Tree species in the boreal forest cycle between periods of active growth and dormancy alter their photosynthetic processes in response to changing environmental conditions. For deciduous species, these changes are readily visible, while evergreen species have subtler foliar changes during seasonal transitions. In this study, we used remotely sensed optical indices to observe seasonal changes in...

In this issue, Farez et al. report that the circadian hormone melatonin, whose levels vary with seasonal changes in night length, shifts the immune response toward an anti-inflammatory state that may explain the seasonal variability of multiple sclerosis disease activity.

Studies of the seasonal fluctuation in carbohydrates in various deciduous, subtropical, and tropical fruit trees have shown that similar changes occur in. such trees as apple, avocado and citrus, despite important physiological differences between, the species (4, 5,10, 11, 18). The studies have indicated that fluctuations in carbohydrates are influenced by seasonal environmental factors and by...

How does the Drosophila circadian control network respond to seasonal environmental changes? Genetic manipulations that target a small subset of clock neurons reveal that they integrate seasonal cues of light and temperature to modulate the daily distribution of rest and activity.

The objective of the present study was to verify the seasonal luteal activity of racehorses in training in Japan from March to August. We allocated 102 horses into a luteal activity group and non-luteal activity group. The luteal activity group included horses with serum progesterone levels that were consistently >1 ng/ml and changed by ± 1 ng/ml. In contrast, the progesterone levels of the non...

BACKGROUND In temperate climates, invasive meningococcal disease (IMD) incidence tends to coincide with or closely follow peak incidence of influenza virus infection; at a seasonal level, increased influenza activity frequently correlates with increased seasonal risk of IMD. METHODS We evaluated 240 cases of IMD reported in central Ontario, Canada, from 2000 to 2006. Associations between envi...

Polar regions are characterized by acute seasonal changes in the environment, with organisms inhabiting these regions lacking diel photoperiodic information for parts of the year. We present, to our knowledge, the first high-resolution analysis of diel and seasonal activity of free-living fishes in polar waters (74°N), subject to extreme variation in photoperiod, temperature and food availabili...

1. introduction in recent years, regarding climate changes, the analysis of natural variability of climate at different time scales has attracted a lot of attention. while, the data series with short statistical period just shows a likelihood estimation of a few decades of climate variability, the data series with long period shows the fluctuations of several decades with statistical importance...

Activity of colonies of the western drywood termite, Incisitermes minor, was measured with acoustic emission (AE) technology in five loquat (Eriobotrya japonica) logs. Termite activity, whether it was feeding, excavation or movement, was monitored for 11 months under ambient conditions in a small wooden structure maintained at the University of California Richmond Field Station. AE, temperature...