The evolutionary sequence of post-starburst galaxies

© 2017 The Authors. There are multiple ways in which to select post-starburst galaxies in the literature. In this work, we present a study into how two well-used selection techniques have consequences on observable post-starburst galaxy parameters, such as colour, morphology and environment, and how this affects interpretations of their role in the galaxy duty cycle. We identify a master sample of Hδ strong (EWHδ> 3Å) post-starburst galaxies from the value-added catalogue in the seventh data release of the Sloan Digital Sky Survey (SDSS DR7) over a redshift range 0.01 -2.5Å) but one having an additional cut onEWHα (> -3Å).We examine the differences in observables and AGN fractions to see what effect the Hα cut has on the properties of post-starburst galaxies and what these differing samples can tell us about the duty cycle of post-starburst galaxies. We find that Hδ strong galaxies peak in the 'blue cloud', E+As in the 'green valley' and pure E+As in the 'red sequence'.We also find that pure E+As have a more early-type morphology and a higher fraction in denser environments compared with the Hδ strong and E+A galaxies. These results suggest that there is an evolutionary sequence in the post-starburst phase from blue discy galaxies with residual star formation to passive red early-types

Dementia Screening Accuracy is Robust to Premorbid IQ Variation: Evidence from the Addenbrooke's Cognitive Examination-III and the Test of Premorbid Function

BACKGROUND: Scores on cognitive screening tools for dementia are associated with premorbid IQ. It has been suggested that screening scores should be adjusted accordingly. However, no study has examined whether premorbid IQ variation affects screening accuracy. OBJECTIVE: To investigate whether the screening accuracy of a widely used cognitive screening tool for dementia, the Addenbrooke's cognitive examination-III (ACE-III), is improved by adjusting for premorbid IQ. METHODS: 171 UK based adults (96 memory service attendees diagnosed with dementia and 75 healthy volunteers over the age of 65 without subjective memory impairments) completed the ACE-III and the Test of Premorbid Function (TOPF). The difference in screening performance between the ACE-III alone and the ACE-III adjusted for TOPF was assessed against a reference standard; the presence or absence of a diagnosis of dementia (Alzheimer's disease, vascular dementia, or others). RESULTS: Logistic regression and receiver operating curve analyses indicated that the ACE-III has excellent screening accuracy (93% sensitivity, 94% specificity) in distinguishing those with and without a dementia diagnosis. Although ACE-III scores were associated with TOPF scores, TOPF scores may be affected by having dementia and screening accuracy was not improved by accounting for premorbid IQ, age, or years of education. CONCLUSION: ACE-III screening accuracy is high and screening performance is robust to variation in premorbid IQ, age, and years of education. Adjustment of ACE-III cut-offs for premorbid IQ is not recommended in clinical practice. The analytic strategy used here may be useful to assess the impact of premorbid IQ on other screening tools

Identifying and prioritizing opportunities for improving efficiency on the farm: holistic metrics and benchmarking with Data Envelopment Analysis

Efficiency benchmarking is a well-established way of measuring and improving farm performance. An increasingly popular efficiency benchmarking tool within agricultural research is Data Envelopment Analysis (DEA). However, the literature currently lacks sufficient demonstration of how DEA could be tuned to the needs of the farm advisor/extension officer, rather than of the researcher. Also, the literature is flooded with DEA terminology that may discourage the non-academic practitioner from adopting DEA. This paper aims at making DEA more accessible to farm consultants/extension officers by explaining the method step-by-step, visually and with minimal use of specialised terminology and mathematics. Then, DEA’s potential for identifying cost-reducing and profit-making opportunities for farmers is demonstrated with a series of examples drawn from commercial UK dairy farm data. Finally, three DEA methods for studying efficiency change and trends over time are also presented. Main challenges are discussed (e.g. data availability), as well as ideas for extending DEA’s applicability in the agricultural industry, such as the use of carbon footprints and other farm sustainability indicators in DEA analyses

Effect of statins on atrial fibrillation: collaborative meta-analysis of published and unpublished evidence from randomised controlled trials

