Detection of solar-like oscillations from Kepler photometry of the open cluster NGC 6819

Asteroseismology of stars in clusters has been a long-sought goal because the assumption of a common age, distance and initial chemical composition allows strong tests of the theory of stellar evolution. We report results from the first 34 days of science data from the Kepler Mission for the open cluster NGC 6819 -- one of four clusters in the field of view. We obtain the first clear detections of solar-like oscillations in the cluster red giants and are able to measure the large frequency separation and the frequency of maximum oscillation power. We find that the asteroseismic parameters allow us to test cluster-membership of the stars, and even with the limited seismic data in hand, we can already identify four possible non-members despite their having a better than 80% membership probability from radial velocity measurements. We are also able to determine the oscillation amplitudes for stars that span about two orders of magnitude in luminosity and find good agreement with the prediction that oscillation amplitudes scale as the luminosity to the power of 0.7. These early results demonstrate the unique potential of asteroseismology of the stellar clusters observed by Kepler.Comment: 5 pages, 4 figures, accepted by ApJ (Lett.

Diatom distributions in space and time – a case study from the polar regions

第3回極域科学シンポジウム/第34回極域生物シンポジウム 11月27日（火） 統計数理研究所 ３階セミナー

Neurocognitieve ontwikkeling van kinderen met een aangeboren hartaandoening

Since more children survive a congenital heart disease (CHD) nowadays, research and public interest have been focusing more on how they survive. Considering the vulnerability of their brain depending on the type of CHD, children born with a CHD, especially the ones who need heart surgery as infants, are at risk for worse neurodevelopmental outcome. They may have difficulties in school and daily life which may be due to deficits in, not only intelligence, but also more specific neurocognitive functions such as attention and higher cognitive executive functions (EFs). Neurocognitive outcome of children with CHD may also relate to perioperative and postoperative intensive care related variables. In a large randomized controlled trial, the Leuven Glucose Control (LGC) Trial, children underwent extensive neurocognitive testing four years after critical illness and treatment with tight glycemic control. Seventy-five percent of the children underwent heart surgery because of a CHD. Neurocognitive data of them were analyzed in this research. A better understanding of the neurocognitive profile and the evolution of this profile can help in optimizing long-term outcome of children with CHD after heart surgery. In a first part, we investigated neurocognitive outcome in children with CHD (1) by reporting the neurocognitive data of children with CHD who were included in the LGC-trial after heart surgery and (2) by means of a systematic review and meta-analysis of intelligence, EFs, attention and memory in children with CHD who underwent heart surgery. We hypothesized EFs to be more affected than intelligence in children with CHD compared to healthy control children. The meta-analysis and results of the LGC-trial revealed that in children with CHD who underwent heart surgery, intelligence and more specific neurocognitive functions were impaired, compared to healthy control children. Contrary to our hypothesis, intelligence, alertness and EFs were equally affected in children with CHD, compared to healthy control children. In a second part, we examined neurocognitive development of children with CHD. Neurocognitive deficits in children with CHD may increase through childhood. We hypothesized that children with CHD, who underwent heart surgery as infants, show more neurocognitive deficits, especially in the EFs, as they get older, compared to healthy control children. In this longitudinal follow-up study children with CHD and healthy control children underwent neurocognitive testing twice, at the age of four and seven. Intelligence, visual-motor integration, alertness, motor coordination, EFs and psychosocial functioning were assessed. Contrary to our hypothesis, children with CHD do not show an increase of neurocognitive deficits between the age of four and seven years. Children with CHD did have consistently lower IQ scores than healthy control children. They remain to have deficits in intelligence, visual-motor integration and psychosocial functioning, but seem to partially grow out of their deficits. In the third study, we investigated the predictive value of neurocognitive tests taken at the age of four for school problems at the age of seven in a group of children with CHD who had no school problems at age four. We hypothesized that a combination of Total IQ and alertness reaction time at age four improves the prediction of school problems at age seven, compared to only IQ. Second, we sought to determine which concise subset of tests could match up to Total IQ in predicting school problems. At age four children with CHD underwent extensive neurocognitive testing. At age seven parents were enquired about school problems of their child. The combination of Total IQ and alertness did not improve the prediction of school problems. Two subsets with the Arithmetic IQ-subtest offer equally good predictability of school problems as Total IQ. These subsets may be part of preschool neurocognitive screening to identify children with CHD at risk for later school problems. In summary, children with CHD who underwent heart surgery, have deficits in intelligence and more specific neurocognitive functions such as alertness and EFs. Our longitudinal study showed no worsening of neurocognitive deficits of children with CHD, compared to healthy control children, between the age of four and seven. Children with CHD keep their deficits in intelligence, but seem to partially grow out of them, illustrating the plasticity of the brain. Ultimately, Total IQ or concise subsets of IQ-subtests at age four are good predictors of school problems at age seven in a group of children with CHD who did not have school problems at age four. A subset with the Arithmetic IQ-subtest could be part of a preschool neurocognitive screening battery to identify children at risk for later school problems.nrpages: 221status: publishe

