158 research outputs found

    LIQUID-LIQUID EQUILIBRIUM FOR IODINE-HYDROIODIC ACID-WATER MIXTURES AT ELEVATED TEMPERATURES AND PRESSURES FOR THE SULFUR-IODINE CYCLE

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    An alternative scenario to the overdependence on fossil fuels is the use of thermochemical cycles to split water into hydrogen and oxygen. The Sulfur-Iodine (SI) cycle, developed at General Atomics in the mid 1970s, is a leading candidate of international interest for the centralized production of hydrogen from nuclear and/or solar power. For a comprehensive assessment of the SI cycle, thermodynamic data for I2-HI-H2O mixtures at elevated temperatures and pressures have been identified as a basic research need. The focus of this study was liquid-liquid equilibrium (LLE) measurements for the above system. To carry out the measurements, a continuous-flow apparatus (CFA) with corrosion-resistant wetted surfaces rated for 350¡C and 150 bar was designed and constructed. In the course of the development of this apparatus, tantalum and its tungsten alloys were found to be capable of withstanding the aggressive chemicals and conditions. Using our CFA, the first observations for the LLE for the binary I2-H2O above 225¡C are presented, with measurements being made to 300¡C and 70 bar. Based on these results, we estimate the upper critical solution temperature for this binary to be 310-315¡C. For the ternary I2-HI-H2O, phase boundaries for the LLE in the HI-lean region of the ternary diagram were mapped at 160 and 200¡C. In addition, equilibrium-tie lines were determined at 160¡C. Phase compositions for the water-rich side were accurately determined by titration, but for the I2-rich side, they were estimated from the overall mass balance. Our results indicate that current models are still inadequate for prediction of the LLE phase behavior for this highly nonideal system

    Taku teina, tōku rangatira. Recruitment, development and retention of Māori and Pasifika in science

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    The tuākana-teina (older-younger sibling) relationship is one of reciprocity that empowers leadership and support (Amopiu 2019). In response to the struggles of Māori and Pasifika students within educational institutions, the tuākana-teina relationship has been incorporated to enhance their cultural and academic well-being (Bishop and Glynn 2003; Callaghan et al. 2018; Oetzel et al. 2021; Parr 2016). In 1991, based upon this philosophy, Professor Michael Walker began the Tuākana programme within the School of Biological Sciences at Waipapa Taumata Rau, the University of Auckland. This paper examines the role of the Tūakana Biology programme in the recruitment, development and retention of Māori in Science at Waipapa Taumata Rau. Drawing from data and experiences of the programme from its inception to current day students, a secondary data analysis was conducted. Here we identify key components that make Tuākana Biology a success and challenges that restrict its implementation. We found the cultural space and community provided by Tuākana enhances Māori and Pasifika recruitment, development, and retention, positioning Tuākana Biology as a potential solution to Māori and Pasifika success within academia. Lack of funding, staffing capacity, and access to student data are the challenges the programme looks to overcome to realise its full potential.&nbsp

    Advance Care Planning in Huntington's Disease

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    Advance care planning (ACP) is a useful tool that benefits adult patients, care providers, and surrogate decision makers, through providing opportunities for patients to consider, express, and formalize their beliefs, preferences, and wishes pertaining to decisions regarding future medical care at a time when they retain decision-making capacity. Early and timely consideration of ACP discussions is paramount in Huntington's disease (HD) given the potential challenges in ascertaining decision-making capacity in the advanced stages of the disease. ACP helps to empower and extend patient autonomy, providing clinicians and surrogate decision makers with reassurance that management is consistent with a patient's expressed wishes. Regular follow up is vital to establish consistency of decisions and wishes. We outline the framework of the dedicated ACP clinic integrated within our HD service to highlight the importance of a patient-centred and tailored care plan that fulfils the patient's expressed goals, preferences, and values

    National trends in heart failure mortality in men and women, United Kingdom, 2000–2017