Objective To examine whether statins can reduce the risk of atrial fibrillation. Design Meta-analysis of published and unpublished results from larger scale statin trials, with comparison of the findings against the published results from smaller scale or shorter duration studies. Data sources Medline, Embase, and Cochrane's CENTRAL up to October 2010. Unpublished data from longer term trials were obtained through contact with investigators. Study selection Randomised controlled trials comparing statin with no statin or comparing high dose versus standard dose statin; all longer term trials had at least 100 participants and at least six months' follow-up. Results In published data from 13 short term trials (4414 randomised patients, 659 events), statin treatment seemed to reduce the odds of an episode of atrial fibrillation by 39% (odds ratio 0.61, 95% confidence interval 0.51 to 0.74; P<0.001), but there was significant heterogeneity (P<0.001) between the trials. In contrast, among 22 longer term and mostly larger trials of statin versus control (105 791 randomised patients, 2535 events), statin treatment was not associated with a significant reduction in atrial fibrillation (0.95, 0.88 to 1.03; P=0.24) (P<0.001 for test of difference between the two sets of trials). Seven longer term trials of more intensive versus standard statin regimens (28 964 randomised patients and 1419 events) also showed no evidence of a reduction in the risk of atrial fibrillation (1.00, 0.90 to 1.12; P=0.99). Conclusions The suggested beneficial effect of statins on atrial fibrillation from published shorter term studies is not supported by a comprehensive review of published and unpublished evidence from larger scale trials

Octilinear Force-Directed Layout with Mental Map Preservation for Schematic Diagrams

We present an algorithm for automatically laying out metro map style schematics using a force-directed approach, where we use a localized version of the standard spring embedder forces combined with an octilinear magnetic force. The two types of forces used during layout are naturally conflicting, and the existing method of simply combining these to generate a resultant force does not give satisfactory results. Hence we vary the forces, emphasizing the standard forces in the beginning to produce a well distributed graph, with the octilinear forces becoming prevalent at the end of the layout, to ensure that the key requirement of line angles at intervals of 45? is obtained. Our method is considerably faster than the more commonly used search-based approaches, and we believe the results are superior to the previous force-directed approach. We have further developed this technique to address the issues of dynamic schematic layout. We use a Delaunay triangulation to construct a schematic “frame”, which is used to retain relative node positions and permits full control of the level of mental map preservation. This technique is the first to combine mental map preservation techniques with the additional layout criteria of schematic diagrams. To conclude, we present the results of a study to investigate the relationship between the level of mental map preservation and the user response time and accuracy

Incremental Grid-like Layout Using Soft and Hard Constraints

We explore various techniques to incorporate grid-like layout conventions into a force-directed, constraint-based graph layout framework. In doing so we are able to provide high-quality layout---with predominantly axis-aligned edges---that is more flexible than previous grid-like layout methods and which can capture layout conventions in notations such as SBGN (Systems Biology Graphical Notation). Furthermore, the layout is easily able to respect user-defined constraints and adapt to interaction in online systems and diagram editors such as Dunnart.Comment: Accepted to Graph Drawing 201

Evolution of starburst galaxies in the Illustris simulation

© 2018 The Author(s). Published by Oxford University Press on behalf of The Royal Astronomical Society. There is a consensus in the literature that starburst galaxies are triggered by interaction events. However, it remains an open question as to what extent both merging and nonmerging interactions have in triggering starbursts. In this study, we make use of the Illustris simulation to test how different triggeringmechanisms can affect starburst events.We examine the star formation rate, colour, and environment of starburst galaxies to determine if this could be why we witness a bimodality in post-starburst populations within observational studies. Further, we briefly test the extent of quenching due to active galactic nuclei feedback. From Illustris, we select 196 starburst galaxies at z = 0.15 and split them into post-merger and pre-merger/harassment-driven starburst samples. We find that 55 % of this sample have not undergone a merger in the past 2 Gyr. Both of our samples are located in low-density environments within the filament regions of the cosmic web; however, we find that premerger/ harassment-driven starbursts are in higher-density environments than post-mergerdriven starbursts. We also find that pre-merger/harassment starbursts are redder than postmerger starbursts; this could be driven by environmental effects. Both, however, produce nuclear starbursts of comparable strengths

