626 research outputs found

    Double-Peaked Narrow-Line Active Galactic Nuclei. II. The Case Of Equal Peaks

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    Active galactic nuclei (AGNs) with double-peaked narrow lines (DPAGNs) may be caused by kiloparsec-scale binary AGNs, bipolar outflows, or rotating gaseous disks. We examine the class of DPAGNs in which the two narrow-line components have closely similar intensity as being especially likely to involve disks or jets. Two spectroscopic indicators support this likelihood. For DPAGNs from Smith et al., the "equal-peaked" objects (EPAGNs) have [Ne V]/[O III] ratios lower than for a control sample of non-double-peaked AGNs. This is unexpected for a pair of normal AGNs in a galactic merger, but may be consistent with [O III] emission from a rotating ring with relatively little gas at small radii. Also, [O III]/H beta ratios of the redshifted and blueshifted systems in the EPAGN are more similar to each other than in a control sample, suggestive of a single ionizing source and inconsistent with the binary interpretation.University Cooperative Society of the University of Texas at AustinJane and Roland Blumberg Cenntenial Professorship in AstronomyAlfred P. Sloan FoundationNational Aeronautics and Space AdministrationNational Science FoundationU.S. Department of EnergyJapanese MonbukagakushoMax Planck SocietyUniversity of ChicagoInstitute for Advanced StudyJapan Participation GroupJohns Hopkins UniversityKorean Scientist GroupLos Alamos National LaboratoryMax-Planck-Institute for Astronomy (MPIA)Max-Planck-Institute for Astrophysics (MPA)New Mexico State UniversityUniversity of PittsburghUniversity of PortsmouthPrinceton UniversityUnited States Naval ObservatoryUniversity of WashingtonFermilabAstronom

    Serum phosphate and social deprivation independently predict all-cause mortality in chronic kidney disease

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    Background: Hyperphosphataemia is linked to cardiovascular disease and mortality in chronic kidney disease (CKD). Outcome in CKD is also affected by socioeconomic status. The objective of this study was to assess the associations between serum phosphate, multiple deprivation and outcome in CKD patients. Methods: All adult patients currently not on renal replacement therapy (RRT), with first time attendance to the renal outpatient clinics in the Glasgow area between July 2010 and June 2014, were included in this prospective study. Area socioeconomic status was assessed as quintiles of the Scottish Index of Multiple Deprivation (SIMD). Outcomes were all-cause and cardiovascular mortality and commencement of RRT. Results: The cohort included 2950 patients with a median (interquartile range) age 67.6 (53.6–76.9) years. Median (interquartile range) eGFR was 38.1 (26.3–63.5) ml/min/1.73 m 2 , mean (±standard deviation) phosphate was 1.13 (±0.24) mmol/L and 31.6 % belonged to the most deprived quintile (SIMD quintile I). During follow-up 375 patients died and 98 commenced RRT. Phosphate ≥1.50 mmol/L was associated with all-cause (hazard ratio (HR) 2.51; 95 % confidence interval (CI) 1.63-3.89) and cardiovascular (HR 5.05; 95 % CI 1.90–13.46) mortality when compared to phosphate 0.90–1.09 mmol/L in multivariable analyses. SIMD quintile I was independently associated with all-cause mortality. Phosphate did not weaken the association between deprivation index and mortality, and there was no interaction between phosphate and SIMD quintiles. Neither phosphate nor SIMD predicted commencement of RRT. Conclusions Multiple deprivation and serum phosphate were strong, independent predictors of all-cause mortality in CKD and showed no interaction. Phosphate also predicted cardiovascular mortality. The results suggest that phosphate lowering should be pursued regardless of socioeconomic status

    A Documentary Video Assignment to Enhance Learning in Large First-Year Science Classes

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    The video documentary assignment described in this paper provides students with learning opportunities in a range of core competencies in biology, framed by and including communication skills. The design, presented as a flow chart to illustrate scaffolding activities, is a culmination of six years of reflective practice and evidence based evaluation (e.g., student perspectives, teacher perspectives and student performance on certain criteria). The assignment forms part of a large (600 student) first year biology course and requires groups of four students to investigate and explain the biology behind an environmental issue to a lay audience. Scaffolding activities support development of interpersonal communication skills (team training activities), visual and oral communication skills (through interaction with a journalist and/or TV presenter) and the basics of audience analysis. They also develop information literacy skills and involve students in evaluation of basic logic and argument in a selection of Youtube videos. Student engagement and motivation with the assignment is very high and it provides a fun and bonding experience for students in their first semester of university. Evidence and justification for design decisions are presented in this article and should prove useful for others looking to implement a similar task in a different context, either as a whole or part

    Egg development, hatching rhythm and moult patterns in Paralomos spinosissima (Decapoda: Anomura: Paguroidea: Lithodidae) from South Georgia waters (Southern Ocean)

