Low and very low birth weight in puppies: definitions, risk factors and survival in a large-scale population.

Background: Neonatal mortality (over the first three weeks of life) is a major concern in canine breeding facilities as an economic and welfare issue. Since low birth weight (LBW) dramatically increases the risk of neonatal death, the risk factors of occurrence need to be identified together with the chances and determinants of survival of newborns at-risk.

Results: Data from 4971 puppies from 10 breeds were analysed.

Birth weight as a risk factor for neonatal mortality: Breed-specific approach to identify at-risk puppies.

In numerous species, low birth weight is a risk factor for neonatal mortality. In the canine species, definition of a low birth weight is complex due to the huge interbreed variability in size. To identify puppies at higher risk of neonatal death, data from 6,694 puppies were analysed.

The short-term temporal spectrum of precipitable water vapor.

Short-term power spectra of the fluctuations in the precipitable water vapor measured with a dual-channel microwave radiometer are presented. The spectra, taken over 34-hour sampling periods, encompass periodicities from I day to about 10 minutes. The fluctuation power is associated with the average precipitable water vapor for the sampling period.

Microwave measurements of the absolute values of absorption by water vapour in the atmosphere.

MEASUREMENT of the absolute value of absorption by water vapour at microwave frequencies is difficult because the effect is so small. Far in the wings of the absorption lines, in the so-called 'windows' of the spectrum, it is especially difficult to achieve high accuracy in the free atmosphere. But it is in these windows that the behaviour of the absorption is important from both applied and scientific points of view.