OBJECTIVES We set out to examine associations between ambient air pollution concentrations and emergency department (ED) visits for migraine/headache in a multi-city study. MATERIALS AND METHODS We designed a time-series study of 64 839 ED visits for migraine (ICD-9: 346) and of 68 495 ED visits for headache (ICD-9: 784) recorded at hospitals in five different cities in Canada. The data (days...

In New York, an epizootic of American crow (Corvus brachyrhynchos) deaths from West Nile virus (WNV) infection occurred during winter 2004-2005, a cold season when mosquitoes are not active. Detection of WNV in feces collected at the roost suggests lateral transmission through contact or fecal contamination.

Satellite measurements in various spectral channels are assimilated through the JCSDA's Community Radiative Transfer Model (CRTM) on the NCEP Gridpoint Statistical Interpolation (GSI) (Wu et al. 2002). Currently, satellite measurements over ocean have been successfully utilized to improve numerical weather prediction (NWP). However, it is found that the amount of satellite data assimilated over...

[1] We construct an extratropical reduced temperature–depth profile for land areas north of 20 N latitude from the global borehole temperature database compiled for climate reconstruction. The mean reduced temperature profile compares well with a time series constructed from an initial baseline temperature (0.6 ± 0.1 C) and the last 140 years of gridded annual surface air temperature data diffu...

Railway traffic has increased over the last decade due to greater energy costs and the need to reduce emissions. Ensuring the dependability and capacity of railway infrastructure requires efficient and effective maintenance which, in turn, requires good understanding of various physical behaviours, e.g. deterioration and environmental effects. This paper studies the effect of cold climate on ra...

Outdoors activities, such as cross-country skiing, may expose the human body to severe thermal stress during training and competitive events in the winter season. Cooling affects all aspects of muscular performance (1), and cold has a profound effect on the functional properties of skeletal muscle. When exercise intensity is high enough to maintain core temperature, but skin cooling is still pr...

Human influenza infections exhibit a strong seasonal cycle in temperate regions. Recent laboratory and epidemiological evidence suggests that low specific humidity conditions facilitate the airborne survival and transmission of the influenza virus in temperate regions, resulting in annual winter epidemics. However, this relationship is unlikely to account for the epidemiology of influenza in tr...

In the midwestern and eastern U.S. populations of Drosophila melanogaster, the Standard gene arrangements show higher frequencies in the north than in the south. In a Missouri population, and to a lesser extent in a south Texas population, the frequencies of Standard chromosomes regularly rise during the cold season and drop during the warm season, thus paralleling the north-south frequency dif...

In temperate regions, the seasonal dynamics of Aedes aegypti (L.) (Diptera: Culicidae) is mainly influenced by temperature. It is assumed that, during the winter season, the population remains as eggs and that the development and population growth of surviving eggs begin during the following spring. The aim of the current study was to assess the temporal dynamics of egg hatching of Ae. aegypti ...