title: Diel surface temperature range scales with lake size

authors: Woolway, R. Iestyn

abstract: Ecological and biogeochemical processes in lakes are strongly dependent upon water temperature. Long-term surface warming of many lakes is unequivocal, but little is known about the comparative magnitude of temperature variation at diel timescales, due to a lack of appropriately resolved data. Here we quantify the pattern and magnitude of diel temperature variability of surface waters using high-frequency data from 100 lakes. We show that the near-surface diel temperature range can be substantial in summer relative to long-term change and, for lakes smaller than 3 km2, increases sharply and predictably with decreasing lake area. Most small lakes included in this study experience average summer diel ranges in their near-surface temperatures of between 4 and 7°C. Large diel temperature fluctuations in the majority of lakes undoubtedly influence their structure, function and role in biogeochemical cycles, but the full implications remain largely unexplored.

text: Diel surface temperature range scales with lake size Ecological and biogeochemical processes in lakes are strongly dependent upon water temperature. Long-term surface warming of many lakes is unequivocal, but little is known about the comparative magnitude of temperature variation at diel timescales, due to a lack of appropriately resolved data. Here we quantify the pattern and magnitude of diel temperature variability of surface waters using high-frequency data from 100 lakes. We show that the near-surface diel temperature range can be substantial in summer relative to long-term change and, for lakes smaller than 3 km2, increases sharply and predictably with decreasing lake area. Most small lakes included in this study experience average summer diel ranges in their near-surface temperatures of between 4 and 7°C. Large diel temperature fluctuations in the majority of lakes undoubtedly influence their structure, function and role in biogeochemical cycles, but the full implications remain largely unexplored.

year: 2016

title: The microbial ecology and colonisation of surfaces in selected hot springs - a molecular-and culture-based approach

authors: Niederberger, Thomas D.

abstract: Traditionally, culture-based approaches have been used to investigate the microbial ecology of thermal habitats. The emergence of alternate molecular approaches based on DNA sequences has shown that terrestrial thermal environments have a rich diversity of uncultured prokaryotes. To the best of our knowledge these latter approaches have not previously been applied to New Zealand thermal environments and this became the central aim of this study. The major objective of the study was to target the metabolically active members of the hot pool community by applying a suite of molecular and microscopical techniques to those species colonising surfaces incubated in situ in the hot pools. 
Two neutral pH pools were investigated in some detail; pool KP1 at 75°C and pool AQ1 at 95°C. Surfaces in pool KP1 were colonised by a high diversity of bacteria (archaea were not detected), as evidenced by complex denaturing gradient gel electrophoresis (DGGE) profiles, and many different species were obtained in enrichment culture. Although colonisation rates were greater in pool AQ1, this was entirely due to only two observed morphotypes and was reflected in DGGE profiles that reflected only two dominant archaeal species. A 16S rDNA clone library of the AQ1 pool water and DGGE profiles of both pool water and colonised slides were dominated by rods of the species Pyrobaculum. Slides incubated deep within AQ1 were also colonised by cocci, the closest cultured relative being Aeropyrum pernix, a marine hyperthermophile. Two pure cultures were obtained from pool AQ1, Pyrobaculum sp. (AQ1.S2) and a novel crenarchaeaotal coccus, (AQ1.S1T). Isolations of the latter organism were also obtained from two other pools in New Zealand. These were obtained as obligate co-cultures with Pyrobaculum rods and could not be isolated into pure culture. A full description of this novel genus of organisms has been accepted for publication in the International Journal of Systematic and Evolutionary Microbiology, with the isolate from pool AQ1 named as the type strain lgnisphaera aggregans AQl .S1T. 
The techniques used to follow colonisation were then applied to a survey of high-temperature pools of New Zealand (>80°C, pH 5.5-9.7), White Island (72-94°C, pH 1.5-3.8) and Yellowstone National Park (75-92.5°C, pH 5.0-8.0). For New Zealand, bacteria were detected by DGGE on colonised slides in pools below 88°C, and archaea, only in pools above 83°C. Bacterial colonisers with dominant signatures included those of Thermodesulfobacteria and Aquificales species, though interestingly, isolations of these organisms were not obtained. The archaeal colonisers were pH dependent: pools with a pH of 6.0-7.0 had a dominant Thermofilum signature; pools above pH 7.0 had both a Pyrobaculum sp. and a relative of the Desulfurococcales; and the acidic pools (including White Island) were dominated by Sulfolobus sp. Pool water DGGE profiles of the New Zealand pools differed from slide colonisation profiles in some respects, e.g. Thermococcus sp. were only detected in pool water. In contrast to the New Zealand results, the Yellowstone National Park slides were dominated by bacteria, with bacterial signatures detected in high-temperature pools (87-92.5°C); representative DGGE bands were sequenced and found to be related to the Aquificales. Nanoarchaeal l 6S rDNA PCR amplicons were also obtained from pool water for most of the New Zealand pools (closest relative of AQ1 amplicon being a nanoarchaeal clone from the Uzon Caldera), including the Pyrobaculum sp. AQl .S2 culture. Attempts were also made to isolate marine nanoarchaea from nascent hydrothermal vents situated on the East Pacific Rise; however, these were unsuccessful.

