We measured the velocity and attenuation of audible sound in the isolated lung of the near-term fetal sheep to test the hypothesis that the acoustic properties of the lung provide a measure of the volume of gas it contains. We introduced pseudorandom noise (bandwidth 70 Hz-7 kHz) to one side of the lung and recorded the noise transmitted to the surface immediately opposite, starting with the lu...

An Euler atmospheric transport model (Canadian Model for Environmental Transport of Organochlorine Pesticides, CanMETOP) was applied and validated to estimate polycyclic aromatic hydrocarbon (PAH) ambient air concentrations at ground level in China based on a high-resolution emission inventory. The results were used to evaluate lung cancer risk for the Chinese population caused by inhalation ex...

to estimate population density of the cabbage aphid, brevicoryne brassicae (l.), a stratified random sampling was conducted in two unsprayed canola fields in isfahan (central iran) during 2011-2012. population density was determined for apterous, and alates, as well as the total population, at two plant growth phases (pgp1: from plant emergence to the end of rosette, and pgp2: from the beginnin...

BACKGROUND The effect of smoking cessation and smoking relapse on lung density was studied using low-dose CT. METHODS Spiral, multidetector, low-dose CT was performed on 726 current and former smokers (>20 pack-years) recruited from a cancer screening trial. Lung density was quantified by calculating the 15th percentile density (PD15), which was adjusted to predicted total lung capacity. Data...

Recently, it was shown that both mean lung density (MLD) and the relative lung area with an attenuation of <-950 HU (RA950) are related to severity of asthma in nonsmoking asthmatics. The aim of the present study was to examine whether reduced computed tomography (CT) lung density during exacerbation could change after treatment. A cross-sectional study was performed to compare CT lung density ...

The paper deals with indirect evaluation of the effective thermal or hydraulic conductivity of a random mixture of two different materials from the known effective complex permittivity of the same mixture. The method is based on deriving information about the microstructure of the composite from measurements of its effective properties; we call this approach inverse homogenization. This structu...

What allows some species to successfully colonize a novel environment while others fail? Numerous studies in invasion biology have sought to answer this question, but those studies have tended to focus on traits of species or individuals (e.g. body size, seed size, seed number), and these traits have largely been found to be weak predictors of invasion success. However, characteristics of colon...

Conspicuous cyclic changes in population density characterize many populations of small northern rodents. The extreme crashes in individual number are expected to reduce the amount of genetic variation within a population during the crash phases of the population cycle. By long-term monitoring of a bank vole (Myodes glareolus) population, we show that despite the substantial and repetitive cras...