785 research outputs found
Dolomite as a flux for High-Alumina Blast Furnace Slags
BLAST FURNACE operators at Jamshedpur have to face a peculiar problem arising out of the high concentration of it alumina in the slag. The normal analyses are 37.3-37.8% CaO, 3.4-3.9% MgO,30.4-31.5% SiO2, 26.2-27.0% Al2O3, 0.69-0.78% FeO and 0.69-0.82% S. The actual level, i.e. 26 to 28% is much higher than that common elsewhere and brings into force a series of adverse effects. Briefly, these consist of the greater viscosity of the alumina slags, greater tendency towards silicon reduction, and less efficient desulphurisation. As a result, it becomes rather difficult consistently to produce low-sulphur hot metal without exceeding the silicon level normally specified for basic iron
An Old Cluster in NGC 6822
We present spectroscopy of two clusters in the dwarf irregular galaxy NGC
6822. From these we deduce an age for Cluster VII of 11 Gyr and [Fe/H] = -1.95
+/- 0.15 dex. Cluster VII appears to be an analog of the metal-poor galactic
globular clusters. Cluster VI is found to be much younger and more metal rich,
with an age of approximately 2 Gyr. Its derived metallicity, [Fe/H], of
approximately -1.0 dex is comparable to that of the gas seen today in NGC 6822.
The existence of a metal-poor old cluster in NGC 6822 rules out models for the
chemical evolution of this galaxy with significant prompt initial enhancement.
We find that a star formation rate which is constant with time and is within a
factor of two of the present star formation rate can reproduce the two points
on the age-metallicity relationship for NGC 6822 over the past 10 Gyr defined
by these two clusters.Comment: 8 pages; accepted for publication in A
Suppressed star formation in circumnuclear regions in Seyfert galaxies
Feedback from black hole activity is widely believed to play a key role in
regulating star formation and black hole growth. A long-standing issue is the
relation between the star formation and fueling the supermassive black holes in
active galactic nuclei (AGNs). We compile a sample of 57 Seyfert galaxies to
tackle this issue. We estimate the surface densities of gas and star formation
rates in circumnuclear regions (CNRs). Comparing with the well-known
Kennicutt-Schmidt (K-S) law, we find that the star formation rates in CNRs of
most Seyfert galaxies are suppressed in this sample. Feedback is suggested to
explain the suppressed star formation rates.Comment: 1 color figure and 1 table. ApJ Letters in pres
Low energy trauma in older persons: where to next?
The global population is increasing rapidly with older persons accounting for the greatest proportion. Associated with this rise is an increased rate of injury, including polytrauma, for which low energy falls has become the main cause. The resultant growing impact on trauma resources represents a major burden to the health system. Frailty, with its related issues of cognitive dysfunction and sarcopenia, is emerging as the unifying concept that relates both to the initial event and subsequent outcomes. Strategies to better assess and manage frailty are key to both preventing injury and improving trauma outcomes in the older population and research that links measures of frailty to trauma outcomes will be critical to informing future directions and health policy. The introduction of “Geriatric Emergency Departments” and the development of “Fracture Units” for frail older people will facilitate increased involvement of Geriatricians in trauma care and aid in the education of other health disciplines in the core principles of geriatric assessment and management. Collectively these should lead to improved care and outcomes for both survivors and those requiring end of life decisions and palliation.Mellick Chehade, Tiffany K Gill, Renuka Visvanatha
Perspectives of frailty and frailty screening: Protocol for a collaborative knowledge translation approach and qualitative study of stakeholder understandings and experiences
Accompanying the unprecedented growth in the older adult population worldwide is an increase in the prevalence of frailty, an age-related clinical state of increased vulnerability to stressor events. This increased vulnerability results in lower social engagement and quality of life, increased dependency, and higher rates of morbidity, health service utilization and mortality. Early identification of frailty is necessary to guide implementation of interventions to prevent associated functional decline. Consensus is lacking on how to clinically recognize and manage frailty. It is unknown how healthcare providers and healthcare consumers understand and perceive frailty, whether or not they regard frailty as a public health concern; and information on the indirect and direct experiences of consumer and healthcare provider groups towards frailty are markedly limited.We will conduct a qualitative study of consumer, practice nurse, general practitioner, emergency department physician, and orthopedic surgeons' perspectives of frailty and frailty screening in metropolitan and non-metropolitan South Australia. We will use tailored combinations of semi-structured interviews and arts-based data collection methods depending on each stakeholder group, followed by inductive and iterative analysis of data using qualitative description.Using stakeholder driven approaches to understanding and addressing frailty and frailty screening in context is critical as the prevalence and burden of frailty is likely to increase worldwide. We will use the findings from the Perceptions of Frailty and Frailty Screening study to inform a context-driven identification, implementation and evaluation of a frailty-screening tool; drive awareness, knowledge, and skills development strategies across stakeholder groups; and guide future efforts to embed emerging knowledge about frailty and its management across diverse South Australian contexts using a collaborative knowledge translation approach. Study findings will help achieve a coordinated frailty and healthy ageing strategy with relevance to other jurisdictions in Australia and abroad, and application of the stakeholder driven approach will help illuminate how its applicability to other jurisdictions.Mandy M. Archibald, Rachel Ambagtsheer, Justin Beilby, Mellick J. Chehade, Tiffany K. Gill, Renuka Visvanathan, and Alison L. Kitso