text: The microbial ecology and colonisation of surfaces in selected hot springs - a molecular-and culture-based approach Traditionally, culture-based approaches have been used to investigate the microbial ecology of thermal habitats. The emergence of alternate molecular approaches based on DNA sequences has shown that terrestrial thermal environments have a rich diversity of uncultured prokaryotes. To the best of our knowledge these latter approaches have not previously been applied to New Zealand thermal environments and this became the central aim of this study. The major objective of the study was to target the metabolically active members of the hot pool community by applying a suite of molecular and microscopical techniques to those species colonising surfaces incubated in situ in the hot pools. 
Two neutral pH pools were investigated in some detail; pool KP1 at 75°C and pool AQ1 at 95°C. Surfaces in pool KP1 were colonised by a high diversity of bacteria (archaea were not detected), as evidenced by complex denaturing gradient gel electrophoresis (DGGE) profiles, and many different species were obtained in enrichment culture. Although colonisation rates were greater in pool AQ1, this was entirely due to only two observed morphotypes and was reflected in DGGE profiles that reflected only two dominant archaeal species. A 16S rDNA clone library of the AQ1 pool water and DGGE profiles of both pool water and colonised slides were dominated by rods of the species Pyrobaculum. Slides incubated deep within AQ1 were also colonised by cocci, the closest cultured relative being Aeropyrum pernix, a marine hyperthermophile. Two pure cultures were obtained from pool AQ1, Pyrobaculum sp. (AQ1.S2) and a novel crenarchaeaotal coccus, (AQ1.S1T). Isolations of the latter organism were also obtained from two other pools in New Zealand. These were obtained as obligate co-cultures with Pyrobaculum rods and could not be isolated into pure culture. A full description of this novel genus of organisms has been accepted for publication in the International Journal of Systematic and Evolutionary Microbiology, with the isolate from pool AQ1 named as the type strain lgnisphaera aggregans AQl .S1T. 
The techniques used to follow colonisation were then applied to a survey of high-temperature pools of New Zealand (>80°C, pH 5.5-9.7), White Island (72-94°C, pH 1.5-3.8) and Yellowstone National Park (75-92.5°C, pH 5.0-8.0). For New Zealand, bacteria were detected by DGGE on colonised slides in pools below 88°C, and archaea, only in pools above 83°C. Bacterial colonisers with dominant signatures included those of Thermodesulfobacteria and Aquificales species, though interestingly, isolations of these organisms were not obtained. The archaeal colonisers were pH dependent: pools with a pH of 6.0-7.0 had a dominant Thermofilum signature; pools above pH 7.0 had both a Pyrobaculum sp. and a relative of the Desulfurococcales; and the acidic pools (including White Island) were dominated by Sulfolobus sp. Pool water DGGE profiles of the New Zealand pools differed from slide colonisation profiles in some respects, e.g. Thermococcus sp. were only detected in pool water. In contrast to the New Zealand results, the Yellowstone National Park slides were dominated by bacteria, with bacterial signatures detected in high-temperature pools (87-92.5°C); representative DGGE bands were sequenced and found to be related to the Aquificales. Nanoarchaeal l 6S rDNA PCR amplicons were also obtained from pool water for most of the New Zealand pools (closest relative of AQ1 amplicon being a nanoarchaeal clone from the Uzon Caldera), including the Pyrobaculum sp. AQl .S2 culture. Attempts were also made to isolate marine nanoarchaea from nascent hydrothermal vents situated on the East Pacific Rise; however, these were unsuccessful.

year: 2005

title: What does 'Ethical Research'' look like? An indigenous perspective on big data & precision medicine

authors: Hudson, Maui

abstract: Southeast Native American Health Data (SENAHD) in partnership with Native BioData Consortium will host an online symposium about the ethical use of Indigenous genetic, environmental, biological, and cultural data. SENAHD is based at UNC Chapel Hill. Our partner, Native BioData Consortium is located on the Cheyanne River Sioux Reservation in South Dakota. NativeBio is one of the most important voices advocating for Indigenous health equity, data sovereignty, and ethical research practices. NativeBio is coming to the Southeast to recognize and include our region in important conversations taking place across Indian Country

text: What does 'Ethical Research'' look like? An indigenous perspective on big data & precision medicine Southeast Native American Health Data (SENAHD) in partnership with Native BioData Consortium will host an online symposium about the ethical use of Indigenous genetic, environmental, biological, and cultural data. SENAHD is based at UNC Chapel Hill. Our partner, Native BioData Consortium is located on the Cheyanne River Sioux Reservation in South Dakota. NativeBio is one of the most important voices advocating for Indigenous health equity, data sovereignty, and ethical research practices. NativeBio is coming to the Southeast to recognize and include our region in important conversations taking place across Indian Country

year: 2022