228 research outputs found

    CyberShake-derived ground-motion prediction models for the Los Angeles region with application to earthquake early warning

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    Real-time applications such as earthquake early warning (EEW) typically use empirical ground-motion prediction equations (GMPEs) along with event magnitude and source-to-site distances to estimate expected shaking levels. In this simplified approach, effects due to finite-fault geometry, directivity and site and basin response are often generalized, which may lead to a significant under- or overestimation of shaking from large earthquakes (M > 6.5) in some locations. For enhanced site-specific ground-motion predictions considering 3-D wave-propagation effects, we develop support vector regression (SVR) models from the SCEC CyberShake low-frequency (415 000 finite-fault rupture scenarios (6.5 ≤ M ≤ 8.5) for southern California defined in UCERF 2.0. We use CyberShake to demonstrate the application of synthetic waveform data to EEW as a ‘proof of concept’, being aware that these simulations are not yet fully validated and might not appropriately sample the range of rupture uncertainty. Our regression models predict the maximum and the temporal evolution of instrumental intensity (MMI) at 71 selected test sites using only the hypocentre, magnitude and rupture ratio, which characterizes uni- and bilateral rupture propagation. Our regression approach is completely data-driven (where here the CyberShake simulations are considered data) and does not enforce pre-defined functional forms or dependencies among input parameters. The models were established from a subset (∼20 per cent) of CyberShake simulations, but can explain MMI values of all >400 k rupture scenarios with a standard deviation of about 0.4 intensity units. We apply our models to determine threshold magnitudes (and warning times) for various active faults in southern California that earthquakes need to exceed to cause at least ‘moderate’, ‘strong’ or ‘very strong’ shaking in the Los Angeles (LA) basin. These thresholds are used to construct a simple and robust EEW algorithm: to declare a warning, the algorithm only needs to locate the earthquake and to verify that the corresponding magnitude threshold is exceeded. The models predict that a relatively moderate M6.5–7 earthquake along the Palos Verdes, Newport-Inglewood/Rose Canyon, Elsinore or San Jacinto faults with a rupture propagating towards LA could cause ‘very strong’ to ‘severe’ shaking in the LA basin; however, warning times for these events could exceed 30 s

    CyberShake-derived ground-motion prediction models for the Los Angeles region with application to earthquake early warning

    Get PDF
    Real-time applications such as earthquake early warning (EEW) typically use empirical ground-motion prediction equations (GMPEs) along with event magnitude and source-to-site distances to estimate expected shaking levels. In this simplified approach, effects due to finite-fault geometry, directivity and site and basin response are often generalized, which may lead to a significant under- or overestimation of shaking from large earthquakes (M>6.5) in some locations. For enhanced site-specific ground-motion predictions considering 3-D wave-propagation effects, we develop support vector regression (SVR) models from the SCEC CyberShake low-frequency (415000 finite-fault rupture scenarios (6.5 ≤ M ≤ 8.5) for southern California defined in UCERF 2.0. We use CyberShake to demonstrate the application of synthetic waveform data to EEW as a ‘proof of concept', being aware that these simulations are not yet fully validated and might not appropriately sample the range of rupture uncertainty. Our regression models predict the maximum and the temporal evolution of instrumental intensity (MMI) at 71 selected test sites using only the hypocentre, magnitude and rupture ratio, which characterizes uni- and bilateral rupture propagation. Our regression approach is completely data-driven (where here the CyberShake simulations are considered data) and does not enforce pre-defined functional forms or dependencies among input parameters. The models were established from a subset (∼20per cent) of CyberShake simulations, but can explain MMI values of all>400 k rupture scenarios with a standard deviation of about 0.4 intensity units. We apply our models to determine threshold magnitudes (and warning times) for various active faults in southern California that earthquakes need to exceed to cause at least ‘moderate', ‘strong' or ‘very strong' shaking in the Los Angeles (LA) basin. These thresholds are used to construct a simple and robust EEW algorithm: to declare a warning, the algorithm only needs to locate the earthquake and to verify that the corresponding magnitude threshold is exceeded. The models predict that a relatively moderate M6.5-7 earthquake along the Palos Verdes, Newport-Inglewood/Rose Canyon, Elsinore or San Jacinto faults with a rupture propagating towards LA could cause ‘very strong' to ‘severe' shaking in the LA basin; however, warning times for these events could exceed 30

    Variation in the Neisseria lactamica porin, and its relationship to meningococcal PorB

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    One potential vaccine strategy in the fight against meningococcal disease involves the exploitation of outer-membrane components of Neisseria lactamica, a commensal bacterium closely related to the meningococcus, Neisseria meningitidis. Although N. lactamica shares many surface structures with the meningococcus, little is known about the antigenic diversity of this commensal bacterium or the antigenic relationships between N. lactamica and N. meningitidis. Here, the N. lactamica porin protein (Por) was examined and compared to the related PorB antigens of N. meningitidis, to investigate potential involvement in anti-meningococcal immunity. Relationships among porin sequences were determined using distance-based methods and FST, and maximum-likelihood analyses were used to compare the selection pressures acting on the encoded proteins. These analyses demonstrated that the N. lactamica porin was less diverse than meningococcal PorB and although it was subject to positive selection, this was not as strong as the positive selection pressures acting on the meningococcal porin. In addition, the N. lactamica porin gene sequences and the protein sequences of the loop regions predicted to be exposed to the human immune system were dissimilar to the corresponding sequences in the meningococcus. This suggests that N. lactamica Por, contrary to previous suggestions, may have limited involvement in the development of natural immunity to meningococcal disease and might not be effective as a meningococcal vaccine component

