The linear matching method applied to the high temperature life integrity of structures. Part 1. Assessments involving constant residual stress fields

Design and life assessment procedures for high temperatures are based on 'expert knowledge' in structural mechanics and materials science, combined with simplified methods of structural analysis. Of these R5 is one of the most widely used life assessment methods internationally with procedures based on reference stress techniques and shakedown calculations using linear elastic solutions. These have been augmented by full finite element analysis and, recently, the development of a new programming method, the Linear Matching Method (LMM), that allows a range of direct solutions that include shakedown methods and simplified analysis in excess of shakedown. In this paper LMM procedures are compared with calculations typical of those employed in R5 for cyclic loading problems when the assumption of a constant residual stress field is appropriate including shakedown and limit analyses, creep rupture analysis and the evaluation of accumulated creep deformation. A typical example of a 3D holed plate subjected to a cyclic thermal load and a constant mechanical load is assessed in detail. These comparisons demonstrate the significant advantages of linear matching methods for a typical case. For a range of cyclic problems when the residual stress field varies during the cycle, which include the evaluation of plastic strain amplitude, ratchet limit and accumulated creep strains during a high temperature dwell periods, the corresponding LMM and R5 procedures are discussed in an accompanying paper

ParaDox: Eliminating Voltage Margins via Heterogeneous Fault Tolerance.

Providing reliability is becoming a challenge for chip manufacturers, faced with simultaneously trying to improve miniaturization, performance and energy efficiency. This leads to very large margins on voltage and frequency, designed to avoid errors even in the worst case, along with significant hardware expenditure on eliminating voltage spikes and other forms of transient error, causing considerable inefficiency in power consumption and performance. We flip traditional ideas about reliability and performance around, by exploring the use of error resilience for power and performance gains. ParaMedic is a recent architecture that provides a solution for reliability with low overheads via automatic hardware error recovery. It works by splitting up checking onto many small cores in a heterogeneous multicore system with hardware logging support. However, its design is based on the idea that errors are exceptional. We transform ParaMedic into ParaDox, which shows high performance in both error-intensive and scarce-error scenarios, thus allowing correct execution even when undervolted and overclocked. Evaluation within error-intensive simulation environments confirms the error resilience of ParaDox and the low associated recovery cost. We estimate that compared to a non-resilient system with margins, ParaDox can reduce energy-delay product by 15% through undervolting, while completely recovering from any induced errors

‘One Is Too Many’ preventing self-harm and suicide in military veterans: a quantitative evaluation

Introduction: In 2021, the Armed Forces Covenant Fund Trust allocated over £2 million to programmes designed to have a clear and demonstrable impact on suicide prevention. Four grant holders delivered a combination of psychotherapeutic interventions, group activities, social prescribing, peer support mentoring, life skills coaching, educational courses and practical help with housing and employment. The evaluation was completed between August 2021 and July 2023. Methods: A survey was completed by 503 participants at entry and 423 at exit. It captured data regarding demographic and military-specific details, health status, situational stressors, predisposing symptoms, help-seeking behaviour, social engagement, housing, living arrangements and employment status. The questionnaire included a number of validated psychometric questionnaires. Results: This evaluation revealed reductions in situational stressors, symptoms and mental health illnesses. Seventy-six per cent of participants had completed an Operational Tour, and 77% were exposed to a traumatic event during service. It was the negative impact of unresolved traumatic effects that influenced service-users to require support. Forty-nine per cent delayed seeking help, and 36% self-referred to the One Is Too Many programme which demonstrates the importance of this option. There were improvements in the participants’ social networking, social activities, club membership and having people to rely on. Only 4% of participants were women which reinforces the requirement to explore initiatives to engage with female veterans. Conclusions: Timely therapeutic and social prescribing interventions in a safe environment lowered depression, anxiety and the associated situational stressors leading to self-harming and may have reduced suicide. It presented another option to veterans and their families regarding where they can obtain support, care and therapeutic interventions. The programme provided a strong foundation for delivery organisations to forge lasting collaborative partnerships that can be extended to working with other authorities and institutes. The results highlight pathways for prevention and intervention strategies to inform policymakers, healthcare professionals and third-sector organisations.Funder: Armed Forces Covenant Fund Trust; Grant(s): 2018-108214 / Change Request 2 dated 14 April 2021Acknowledgements: Lauren West & Annie Ellerton, Westminster Centre for Research in Veterans, University of Chester; Natasha Green, Defence Medical Welfare Services; Sonia Howe and Steven Inman, Armed Forces Covenant Fund Trust

Operation of a hybrid modular multilevel converter during grid voltage unbalance

The recently proposed parallel hybrid modular multilevel converter is considered to be a low loss, low component count converter with soft switching capability of the ‘main’ H-bridge. The converter has similar advantages to other emerging modular multilevel converter circuits being considered for HVDC power transmission and can be made compact which is desirable for offshore application. However, during ac network unbalance the individual ‘chain-links’ exchange unequal amounts of power with the grid which requires appropriate remedial action. This paper presents research into the performance of the converter and proposes a suitable control method that enables the converter to operate during grid voltage unbalance. The proposed control concept involves the use of asymmetric third harmonic voltage generation in the ‘chain-links’ of the converter to redistribute the power exchanged between the individual ‘chain-links’ and the grid. Mathematical analysis and simulation modelling with results are presented to support the work described

