Sensitivity of the r-process to nuclear masses

The rapid neutron capture process (r-process) is thought to be responsible for the creation of more than half of all elements beyond iron. The scientific challenges to understanding the origin of the heavy elements beyond iron lie in both the uncertainties associated with astrophysical conditions that are needed to allow an r-process to occur and a vast lack of knowledge about the properties of nuclei far from stability. There is great global competition to access and measure the most exotic nuclei that existing facilities can reach, while simultaneously building new, more powerful accelerators to make even more exotic nuclei. This work is an attempt to determine the most crucial nuclear masses to measure using an r-process simulation code and several mass models (FRDM, Duflo-Zuker, and HFB-21). The most important nuclear masses to measure are determined by the changes in the resulting r-process abundances. Nuclei around the closed shells near N=50, 82, and 126 have the largest impact on r-process abundances irrespective of the mass models used.Comment: 5 pages, 4 figures, accepted in European Physical Journal

Sensitivity studies for r-process nucleosynthesis in three astrophysical scenarios

In rapid neutron capture, or r-process, nucleosynthesis, heavy elements are built up via a sequence of neutron captures and beta decays that involves thousands of nuclei far from stability. Though we understand the basics of how the r-process proceeds, its astrophysical site is still not conclusively known. The nuclear network simulations we use to test potential astrophysical scenarios require nuclear physics data (masses, beta decay lifetimes, neutron capture rates, fission probabilities) for all of the nuclei on the neutron-rich side of the nuclear chart, from the valley of stability to the neutron drip line. Here we discuss recent sensitivity studies that aim to determine which individual pieces of nuclear data are the most crucial for r-process calculations. We consider three types of astrophysical scenarios: a traditional hot r-process, a cold r-process in which the temperature and density drop rapidly, and a neutron star merger trajectory.Comment: 8 pages, 4 figures, submitted to the Proceedings of the International Nuclear Physics Conference (INPC) 201

Precision mass measurements on neutron-rich rare-earth isotopes at JYFLTRAP - reduced neutron pairing and implications for the rr-process calculations

The rare-earth peak in the $r$-process abundance pattern depends sensitively on both the astrophysical conditions and subtle changes in nuclear structure in the region. This work takes an important step elucidating the nuclear structure and reducing the uncertainties in $r$-process calculations via precise atomic mass measurements at the JYFLTRAP double Penning trap. $^{158}$Nd, $^{160}$Pm, $^{162}$Sm, and $^{164-166}$Gd have been measured for the first time and the precisions for $^{156}$Nd, $^{158}$Pm, $^{162,163}$Eu, $^{163}$Gd, and $^{164}$Tb have been improved considerably. Nuclear structure has been probed via two-neutron separation energies $S_{2n}$ and neutron pairing energy metrics $D_n$. The data do not support the existence of a subshell closure at $N=100$. Neutron pairing has been found to be weaker than predicted by theoretical mass models. The impact on the calculated $r$-process abundances has been studied. Substantial changes resulting in a smoother abundance distribution and a better agreement with the solar $r$-process abundances are observed.Comment: 8 pages, 4 figures, accepted for publication in Physical Review Letter

The Management of Frailty: Barking Up the Wrong Tree

Frailty is today a hot topic in the scientific community and among clinicians. Geriatricians are no longer the only specialists discussing this age-related condition. Many medical disciplines (e.g., oncologists (1), cardiologists (2), neurologists (3), nephrologists (4), infectious disease specialists (5), pneumologists (6), anesthesiologists (7)) have finally started looking at this critical aspect in older persons, particularly impactful on prognosis and treatment modalities (e.g., (8, 9)). In the debate about this “novel” condition, it may sometimes happen that the word “frailty” is inappropriately used, suggesting a still incomplete understanding of the condition of interest. Some concepts seem difficult to get through, especially in those fields that are not used to the holistic approach and multidisciplinarity typical of geriatrics