The association between benzodiazepine use and sleep quality in residential aged care facilities: a cross-sectional study
BACKGROUND: Benzodiazepines are commonly prescribed in residential aged care facilities (RACFs) for their sedative and anxiolytic effects. The objective of this study was to investigate the association between benzodiazepine use and sleep quality in residents of RACFs. METHODS: A cross-sectional study involving 383 participants was conducted in six Australian RACFs. Night-time sleep quality, day-time drowsiness and day-time napping behavior were assessed using a validated questionnaire. Logistic regression was used to compute adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for the association between benzodiazepine use and sleep quality. Covariates included pain, dementia severity, depression, insomnia and other sedative use. RESULTS: Of the 383 residents (mean age 87.5 years, 77.5% female), 96(25.1%) used a benzodiazepine on a regular basis. Residents who used long-acting benzodiazepines on a regular basis had higher night-time sleep quality than non-users (AOR = 4.00, 95%CI 1.06 - 15.15). Residents who used short-acting benzodiazepines on a PRN only basis had longer daytime napping times than non-users (AOR = 1.77, 95%CI 1.01 - 3.08). No benzodiazepine category was associated with day-time drowsiness. CONCLUSIONS: The association between benzodiazepine use and sleep quality is dependent on the half-life and prescribing pattern of the benzodiazepine. Short-acting PRN benzodiazepines were associated with lower night time sleep quality and longer day-time napping compared to long-acting regular benzodiazepines. Longitudinal studies are needed to determine whether these findings reflect channeling of short-acting agents to residents at higher risk of sleep disorders.Lynna Chen, J. Simon Bell, Renuka Visvanathan, Sarah N. Hilmer, Tina Emery, Leonie Robson, Jessica M. Hughes and Edwin C. K. Ta
The association between sarcopenia and quality of life is different in community dwelling older Australian men and women
Published: June 09, 2018Background: The impact of sarcopenia on health-related quality of life (HRQoL) in community dwelling older people in Australia is not known. The aim of this study was to evaluate the relationship between sarcopenia and HRQoL in older Australian men and women. Methods: 357 men and 370 women aged 65 years and older from the North West Adelaide Health Study at Stage 2 (2002-2004). Sarcopenia was defined as the presence of low muscle mass and low grip strength. HRQoL was assessed using the Short Form-36 (SF-36) questionnaire: physical component summary (PCS) and mental component summary (MCS). Analyses were performed using multiple regression and adjustments were made for age, physical activity, smoking status, co-morbidity and depression. Results: The prevalence of sarcopenia was 10.1% in men and 9.5% in women. Men with sarcopenia was significantly associated with the PCS score in the unadjusted model (P = 0.012) and only model 1 adjusted for age (P = 0.041). No significant association was noted in model 2 (model 1 + physical activity and smoking status) and model 3 (model 2 + Charlson co-morbidity index and depression). In men, a significant association between sarcopenia and MCS score was seen in the unadjusted and all 3 adjusted models. No association was seen between sarcopenia and the PCS or MCS score in women for both the adjusted and unadjusted models. Conclusion: After adjusting for multiple confounders, the association between sarcopenia only remained for the MCS score, in men. No association between sarcopenia and HRQoL was seen in women.Tsung Woo, Solomon Yu, Robert Adams and Renuka Visvanatha
The Frailty In Residential Sector over Time (FIRST) study: methods and baseline cohort description
Published online: 03 February 2021Background: The Frailty In Residential Sector over Time (FIRST) Study is a 3-year prospective cohort study investigating the health of residents living in residential aged care services (RACS) in South Australia. The study aims to examine the change in frailty status and associated health outcomes. Methods: This interim report presents data from March 2019–October 2020. The study setting is 12 RACS from one organisation across metropolitan and rural South Australia involving 1243 residents. All permanent (i.e. respite or transition care program excluded) residents living in the RACS for at least 8 weeks were invited to participate. Residents who were deemed to be medically unstable (e.g. experiencing delirium), have less than 3 months to live, or not fluent in English were excluded. Data collected included frailty status, medical diagnoses, medicines, pain, nutrition, sarcopenia, falls, dementia, anxiety and depression, sleep quality, quality of life, satisfaction with care, activities of daily living, and life space use at baseline and 12-months. Data Linkage will occur over the 3 years from baseline. Results: A total of 561 permanent residents (mean age 87.69 ± 7.25) were included. The majority of residents were female (n = 411, 73.3%) with 95.3% (n = 527) being classified as either frail (n = 377, 68.2%) or most-frail (n = 150, 27.1%) according to the Frailty Index (FI). Most residents were severely impaired in their basic activities of daily living (n = 554, 98.8%), and were at-risk of malnutrition (n = 305, 55.0%) and at-risk of sarcopenia (n = 492, 89.5%). Most residents did not experience pain (n = 475, 85.4%), had normal daytime sleepiness (n = 385, 69.7%), and low anxiety and depression scores (n = 327, 58.9%). Conclusion: This study provides valuable information on the health and frailty levels of residents living in RACS in South Australia. The results will assist in developing interventions that can help to improve the health and wellbeing of residents in aged care services. Trial registration: Prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN1261 9000500156).Agathe Daria Jadczak, Leonie Robson, Tina Cooper, J. Simon Bell, Renuka Visvanathan, on behalf of the FIRST Study Collaborator
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