 1.81 to 1.87 Å, in contrast to previous studies that have suggested that the uranyl bond is lost altogether upon incorporation into hematite the results of this study both provide a new mechanistic understanding of uranium incorporation into hematite and define the nature of the bonding environment of uranium within the mineral structure. Immobilization of U(VI) by incorporation into hematite has clear and important implications for limiting uranium migration in natural and engineered environments. © 2014 American Chemical Society

    Susceptibility and immunity to helminth parasites

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    Parasitic helminth infection remains a global health problem, whilst the ability of worms to manipulate and dampen the host immune system is attracting interest in the fields of allergy and autoimmunity. Much progress has been made in the last two years in determining the cells and cytokines involved in induction of Type 2 immunity, which is generally protective against helminth infection. Innate cells respond to ‘alarmin’ cytokines (IL-25, IL-33, TSLP) by producing IL-4, IL-5 and IL-13, and this sets the stage for a more potent subsequent adaptive Th2 response. CD4+ Th2 cells then drive a suite of type 2 anti-parasite mechanisms, including class-switched antibodies, activated leukocytes and innate defence molecules; the concerted effects of these multiple pathways disable, degrade and dislodge parasites, leading to their destruction or expulsion
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