36 research outputs found

    DESIGN, ENGINEERING, AND ASSESSMENT OF MOBILE MINEFIELDS

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    Naval mine warfare typically supports a sea denial strategy through the denial and/or delay of the enemy’s use of the water space or by controlling sea traffic in a designated area. Sea mines have been effective for decades. However, with technological progress, mine countermeasure (MCM) efforts have reduced the risks of a minefield by detecting and/or neutralizing mines to establish and maintain a Q-route for safe passage. The concept of a mobile minefield is proposed to increase the difficulty of the enemy’s MCM and improve the survivability of the minefield by adding mobility. This research explores both the physical design concepts and the operational effectiveness of mobile mines based on simulations and models. The simulation results show that, compared to static mines, mobile mines improved the number of enemy ships destroyed by at least 200% and increased the time it took the enemy to transition through the minefield by 50%. The results suggest that the mobile minefield would be operationally useful for the Department of the Navy and this technology is worth pursing and exploring.Distribution Statement A. Approved for public release: Distribution is unlimited.Captain, Singapore ArmyCaptain, Singapore ArmyMajor, Singapore ArmyLieutenant, Taiwan NavyMajor, United States ArmyCivilian, Department of the NavyLieutenant, United States NavyCivilian, Singapore Technologies Engineering, SingaporeMajor, Singapore ArmyMajor, Singapore ArmyMajor, Singapore ArmyCommander, United States NavyCivilian, Defense Science and Technology Agency (DSTA), SingaporeMajor, Singapore ArmyMajor, Republic of Singapore Air ForceTenente-Coronel, Brazilian Air ForceLieutenant, United States NavyCivilian, Department of the ArmyMajor, Singapore ArmyMajor, Israel Defense ForcesCivilian, Defense Science Organisation, SingaporeCaptain, Singapore Arm

    Charge-changing cross section measurements of 300 MeV/nucleon 28^{28}Si on carbon and data analysis

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    Charge-changing cross section (σcc\sigma_{\text{cc}}) measurements via the transmission method have made important progress recently aiming to determine the charge radii of exotic nuclei. In this work, we report a new σcc\sigma_{\text{cc}} measurement of 304(9) MeV/nucleon 28^{28}Si on carbon at the second Radioactive Ion Beam Line in Lanzhou (RIBLL2) and describe the data analysis procedure in detail. This procedure is essential to evaluate the systematic uncertainty in the transmission method. The determined σcc\sigma_{\mathrm{cc}} of 1125(11) mb is found to be consistent with the existing data at similar energies. The present work will serve as a reference in the σcc\sigma_{\text{cc}} determinations at RIBLL2.Comment: 9 pages, 13 figures, to be published in Chinese Physics

    Postgraduate ethics training programs: a systematic scoping review

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    BACKGROUND: Molding competent clinicians capable of applying ethics principles in their practice is a challenging task, compounded by wide variations in the teaching and assessment of ethics in the postgraduate setting. Despite these differences, ethics training programs should recognise that the transition from medical students to healthcare professionals entails a longitudinal process where ethics knowledge, skills and identity continue to build and deepen over time with clinical exposure. A systematic scoping review is proposed to analyse current postgraduate medical ethics training and assessment programs in peer-reviewed literature to guide the development of a local physician training curriculum. METHODS: With a constructivist perspective and relativist lens, this systematic scoping review on postgraduate medical ethics training and assessment will adopt the Systematic Evidence Based Approach (SEBA) to create a transparent and reproducible review. RESULTS: The first search involving the teaching of ethics yielded 7669 abstracts with 573 full text articles evaluated and 66 articles included. The second search involving the assessment of ethics identified 9919 abstracts with 333 full text articles reviewed and 29 articles included. The themes identified from the two searches were the goals and objectives, content, pedagogy, enabling and limiting factors of teaching ethics and assessment modalities used. Despite inherent disparities in ethics training programs, they provide a platform for learners to apply knowledge, translating it to skill and eventually becoming part of the identity of the learner. Illustrating the longitudinal nature of ethics training, the spiral curriculum seamlessly integrates and fortifies prevailing ethical knowledge acquired in medical school with the layering of new specialty, clinical and research specific content in professional practice. Various assessment methods are employed with special mention of portfolios as a longitudinal assessment modality that showcase the impact of ethics training on the development of professional identity formation (PIF). CONCLUSIONS: Our systematic scoping review has elicited key learning points in the teaching and assessment of ethics in the postgraduate setting. However, more research needs to be done on establishing Entrustable Professional Activities (EPA)s in ethics, with further exploration of the use of portfolios and key factors influencing its design, implementation and assessment of PIF and micro-credentialling in ethics practice. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12909-021-02644-5

