Chromospheric Activity of HAT-P-11: an Unusually Active Planet-Hosting K Star

Kepler photometry of the hot Neptune host star HAT-P-11 suggests that its spot latitude distribution is comparable to the Sun's near solar maximum. We search for evidence of an activity cycle in the CaII H & K chromospheric emission $S$-index with archival Keck/HIRES spectra and observations from the echelle spectrograph on the ARC 3.5 m Telescope at APO. The chromospheric emission of HAT-P-11 is consistent with a $\gtrsim 10$ year activity cycle, which plateaued near maximum during the Kepler mission. In the cycle that we observed, the star seemed to spend more time near active maximum than minimum. We compare the $\log R^\prime_{HK}$ normalized chromospheric emission index of HAT-P-11 with other stars. HAT-P-11 has unusually strong chromospheric emission compared to planet-hosting stars of similar effective temperature and rotation period, perhaps due to tides raised by its planet.Comment: 16 pages, 8 figures; accepted to the Astrophysical Journa

Reconceptualising Atrial Fibrillation Using Renewal Theory: A Novel Approach to the Assessment of Atrial Fibrillation Dynamics

Despite a century of research, the mechanisms of AF remain unresolved. A universal motif within AF research has been unstable re-entry, but this remains poorly characterised, with competing key conceptual paradigms of multiple wavelets and more driving rotors. Understanding the mechanisms of AF is clinically relevant, especially with regard to treatment and ablation of the more persistent forms of AF. Here, the authors outline the surprising but reproducible finding that unstable re-entrant circuits are born and destroyed at quasi-stationary rates, a finding based on a branch of mathematics known as renewal theory. Renewal theory may be a way to potentially unify the multiple wavelet and rotor theories. The renewal rate constants are potentially attractive because they are temporally stable parameters of a defined probability distribution (the exponential distribution) and can be estimated with precision and accuracy due to the principles of renewal theory. In this perspective review, this new representational architecture for AF is explained and placed into context, and the clinical and mechanistic implications are discussed

The association between contrast-enhanced ultrasound and near-infrared spectroscopy-derived measures of calf muscle microvascular responsiveness in older adults

Background and Aim Contrast-enhanced ultrasound (CEUS) measures of post-occlusion skeletal muscle microvascular responsiveness demonstrate the microvascular dysfunction associated with ageing and age-related disease. However, the accessibility of CEUS is limited by the need for intravenous administration of ultrasound contrast agents and sophisticated imaging analysis. Alternative methods are required for the broader assessment of microvascular dysfunction in research and clinical settings. Therefore, we aimed to evaluate the level of association and agreement between CEUS and near-infrared spectroscopy (NIRS)-derived measures of post-occlusion skeletal muscle microvascular responsiveness in older adults. Methods During supine rest, participants (n=15, 67±11 years) underwent 5 minutes of thigh cuff-occlusion (200 mmHg). Post-occlusion CEUS measures of calf muscle microvascular responsiveness were made, including time to 95% peak acoustic intensity (TTP95 AI) and the rate of rise (slope AI). Simultaneous measures, including time to 95% peak oxygenated haemoglobin (TTP95 O2Hb) and slope O2Hb, were made using continuous-wave NIRS in the same muscle region. Results There were strong correlations between TTP95 measures derived from CEUS and NIRS (r=0.834, p=<0.001) and the corresponding measures of slope (r=0.735, p=0.004). The limits of agreement demonstrated by Bland Altman plot analyses for CEUS and NIRS-derived measures of TTP95 (-9.67–1.98 s) and slope (-1.29–5.23%. s-1) were smaller than the minimum differences expected in people with microvascular dysfunction. Conclusions The strong correlations and level of agreement in the present study support the use of NIRS as a non-invasive, portable and cost-effective method for assessing post-occlusion skeletal muscle microvascular responsiveness in older adults

Longitudinal Analysis Between Maternal Feeding Practices and Body Mass Index (BMI): A Study in Asian Singaporean Preschoolers

