A study was conducted to evaluate the effect of yeast Saccharomyces cerevisiae and algae Chlorella vulgaris on the production of rotifer Brachionus calyciflorus. The Brachionus calyciflorus were cultured using four different types of diets: fresh Chlorella vulgaris (T1), yeast with fresh Chlorella vulgaris (T2), powder Chlorella vulgaris with fresh Chlorella vulgaris (T3) and yeast with powder ...

We studied the zooplankton community composition at different depths (2, 4, 8, 12 and 20 m) of Valle de Bravo, a drinking water reservoirin central Mexico during December 2005 to November 2006. Temperature, dissolved oxygen, pH and chlorophyll a were measured simultaneously. While physicochemical values were similar to those found in previous studies, total zooplankton abundance was higher (mea...

We investigated seasonal variation in membrane fouling in membrane bioreactors (MBRs) treating municipal wastewater regarding the difference between physically reversible and irreversible fouling. Two separate MBRs with different solid retention times (SRTs) operated in parallel for about 200 days including high- and low-temperature periods to evaluate the effect of operating conditions on seas...

Inpatient admissions to all psychiatric hospital beds in England and Wales in 1970-73 were studied by month of admission for eight diagnostic groups. The admission rates for schizophrenia showed a pronounced seasonal variation, with a maximum in summer. The seasonal pattern for schizophrenia was very similar to the one shown for mania, although somewhat less marked. The admission rates for neur...

We studied the seasonal incidence of onset of symptoms of central retinal vein occlusion (CRVO) in 105 patients over a 5-year period. Their onset showed a significant cyclic variation (p less than 0.01), being most frequent in the months September through to February. We believe this seasonal variation may in part reflect seasonal changes in haemostasis and retinal perfusion, though other unide...

OBJECTIVES This study examined the variation in the U.S. road fatality rate per distance driven across the months of the year. METHOD The monthly fatality rates were analyzed for a 13-year period from 1994 through 2006. RESULTS The results indicate a systematic seasonal variation in the road fatality rate, with the highest rate in October and the lowest rate in March. CONCLUSION The obtai...

Animals cope with seasonal variation in environmental factors by adjustments of physiology and life history. When seasonal variation is partly predictable, such adjustments can be based on a genetic component or be phenotypically flexible. Animals have to allocate limited resources over different demands, including immune function. Accordingly, immune traits could change seasonally, and such ch...

The main purpose of this study was to evaluate the influence of the photoperiod on the seminal traits of crossbreed wool-producing rams throughout on year period. For the effect of photoperiod two periods were considered: decreasing daylight length (summer and autumn) and increasing daylight length (winter and spring). For the study 5 Baluchi × Moghani (BL×MG) and 5 Arkharmerino × Moghani (AM×M...