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    Aims: To understand gender differences in the prognosis of women and men with heart failure, we compared mortality, cause of death and survival trends over time. Methods and results: We analysed UK primary care data for 26 725 women and 29 234 men over age 45 years with a new diagnosis of heart failure between 1 January 2000 and 31 December 2017 using the Clinical Practice Research Datalink, inpatient Hospital Episode Statistics and the Office for National Statistics death registry. Age-specific overall survival and cause-specific mortality rates were calculated by gender and year. During the study period 15 084 women and 15 822 men with heart failure died. Women were on average 5 years older at diagnosis (79.6 vs. 74.8 years). Median survival was lower in women compared to men (3.99 vs. 4.47 years), but women had a 14% age-adjusted lower risk of all-cause mortality [hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.84–0.88]. Heart failure was equally likely to be cause of death in women and men (HR 1.03, 95% CI 0.96–1.12). There were modest improvements in survival for both genders, but these were greater in men. The reduction in mortality risk in women was greatest for those diagnosed in the community (HR 0.83, 95% CI 0.80–0.85). Conclusions: Women are diagnosed with heart failure older than men but have a better age-adjusted prognosis. Survival gains were less in women over the last two decades. Addressing gender differences in heart failure diagnostic and treatment pathways should be a clinical and research priority.</p

    Measuring the complexity of general practice consultations:development and validation of a complexity measure

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    Background: The complexity of general practice consultations may be increasing and varies in different settings. A measure of complexity is required to test these hypotheses. Aim: To develop a valid measure of general practice consultation complexity applicable to routine medical records. Design and setting: Delphi study to select potential indicators of complexity followed by a cross-sectional study in English general practices to develop and validate a complexity measure. Method: The online Delphi study over two rounds identified potential indicators of consultation complexity. The cross-sectional study used an age–sex stratified random sample of patients and general practice face-to-face consultations from 2013/2014 in the Clinical Practice Research Datalink. The authors explored independent relationships between each indicator and consultation duration using mixed-effects regression models, and revalidated findings using data from 2017/2018. The proportion of complex consultations in different age–sex groups was assessed. Results: A total of 32 GPs participated in the Delphi study. The Delphi panel endorsed 34 of 45 possible complexity indicators after two rounds. After excluding factors because of low prevalence or confounding, 17 indicators were retained in the cross-sectional study. The study used data from 173 130 patients and 725 616 face-to-face GP consultations. On defining complexity as the presence of any of these 17 factors, 308 370 consultations (42.5%) were found to be complex. Mean duration of complex consultations was 10.49 minutes, compared to 9.64 minutes for non-complex consultations. The proportion of complex consultations was similar in males and females but increased with age. Conclusion: The present consultation complexity measure has face and construct validity. It may be useful for research, management and policy, and for informing decisions about the range of resources needed in different practices

    Trends in survival after a diagnosis of heart failure in the United Kingdom 2000-2017:population based cohort study

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    Objectives To report reliable estimates of short term and long term survival rates for people with a diagnosis of heart failure and to assess trends over time by year of diagnosis, hospital admission, and socioeconomic group. Design Population based cohort study. Setting Primary care, United Kingdom. Participants Primary care data for 55 959 patients aged 45 and overwith a new diagnosis of heart failure and 278 679 age and sex matched controls in the Clinical Practice Research Datalink from 1 January 2000 to 31 December 2017 and linked to inpatient Hospital Episode Statistics and Office for National Statistics mortality data. Main outcome measures Survival rates at one, five, and 10 years and cause of death for people with and without heart failure; and temporal trends in survival by year of diagnosis, hospital admission, and socioeconomic group. Results Overall, one, five, and 10 year survival rates increased by 6.6% (from 74.2% in 2000 to 80.8% in 2016), 7.2% (from 41.0% in 2000 to 48.2% in 2012), and 6.4% (from 19.8% in 2000 to 26.2% in 2007), respectively. There were 30 906 deaths in the heart failure group over the study period. Heart failure was listed on the death certificate in 13 093 (42.4%) of these patients, and in 2237 (7.2%) it was the primary cause of death. Improvement in survival was greater for patients not requiring admission to hospital around the time of diagnosis (median difference 2.4 years; 5.3 v 2.9 years, P<0.001). There was a deprivation gap in median survival of 2.4 years between people who were least deprived and those who were most deprived (11.1 v 8.7 years, P<0.001). Conclusions Survival after a diagnosis of heart failure has shown only modest improvement in the 21st century and lags behind other serious conditions, such as cancer. New strategies to achieve timely diagnosis and treatment initiation in primary care for all socioeconomic groups should be a priority for future research and policy

    Ciudades en construcción permanente: ¿Destino de casas para todos?

