The low-luminosity Type II SN2016aqf Müller-Bravo, Tomás E.; Gutiérrez, Claudia P.; Sullivan, Mark ...
Monthly notices of the Royal Astronomical Society,
09/2020, Volume:
497, Issue:
1
Journal Article
Peer reviewed
Low-luminosity Type II supernovae (LL SNe II) make up the low explosion energy end of core-collapse SNe, but their study and physical understanding remain limited. We present SN 2016aqf, an LL SN II ...with extensive spectral and photometric coverage. We measure a V -band peak magnitude of −14.58 mag, a plateau duration of ∼100 d, and an inferred 56 Ni mass of 0.008 ± 0.002 M ⊙ . The peak bolometric luminosity, L bol ≈ 10 41.4 erg s −1 , and its spectral evolution are typical of other SNe in the class. Using our late-time spectra, we measure the O i λλ6300, 6364 lines, which we compare against SN II spectral synthesis models to constrain the progenitor zero-age main-sequence mass. We find this to be 12 ± 3 M ⊙ . Our extensive late-time spectral coverage of the Fe ii λ7155 and Ni ii λ7378 lines permits a measurement of the Ni/Fe abundance ratio, a parameter sensitive to the inner progenitor structure and explosion mechanism dynamics. We measure a constant abundance ratio evolution of 0.081+0.009−0.010 and argue that the best epochs to measure the ratio are at ∼200–300 d after explosion. We place this measurement in the context of a large sample of SNe II and compare against various physical, light-curve, and spectral parameters, in search of trends that might allow indirect ways of constraining this ratio. We do not find correlations predicted by theoretical models; however, this may be the result of the exact choice of parameters and explosion mechanism in the models, the simplicity of them, and/or primordial contamination in the measured abundance ratio.
Fluid energy mill (FEM) was utilized to
simultaneously realize several functions, namely: size reduction of coarse micron-sized pre-coated particles into smaller (ca. 1–10
μm) particles, as well as ...de-agglomeration and coating of nanoparticles onto the ground particles, all within the FEM chamber. Three types of coating nanoparticles – silica, alumina, and titania – were applied to study the effects of the nanoparticle type on the coating performance. It was found that material type and surface modification play a significant role in coating uniformity. The results show that the flowability of the ground KCl particulates can be improved significantly by the addition of nanoparticles. The flowability of the ground particulates is sensitive to the amount of the nanoparticles added. This study demonstrates that the novel process can be used to fluidize and coat highly cohesive particles.
An experimental study on the simultaneous size reduction of coarse particulates and coating of the resultant smaller particulates with nanoparticles in a fluid energy mill is described. The flowability of the ground coarse particulates can be improved significantly by the nanoparticles coating. The effect of material type, surface modification and the amount of the nanoparticles added has been investigated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Heart transplant-related stressors and coping are related to poor outcomes early after transplant. The purposes of our study were to (1) identify the most frequent and bothersome stressors and most ...used and effective coping strategies and (2) compare the most frequent and bothersome stresses and most used and effective coping styles between patients at 5 and 10 years after heart transplantation. We also examined differences in coping styles by patient characteristics and factors associated with frequency and intensity of stress at 5 and 10 years after heart transplantation.
This report is a secondary analysis of data from a prospective, multisite study of quality of life outcomes. Data are from separate cohorts of 199 patients at 5 years after transplant and 98 patients at 10 years. Patients completed the Heart Transplant Stressor Scale and Jalowiec Coping Scale. Statistical analyses included frequencies, measures of central tendency, t-tests, chi-square, and generalized linear models.
At 5 and 10 years after heart transplantation, the most bothersome stressors were regarding work, school, and financial issues. Patients who were 10 years after transplant reported less stress, similar stress intensity, and less use and perceived effectiveness of negative coping than patients who were 5 years after transplant. Long-term after transplant, demographic characteristics, psychologic problems, negative coping, and clinical factors were related to stress frequency and/or intensity.