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    Larval release, hatching rhythms and moult patterns were examined in a captive population of the subantarctic lithodid, Paralomis spinosissima from the South Georgia and Shag Rocks region. Larvae hatched throughout the year with the majority of females starting to release larvae at the end of the austral summer and beginning of autumn. Larval release continued over a period of up to 9 weeks with high variability in the numbers that hatched each day. A similar seasonal pattern to hatching was evident in the moulting of females. Intermoult period for two adult females (CL = 63 and 85 mm) ranged from 894 to 1,120 days while an intermoult period for males was estimated to be in excess of 832 days. The results are consistent with other species of Paralomis and are discussed in relation to physiological and environmental adaptations to the cold-water conditions south of the Antarctic Convergence

    Communication in Undergraduate Science - What are we doing?

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    BACKGROUND Communication is a ubiquitous graduate attribute and learning outcome for undergraduate science degrees across the world and an invaluable tool for students to demonstrate their learning. Most vocation-focussed science degrees, such as engineering and health professions, articulate clear, highly specific communication outcomes for students that are informed by feedback from industry groups. These outcomes combined with best practice within the profession help to guide the design and implementation of student learning activities. General science degrees, such as a Bachelor of Science, have neither clear, specific goals nor feedback from specific industry groups. A valuable start has been made to guide good practice in educating undergraduate science students in the TLO4: Communication (Colthorpe, Rowland & Leach, 2013). However, there is little evidence available as to what aspects of communication are currently taught in a science context, and detailed discussions have not yet been had as to what elements of communication are most relevant for modern undergraduate science students to learn. This presentation will bring these two topics into focus by reporting on preliminary research findings to help stimulate and garner momentum for clarity and change around the education of undergraduate science students in communication. AIMS 1. Quantify the proportion and types of communication-style assessment tasks in the Bachelor of Science program (across all majors) at research-intensive universities. 2. Review and critique existing literature on what constitutes effective science communication. DESIGN AND METHODS 1. Data for 1500 units of study (e.g., courses) assessment tasks were collected from profiles publicly available on university websites from five research-intensive Go8 in 2012/2013. Assessment tasks were categorised as “exam”, “communication” or “other”. “Communication” assessment tasks across 8 majors were categorised according to audience, medium and purpose. 2. Over 25 relevant published articles, mostly peer-reviewed, from the disciplines of science, communication and science communication were reviewed and critiqued according to research methodology and relevance to undergraduate education. RESULTS Communication style assessment tasks constituted about 20-30% of assessment in BSc programs, with the exception of mathematics

    Fatal S. aureus Hemorrhagic Pneumonia: Genetic Analysis of a Unique Clinical Isolate Producing both PVL and TSST-1

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    In 2008, an unusual strain of methicillin-sensitive Staphylococcus aureus (MSSA68111), producing both Panton-Valentine leukocidin (PVL) and toxic shock syndrome toxin-1 (TSST-1), was isolated from a fatal case of necrotizing pneumonia. Because PVL/TSST-1 co-production in S. aureus is rare, we characterized the molecular organization of these toxin genes in strain 68111. MSSA68111 carries the PVL genes within a novel temperate prophage we call ФPVLv68111 that is most similar, though not identical, to phage ФPVL – a phage type that is relatively rare worldwide. The TSST-1 gene (tst) in MSSA68111 is carried on a unique staphylococcal pathogenicity island (SaPI) we call SaPI68111. Features of SaPI68111 suggest it likely arose through multiple major recombination events with other known SaPIs. Both ФPVLv68111 and SaPI68111 are fully mobilizable and therefore transmissible to other strains. Taken together, these findings suggest that hypervirulent S. aureus have the potential to emerge worldwide

    Deleterious effects of phosphate on vascular and endothelial function via disruption to the nitric oxide pathway

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    Background: Hyperphosphataemia is an independent risk factor for accelerated cardiovascular disease in chronic kidney disease (CKD), although the mechanism for this is poorly understood. We investigated the effects of sustained exposure to a high-phosphate environment on endothelial function in cellular and preclinical models, as well as in human subjects. Methods: Resistance vessels from rats and humans (± CKD) were incubated in a normal (1.18 mM) or high (2.5 mM) phosphate concentration solution and cells were cultured in normal- (0.5 mM) or high-phosphate (3 mM) concentration media. A single-blind crossover study was performed in healthy volunteers, receiving phosphate supplements or a phosphate binder (lanthanum), and endothelial function measured was by flow-mediated dilatation. Results: Endothelium-dependent vasodilatation was impaired when resistance vessels were exposed to high phosphate; this could be reversed in the presence of a phosphodiesterase-5-inhibitor. Vessels from patients with CKD relaxed normally when incubated in normal-phosphate conditions, suggesting that the detrimental effects of phosphate may be reversible. Exposure to high-phosphate disrupted the whole nitric oxide pathway with reduced nitric oxide and cyclic guanosine monophosphate production and total and phospho endothelial nitric oxide synthase expression. In humans, endothelial function was reduced by chronic phosphate loading independent of serum phosphate, but was associated with higher urinary phosphate excretion and serum fibroblast growth factor 23. Conclusions: These directly detrimental effects of phosphate, independent of other factors in the uraemic environment, may explain the increased cardiovascular risk associated with phosphate in CKD

