Photoplethysmography-Based Machine Learning Approaches for Atrial Fibrillation Prediction:A Report From the Huawei Heart Study

BACKGROUND: Current wearable devices enable the detection of atrial fibrillation (AF), but a machine learning (ML)–based approach may facilitate accurate prediction of AF onset. OBJECTIVES: The present study aimed to develop, optimize, and validate an ML-based model for real-time prediction of AF onset in a population at high risk of incident AF. METHODS: A primary ML-based prediction model of AF onset (M1) was developed on the basis of the Huawei Heart Study, a general-population AF screening study using photoplethysmography (PPG)–based smart devices. After optimization in 554 individuals with 469,267 PPG data sets, the optimized ML-based model (M2) was further prospectively validated in 50 individuals with paroxysmal AF at high risk of AF onset, and compared with 72-hour Holter electrocardiographic (ECG) monitoring, a criterion standard, from September 1, 2019, to November 5, 2019. RESULTS: Among 50 patients with paroxysmal AF (mean age 67 ± 12 years, 40% women), there were 2,808 AF events from a total of 14,847,356 ECGs over 72 hours and 6,860 PPGs (45.83 ± 13.9 per subject per day). The best performance of M1 for AF onset prediction was achieved 4 hours before AF onset (area under the receiver operating characteristic curve: 0.94; 95% confidence interval: 0.93-0.94). M2 sensitivity, specificity, positive predictive value, negative predictive value, and accuracy (at 0 to 4 hours before AF onset) were 81.9%, 96.6%, 96.4%, 83.1%, and 88.9%, respectively, compared with 72-hour Holter ECG. CONCLUSIONS: The PPG- based ML model demonstrated good ability for AF prediction in advance. (Mobile Health [mHealth] technology for improved screening, patient involvement and optimizing integrated care in atrial fibrillation; ChiCTR-OOC-17014138

The Exact MSSM Spectrum from String Theory

We show the existence of realistic vacua in string theory whose observable sector has exactly the matter content of the MSSM. This is achieved by compactifying the E_8 x E_8 heterotic superstring on a smooth Calabi-Yau threefold with an SU(4) gauge instanton and a Z_3 x Z_3 Wilson line. Specifically, the observable sector is N=1 supersymmetric with gauge group SU(3)_C x SU(2)_L x U(1)_Y x U(1)_{B-L}, three families of quarks and leptons, each family with a right-handed neutrino, and one Higgs-Higgs conjugate pair. Importantly, there are no extra vector-like pairs and no exotic matter in the zero mode spectrum. There are, in addition, 6 geometric moduli and 13 gauge instanton moduli in the observable sector. The holomorphic SU(4) vector bundle of the observable sector is slope-stable.Comment: 15 pages, LaTeX; v2: Hidden sector is unstable, symbol typesetting error corrected, clarifications and references added; v3: New discussion of hidden secto

The Spectra of Heterotic Standard Model Vacua

A formalism for determining the massless spectrum of a class of realistic heterotic string vacua is presented. These vacua, which consist of SU(5) holomorphic bundles on torus-fibered Calabi-Yau threefolds with fundamental group Z_2, lead to low energy theories with standard model gauge group (SU(3)_C x SU(2)_L x U(1)_Y)/Z_6 and three families of quarks and leptons. A methodology for determining the sheaf cohomology of these bundles and the representation of Z_2 on each cohomology group is given. Combining these results with the action of a Z_2 Wilson line, we compute, tabulate and discuss the massless spectrum.Comment: 41+1pp, 2 fig

Meat Science and Applications (pp. 222-248)

The chapter discusses the following topics: Continuous Measurement and Monitoring, Meat Quality Correlations, How Stressful is Slaughter?, Causes of Poor Welfare Audit Scores, Animal Vision, Hearing and Smell, Basic Handling Principles, Handler Movement Patterns, Design of Handling Facilities, Design and Operation of Restraint Devices, Stunning, Stunning Method and Blood-Splash, Bruising and Meat Quality

Patterns in Calabi-Yau Distributions

We explore the distribution of topological numbers in Calabi–Yau manifolds, using the Kreuzer–Skarke dataset of hypersurfaces in toric varieties as a testing ground. While the Hodge numbers are well-known to exhibit mirror symmetry, patterns in frequencies of combination thereof exhibit striking new patterns. We find pseudo-Voigt and Planckian distributions with high confidence and exact fit for many substructures. The patterns indicate typicality within the landscape of Calabi–Yau manifolds of various dimension

Uptake of evidence-based statin therapy among atrial fibrillation patients in China:a report from the CAFR (Chinese Atrial Fibrillation Registry) Study

Background:Atrial fibrillation (AF) is associated with increased incidence of cardiovascular disease, and hence, statin therapy is indicated in majority of AF patients.Methods and results:We analyzed data from the Chinese Atrial Fibrillation Registry (CAFR) involving 11,496 AF patients from 2011 to 2014. Practice patterns of statin therapy and factors associated with statin underuse were analyzed.Based on the 2013 ACC/AHA cholesterol management guidelines, statins should be recommended for 67.4% (7720/11,461) of AF participants in CAFR, but only 43.4% (3352/7720) with appropriate indications were taking statins. Statin underuse in AF patients was independently associated with male sex, tertiary hospital treatment, outpatient attendance, and absence of ‘high risk’ cardiovascular risk factors (overweight, diabetes, coronary heart disease, stroke/transient ischemic attack/peripheral embolism and hypertension).Conclusions:A high proportion of Chinese AF patients had indications for statin therapy. Evidence-based statin prescribing was suboptimal in this population. Greater efforts should be made to improve a holistic approach to cardiovascular risk management in the Chinese AF population