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    La presente colección Ciudades de la Gente representa a hombres y mujeres cuya cultura popular, producto de las mezclas de todos aquellos que vivían y otros que han llegado a nuestros territorios, han hecho de lugares declarados como no aptos, lugares donde vivir, y han creado dentro de nuestras ciudades, la extensión de lo distinto. Son hombres y mujeres cuyo trabajo, el que tienen para aportar, junto al de otros y otras de su misma condición, les ha permitido autoproducir interesantes y sin duda bellos espacios donde convivir. Los profesores e investigadores miembros del Grupo de Trabajo Habitat Popular e Inclusión Social de CLACSO, nos unimos a todos aquellos hacedores que, superando los miedos y con deseos de avanzar, se atreven a caminar por lo desconocido y a no conformarse con lo conocido de otras realidades, buscando en conjunto afirmar, como derechos universales, las posibilidades de vidas dignas y de construcciones colectivas dentro de nuestras ciudades. Emprendemos la tarea de describir e interpretar el habitat popular y la inclusión social, abriendo posibilidades para que, experimentados y debutantes líderes populares e investigadores, hablen sobre "las ciudades de la gente" de muy diversos modos

    The Baryon Oscillation Spectroscopic Survey of SDSS-III

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    The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses 1.5 million luminous galaxies as faint as i=19.9 over 10,000 square degrees to measure BAO to redshifts z<0.7. Observations of neutral hydrogen in the Lyman alpha forest in more than 150,000 quasar spectra (g<22) will constrain BAO over the redshift range 2.15<z<3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Lyman alpha forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance D_A to an accuracy of 1.0% at redshifts z=0.3 and z=0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Lyman alpha forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D_A(z) and H^{-1}(z) parameters to an accuracy of 1.9% at z~2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS.Comment: 49 pages, 16 figures, accepted by A

    Identification of the Pangenome and Its Components in 14 Distinct Aggregatibacter actinomycetemcomitans Strains by Comparative Genomic Analysis

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    Aggregatibacter actinomycetemcomitans is genetically heterogeneous and comprises distinct clonal lineages that may have different virulence potentials. However, limited information of the strain-to-strain genomic variations is available.The genome sequences of 11 A. actinomycetemcomitans strains (serotypes a-f) were generated de novo, annotated and combined with three previously sequenced genomes (serotypes a-c) for comparative genomic analysis. Two major groups were identified; serotypes a, d, e, and f, and serotypes b and c. A serotype e strain was found to be distinct from both groups. The size of the pangenome was 3,301 genes, which included 2,034 core genes and 1,267 flexible genes. The number of core genes is estimated to stabilize at 2,060, while the size of the pangenome is estimated to increase by 16 genes with every additional strain sequenced in the future. Within each strain 16.7-29.4% of the genome belonged to the flexible gene pool. Between any two strains 0.4-19.5% of the genomes were different. The genomic differences were occasionally greater for strains of the same serotypes than strains of different serotypes. Furthermore, 171 genomic islands were identified. Cumulatively, 777 strain-specific genes were found on these islands and represented 61% of the flexible gene pool.Substantial genomic differences were detected among A. actinomycetemcomitans strains. Genomic islands account for more than half of the flexible genes. The phenotype and virulence of A. actinomycetemcomitans may not be defined by any single strain. Moreover, the genomic variation within each clonal lineage of A. actinomycetemcomitans (as defined by serotype grouping) may be greater than between clonal lineages. The large genomic data set in this study will be useful to further examine the molecular basis of variable virulence among A. actinomycetemcomitans strains
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