| Data Tables, Images, and Other Entities: |
| Data Table: | Units_And_Column_Descriptions
View Table Metadata |
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Short Name: | limno_bacteria |
| Online Distribution Info: |
| Download File: |
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| Data Set Owner(s): |
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Individual: | John Priscu |
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Address: |
| Department of Biology, |
| 309 Lewis Hall, |
| Montana State University , |
| Bozeman, MT 59717 USA |
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Phone:
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Email Address:
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| Metadata Provider(s): |
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Organization: | McMurdo Dry Valleys LTER |
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Address: |
| Byrd Polar Research Center , |
| 108 Scott Hall, |
| 1090 Carmack Rd, |
| Columbus, OH 43210-1002 USA |
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Phone:
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Phone:
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Email Address:
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| Abstract: |
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An important part of the McMurdo Long Term Ecological Research
(LTER) is monitoring of spatial and temporal patterns, and processes that
control bacterial production in perennial ice-covered lakes. This data set
quantifies thymidine uptake by bacteria and can be used to estimate
bacterial production.
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| Keywords: |
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- lake
(theme)
- limnology
(theme)
- thymidine
(theme)
- bacteria
(theme)
- production
(theme)
- Antarctica
(theme)
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| Additional Information: |
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| Comments |
The energy of activation was experimentally derived for Lake
Bonney (Priscu, unpublished). If the average of the kill treatment uptake
exceeds live treatment uptake, uptake is reported as zero.
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| Citations |
| Notes |
Data contained in these files has been subjected to quality
control standards imposed by the investigator. The user of this data should
be aware that, while efforts have been taken to ensure that these data are
of the highest quality, there is no guarantee of perfection for the data
contained herein and the possibility of errors exists. If you encounter
questionable data, please contact the MCM LTER data manager corrected or
qualified. Thus, these data may be modified and future data will be
appended.
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| License and Usage Rights: |
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| MCM LTER data may be used freely with the following restrictions: |
The Principal Investigator be sent a notice stating
reasons for acquiring any data and a description of the
publication intentions.
The Principal Investigator of the data set be sent a
copy of the report or manuscript prior to submission and be
adequately cited in any resultant publications.
A copy of any resultant publications should be sent
to the McMurdo data manager and principal
investigator.
The end-user follow the guidelines set forth in the
LTER Network Data Access Policy, Data Access Requirements, and
General Data Use Agreement found at
http://www.mcmlter.org/data_guidelines.htm
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| Geographic Coverage: |
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Geographic Description: | Samples were collected from the East Lake Bonney, West Lake
Bonney, Lake Hoare, and Lake Fryxell limnological sampling stations, located in
the McMurdo Dry Valleys of Antarctica. |
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Bounding Coordinates:
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| West: | 162 degrees
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| East: | 163.6 degrees
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| North: | -77.2 degrees
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| South: | -77.8 degrees
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Mimimum Altitude: | 0 meter |
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Maximum Altitude: | 1000 meter |
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| Temporal Coverage: |
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Begin:
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End:
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| Maintenance: |
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Description:
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Data from this table was submitted to INSTAAR by John
Priscu's team at Montana State University. The raw data files listed
under 'file name' are the names of the original files submitted. The
1993/94 and 1994/95 datasets are Microsoft Excel version 6.0 files, and
the 1995/96, 1996/97 and 1997/98 datasets are ascii text files. Upon
arrival at INSTAAR, the data manager fine-tuned the location codes and
limno runs to match those provided in the "locations, dates, codes for
lake chemistry, biology samples" file. The file was imported into
Microsoft Access on INSTAAR's Unix system, and can currently be found
there. The file was then exported in ascii, comma delimited text and
MS-DOS text (table layout) on the MCM LTER web site. Both of these files
are linked to this web page above. Information for the metadata was
obtained from the Metatdr9697.rtf file. The file was called up using
Microsoft Word version 6.0. Text from this file was used to create this
page in html format.
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Frequency:
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| Contact: |
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Organization: | McMurdo Dry Valleys LTER |
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Position: | Data Manager |
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Address: |
| Byrd Polar Research Center , |
| 108 Scott Hall, |
| 1090 Carmack Rd, |
| Columbus, OH 43210-1002 USA |
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Phone:
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Email Address:
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| Publisher: |
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Organization: | McMurdo Dry Valleys LTER |
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Address: |
| Byrd Polar Research Center , |
| 108 Scott Hall, |
| 1090 Carmack Rd, |
| Columbus, |
| Columbus, OH 43210-1002 USA |
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Phone:
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| Methods Info: |
| Step 1: |
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Description:
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Lake water samples were collected at specific depths with a
five-liter Niskin bottle during normal LTER limnological sampling.
Sub-samples were decanted into three 1-L Nalgene bottles (2-light and
1-amber), two-500 mL amber Nalgene bottles, three-150 mL borosilicate
glass bottles, two-20 mL scintillation vials, and one-30 mL serum vial.
Five-20 mL scintillation vials (3-live treatments, 2-kill treatments)
were prepared at each depth for TDR analysis. TDR samples (10 mL) were
taken from the one-liter amber Nalgene bottle and placed in each
scintillation vial. 0.5 mL filtered formalin (0.2 micro m) was pipetted
into each killed treatment vial. 3H Thymidine was pipetted into each
vial (final concentration of 20 nM thymidine), first the live treatments
and then the kill treatments. Samples were incubated in the dark at
1-4micro degC for 20 hours (thymidine incorporation has been shown to be
linear for 20 hours under these conditions, Priscu unpublished). At the
end of the incubation period 10 mL of ice cold 10 percent TCA was added
to stop thymidine uptake and precipitate nucleotides. Vials were stored
at 4micro eg;C until filtered. Each sample was filtered through a 0.2
micro m Nucleopore polycarbonate membrane filter. Both the scintillation
vial and filter tower were rinsed three times with 5percent TCA. Each
filter was placed into a new scintillation vial and 15 mL of Cytoscint
cocktail was added. Samples were counted with a pre-calibrated (3H)
liquid scintillation counter. Thymidine uptake rate (TDR nM d-1) was
calculated using the following equation: TDRadj = TDR * e^(Ea (( 1 / (CI
+ 273 K)) - ( 1 / (CA + 273 K))) / R ) where Ea is the energy of
activation (12,600 cal mol-1, Q10 = 2.2), degCI is the incubation
temperature (degC), degCA is the ambient lake water temperature at specific
depth, and R is a gas constant (1.987 cal mol-1 K-1).
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TDR = (DPML - DPMK) * a alpha * t
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where DPML is the average dpm for the live treatment, DPMK
is the average dpm for the kill treatment, a is the final concentration
of thymidine in each vial (20nM), alpha is the total dpm added to each
vial, and t is the incubation period. The thymidine uptake rate was
adjusted to the ambient lake temperature using the Arrhenius equation:
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TDRadj = TDR * e^(Ea (( 1 / (CI + 273 K)) - ( 1 / (CA + 273
K))) / R ) where Ea is the energy of activation (12,600 cal mol-1, Q10 =
2.2), degCI is the incubation temperature (degC), degCA is the ambient lake
water temperature at specific depth, and R is a gas constant (1.987 cal
mol-1 K-1).
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