Heart transplant-related stress occurs long-term after surgery. Types of transplant-related stress and factors related to stress confirm the importance of ongoing psychologic and clinical support after heart transplantation.
Although studies have provided us with a cross-sectional analysis of long-term quality of life (QOL) after transplantation, relatively few longitudinal studies have been done that allow us to ...understand changes in QOL over time. The purposes of our study were to describe QOL over time and identify predictors of QOL longitudinally from 5 to 10 years after heart transplantation.
All 555 subjects enrolled in this study completed booklets of questionnaires. These patients had a mean age of approximately 54 years (range 21 to 75 years) at time of transplant. Seventy-eight percent were men and 88% were white. Participants completed nine self-report QOL instruments for this study. Statistical analyses included frequencies, means +/- standard deviations (plotted over time), Pearson correlation coefficients and multiple regression coupled with repeated measures.
At 5 to 10 years after heart transplantation, recipients reported high levels of satisfaction with overall QOL and with health-related QOL, which was stable over the 5-year period. Predictors of satisfaction with overall QOL (that individually accounted for 1% variance or more) were primarily psychosocial variables (overall model explaining 71% of variance), whereas predictors of satisfaction with QOL related to health and functioning (that also explained > or =1% variance) included symptom distress and physical function, as well as psychosocial variables (overall model explaining 72% of variance).
At 5 to 10 years after heart transplantation, QOL remained positive and stable. Bio-psychosocial variables predicted satisfaction with overall QOL and health-related QOL. Understanding of these bio-psychosocial variables provides direction for the development of long-term therapeutic strategies after heart transplantation so that patients can have good post-transplant outcomes.
Questions regarding how best to communicate warnings and risk information, whether such communications are likely to be effective, and what factors influence the communication process are important ...across many of society's facets today. Stimulated by the tremendous growth in litigation on product liability and associated personal injury, research i
Researchers have not examined relationships between perception of physical functional disability and demographic, clinical, and psychological variables at 5 to 10 years after heart transplantation. ...Therefore, the purposes of this study were to describe physical functional disability over time and identify predictors of physical functional disability from 5 to 10 years after heart transplantation.
The study enrolled 555 patients who were between 5 and 10 years post-heart transplant (age, 54 +/- 9 years; 78% male, 88% white, 79% married). Patients completed 6 instruments that measure physical functional disability and factors that may impact physical functional disability. Statistical analyses included calculation of frequencies, means +/- standard deviation (plotted over time), Pearson correlation coefficients, and multiple regression coupled with repeated measures.
Between 5 and 10 years after heart transplantation, physical functional disability was low, and 34% to 45% of patients reported having no functional disability. More physical functional disability was associated with having more symptoms, having depression/mood/negative affect and lower use of negative coping strategies, having more comorbidities and more specific comorbidities (e.g., more orthopedic problems and diabetes); higher New York Heart Association functional class; having more acute rejection, infection, or cardiac allograft vasculopathy; being female, older, less educated, and unemployed; higher body mass index; and more hospital readmissions (explaining 46% of variance F = 84.75, p < 0.0001).
Demographic, clinical, and psychological factors were significantly related to physical functional disability. Knowledge of these factors provides the basis for development of therapeutic plans of care.
Patterns of symptom frequency and distress have not been examined long-term after heart transplantation, nor have predictors of long-term symptom frequency and distress. This report identified the ...most commonly reported and distressful symptoms long-term after transplantation, described patterns of symptom frequency and distress over time, and examined predictors of symptom frequency and distress at 5 and 10 years after heart transplantation.
The sample included 555 participants from a prospective, multisite, longitudinal study of quality of life outcomes. Patients were 78% male, 88% white, 79% married, and mean age of 54 years at time of heart transplantation. Data were collected using patient self-report and medical records review. Statistical analyses included descriptive statistics, Pearson correlations, t-tests, and generalized linear models.
Significant predictors of lower symptom frequency after heart transplantation were not having psychological problems and not having cardiac allograft vasculopathy at 5 years, and not having psychological problems and not having infection at 10 years. Significant predictors of less symptom distress were having more than a high school education, having no psychological problems, and having gout at 5 years, and being married at 10 years.