    Development and evaluation of a collaborative care intervention for male prison leavers with mental health problems: the Engager research programme

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    BackgroundMany male prison leavers have significant mental health problems. Prison leavers often have a history of trauma, ongoing substance misuse and housing insecurity. Only a minority of prison leavers receive mental health care on release from prison.ObjectivesThe aim of the Engager research programme was to develop and evaluate a theory- and evidence-informed complex intervention designed to support individuals with common mental health problems (e.g. anxiety, depression) and other complex needs, including mental health comorbidity, before and after release from prison.MethodsIn phase 1, the intervention was developed through a set of realist-informed substudies, including a realist review of psychosocial care for individuals with complex needs, case studies within services demonstrating promising intervention features, focus groups with individuals from under-represented groups, a rapid realist review of the intervention implementation literature and a formative process evaluation of the prototype intervention. In a parallel randomised trial, methodological development included selecting outcome measures through reviewing literature, piloting measures and a consensus process, developing ways to quantify intervention receipt, piloting trial procedures and modelling economic outcomes. In phase 2, we conducted an individually randomised superiority trial of the Engager intervention, cost-effectiveness and cost–consequence analyses and an in-depth mixed-methods process evaluation. Patient and public involvement influenced the programme throughout, primarily through a Peer Researcher Group.ResultsIn phase 1, the Engager intervention included multiple components. A practitioner offered participants practical support, emotional help (including mentalisation-based approaches) and liaison with other services in prison on the day of the participant’s release and for 3–5 months post release. An intervention delivery platform (i.e. training, manual, supervision) supported implementation. Outcome measures were selected through testing and stakeholder consensus to represent a broad range of domains, with a general mental health outcome as the primary measure for the trial. Procedures for recruitment and follow-up were tested and included flexible approaches to engagement and retention. In phase 2, the trial was conducted in three prison settings, with 280 participants randomised in a 1 : 1 ratio to receive either Engager plus usual care (n = 140) or usual care only (n = 140). We achieved a follow-up rate of 65% at 6 months post release from prison. We found no difference between the two groups for the Clinical Outcomes in Routine Evaluation – Outcome Measure at 6 months. No differences in secondary measures and sensitivity analyses were found beyond those expected by chance. The cost-effectiveness analysis showed that Engager cost significantly more at £2133 (95% of iterations between £997 and £3374) with no difference in quality-adjusted life-years (–0.017, 95% of iterations between –0.042 and 0.007). The mixed-methods process evaluation demonstrated implementation barriers. These barriers included problems with retention of the intervention team, and the adverse health and criminal justice system context. Seventy-seven per cent (108/140) of individuals had at least one community contact. Significant proportions of participants engaging received day release work and practical support. In contrast, there was evidence that the psychological components, mentalisation and developing a shared understanding were used less consistently. When engagement was positive, these components were associated with positive achievement of goals for individuals. We were also able to identify how to improve the intervention programme theory, including how to support individuals who were unrealistic in their perception of their ability to cope with challenges post release.Strengths and limitationsOur development work provides a worked example of the development of a complex intervention, particularly given little prior evidence or theory specific to male offenders to build on. Our trial methodological development enabled the completion of, to the best of our knowledge, the first fully powered trial of a mental health intervention for prison leavers with common mental health problems. There were potential weaknesses in the trial methodology in terms of follow-up rates and outcome measures, with the latter potentially being insufficiently sensitive to important but highly individual changes in participants who responded to the intervention.ConclusionsDelivering a randomised controlled trial for prison leavers with acceptable levels of follow-up is possible, despite adverse conditions. Full intervention implementation was challenging, but this is to be expected. Some individuals did respond well to the intervention when both practical and psychological support were flexibly deployed as intended, with evidence that most components were experienced as helpful for some individuals. It is recommended that several key components be developed further and tested, along with improved training and supervision, to support delivery of the Engager intervention within existing teams working with prison leavers

    Task shifting to non-physician clinicians for integrated management of hypertension and diabetes in rural Cameroon: a programme assessment at two years

