OBJECTIVE To investigate the hypothesis that alterations in heart rate variability, peak systolic velocity variability and time-averaged velocity variability in the human umbilical artery may predict early signs of dysfunctional fetal-placental coupling in pregnancies that later develop pregnancy-induced hypertension. METHODS Doppler flow velocity recordings from the umbilical artery were per...

there is a general consensus that climate change has impact on the intensity and frequency of rainfall events. however, very little research is available about the changes in short term rainfall extremes. the focus of this paper has been on the change in annual and monthly rainfall extremes in ontario. the results indicate a greater variability (increase and decrease) among stations for shorter...

We present paper six of the NIRSPEC Brown Dwarf Spectroscopic Survey, an analysis of multi-epoch, highresolution (R ∼ 20,000) spectra of 25 field dwarf systems (3 late-type M dwarfs, 16 L dwarfs, and 6 T dwarfs) taken with the NIRSPEC infrared spectrograph at the W. M. Keck Observatory. With a radial velocity (RV) precision of ∼2 km s, we are sensitive to brown dwarf companions in orbits with p...

We investigate the relation between the Doppler factor determined from variations in total flux at 22 and 37 GHz, and the apparent transverse velocity determined from VLBA observations at 2 cm. The data are consistent with the relativistic beaming theory for compact radio sources, in that the distribution of β app /δ var , for 30 quasars, is roughly consistent with a Monte Carlo simulation. The...

1. The aim of this study was to define from umbilical artery flow velocity waveforms absolute peak systolic and time-averaged velocity, fetal heart rate, fetal heart rate variability and flow velocity variability, and the relation between fetal heart rate and velocity variables in early pregnancy.2.A total of 108 women presenting with a normal pregnancy from 10 to 20 weeks of gestation consente...

OBJECTIVES Determination of gestational age-related modulations in fetal heart rate and descending aorta blood flow velocity in the early human fetus and comparison of aortic variability data with data obtained from the umbilical artery. It is hypothesized that these modulations present in the umbilical artery also occur in the descending aorta. METHODS Doppler studies of descending aorta vel...