Neurocognition in children with congenital heart disease: a systematic review and meta-analysis

status: publishe

Neurocognitive Development After Pediatric Heart Surgery

Children with congenital heart disease (CHD) often have neurocognitive deficits, sometimes with a detrimental impact on daily and school functioning. These deficits may increase through childhood. In this study, we investigated whether children with CHD, who underwent heart surgery as infants, show more neurocognitive deficits, especially in the executive functions, as they get older, compared with healthy controls.status: publishe

Neurocognition after paediatric heart surgery: a systematic review and meta-analysis

Children with congenital heart disease (CHD) often experience difficulties in academic and daily functioning, which have been associated with intelligence and neurocognitive skills, including executive functions (EFs), attention and memory. We report the neurocognitive data of children with CHD who were included in the Leuven glucose control trial (LGC trial). Through a systematic review and meta-analysis, we aimed to find which neurocognitive functions are most consistently and prominently affected. 365 children with CHD and 216 healthy control children underwent extensive neurocognitive testing in the LGC trial. A comprehensive search of electronic databases PubMed, EMBASE and Cochrane was conducted for studies measuring intelligence, EFs, attention and memory in children who underwent heart surgery for CHD. Standardised mean differences (SMDs) between the CHD group and a healthy control group were calculated for these neurocognitive functions. LGC trial data were included in the meta-analysis. Twelve studies with a healthy control group were included in the meta-analysis, involving 647 patients with CHD and 633 controls. The CHD group (median age 7.35 years at testing) had worse scores than healthy control children, for all investigated neurocognitive functions. A medium SMD was found for intelligence (SMD=-0.53 (95% CI -0.68 to -0.38), p<0.00001). Alertness, an attentional function, was also consistently poorer in the CHD group. Memory was less affected, while EF had a medium SMD with large heterogeneity. Children with CHD risk displayed lower performance on intelligence and alertness assessment, which may contribute to difficulties in daily life and school. Heterogeneity in neurocognitive assessment and small sizes in most studies limit the interpretation.status: publishe

Outcome of patients on heart transplant list treated with a continuous-flow left ventricular assist device : Insights from the TRans-Atlantic registry on VAd and TrAnsplant (TRAViATA)

Background: Geographic variations in management and outcomes of individuals supported by continuous-flow left ventricular assist devices (CF-LVAD) between the United States (US) and Europe (EU) is largely unknown. Methods: We created a retrospective, multinational registry of 524 patients who received a CF-LVAD (either HVAD or Heartmate II) between January 2008 and April 2017. Follow up spanned from date of CF-LVAD implant to post-HTx period with a median follow up of 44.8 months. Results: The cohort included 299 (57.1%) EU and 225 (42.9%) US patients. Although the US cohort was significantly older with a higher prevalence of comorbidities, survival was similar between the cohorts (US 63.1%, EU 68.4% at 5 years, unadjusted log-rank test p = 0.43).Multivariate analyses suggested that older age, higher body mass index, elevated creatinine, use of temporary mechanical circulatory support prior CF-LVAD, and implantation of HVAD were associated with increased mortality. Among CF-LVAD patients undergoing HTx, the median time on CF-LVAD support was shorter in the US, meanwhile US donors were younger. Finally, the pattern of adverse events (stroke, gastrointestinal bleedings, late right ventricular failure, and driveline infection) during support differed significantly between US and EU. Conclusions: Although waitlisted patients in the US on CF-LVAD have higher risk comorbid conditions, the overall outcome is similar in US and EU. Geographic variations with regards to donor characteristics, duration of CF-LVAD support prior to transplant, and adverse events on support can explain the disparity in the utilization of mechanical bridge to transplant strategy between US and EU