Seasonal and Spatial Variations in Human Cell Mutagenicity of Respirable Airborne Particles in the Northeastern United States

1999 ◽  
Vol 33 (24) ◽  
pp. 4407-4415 ◽  
Author(s):  
Daniel U. Pedersen ◽  
John L. Durant ◽  
Bruce W. Penman ◽  
Charles L. Crespi ◽  
Harold F. Hemond ◽  
...  
Keyword(s):  
United States ◽  
Human Cell ◽  
Spatial Variations ◽  
Airborne Particles ◽  
Northeastern United States ◽  
Seasonal And Spatial Variations

Human-Cell Mutagens in Respirable Airborne Particles in the Northeastern United States. 1. Mutagenicity of Fractionated Samples

2004 ◽  
Vol 38 (3) ◽  
pp. 682-689 ◽  
Author(s):  
Daniel U. Pedersen ◽  
John L. Durant ◽  
Bruce W. Penman ◽  
Charles L. Crespi ◽  
Harold F. Hemond ◽  
...  
Keyword(s):  
United States ◽  
Human Cell ◽  
Airborne Particles ◽  
Northeastern United States

Human Cell Mutagens in Respirable Airborne Particles from the Northeastern United States. 2. Quantification of Mutagens and Other Organic Compounds

2005 ◽  
Vol 39 (24) ◽  
pp. 9547-9560 ◽  
Author(s):  
Daniel U. Pedersen ◽  
John L. Durant ◽  
Koli Taghizadeh ◽  
Harold F. Hemond ◽  
Arthur L. Lafleur ◽  
...  
Keyword(s):  
United States ◽  
Organic Compounds ◽  
Human Cell ◽  
Airborne Particles ◽  
Northeastern United States

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.

Monitoring air quality in class I wilderness areas of the northeastern United States using lichens and bryophytes

2016 ◽  
Author(s):  
Alison C. Dibble ◽  
James W. Hinds ◽  
Ralph Perron ◽  
Natalie Cleavitt ◽  
Richard L. Poirot ◽  
...  
Keyword(s):  
United States ◽  
Air Quality ◽  
Class I ◽  
Northeastern United States ◽  
Wilderness Areas
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