On-farm comparison of different postharvest storage technologies in a maize farming system of Tanzania Central Corridor

Article purchased; Published online: 16 March 2018Seven methods for storing maize were tested and compared with traditional storage of maize in polypropylene bags. Twenty farmers managed the experiment under their prevailing conditions for 30 weeks. Stored grain was assessed for damage every six weeks. The dominant storage insect pests identified were the Maize weevil (Sitophilus zeamais) and the Red flour beetle (Tribolium castaneum). The moisture content of grain in hermetic conditions increased from 12.5 ± 0.2% at the start of storage to a range of 13.0 ± 0.2–13.5 ± 0.2% at 30 weeks. There was no significant difference (F = 87.09; P < 0.0001) regarding insect control and grain damage between hermetic storage and fumigation with insecticides. However, the insecticide treatment of polypropylene yarn (ZeroFly®) did not control the insect populations for the experimental period under farmers' management. Grain damage was significantly lower in hermetic storage and fumigated grain than ZeroFly® and polypropylene bags without fumigation. No significant difference in grain damage was found between airtight treatment alone and when combined with the use of insecticides. During storage, S. zeamais was predominant and could be of more economic importance than T. castaneum as far as maize damage is concerned. At 30 weeks, the germination rate of grain stored with insecticides or in hermetic storage (68.5 ± 3.6% to 81.4 ± 4.0%) had not significantly reduced from the rate before storage (F = 15.55; P < 0.0001) except in ZeroFly®, also in polypropylene bags without treatment. Even though such bags did not control storage pests, farmers still liked this cheap technology. Hermetic storage techniques can be recommended to farmers without the use of insecticides provided they are inexpensive, and the proper application of technologies is ensured

Male swimmers cross the English Channel faster than female swimmers

We examined the gender difference in performance of open-water ultra-swimmers crossing the English Channel between 1875 and 2011. A total of 1606 swimmers (1120 males and 486 females) crossed the English Channel within a mean time of 809.6 ± 175.6 min. The overall female swim time of 796.3 ± 188.7 min was not different compared with the overall male swim time of 815.4 ± 169.4 min (P > 0.05). The fastest male swim time ever of 417 min was 6.7% faster than the fastest female swim time ever with 445 min. The gender difference in performance of the top three times ever was 8.9 ± 2.3%. Over the last 36 years, the performance of the annual top three swimmers showed no changes for both females and males. The top three males (564.3 ± 63.8 min) were significantly faster than the top three females (602.1 ± 58.7 min; P < 0.01). The gender difference remained unchanged at 12.5 ± 9.6% over the years. To summarize, the top three male swimmers in the English Channel were ∼12% faster than the females in the last 36 years. It seems unlikely that female open-water ultra-swimmers will overtop males in the near future in the English Channel

European athletes dominate performances in Double Iron ultra-triathlons – A retrospective data analysis from 1985 to 2010

We investigated the participation and performance trends of ultra-endurance triathletes from all nationalities competing in a Double Iron ultra-triathlon (7.6-km swim, 360-km cycle and 84.4-km run) from 1985 to 2010. A total of 1854 athletes participated in 92 Double Iron ultra-triathlons. The majority of the winners came from Europe with 72 victories, followed by North America with 17 victories. The race time for the European ultra-triathletes was 1340 (s=95.3) min, decreasing highly significantly (r 2=0.28; P<0.0001) across the years. North American ultra-triathletes finished the races within 1556 (s=124.5) min; their race time showed no changes across the years (r 2=0.045; P=0.07). The race time for the Europeans was highly significantly faster compared to the North Americans (P<0.0001). Future studies should investigate each country in Europe and North America in order to find the country with the largest participation of athletes and their best performance

The changes in age of peak swim speed for elite male and female Swiss freestyle swimmers between 1994 and 2012