    Factors associated with consultation rates in general practice in England, 2013-2014:a cross-sectional study

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    Background Workload in general practice has risen during the last decade, but the factors associated with this increase are unclear. Aim To examine factors associated with consultation rates in general practice. Design and setting A cross-sectional study. A sample of 304,937 patients registered at 316 English practices between 2013 and 2014 was drawn from the Clinical Practice Research Datalink. Method We linked age, sex, ethnicity, smoking status, and deprivation measures with practice level data on staffing, rurality, training practice status, and Quality and Outcomes Framework performance. We conducted multilevel analyses of patient consultation rates. Results Consultations were grouped into three types: General practitioner or nurse (All), general practitioner (GP), and nurse. Non-smokers consulted less than current smokers (All: RR=0.88, 95% CI: 0.87 to 0.89; GP: 0.88 [0.87 to 0.89]; nurse: 0.91 [0.90 to 0.92]. Consultation rates were higher for those in the most deprived quintile compared to the least deprived quintile (All: 1.18 [1.16 to 1.19]; GP: 1.17 [1.15 to 1.19]; nurse: 1.13 [1.11 to 1.15]. For all three consultation types, consultation rates increased with age, female sex, and varied by ethnicity. Rates in practices with between >8 and Conclusions Our analyses show consistent trends in factors related to consultation rates in general practice across three types of consultation. These data can be used inform the development of more sophisticated staffing models, and resource allocation formulae.</p

    The association between antihypertensive treatment and serious adverse events by age and frailty: A cohort study

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    BACKGROUND: Antihypertensives are effective at reducing the risk of cardiovascular disease, but limited data exist quantifying their association with serious adverse events, particularly in older people with frailty. This study aimed to examine this association using nationally representative electronic health record data. METHODS AND FINDINGS: This was a retrospective cohort study utilising linked data from 1,256 general practices across England held within the Clinical Practice Research Datalink between 1998 and 2018. Included patients were aged 40+ years, with a systolic blood pressure reading between 130 and 179 mm Hg, and not previously prescribed antihypertensive treatment. The main exposure was defined as a first prescription of antihypertensive treatment. The primary outcome was hospitalisation or death within 10 years from falls. Secondary outcomes were hypotension, syncope, fractures, acute kidney injury, electrolyte abnormalities, and primary care attendance with gout. The association between treatment and these serious adverse events was examined by Cox regression adjusted for propensity score. This propensity score was generated from a multivariable logistic regression model with patient characteristics, medical history and medication prescriptions as covariates, and new antihypertensive treatment as the outcome. Subgroup analyses were undertaken by age and frailty. Of 3,834,056 patients followed for a median of 7.1 years, 484,187 (12.6%) were prescribed new antihypertensive treatment in the 12 months before the index date (baseline). Antihypertensives were associated with an increased risk of hospitalisation or death from falls (adjusted hazard ratio [aHR] 1.23, 95% confidence interval (CI) 1.21 to 1.26), hypotension (aHR 1.32, 95% CI 1.29 to 1.35), syncope (aHR 1.20, 95% CI 1.17 to 1.22), acute kidney injury (aHR 1.44, 95% CI 1.41 to 1.47), electrolyte abnormalities (aHR 1.45, 95% CI 1.43 to 1.48), and primary care attendance with gout (aHR 1.35, 95% CI 1.32 to 1.37). The absolute risk of serious adverse events with treatment was very low, with 6 fall events per 10,000 patients treated per year. In older patients (80 to 89 years) and those with severe frailty, this absolute risk was increased, with 61 and 84 fall events per 10,000 patients treated per year (respectively). Findings were consistent in sensitivity analyses using different approaches to address confounding and taking into account the competing risk of death. A strength of this analysis is that it provides evidence regarding the association between antihypertensive treatment and serious adverse events, in a population of patients more representative than those enrolled in previous randomised controlled trials. Although treatment effect estimates fell within the 95% CIs of those from such trials, these analyses were observational in nature and so bias from unmeasured confounding cannot be ruled out. CONCLUSIONS: Antihypertensive treatment was associated with serious adverse events. Overall, the absolute risk of this harm was low, with the exception of older patients and those with moderate to severe frailty, where the risks were similar to the likelihood of benefit from treatment. In these populations, physicians may want to consider alternative approaches to management of blood pressure and refrain from prescribing new treatment
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