Water Replacement before, during, and after Exercise

Author(s):  
Ronald J. Maughan ◽  
Susan M. Shirreffs
Keyword(s):  
2020 ◽  
Vol 139 ◽  
pp. 213-221
Author(s):  
C Birkett ◽  
R Lipscomb ◽  
T Moreland ◽  
T Leeds ◽  
JP Evenhuis

Flavobacterium columnare immersion challenges are affected by water-related environmental parameters and thus are difficult to reproduce. Whereas these challenges are typically conducted using flow-through systems, use of a recirculating challenge system to control environmental parameters may improve reproducibility. We compared mortality, bacterial concentration, and environmental parameters between flow-through and recirculating immersion challenge systems under laboratory conditions using 20 rainbow trout families. Despite identical dose concentration (1:75 dilution), duration of challenge, lot of fish, and temperature, average mortality in the recirculating system (42%) was lower (p < 0.01) compared to the flow-through system (77%), and there was low correlation (r = 0.24) of family mortality. Mean days to death (3.25 vs. 2.99 d) and aquaria-to-aquaria variation (9.6 vs. 10.4%) in the recirculating and flow-through systems, respectively, did not differ (p ≥ 0.30). Despite 10-fold lower water replacement rate in the recirculating (0.4 exchanges h-1) compared to flow-through system (4 exchanges h-1), differences in bacterial concentration between the 2 systems were modest (≤0.6 orders of magnitude) and inconsistent throughout the 21 d challenge. Compared to the flow-through system, dissolved oxygen during the 1 h exposure and pH were greater (p ≤ 0.02), and calcium and hardness were lower (p ≤ 0.03), in the recirculating system. Although this study was not designed to test effects of specific environmental parameters on mortality, it demonstrates that the cumulative effects of these parameters result in poor reproducibility. A recirculating immersion challenge model may be warranted to empirically identify and control environmental parameters affecting mortality and thus may serve as a more repeatable laboratory challenge model.


2016 ◽  
Vol 83 (5) ◽  
pp. AB638-AB639
Author(s):  
Tomonori Yano ◽  
Masahiro Okada ◽  
Hisashi Fukuda ◽  
Hirotsugu Sakamoto ◽  
Manabu Nagayama ◽  
...  

2017 ◽  
Author(s):  
Susiana Nugraha

Dengue hemorrhagic fever is a severe and fatal infection that occurs in tropical regions such as Indonesia. In 2014, recorded that dengue morbidity rate was 5.17 per 100,000 inhabitants (approximately 13031 cases) with mortality rate of 0.84% (110 deaths). Demographic and societal changes such as population growth, urbanization, and modern transportation appear to play an important role in the increased incidence and geographical spread of dengue virus. Aedes aegypti, the urban yellow fever mosquito, is also the principal dengue-carrying vector. The Aedes aegypti mosquitoes as a vector of dengue virus normally live and breed in clean water reservoirs that are not directly related to the land such as: bath, bird drinks, water pot, water jars / barrel, cans, old tires, etc. In Indonesia, dengue outbreaks often occur when the seasons change from dry to rain hor vice versa. This study aimed to figure out the influence of natural environment and the existence of the vector’s larva. A logistic regression was performed to ascertain the effects of temperature, humidity, water replacement and the existence of water reservoir on the likelihood of the existence of the vector’s larva . The logistic regression model was statistically significant, p &lt; .005 and the model explained 69% (Nagelkerke R2). This finding shows that the existence of the mosquito’s larva, influenced by temperature, water replacement activity and the existence of water reservoir. Health education about vector control and environmental engineering are necessary to break the chain of mosquito breeding.


2018 ◽  
Vol 67 ◽  
pp. 01009
Author(s):  
Arrad Ghani Safitra ◽  
Fifi Hesty Sholihah ◽  
Erik Tridianto ◽  
Ikhsan Baihaqi ◽  
Ni Nyoman Ayu Indah T.

Photovoltaic (PV) modules require solar radiation to generate electricity. This study aims to determine the effect of water cooling PV modules on heat transfer, output power, and electrical efficiency of PV modules. The experiments carried out in this study were to vary the heights of flooded water (with and without cooling water replacement control) and cooling water flow. Variations in the height of flooded water are 0,5 cm, 1 cm, 2 cm, and 4 cm. While the flow rate variations are 2 L/min, 4 L/min, and 8 L/min. The flooded water replacement control will be active when the PV surface temperature reached 45°C. When the temperature dropped to 35°C, the cooler is disabled to let more photon to reach PV surface. The results showed that the lowest heat transfer occurred in the variation of 4 cm flooded water height without water replacement control, i.e. 28.53 Watt, with an average PV surface temperature of 32.92°C. The highest average electric efficiency occurred in the variation of 0,5 cm flooded water height with water replacement control, i.e. 13.12%. The use of cooling water replacement control is better due to being able to skip more photons reach PV surface with low PV temperature.


Author(s):  
John H. Crowe ◽  
James S. Clegg ◽  
Lois M. Crowe
Keyword(s):  

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