Evaluation of the NHS England ‘Op COURAGE’ High Intensity Service for military veterans with significant mental health problems

In November 2020, The NHS for England launched a pilot High Intensity Service (HIS) programme for treating military veterans complex mental health problems. Seven regional grants were awarded to manage the HIS, including NHS Solent, in South East England. This paper details an evaluation of the HIS, which was conducted from February 2021 to August 2022. Methods: This mixed-methods study gained quantitative data from a specifically designed questionnaire that included a number of validated psychometric questionnaires. These were completed by either HIS staff or beneficiaries at entry and exit from the HIS, and qualitative data were gained from semi-structured interviews with the HIS staff. Results: Data were sourced from 45 pre-questionnaires, 25 post programme questionnaires and 11 interviews. This evaluation identified reductions in situational stressors, symptoms and reported illnesses for veterans in crisis. There were reductions in depression, anxiety and post-traumatic stress disorder following programme exit. Staff reported that there was no notable changes in stress levels which appeared to remain high at programme exit. Staff interviews highlighted the importance of simultaneously understanding the social and psychological needs of veterans in mental health crisis. The benefits of integrating veteran staff members into military veteran health services were identified, demonstrating improvements in education around military culture in civilian services. Conclusions: The importance of collaboration between clinical and veteran staff members in veteran health services was noted, demonstrating the positive impact social care provision has on veteran’s overall health and well-being. Veteran engagement with the service was advocated as a result of veterans accessing the service feeling understood. This first independent evaluation of the HIS provides a positive reflection, and adds to the limited empirical evidence exploring veteran engagement in health services.Acknowledgements: The authors would like to thank Tamsyn Howells, Talking Change Psychological Services, Solent NHS Trust

Genetic and epigenetic profiling of BRCA1/2 in ovarian tumors reveals additive diagnostic yield and evidence of a genomic BRCA1/2 DNA methylation signature

Poly-ADP-ribose-polymerase inhibitor (PARPi) treatment is indicated for advanced-stage ovarian tumors with BRCA1/2 deficiency. The “BRCAness” status is thought to be attributed to a tumor phenotype associated with a specific epigenomic DNA methylation profile. Here, we examined the diagnostic impact of combined BRCA1/2 sequence, copy number, and promoter DNA methylation analysis, and evaluated whether genomic DNA methylation patterns can predict the BRCAness in ovarian tumors. DNA sequencing of 172 human tissue samples of advanced-stage ovarian adenocarcinoma identified 36 samples with a clinically significant tier 1/2 sequence variants (point mutations and in/dels) and 9 samples with a CNV causing a loss of function in BRCA1/2. DNA methylation analysis of the promoter of BRCA1/2 identified promoter hypermethylation of BRCA1 in two mutation-negative samples. Computational modeling of genome-wide methylation markers, measured using Infinium EPIC arrays, resulted in a total accuracy of 0.75, sensitivity: 0.83, specificity: 0.64, positive predictive value: 0.76, negative predictive value: 0.74, and area under the receiver’s operating curve (AUC): 0.77, in classifying tumors harboring a BRCA1/2 defect from the rest. These findings indicate that the assessment of CNV and promoter DNA methylation in BRCA1/2 increases the cumulative diagnostic yield by 10%, compared with the 20% yield achieved by sequence variant analysis alone. Genomic DNA methylation data can partially predict BRCAness in ovarian tumors; however, further investigation in expanded BRCA1/2 cohorts is needed, and the effect of other double strand DNA repair gene defects in these tumors warrants further investigations

Clinical Next-Generation Sequencing Pipeline Outperforms a Combined Approach Using Sanger Sequencing and Multiplex Ligation-Dependent Probe Amplification in Targeted Gene Panel Analysis

Advances in next-generation sequencing (NGS) have facilitated parallel analysis of multiple genes enabling the implementation of cost-effective, rapid, and high-throughput methods for the molecular diagnosis of multiple genetic conditions, including the identification of BRCA1 and BRCA2 mutations in high-risk patients for hereditary breast and ovarian cancer. We clinically validated a NGS pipeline designed to replace Sanger sequencing and multiplex ligation-dependent probe amplification analysis and to facilitate detection of sequence and copy number alterations in a single test focusing on a BRCA1/BRCA2 gene analysis panel. Our custom capture library covers 46 exons, including BRCA1 exons 2, 3, and 5 to 24 and BRCA2 exons 2 to 27, with 20 nucleotides of intronic regions both 5′ and 3′ of each exon. We analyzed 402 retrospective patients, with previous Sanger sequencing and multiplex ligation-dependent probe amplification results, and 240 clinical prospective patients. One-hundred eighty-three unique variants, including sequence and copy number variants, were detected in the retrospective (n = 95) and prospective (n = 88) cohorts. This standardized NGS pipeline demonstrated 100% sensitivity and 100% specificity, uniformity, and high-depth nucleotide coverage per sample (approximately 7000 reads per nucleotide). Subsequently, the NGS pipeline was applied to the analysis of larger gene panels, which have shown similar uniformity, sample-to-sample reproducibility in coverage distribution, and sensitivity and specificity for detection of sequence and copy number variants