Correction [to “Nitrite photolysis as a source of free radicals in productive surface waters”]

1979 ◽  
Vol 6 (6) ◽  
pp. 535-535
Author(s):  
Oliver C. Zafiriou ◽  
Mary B. True
Keyword(s):  
Free Radicals ◽  
Surface Waters ◽  
Productive Surface

scholarly journals Diazotrophic Cyanobacteria are Associated With a Low Nitrate Resupply to Surface Waters in Lake Tanganyika

2021 ◽  
Vol 9 ◽  
Author(s):  
Benedikt Ehrenfels ◽  
Maciej Bartosiewicz ◽  
Athanasio Stephano Mbonde ◽  
Kathrin B.L. Baumann ◽  
Christian Dinkel ◽  
...  
Keyword(s):  
Surface Waters ◽  
Phytoplankton Community ◽  
Lake Tanganyika ◽  
Euphotic Zone ◽  
Convective Mixing ◽  
Nitrate Supply ◽  
Upward Transport ◽  
Diazotrophic Cyanobacteria ◽  
Nitrate Depletion ◽  
Productive Surface

In Lake Tanganyika, blooms of nitrogen-fixing (diazotrophic) cyanobacteria emerge, when the upper water column re-stratifies after a period of upwelling and convective mixing. During this seasonal transition, diazotrophic cyanobacteria exploit the abundant phosphate and fix nitrogen after other phytoplankton taxa have consumed the available nitrate. However, it remains less clear, which mechanisms favour diazotrophic cyanobacteria under more heavily stratified conditions with lower levels of excess phosphate and persistent nitrate-depletion. Here, we collected profiles of physicochemical parameters, nutrients and photo-pigments, as well as the medium- to large-sized phytoplankton community during two lake-wide cruises to elucidate to what extent the abundance of diazotrophic cyanobacteria in Lake Tanganyika may be controlled by the nitrate resupply through the thermocline into the euphotic zone. At stations where nitrate was depleted, but phosphate remained available near the surface, high densities of diazotrophic cyanobacteria were associated with a low nitrate supply to surface waters. Our data provide first support for two conceptual scenarios, where the relative position of the thermocline and the euphotic depth may create a functional niche for diazotrophic cyanobacteria: when the upward transport of nitrate into the euphotic zone is reduced by a subjacent thermocline, diazotrophic cyanobacteria, comprising Dolichospermum and Anabaenopsis, are key players in the medium-to large-sized phytoplankton community. By contrast, a thermocline located within the euphotic zone allows for a rapid vertical transport of nitrate for a thriving nitrate-assimilating phytoplankton community that evidently outcompetes diazotrophic cyanobacteria. This study highlights that, under nitrogen-depleted conditions, diazotrophic cyanobacteria can also grow in response to a reduced nutrient resupply to the productive surface waters.

Habitat Association of Klebsiella Species

1985 ◽  
Vol 6 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Susan T. Bagley
Keyword(s):  
Drinking Water ◽  
Gastrointestinal Tract ◽  
Surface Waters ◽  
Industrial Effluents ◽  
Opportunistic Pathogen ◽  
Habitat Associations ◽  
Habitat Association ◽  
Klebsiella Species ◽  
Almost All ◽  
Polluted Waters

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

Identifying Sources of Sulfate Aerosols Reaching Whiteface Mountain, NY

1985 ◽  
Vol 43 ◽  
pp. 98-101
Author(s):  
James S. Webber
Keyword(s):  
Trace Metals ◽  
Acid Deposition ◽  
Surface Waters ◽  
Dry Deposition ◽  
Coal Combustion ◽  
Public Awareness ◽  
Sulfate Aerosols ◽  
Wet And Dry Deposition ◽  
Whiteface Mountain ◽  
Toxic Trace Metals

INTRODUCTION“Acid rain” and “acid deposition” are terms no longer confined to the lexicon of atmospheric scientists and 1imnologists. Public awareness of and concern over this phenomenon, particularly as it affects acid-sensitive regions of North America, have increased dramatically in the last five years. Temperate ecosystems are suffering from decreased pH caused by acid deposition. Human health may be directly affected by respirable sulfates and by the increased solubility of toxic trace metals in acidified waters. Even man's monuments are deteriorating as airborne acids etch metal and stone features.Sulfates account for about two thirds of airborne acids with wet and dry deposition contributing equally to acids reaching surface waters or ground. The industrial Midwest is widely assumed to be the source of most sulfates reaching the acid-sensitive Northeast since S02 emitted as a byproduct of coal combustion in the Midwest dwarfs S02 emitted from all sources in the Northeast.

STRESS PADA LANSIA MENJADI FAKTOR PENYEBAB DAN AKIBAT TERJADINYA PENYAKIT

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Nur Hidaayah
Keyword(s):  
Drinking Water ◽  
Free Radicals ◽  
The Elderly ◽  
The State ◽  
Young Age ◽  
Fresh Fruit ◽  
Stress Conditions ◽  
Harmful Substances ◽  
Available Resources

Stress conditions in the elderly means an imbalance condition of biological, psychological, and social are closely related to the response to the threats and dangers faced by the elderly. Pressure or interference that is not fun is usually created when the elderly see a mismatch between the state and the 3 systems available resources. Maintenance actions that need to be done there are 2 types, namely : prevention of exposure to a stressor (precipitation factor) and serious treatment of the imbalance condition/ illness (precipitation factor). Prevention includes: sports, hobbies, friendship, avoid eating foods high in free radicals and harmful substances, sex and setting arrangements adequate rest. Habits of the above if done at a young age to avoid exposure to stress in the elderly. Treatment of the imbalance condition / illness, include : drinking water, meditation, eating fresh fruit, and adequate rest.

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