The Value of Participating in British Exploring Society Expeditions: A Three Year Multi Cohort Study

A primary aim of many expeditions is to facilitate personal development of young people and 15 while there is much anecdotal evidence to support this aim, there is limited empirical work of 16 varied quality that explores the specific nature of such benefits. This research examined nine 17 summer BES expeditions (Norway, Namibia & Amazon in 2012; Finnmark, Ladakh and 18 Namibia in 2013 and 2014) involving 58 young people (aged between 15 and 22) who completed 19 three on-line questionnaires to collect qualitative (open ended questions) and quantitative (likert 20 scale) data. Measurement of four psychological attributes associated with effective character 21 development were used: mental toughness, coping skills, GRIT and leadership skills. Surveys 22 were completed at three stages; 1) pre expedition, 2) immediately post expedition and 3) three 23 months post expedition. Results indicated that the expeditions impacted positively on the 24 psychological attributes of young people, with short term effects (three months). 25 For the 58 participants, there were statistically significant improvements and small positive 26 effect sizes in mental toughness (P=.006; ηp 2 .167), leadership skills (P=.004; ηp 2 .18), and 27 GRIT (P=.001; ηp 2 .218). There was no significant difference (P>0.05) or effect size for the 28 application of coping strategies. Qualitative data provided insights into how the learning took 29 place and individual perspectives on the overall value of the expedition in relation to narrative 30 understandin

Analytical modeling of micelle growth. 3. Electrostatic free energy of ionic wormlike micelles -- effects of activity coefficients and spatially confined electric double layers

Hypotheses: To correctly predict the aggregation number and size of wormlike micelles from ionic surfactants, the molecular-thermodynamic theory has to calculate the free energy per molecule in the micelle with accuracy better than 0.01 kT, which is a serious challenge. The problem could be solved if the effects of mutual confinement of micelle counterion atmospheres, as well as the effects of counterion binding, surface curvature and ionic interactions in the electric double layer (EDL), are accurately described. Theory: The electric field is calculated using an appropriate cell model, which takes into account the aforementioned effects. Expressions for the activity coefficients have been used, which vary across the EDL and describe the electrostatic, hard sphere, and specific interactions between the ions. New approach for fast numerical calculation of the electrostatic free energy is developed. Findings: The numerical results demonstrate the variation of quantities characterizing the EDL of cylindrical and spherical micelles with the rise of electrolyte concentration. The effect of activity coefficients leads to higher values of the free energy per surfactant molecule in the micelle as compared with the case of neglected ionic interactions. The results are essential for the correct prediction of the size of wormlike micelles from ionic surfactants. This study can be extended to mixed micelles of ionic and nonionic surfactants for interpretation of the observed synergistic effects.Comment: 36 pages, 6 figures, Supplementary Information: 12 pages, 1 figur

iSupport for Young Carers: An Adaptation of an e-Health Intervention for Young Dementia Carers

Young dementia carers need to be recognised and supported in their role. They need help to understand the illness, what changes are expected and how it can affect their family member. Many support services, partly due to the COVID pandemic, have moved online and have been shown to be acceptable as they are low cost and reduce access barriers. iSupport is an evidence-informed e-health training programme developed by the World Health Organization (WHO) to support adult dementia carers. This paper reports on the co-design of an adapted version of iSupport for young carers. A theoretically driven co-design approach, drawing on the lived experiences of young dementia carers and experts who work with this target group was followed. As a result of this study iSupport for Young Carers was created. It is the first e-health intervention of its kind and aims to support the mental health, knowledge and skills of young dementia carers. In turn, it could improve the quality of the support that service providers can offer, and this can result in increased levels of identification of these young people. The work presented also provides opportunities for other countries and demographic groups to translate and adapt iSupport for Young Carers to their specific cultural context