Excess mortality in depressive and anxiety disorders:The Lifelines Cohort Study

BACKGROUND: To examine the mortality risk of current and life-time depressive as well as anxiety disorders, whether this risk is moderated by sex or age, and whether this risk can be explained by lifestyle and/or somatic health status. METHODS: A cohort study (Lifelines) including 141,377 participants (18–93 years) which were followed-up regarding mortality for 8.6 years (range 3.0–13.7). Baseline depressive and anxiety disorders according to Diagnostic and Statistical Manual of Mental Disorders, fourth edition criteria were assessed with the Mini International Neuropsychiatric Interview and lifetime diagnoses by self-report. All-cause mortality was retrieved from Statistics Netherlands. Cox-regression was applied to calculate proportional hazard ratios, adjusted for lifestyle (physical activity, alcohol use, smoking, and body mass index) and somatic health status (multimorbidity and frailty) in different models. RESULTS: The mortality rate of depressive and anxiety disorders was conditional upon age but not on sex. Only in people below 60 years, current depressive and anxiety disorders were associated with mortality. Only depressive disorder and panic disorder independently predicted mortality when all mental disorders were included simultaneously in one overall model (hazard ratio [HR] = 2.18 [95% confidence intervals (CI): 1.56–3.05], p < 0.001 and HR = 2.39 [95% CI: 1.15–4.98], p = 0.020). Life-time depressive and anxiety disorders, however, were independent of each other associated with mortality. Associations hardly changed when adjusted for lifestyle characteristics but decreased substantially when adjusted for somatic health status (in particular physical frailty). CONCLUSIONS: In particular, depressive disorder is associated with excess mortality in people below 60 years, independent of their lifestyle. This effect seems partly explained by multimorbidity and frailty, which suggest that chronic disease management of depression-associated somatic morbidity needs to be (further) improved

Course of frailty stratified by physical and mental multimorbidity patterns:a 5-year follow-up of 92,640 participants of the LifeLines cohort study

Background: The frailty index (FI) is a well-recognized measurement for risk stratification in older people. Among middle-aged and older people, we examined the prospective association between the FI and mortality as well as its course over time in relation to multimorbidity and specific disease clusters. Methods: A frailty index (FI) was constructed based on either 64 (baseline only) or 35 health deficits (baseline and follow-up) among people aged ≥ 40 years who participated in LifeLines, a prospective population-based cohort living in the Northern Netherlands. Among 92,640 participants, multivariable Cox proportional hazard models were fitted to study the hazard ratio (HR) of the FI at baseline, as well as for 10 chronic disease clusters for all-cause mortality over a 10-year follow-up. Among 55,426 participants, linear regression analyses were applied to study the impact of multimorbidity and of specific chronic disease clusters (independent variables) on the change of frailty over a 5-year follow-up, adjusted for demographic and lifestyle characteristics. Results: The FI predicted mortality independent of multimorbidity and specific disease clusters, with the highest impact in people with either endocrine, lung, or heart diseases. Adjusted for demographic and lifestyle characteristics, all chronic disease clusters remained independently associated with an accelerated increase of frailty over time. Conclusions: Frailty may be seen as a final common pathway for premature death due to chronic diseases. Our results suggest that initiating frailty prevention at middle age, when the first chronic diseases emerge, might be relevant from a public health perspective

Longitudinal Association between Late-Life Depression (LLD) and Frailty:Findings from a Prospective Cohort Study (MiMiCS-FRAIL)

OBJECTIVES: The aim of the present study was to investigate whether late-life depression (LLD) is associated with incident frailty over time. DESIGN: Prospective cohort study, one-year follow-up. SETTING: Geriatric outpatient clinic, Southwestern of Brazil. PARTICIPANTS: 181 follow-up participants aged 60 years or over. MEASUREMENTS: Depressive disorders were classified as Major Depressive disorder (MDD) or Subthreshold Depression (STD) according to DSM-5 criteria. Depressive symptoms were assessed with validated versions of 15-item Geriatric Depression Scale (GDS-15) and 9-item Patient Health Questionnaire (PHQ-9). We performed binary logistic regressions to estimate the odds ratio (OR) for frailty in LLD adjusting for multiple confounders. Participants who were frail at baseline were excluded from the analyses according to measures of frailty (FRAIL questionnaire and 36-item Frailty Index, FI-36). We also estimated the risk ratio or relative risk (RR) and the risk difference (RD) for incident frailty. RESULTS: We observed a 2 to 4-fold increased risk for incident frailty among participants with LLD. The presence of a depressive disorder was significantly associated with the onset of frailty (adjusted OR for FRAIL and FI-36: 3.07 [95% CI = 1.03 - 9.17] and 3.76 [95% CI = 1.09 - 12.97], respectively. Notably, the risk for frailty due to LLD was significantly higher with the FI-36 compared to the FRAIL (RR: 3.03 versus 2.23). RD was of 17.3% and 12.7% with the FRAIL and the FI-36, respectively. CONCLUSION: Our data support the association between LLD and incident frailty over one year among geriatric outpatients, reinforcing longitudinal evidence from population-based studies