Measuring the Static Modulus of Nuclear Graphite from Four-Point Flexural Strength Tests and DIC

Abstract The paper describes a novel method based on Digital Image Correlation (DIC) for measuring the static modulus of active PGA graphite specimens during conventional four-point bend strength tests. DIC has been used in combination with finite element and numerical modelling to monitor the displacement fields developing in the specimen during testing, and calculate representative modulus values. Details of the model and results are presented for two specimen geometries and a range of materials with different levels of exposure and density, tested in the perpendicular and parallel orientations. The calculated static modulus values from the DIC measurements confirm the trend between modulus, flexural strength and density. Comments and observations on the uncertainty in the measurement are also presented

Patterns of ambulatory care utilization in Taiwan

BACKGROUND: We used the insurance claims of a representative cohort to quantify the patterns of ambulatory care visits, especially the doctor-shopping phenomenon, in Taiwan. METHODS: The ambulatory visit files of the 200,000-person cohort datasets from the National Health Insurance Research Database in 2002 were analyzed. Only a visit with physician consultation would be considered. We computed the visit patterns both by visit count and by patient count. RESULTS: In 2002, there were 182,474 eligible people with 2,443,003 physician consultations. During the year, 87.4% of the cohort had visited physician clinics and 57.5% had visited hospital-based outpatient or emergency departments. On average, a person had 13.4 physician consultations and consulted 3.4 specialties, 5.2 physicians, and 3.9 healthcare facilities in a year. In 2002, 17.3% of the cohort had ever visited different healthcare facilities on the same day; 23.5% had ever visited physicians of the same specialty at different healthcare facilities within 7 days and the percentage of second visits was 3.8% of all visits. Besides, 7.6% of the cohort had visited two or more specialties at the same facility on the same day, and such visits make up 2.5% of all visits. CONCLUSION: The people in Taiwan did visit the physicians and outpatient departments frequently. Many patients not only consulted several physicians of different specialties and at different healthcare facilities during the year, but also switched the physicians and facilities quickly. An effective referral system with efficient data exchange between facilities might be the solution

Effective refractive error coverage in adults aged 50 years and older: estimates from population-based surveys in 61 countries

Background: In 2021, WHO Member States endorsed a global target of a 40-percentage-point increase in effective refractive error coverage (eREC; with a 6/12 visual acuity threshold) by 2030. This study models global and regional estimates of eREC as a baseline for the WHO initiative. Methods: The Vision Loss Expert Group analysed data from 565 448 participants of 169 population-based eye surveys conducted since 2000 to calculate eREC (met need/[met need + undermet need + unmet need]). A binary logistic regression model was used to estimate eREC by Global Burden of Disease (GBD) Study super region among adults aged 50 years and older. Findings: In 2021, distance eREC was 79·1% (95% CI 72·4–85·0) in the high-income super region; 62·1% (54·7–68·8) in north Africa and Middle East; 49·5% (45·0–54·0) in central Europe, eastern Europe, and central Asia; 40·0% (31·7–48·2) in southeast Asia, east Asia, and Oceania; 34·5% (29·4–40·0) in Latin America and the Caribbean; 9·0% (6·5–12·0) in south Asia; and 5·7% (3·1–9·0) in sub-Saharan Africa. eREC was higher in men and reduced with increasing age. Global distance eREC increased from 2000 to 2021 by 19·0%. Global near vision eREC for 2021 was 20·5% (95% CI 17·8–24·4). Interpretation Over the past 20 years, distance eREC has increased in each super region yet the WHO target will require substantial improvements in quantity and quality of refractive services in particular for near vision impairmen

Economy, environment and resources in prehistoric Malta

Book Chapte

Networking and the development of professionals: Beginning teachers building social capital

Beginning teachers need support when starting their teaching career. Networking can help teachers develop social capital which supports their development as professionals on their career journey. This paper presents case studies of three secondary school trainee teachers during an English year-long initial teacher education programme. The relationships supporting trainees were characterised differently: for practice development as opposed to enhancing a sense of belonging to the profession. Whether supportive relationships developed depended not only on the trainees but also on others. The paper encourages those involved in teacher education to promote social-capital building as supportive of the development of teachers as professionals

Is Cortisol Excretion Independent of Menstrual Cycle Day? A Longitudinal Evaluation of First Morning Urinary Specimens

