Alpine and northern treelines are primarily controlled by low temperatures. However, little is known about the impact of low soil temperature on tree transpiration at treelines. We aim to test the hypothesis that in cold-limited forests, the main limiting factors for tree transpiration switch from low soil temperature before summer solstice to atmospheric evaporative demand after summer solstic...

BACKGROUND Many studies have shown a consistent association between ambient air pollution and an increase in death due to cardiovascular causes. An increase in blood pressure is a common risk factor for a variety of cardiovascular diseases. However, the association between air pollution and blood pressure has not been evaluated extensively. METHODS In this cross-sectional study, we measured b...

To learn whether asthmatic children are affected by passive smoking, we studied 240 unselected consecutively referred asthmatic subjects, aged 7 to 17 years. To discover whether children of smokers are affected more severely during the cold, wet season, when windows are closed and children are indoors, than during the warm, dry season, when houses are well ventilated and children spend more tim...

BACKGROUND This study's aim was to design and validate a semi-quantitative food frequency questionnaire (FFQ) for assessment of fruits and vegetables (FV) consumption in adults of Isfahan by comparing the FFQ with dietary reference method and blood plasma levels of beta-carotene, vitamin C, and retinol. METHODS This validation study was performed on 123 healthy adults of Isfahan. FV intake wa...

Hybrid bermudagrasses occasionally suffer significant damage when below-normal winter conditions occur. In an attempt to enhance cold tolerance of these grasses, a study was undertaken to assess the effects of late-season nitrogen (N) fertilization and applications of the growth regulator trinexapac-ethyl (Primo) on morphology and cold tolerance of ‘Tifton 419’ hybrid bermudagrass. Nitrogen app...

In this second part of the series, an overview of applications of polarimetric radar observations is given. This includes a summary of improvements to data quality, and interpretation of signatures and output of algorithms for observations made in warmand cold-season precipitation. Examples of operational products include hydrometeor classification, hail detection and sizing, and quantitative p...

BACKGROUND Despite the prediction that temperatures are expected to increase in the future, little is known about the health effects of increasing temperatures on pregnant women. The objective of this study was to investigate the impact of apparent temperature on spontaneous preterm delivery (PTD). METHODS A case-crossover study of 14,466 singleton spontaneous preterm deliveries occurring bet...

[1] We have analyzed the relationship between surface air temperature (SAT), ground surface temperature (GST), and snow cover (SNC) over the terrestrial Northern Hemisphere based on general circulation model (GCM) simulations using GISS modelE forced with the observed SST and radiative forcing changes from 1951–1998. While SAT is the dominant influence on GST during the warm-season, it explains...

BACKGROUND Controversy remains regarding the relationship between ambient ozone and mortality worldwide. In mainland China, the largest developing country, there has been no prior study investigating the acute effect of O3 on death risk. Given the changes in types of air pollution from conventional coal combustion to the mixed coal combustion/motor vehicle emissions in China's large cities, it ...

Ozone uptake was studied in a pine forest in Tenerife, Canary Islands, an ecotone with strong seasonal changes in climate. Ambient ozone concentration showed a pronounced seasonal course with high concentrations during the dry and warm period and low concentrations during the wet and cold season. Ozone uptake by contrast showed no clear seasonal trend. This is because canopy conductance signifi...