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    PANC Study (Pancreatitis: A National Cohort Study): national cohort study examining the first 30 days from presentation of acute pancreatitis in the UK

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    Abstract Background Acute pancreatitis is a common, yet complex, emergency surgical presentation. Multiple guidelines exist and management can vary significantly. The aim of this first UK, multicentre, prospective cohort study was to assess the variation in management of acute pancreatitis to guide resource planning and optimize treatment. Methods All patients aged greater than or equal to 18 years presenting with acute pancreatitis, as per the Atlanta criteria, from March to April 2021 were eligible for inclusion and followed up for 30 days. Anonymized data were uploaded to a secure electronic database in line with local governance approvals. Results A total of 113 hospitals contributed data on 2580 patients, with an equal sex distribution and a mean age of 57 years. The aetiology was gallstones in 50.6 per cent, with idiopathic the next most common (22.4 per cent). In addition to the 7.6 per cent with a diagnosis of chronic pancreatitis, 20.1 per cent of patients had a previous episode of acute pancreatitis. One in 20 patients were classed as having severe pancreatitis, as per the Atlanta criteria. The overall mortality rate was 2.3 per cent at 30 days, but rose to one in three in the severe group. Predictors of death included male sex, increased age, and frailty; previous acute pancreatitis and gallstones as aetiologies were protective. Smoking status and body mass index did not affect death. Conclusion Most patients presenting with acute pancreatitis have a mild, self-limiting disease. Rates of patients with idiopathic pancreatitis are high. Recurrent attacks of pancreatitis are common, but are likely to have reduced risk of death on subsequent admissions. </jats:sec

    Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

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    BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

    Choosing to Forget: A Discussion on Singapore's National Identity with respect to Demolished Buildings

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    10.25818/y1ph-g23p1-24CSU Case Studies (Case Study Unit

    Preoperative concerns of patients undergoing general surgery

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    Objectives: This qualitative review aims to provide a clearer understanding of concerns general surgery (GS) patients face in the preoperative period. Methods: Medline, CINAHL, PsycINFO and Web of Science were searched for articles describing the preoperative concerns of GS patients. Qualitative and mixed method studies were included. Key quotes were extracted, coded, and thematically analyzed according to Thomas and Harden’s methodology. Results: 27 articles were included. Three main themes were generated: (1) lead-up to surgery, (2) postoperative recovery process and (3) standard of care. While waiting for surgery, patients were often shrouded with uncertainty and concerned themselves with the potential impacts of their disease and surgery on their wellbeing and recovery. Furthermore, patients’ trust and confidence in Healthcare Professionals (HCPs) was compromised when standard of care was perceived to be deficient, resulting in doubts about HCPs’ credibility and capabilities. Conclusion: Patients’ preoperative concerns often stem from the uncertainty and unfamiliarity surrounding surgery. To address this, a combination of effective preoperative education, individualised communication and involvement of social support should be considered. Practice implications: Preoperative concerns can negatively impact patients and effective interventions will result in a better perioperative experience with fewer negative consequences arising from patients’ fear and anxiety
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