Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

The $B^0$-$\bar B^0$ oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives $\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)}$ ps$^{-1}$.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)

[no abstract available

Measurements of 2H and 18O in body water: analytical considerations and physiological implications

International audienc

Revision of calculations in the doubly labeled water method for measurements of energy expenditure in humans

International audienc

The contribution of fat and fat-free tissue to body mass index in contemporary children and the reference child

BACKGROUND: Body mass index (BMI) is widely used to assess the prevalence of childhood obesity in populations, and to infer risk of subsequent obesity-related disease. However, BMI does not measure fat directly, and its relationship with body fatness is not necessarily stable over time

Interactions between H-2 and O-18 natural abundance variations and DLW measurements of energy expenditure

Appropriate corrections for H-2 and O-18 natural abundance are necessary in energy expenditure measurements with the doubly labeled water (DLW) method. The contribution of natural abundance variations to errors in the method is generally ignored if an appropriate dose level is given. Calculation of the appropriate dose level assumes that H-2 and O-18 natural abundance values are covariant and have a fixed slope. This study has investigated the between- and within-subject natural abundance variations, the latter over periods of time similar to those used in DLW experiment. Although H-2 and O-18 natural abundance values are covariant between subjects, the slope of their relationship is different from that of the Meteoric Water Line. Within subjects there is no such demonstrable covariance. It is concluded that: ii the determinants of H-2 and O-18 natural abundance are different within and between subjects; 2) the concept of an optimal ratio of doses is not valid, and a safer strategy is probably to use a ratio > 10; 3) natural abundance variations may contribute significantly to the magnitude of error in the DLW measurements of energy expenditure

Increased energy expenditure in young children with cystic fibrosis

To investigate the role of energy expenditure in the altered energy balance in cystic fibrosis (CF), total energy expenditure (TEE) was measured by the doubly-labelled water method in 9 clinically well CF infants (body weight 7·3-10·9 kg) without chronic lung disease. CF infants had 25% higher rates of energy expenditure when compared with data derived from measurements of TEE obtained by the same method in 16 healthy infants, matched for age and body weight. Mean TEE (SEM) for CF was 950 (38) kcal, vs 876 (72) kcal for controls matched for age and 758 (46) kcal for controls matched for weight. Although subclinical disease activity cannot be excluded as a determinant of the excess TEE, the possibility of an energy-requiring basic defect is suggested, because further analysis indicated that factors other than body weight, degree of underweight, presence of pancreatic insufficiency, or presence of lung disease were important. Increased TEE may contribute to undernutrition in CF, even in the absence of chronic lung disease