Seasonal and spatial variations of enhanced gamma ray dose rates derived from 222Rn progeny during precipitation in Japan

2007 ◽  
Vol 41 (37) ◽  
pp. 8043-8057 ◽  
Author(s):  
Y. Inomata ◽  
M. Chiba ◽  
Y. Igarashi ◽  
M. Aoyama ◽  
K. Hirose
Keyword(s):  
Gamma Ray ◽  
Spatial Variations ◽  
Dose Rates ◽  
Seasonal And Spatial Variations

Contribution of large bacteria to bacterial biomass in a deep freshwater lake (Lake Biwa, Japan)

2020 ◽  
Vol 85 ◽  
pp. 131-139
Author(s):  
S Shen ◽  
Y Shimizu
Keyword(s):  
Cell Volume ◽  
Bacterial Cell ◽  
Lake Biwa ◽  
Bacterial Biomass ◽  
Spatial Variations ◽  
Freshwater Lake ◽  
Heterotrophic Nanoflagellates ◽  
Bacterial Productivity ◽  
Transmission Electron ◽  
Seasonal And Spatial Variations

Despite the importance of bacterial cell volume in microbial ecology in aquatic environments, literature regarding the effects of seasonal and spatial variations on bacterial cell volume remains scarce. We used transmission electron microscopy to examine seasonal and spatial variations in bacterial cell size for 18 mo in 2 layers (epilimnion 0.5 m and hypolimnion 60 m) of Lake Biwa, Japan, a large and deep freshwater lake. During the stratified period, we found that the bacterial cell volume in the hypolimnion ranged from 0.017 to 0.12 µm3 (median), whereas that in the epilimnion was less variable (0.016 to 0.033 µm3, median) and much lower than that in the hypolimnion. Additionally, in the hypolimnion, cell volume during the stratified period was greater than that during the mixing period (up to 5.7-fold). These differences in cell volume resulted in comparable bacterial biomass in the hypolimnion and epilimnion, despite the fact that there was lower bacterial abundance in the hypolimnion than in the epilimnion. We also found that the biomass of larger bacteria, which are not likely to be grazed by heterotrophic nanoflagellates, increased in the hypolimnion during the stratified period. Our data suggest that estimation of carbon flux (e.g. bacterial productivity) needs to be interpreted cautiously when cell volume is used as a constant parametric value. In deep freshwater lakes, a difference in cell volume with seasonal and spatial variation may largely affect estimations.

scholarly journals Modelling the bimodal distribution of indoor gamma-ray dose-rates in Great Britain

2018 ◽  
Vol 57 (4) ◽  
pp. 321-347 ◽  
Author(s):  
G. M. Kendall ◽  
P. Chernyavskiy ◽  
J. D. Appleton ◽  
J. C. H. Miles ◽  
R. Wakeford ◽  
...  
Keyword(s):  
Great Britain ◽  
Gamma Ray ◽  
Bimodal Distribution ◽  
Dose Rates

scholarly journals Seasonal and spatial variations in biomarker baseline levels within Arctic populations of mussels (Mytilus spp.)

2019 ◽  
Vol 656 ◽  
pp. 921-936 ◽  
Author(s):  
Ekaterina Storhaug ◽  
Jasmine Nahrgang ◽  
Kristine Bondo Pedersen ◽  
Steven J. Brooks ◽  
Laura Petes ◽  
...  
Keyword(s):  
Spatial Variations ◽  
Seasonal And Spatial Variations ◽  
Baseline Levels

scholarly journals TL, OSL and C-14 dating results of the sediments and bricks from mummified nuns' grave

2012 ◽  
Vol 84 (2) ◽  
pp. 237-244 ◽  
Author(s):  
Diego R.G. Tudela ◽  
Sonia H. Tatumi ◽  
Márcio Yee ◽  
Silvio L.M. Brito ◽  
José L. Morais ◽  
...  
Keyword(s):  
Eighteenth Century ◽  
Neutron Activation Analysis ◽  
Activation Analysis ◽  
Neutron Activation ◽  
Gamma Ray ◽  
The State ◽  
Osl Dating ◽  
Annual Dose ◽  
Dose Rates ◽  
Gamma Ray Spectroscopy

This paper presents the results of TL and OSL dating of soil and fragments of bricks from a grave, which was occupied by two mummified nuns, found at "Luz" Monastery, located in the state of São Paulo, Brazil. The TL and OSL ages were compared to C-14 dating ones obtained from bone collagens of the mummies. The majority of the ages is related to the eighteenth century. The gamma-ray spectroscopy was used to evaluate natural radioisotope concentrations in the samples, and by using these concentrations the annual dose rates, from 3.0 to 5.3 Gy/kyr, were obtained. Neutron activation analysis was performed and the radioisotope contents results are in agreement with those obtained by gamma-ray spectroscopy. The contents of U, Th and Ce elements were higher than those found in usual sediments.

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