Background Cortisol is frequently used as a marker of physiologic stress levels. Using cortisol for that purpose, however, requires a thorough understanding of its normal longitudinal variability. The current understanding of longitudinal variability of basal cortisol secretion in women is very limited. It is often assumed, for example, that basal cortisol profiles do not vary across the menstrual cycle. This is a critical assumption: if cortisol were to follow a time dependent pattern during the menstrual cycle, then ignoring this cyclic variation could lead to erroneous imputation of physiologic stress. Yet, the assumption that basal cortisol levels are stable across the menstrual cycle rests on partial and contradictory evidence. Here we conduct a thorough test of that assumption using data collected for up to a year from 25 women living in rural Guatemala. Methodology We apply a linear mixed model to describe longitudinal first morning urinary cortisol profiles, accounting for differences in both mean and standard deviation of cortisol among women. To that aim we evaluate the fit of two alternative models. The first model assumes that cortisol does not vary with menstrual cycle day. The second assumes that cortisol mean varies across the menstrual cycle. Menstrual cycles are aligned on ovulation day (day 0). Follicular days are assigned negative numbers and luteal days positive numbers. When we compared Models 1 and 2 restricting our analysis to days between −14 (follicular) and day 14 (luteal) then day of the menstrual cycle did not emerge as a predictor of urinary cortisol levels (p-value >0.05). Yet, when we extended our analyses beyond that central 28-day-period then day of the menstrual cycle become a statistically significant predictor of cortisol levels. Significance The observed trend suggests that studies including cycling women should account for day dependent variation in cortisol in cycles with long follicular and luteal phases

Quasispecies Theory and the Behavior of RNA Viruses

A large number of medically important viruses, including HIV, hepatitis C virus, and influenza, have RNA genomes. These viruses replicate with extremely high mutation rates and exhibit significant genetic diversity. This diversity allows a viral population to rapidly adapt to dynamic environments and evolve resistance to vaccines and antiviral drugs. For the last 30 years, quasispecies theory has provided a population-based framework for understanding RNA viral evolution. A quasispecies is a cloud of diverse variants that are genetically linked through mutation, interact cooperatively on a functional level, and collectively contribute to the characteristics of the population. Many predictions of quasispecies theory run counter to traditional views of microbial behavior and evolution and have profound implications for our understanding of viral disease. Here, we discuss basic principles of quasispecies theory and describe its relevance for our understanding of viral fitness, virulence, and antiviral therapeutic strategy

Effective cataract surgical coverage in adults aged 50 years and older: estimates from population-based surveys in 55 countries.

BACKGROUND: Cataract is the leading cause of blindness globally. Effective cataract surgical coverage (eCSC) measures the number of people in a population who have been operated on for cataract, and had a good outcome, as a proportion of all people operated on or requiring surgery. Therefore, eCSC describes service access (ie, cataract surgical coverage, [CSC]) adjusted for quality. The 74th World Health Assembly endorsed a global target for eCSC of a 30-percentage point increase by 2030. To enable monitoring of progress towards this target, we analysed Rapid Assessment of Avoidable Blindness (RAAB) survey data to establish baseline estimates of eCSC and CSC. METHODS: In this secondary analysis, we used data from 148 RAAB surveys undertaken in 55 countries (2003-21) to calculate eCSC, CSC, and the relative quality gap (% difference between eCSC and CSC). Eligible studies were any version of the RAAB survey conducted since 2000 with individual participant survey data and census population data for people aged 50 years or older in the sampling area and permission from the study's principal investigator for use of data. We compared median eCSC between WHO regions and World Bank income strata and calculated the pooled risk difference and risk ratio comparing eCSC in men and women. FINDINGS: Country eCSC estimates ranged from 3·8% (95% CI 2·1-5·5) in Guinea Bissau, 2010, to 70·3% (95% CI 65·8-74·9) in Hungary, 2015, and the relative quality gap from 10·8% (CSC: 65·7%, eCSC: 58·6%) in Argentina, 2013, to 73·4% (CSC: 14·3%, eCSC: 3·8%) in Guinea Bissau, 2010. Median eCSC was highest among high-income countries (60·5% [IQR 55·6-65·4]; n=2 surveys; 2011-15) and lowest among low-income countries (14·8%; [IQR 8·3-20·7]; n=14 surveys; 2005-21). eCSC was higher in men than women (148 studies pooled risk difference 3·2% [95% CI 2·3-4·1] and pooled risk ratio of 1·20 [95% CI 1·15-1·25]). INTERPRETATION: eCSC varies widely between countries, increases with greater income level, and is higher in men. In pursuit of 2030 targets, many countries, particularly in lower-resource settings, should emphasise quality improvement before increasing access to surgery. Equity must be embedded in efforts to improve access to surgery, with a focus on underserved groups. FUNDING: Indigo Trust, Peek Vision, and Wellcome Trust