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    <p>Abstract</p> <p>Background</p> <p>The burden of non-communicable chronic diseases, such as hypertension and diabetes, increases in sub-Saharan Africa. However, the majority of the rural population does still not have access to adequate care. The objective of this study is to examine the effectiveness of integrating care for hypertension and type 2 diabetes by task shifting to non-physician clinician (NPC) facilities in eight rural health districts in Cameroon.</p> <p>Methods</p> <p>Of the 75 NPC facilities in the area, 69 (87%) received basic equipment and training in hypertension and diabetes care. Effectiveness was assessed after two years on status of equipment, knowledge among trained NPCs, number of newly detected patients, retention of patients under care, treatment cost to patients and changes in blood pressure (BP) and fasting plasma glucose (FPG) among treated patients.</p> <p>Results</p> <p>Two years into the programme, of 54 facilities (78%) available for re-assessment, all possessed a functional sphygmomanometer and stethoscope (65% at baseline); 96% stocked antihypertensive drugs (27% at baseline); 70% possessed a functional glucose meter and 72% stocked oral anti-diabetics (15% and 12% at baseline). NPCs' performance on multiple-choice questions of the knowledge-test was significantly improved. During a period of two years, trained NPCs initiated treatment for 796 patients with hypertension and/or diabetes. The retention of treated patients at one year was 18.1%. Hypertensive and diabetic patients paid a median monthly amount of 1.4 and 0.7 Euro respectively for their medication. Among hypertensive patients with ≥ 2 documented visits (n = 493), systolic BP decreased by 22.8 mmHg (95% CI: -20.6 to -24.9; p < 0.0001) and diastolic BP by 12.4 mmHg (-10.9 to -13.9; p < 0.0001). Among diabetic patients (n = 79) FPG decreased by 3.4 mmol/l (-2.3 to -4.5; p < 0.001).</p> <p>Conclusions</p> <p>The integration of hypertension and diabetes into primary health care of NPC facilities in rural Cameroon was feasible in terms of equipment and training, accessible in terms of treatment cost and showed promising BP- and FPG-trends. However, low case-detection rates per NPC and a very high attrition among patients enrolled into care, limited the effectiveness of the programme.</p

    Defining Global Gene Expression Changes of the Hypothalamic-Pituitary-Gonadal Axis in Female sGnRH-Antisense Transgenic Common Carp (Cyprinus carpio)

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    BACKGROUND: The hypothalamic-pituitary-gonadal (HPG) axis is critical in the development and regulation of reproduction in fish. The inhibition of neuropeptide gonadotropin-releasing hormone (GnRH) expression may diminish or severely hamper gonadal development due to it being the key regulator of the axis, and then provide a model for the comprehensive study of the expression patterns of genes with respect to the fish reproductive system. METHODOLOGY/PRINCIPAL FINDINGS: In a previous study we injected 342 fertilized eggs from the common carp (Cyprinus carpio) with a gene construct that expressed antisense sGnRH. Four years later, we found a total of 38 transgenic fish with abnormal or missing gonads. From this group we selected the 12 sterile females with abnormal ovaries in which we combined suppression subtractive hybridization (SSH) and cDNA microarray analysis to define changes in gene expression of the HPG axis in the present study. As a result, nine, 28, and 212 genes were separately identified as being differentially expressed in hypothalamus, pituitary, and ovary, of which 87 genes were novel. The number of down- and up-regulated genes was five and four (hypothalamus), 16 and 12 (pituitary), 119 and 93 (ovary), respectively. Functional analyses showed that these genes involved in several biological processes, such as biosynthesis, organogenesis, metabolism pathways, immune systems, transport links, and apoptosis. Within these categories, significant genes for neuropeptides, gonadotropins, metabolic, oogenesis and inflammatory factors were identified. CONCLUSIONS/SIGNIFICANCE: This study indicated the progressive scaling-up effect of hypothalamic sGnRH antisense on the pituitary and ovary receptors of female carp and provided comprehensive data with respect to global changes in gene expression throughout the HPG signaling pathway, contributing towards improving our understanding of the molecular mechanisms and regulative pathways in the reproductive system of teleost fish

    Identification of Arx transcriptional targets in the developing basal forebrain

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    Mutations in the aristaless-related homeobox (ARX) gene are associated with multiple neurologic disorders in humans. Studies in mice indicate Arx plays a role in neuronal progenitor proliferation and development of the cerebral cortex, thalamus, hippocampus, striatum, and olfactory bulbs. Specific defects associated with Arx loss of function include abnormal interneuron migration and subtype differentiation. How disruptions in ARX result in human disease and how loss of Arx in mice results in these phenotypes remains poorly understood. To gain insight into the biological functions of Arx, we performed a genome-wide expression screen to identify transcriptional changes within the subpallium in the absence of Arx. We have identified 84 genes whose expression was dysregulated in the absence of Arx. This population was enriched in genes involved in cell migration, axonal guidance, neurogenesis, and regulation of transcription and includes genes implicated in autism, epilepsy, and mental retardation; all features recognized in patients with ARX mutations. Additionally, we found Arx directly repressed three of the identified transcription factors: Lmo1, Ebf3 and Shox2. To further understand how the identified genes are involved in neural development, we used gene set enrichment algorithms to compare the Arx gene regulatory network (GRN) to the Dlx1/2 GRN and interneuron transcriptome. These analyses identified a subset of genes in the Arx GRN that are shared with that of the Dlx1/2 GRN and that are enriched in the interneuron transcriptome. These data indicate Arx plays multiple roles in forebrain development, both dependent and independent of Dlx1/2, and thus provides further insights into the understanding of the mechanisms underlying the pathology of mental retardation and epilepsy phenotypes resulting from ARX mutations
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