Symptom frequency is low and symptom distress is moderate long-term after heart transplantation. Significant relationships exist between both demographic and clinical variables and symptom frequency and distress. Identification of the most common and bothersome symptoms after heart transplantation provides clinicians with important information from which to develop a plan of care.
Low-luminosity type II supernovae (LL SNe~II) make up the low explosion energy end of core-collapse SNe, but their study and physical understanding remain limited. We present SN\,2016aqf, a LL SN~II ...with extensive spectral and photometric coverage. We measure a \(V\)-band peak magnitude of \(-14.58\)\,mag, a plateau duration of \(\sim\)100\,days, and an inferred \(^{56}\)Ni mass of \(0.008 \pm 0.002\)\,\msun. The peak bolometric luminosity, L\(_{\rm bol} \approx 10^{41.4}\)\,erg\,s\(^{-1}\), and its spectral evolution is typical of other SNe in the class. Using our late-time spectra, we measure the \ion{O}{i} \(\lambda\lambda6300, 6364\) lines, which we compare against SN II spectral synthesis models to constrain the progenitor zero-age main-sequence mass. We find this to be 12 \(\pm\) 3\,\msun. Our extensive late-time spectral coverage of the \ion{Fe}{ii} \(\lambda7155\) and \ion{Ni}{ii} \(\lambda7378\) lines permits a measurement of the Ni/Fe abundance ratio, a parameter sensitive to the inner progenitor structure and explosion mechanism dynamics. We measure a constant abundance ratio evolution of \(0.081^{+0.009}_{-0.010}\), and argue that the best epochs to measure the ratio are at \(\sim\)200 -- 300\,days after explosion. We place this measurement in the context of a large sample of SNe II and compare against various physical, light-curve and spectral parameters, in search of trends which might allow indirect ways of constraining this ratio. We do not find correlations predicted by theoretical models; however, this may be the result of the exact choice of parameters and explosion mechanism in the models, the simplicity of them and/or primordial contamination in the measured abundance ratio.
Large modern surveys require efficient review of data in order to find transient sources such as supernovae, and to distinguish such sources from artefacts and noise. Much effort has been put into ...the development of automatic algorithms, but surveys still rely on human review of targets. This paper presents an integrated system for the identification of supernovae in data from Pan-STARRS1, combining classifications from volunteers participating in a citizen science project with those from a convolutional neural network. The unique aspect of this work is the deployment, in combination, of both human and machine classifications for near real-time discovery in an astronomical project. We show that the combination of the two methods outperforms either one used individually. This result has important implications for the future development of transient searches, especially in the era of LSST and other large-throughput surveys.
- Novel therapeutics often target complex cellular mechanisms. Increasingly, quantitative methods like digital tissue image analysis (tIA) are required to evaluate correspondingly complex biomarkers ...to elucidate subtle phenotypes that can inform treatment decisions with these targeted therapies. These tIA systems need a gold standard, or reference method, to establish analytical validity. Conventional, subjective histopathologic scores assigned by an experienced pathologist are the gold standard in anatomic pathology and are an attractive reference method. The pathologist's score can establish the ground truth to assess a tIA solution's analytical performance. The paradox of this validation strategy, however, is that tIA is often used to assist pathologists to score complex biomarkers because it is more objective and reproducible than manual evaluation alone by overcoming known biases in a human's visual evaluation of tissue, and because it can generate endpoints that cannot be generated by a human observer.
- To discuss common visual and cognitive traps known in traditional pathology-based scoring paradigms that may impact characterization of tIA-assisted scoring accuracy, sensitivity, and specificity.
- This manuscript reviews the current literature from the past decades available for traditional subjective pathology scoring paradigms and known cognitive and visual traps relevant to these scoring paradigms.
- Awareness of the gold standard paradox is necessary when using traditional pathologist scores to analytically validate a tIA tool because image analysis is used specifically to overcome known sources of bias in visual assessment of tissue sections.
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DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
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