Bidirectional studies between maternal feeding practices with subsequent child weight are limited, with no studies in Asian populations. In longitudinal analyses, we assessed the directionality of the associations between maternal feeding practices and body mass index (BMI) in preschoolers. Participants were 428 mother child dyads from the GUSTO (Growing Up in Singapore Toward healthy Outcomes) cohort. Feeding practices were assessed using the Comprehensive Feeding Practices Questionnaire (CFPQ) at age 5 y. Child BMI was measured at ages 4 and 6 y. BMI and maternal feeding practices subscales were transformed to SD scores and both directions of their associations examined with multivariable linear regression and pathway modeling. Higher BMI at age 4 was associated with lower encouragement of balance and variety (β = −0.33; 95%CI: −0.53, −0.13), lower pressure to eat (β = −0.49; −0.68, −0.29) and higher restriction (β = 1.10; 0.67, 1.52) at age 5, adjusting for confounders and baseline feeding practices at 3 years. In the reverse direction, only pressure and restriction at age 5 were associated with lower and higher child BMI at age 6 years, respectively. After the adjustment for baseline BMI at age 5, the association with pressure was attenuated to non-significance (β = 0.01 (−0.01, 0.03), while the association with restriction remained significant (β = 0.02; 0.002, 0.03). Overall, associations from child BMI to maternal restriction for weight control and pressure feeding practices was stronger than the association from these maternal feeding practices to child BMI (Wald's statistics = 24.3 and 19.5, respectively; p &lt; 0.001). The strength and directionality suggests that the mothers in the Asian population were likely to adopt these feeding practices in response to their child's BMI, rather than the converse.Clinical Trial Registry Number and Website This study was registered at clinicaltrials.gov as NCT01174875 (www.clinicaltrials.gov, NCT01174875)

The global retinoblastoma outcome study : a prospective, cluster-based analysis of 4064 patients from 149 countries

DATA SHARING : The study data will become available online once all analyses are complete.BACKGROUND : Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. METHODS : We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. FINDINGS : The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope). INTERPRETATION : This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.The Queen Elizabeth Diamond Jubilee Trust and the Wellcome Trust.https://www.thelancet.com/journals/langlo/homeam2023Paediatrics and Child Healt

Relationship between epicardial fat volume and coronary microvascular dysfunction in patients with chest pain and unobstructed coronary arteries

Objective Epicardial fat (EF) is metabolically active adipose tissue positioned between the epicardial surface of the heart and the pericardium. We investigated whether there is a relationship between EF and Coronary Microvascular Dysfunction (CMD) in patients presenting with chest pain and unobstructed coronary arteries. Materials and Methods This study recruited patients referred to cardiology clinics for assessment of chest pain who subsequently underwent assessment via CT coronary angiogram (CTA). Myocardial blood flow reserve (MBFR) was assessed using myocardial contrast echocardiography. Epicardial fat volume (EFV) was measured by tracing serial slices on CTA with corresponding Hounsfield units of −195 to −45. Results We recruited 134 participants with a mean age of 59.2 (9.8) years. CMD was present in 54 (40%) patients, and the measured mean EFV was 128 mm3 (96, 168). Fortythree patients (32%) had a coronary artery calcium score (CACS) of 0, 64 (48%) had a CACS of 1–100, 18 (13%) had a CACS of 101–400, and 9 (7%) had a CACS >400. Univariate regression analysis showed that EFV and MBFR had a correlation coefficient of R=−0.22, with a significant regression slope (β=−0.002, p=0.012). Multivariable linear regression analysis using MBFR as a continuous outcome variable revealed age (β=−0.012, p=0.011) and CACS (β=−0.003, p=0.023) to be associated with MBFR. EFV was not associated with MBFR (β=−0.0007, p=0.538). Model repetition with MBFR as a dichotomous variable (MBFR ≥2 o

Relationship between coronary microvascular dysfunction and left ventricular diastolic function in patients with chest pain and unobstructed coronary arteries

Backgroud: Diastolic dysfunction (DD) is reported to affect up to 35% of the adult general population. The consequence of progressive DD is heart failure with preserved ejection fraction (HFpEF). Coronary microvascular dysfunction (CMD) has been suggested as one of the pathologic mechanisms leading to HFpEF. We investigated whether there was an association between coronary microvascular function and echocardiographic indices of left ventricular diastolic function at rest in patients with chest pain and unobstructed coronary arteries (CPUCA). Methods: This retrospective observational study recruited patients referred to cardiology clinics assessment of chest pain who subsequently underwent assessment via CT coronary angiogram (CTA). Coronary microvascular dysfunction was determined by myocardial blood flow reserve (MBFR