background & aim: achillea filipendulina is one of the most important species of the family asteraceae and, it considered as one of the most valuable medicinal and ornamental plants. environmental factors affected on quality and quantity of the essential oil of medicinal and aromatic plants. so, selecting of appropriate season for harvesting can lead to increase quality and quantity yield. ...

Fifty patients of recurrent mania were studied for seasonality of which 11 patients fulfilled our study criteria for Seasonal Affective Disorder (recurrent mania). The two groups of seasonal and nonseasonal recurrent mania were compared on clinical and socio-demographic variables. Results characterised recurrent seasonal mania with psychotic features and occurrence of episodes mainly in summer ...

This paper tests whether atmospheric brightness is related to Canadian birth seasonality ten-eleven months earlier. Births and visibility (brightness) are correlated nation-wide and in nine provinces/ cities. For the national correlation, r=0.928. Therefore, seasonal brightness provides a plausible explanation for inter-annual changes in seasonality, and may reconcile divergent viewpoints. Easy...

We consider a SIRS model with time dependent transmission rate. We assume time dependent vaccination which confers the same immunity as natural infection. We study two types of vaccination strategies: (i) optimal vaccination, in the sense that it minimizes the effort of vaccination in the set of vaccination strategies for which, for any sufficiently small perturbation of the disease free state,...

Seasonal declines in avian clutch size are well documented, but seasonal variation in other reproductive parameters has received less attention. For example, the probability of complete brood mortality typically explains much of the variation in reproductive success and often varies seasonally, but we know little about the underlying cause of that variation. This oversight is surprising given t...

Violence is widespread throughout the natural world, prominent examples being predatory violence between species, seasonal violent competition for mating rights and territories within species and food competition both within and between species. These interactions are generally between unrelated individuals with no social connection. There are, however, examples of violent behaviour which occur...

In healthy subjects, both the duration of wakefulness and the circadian pacemaker have been demonstrated to be involved in the regulation of mood. Some features of affective disorders suggest that these two factors also play a role in the dysregulation of mood. In particular, disturbances of the circadian pacemaker have been proposed to be a pathogenetic factor in Seasonal Affective Disorder, w...

Both influenza and respiratory syncytial virus (RSV) are active throughout the year in subtropical or tropical regions, but few studies have reported on age-specific seasonal patterns of these viruses. We examined the age-specific epidemic curves of laboratory-confirmed cases of influenza A (subtyped into seasonal A(H1N1), A(H3N2), and pandemic virus A(H1N1)pdm09), influenza B and respiratory s...

Use of scasonal climnte forecasts is ;1 rapidly evolving arca. Effective rcscarch and npplication of climate forecasts require close cooperation between scientists i n diverse disciplines and decision makers. Successful collaboration requires all players to at least partially uilderstand each other's perspective%. Issues associated with seasonal forecasts, through a selected review of both phys...