Abstract This study determined the age and its changes across years of peak swimming performance from 50 to 1,500 m freestyle. Data of 70,059 Swiss freestyle swimmers (33,725 women and 36,334 men) aged 10-40 years and competing from 50 to 1,500 m were analysed. The association between age and swimming speed of the annual ten fastest swimmers was investigated using single and multi-level hierarchical regression analyses. For women, age of peak swimming speed increased in 50 m from 18.9 (s = 2.3) to 20.4 (s = 4.2) years but decreased in 1,500 m from 25.0 (s = 13.1) (1996) to 18.1 (s = 3.7) years. For 100-800 m, age remained at 19.1 (s = 1.1), 19.3 (s = 1.1), 18.7 (s = 1.5) and 18.5 (s = 1.3) years, respectively. For men, age of peak swimming speed decreased in 50 m from 23.0 (s = 4.0) to 23.0 (s = 3.5) but remained for 100-1,500 m at 22.5 (s = 1.4), 21.4 (s = 0.9), 20.3 (s = 0.9), 20.3 (s = 0.9) and 20.3 (s = 1.1) years, respectively. Age was positively associated with swimming speed for 50-800 m, but negatively for 1,500 m. In conclusion, the age of peak swimming speed was younger in women compared to men for 50-800 m freestyle. For women, age of peak swimming speed increased in 50 m but decreased in 1,500 m freestyle across years. For men, age of peak swimming speed decreased in 50 m freestyle

Regulation of electrolyte and fluid metabolism in multi-stage ultra-marathoners

The purposes of this study were (i) to determine the prevalence of exercise-associated hyponatremia (EAH) in multi-stage ultra-marathoners and (ii) to gain more insight into fluid and electrolyte regulation during a multi-stage race. Body mass, sodium concentration ([Na+]), potassium concentration ([K+]), creatinine, urea, specific gravity, and osmolality in urine were measured in 25 male ultra-marathoners in the 'Swiss Jura Marathon' 2008 with 11 000 m gain of altitude over 7 stages covering 350 km, before and after each stage. Haemoglobin, haematocrit, creatinine, urea, [Na+], [K+], and osmolality were measured in plasma before stage 1 and after stages 1, 3, 5, and 7. Two athletes (8%) showed plasma [Na+] 0.05). Urine specific gravity (p1.0 after each stage and returned to <1.0 the morning of the next stage (p<0.001). To summarize, more sodium than potassium was excreted during rest. The increased urinary sodium losses during rest are compatible with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) or the cerebral salt-wasting syndrome (CSWS). Further studies are needed to determine the antidiuretic hormone (ADH) and both the atrial natriuretic peptide (ANP) and the brain natriuretic peptide (BNP) during multi-stage races

Sex and age-related differences in performance in a 24-hour ultra-cycling draft-legal event - a cross-sectional data analysis

Background The purpose of this study was to examine the sex and age-related differences in performance in a draft-legal ultra-cycling event. Methods Age-related changes in performance across years were investigated in the 24-hour draft-legal cycling event held in Schotz, Switzerland, between 2000 and 2011 using multi-level regression analyses including age, repeated participation and environmental temperatures as co-variables. Results For all finishers, the age of peak cycling performance decreased significantly (Ss = -0.273, p = 0.036) from 38 +/- 10 to 35 +/- 6 years in females but remained unchanged (Ss = -0.035, p = 0.906) at 41.0 +/- 10.3 years in males. For the annual fastest females and males, the age of peak cycling performance remained unchanged at 37.3 +/- 8.5 and 38.3 +/- 5.4 years, respectively. For all female and male finishers, males improved significantly (Ss = 7.010, p = 0.006) the cycling distance from 497.8 +/- 219.6 km to 546.7 +/- 205.0 km whereas females (Ss = -0.085, p = 0.987) showed an unchanged performance of 593.7 +/- 132.3 km. The mean cycling distance achieved by the male winners of 960.5 +/- 51.9 km was significantly (p 0.05). The sex difference in performance for the annual winners of 19.7 +/- 7.8% remained unchanged across years (p > 0.05). The achieved cycling distance decreased in a curvilinear manner with advancing age. There was a significant age effect (F = 28.4, p < 0.0001) for cycling performance where the fastest cyclists were in age group 35-39 years. Conclusion In this 24-h cycling draft-legal event, performance in females remained unchanged while their age of peak cycling performance decreased and performance in males improved while their age of peak cycling performance remained unchanged. The annual fastest females and males were 37.3 +/- 8.5 and 38.3 +/- 5.4 years old, respectively. The sex difference for the fastest finishers was ~20%. It seems that women were not able to profit from drafting to improve their ultra-cycling performance