Weather sensitivity in migraineurs

The scientific evidence for weather being a trigger factor for migraine attacks is inconclusive. We investigated the association between weather components and the onset and severity of attacks. Headache diaries of 20 migraineurs were analyzed retrospectively and correlated in 4-h intervals to atmospheric air pressure, temperature, and relative air humidity in Berlin (Germany) for a period of 12 consecutive months. Absolute values and relative changes within the preceding 24 h were analyzed. Migraine attacks started most frequently at 4 a.m. and reached the highest intensity between 4 and 8 a.m. A highly significant association between meteorological variables and the occurrence of migraine attacks was found in six patients. The onset of an attack as well as high headache intensity was associated with lower temperature and higher humidity. Our data indicate that a subgroup of migraineurs is highly sensitive to changes of certain weather components

Weather and the risk of sudden infant death syndrome: the effect of wind

STUDY OBJECTIVE—To examine and identify relations between sudden infant death syndrome (SIDS) and wind, particularly the föhn wind, in Christchurch, New Zealand.
DESIGN—A retrospective epidemiological study combining details of regional hourly meteorological variables and reported SIDS cases.
SETTING—Christchurch, New Zealand, between 1968 and 1997( )inclusively.
PARTICIPANTS—All 646 infants reported as dying from SIDS within the greater Christchurch region.
MAIN RESULTS—Analysis of 1968-1989 data revealed nine wind variables significantly related to SIDS. When compared with corresponding variables calculated over the 1990-1997 period, only the northerly wind on the day of death and the southerly wind three days before a SIDS death had estimated associations with similar effect size and sign. However, both these variables had confidence intervals that included unity.
CONCLUSIONS—No evidence was found to suspect that föhn winds influenced SIDS occurrence. The relations identified between SIDS incidence and wind, after controlling for the effects of temperature and trend, were tenuous and relatively small. More data are necessary to substantiate whether northerly winds on the day of death or southerly winds occurring three days before a death are truly associated with SIDS. It seems that wind has little, if any effect on SIDS incidence in Christchurch.


Keywords: sudden infant death syndrome; weather; föhn win

Evidence for density-dependent habitat occupancy at varying scales in an expanding bird population

International audienceUnderstanding factors shaping the spatial distribution of animals is crucial for the conservation and management of wildlife species. However, few studies have investigated density-dependent habitat selection in wild populations in non-equilibrium conditions and at varying spatial scales. Here, we investigated densitydependent habitat selection at varying spatial scales in an increasing white stork Ciconia ciconia population using a long term data set in western France. During a 16-year study period, the breeding population density increased from 0.66 nests per 100 km2 to 6.6 nests per 100 km2. At the beginning of the colonisation of the area settlement probability of storks was mainly positively affected by grasslands located near wetlands. Areas with intensive or moderately intensive agriculture were extremely unlikely to be occupied by breeding birds. However, selection for the initially preferred habitats faded as stork density increased although the proportions of habitat types remained unchanged. At the same time selection for initially less favoured habitats had increased. Moreover, we found that the spatial scale of selection for each foraging habitat variable was consistent over time. Our results suggest that snapshot analyses of resource selection in populations at high density may be misleading for population conservation or management. In contrast, a longitudinal approach to resource selection can be a valuable tool for understanding resource limitation