scholarly journals Leaf- and cell-level carbon cycling responses to a nitrogen and phosphorus gradient in two Arctic tundra species

2012 ◽  
Vol 99 (10) ◽  
pp. 1702-1714 ◽  
Author(s):  
Mary A. Heskel ◽  
O. Roger Anderson ◽  
Owen K. Atkin ◽  
Matthew H. Turnbull ◽  
Kevin L. Griffin
Keyword(s):  
Carbon Cycling ◽  
Arctic Tundra ◽  
Cell Level ◽  
Nitrogen And Phosphorus

Integrating soil carbon cycling with that of nitrogen and phosphorus in the watershed model SWAT: Theory and model testing

2011 ◽  
Vol 222 (12) ◽  
pp. 1913-1921 ◽  
Author(s):  
Armen R. Kemanian ◽  
Stefan Julich ◽  
Valipuram S. Manoranjan ◽  
Jeffrey R. Arnold
Keyword(s):  
Soil Carbon ◽  
Carbon Cycling ◽  
Model Testing ◽  
Watershed Model ◽  
Nitrogen And Phosphorus ◽  
Soil Carbon Cycling ◽  
Theory And Model

scholarly journals Pulse-labeling studies of carbon cycling in Arctic tundra ecosystems: The contribution of photosynthates to methane emission

2002 ◽  
Vol 16 (4) ◽  
pp. 10-1-10-8 ◽  
Author(s):  
J. Y. King ◽  
W. S. Reeburgh ◽  
K. K. Thieler ◽  
G. W. Kling ◽  
W. M. Loya ◽  
...  
Keyword(s):  
Carbon Cycling ◽  
Methane Emission ◽  
Arctic Tundra ◽  
Tundra Ecosystems

scholarly journals Pulse-labeling studies of carbon cycling in arctic tundra ecosystems: Contribution of photosynthates to soil organic matter

2002 ◽  
Vol 16 (4) ◽  
pp. 48-1-48-8 ◽  
Author(s):  
Wendy M. Loya ◽  
Loretta C. Johnson ◽  
George W. Kling ◽  
Jennifer Y. King ◽  
William S. Reeburgh ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Carbon Cycling ◽  
Arctic Tundra ◽  
Tundra Ecosystems

REVEGETATION OF ARCTIC TUNDRA AFTER AN OIL SPILL: A CASE HISTORY

1985 ◽  
Vol 1985 (1) ◽  
pp. 315-318
Author(s):  
Judith Brendel
Keyword(s):  
Oil Spill ◽  
Arctic Tundra ◽  
Grass Species ◽  
Nitrogen And Phosphorus ◽  
Species Survival ◽  
Degrading Bacteria ◽  
One Year ◽  
Prudhoe Bay ◽  
Heavy Application ◽  
Crude Oil Spill

ABSTRACT A comparison of revegetation techniques for arctic tundra was conducted in 1982, 1983, and 1984 on a crude oil spill that occurred January 1, 1981, about 125 miles south of Prudhoe Bay, Alaska. The oiling rate was approximately 37 L/m2, with oil contents of soil averaging 60,000 to 275,000 ppm. The following revegetation methods were compared: cover with clean material, remove contaminated material and replace with clean material, seed and fertilize, till and seed and fertilize, and apply oil degrading bacteria. Parameters monitored in this study included oil content of soil, grass species survival, yield, and grass percentage growth. Survival and yield of grass were best in areas of heavy application (1,000 lb/acre) of a fertilizer high in nitrogen and phosphorus (20-20-10), combined with soil tilling. Yields on control areas averaged 0.74 g/m2 and on fertilized and tilled areas 6.6 g/m2. Soil oil contents appear to be reduced by fertilization and aeration, perhaps by up to 20 percent in one year.

Systematic zone-Axis orientation of NM-scale particles for microdiffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 262-263
Author(s):  
E D Boyes ◽  
L Hanna
Keyword(s):  
Real Space ◽  
Dark Field ◽  
Zone Axis ◽  
High Symmetry ◽  
Lattice Imaging ◽  
Cell Level ◽  
Bright Field ◽  
Axis Orientation ◽  
Annular Dark Field ◽  
Target Designation

A VG HB501 FEG STEM has been modified to provide track whilst tilt [TWIT] facilities for controllably tilting selected and initially randomly aligned nanometer-sized particles into the high symmetry zone-axis orientations required for microdiffraction, lattice imaging and chemical microanalysis at the unit cell level. New electronics display in alternate TV fields and effectively in parallel on split [+VTR] or adjacent externally synchronized screens, the micro-diffraction pattern from a selected area down to <1nm2 in size, together with the bright field and high angle annular dark field [HADF] STEM images of a much wider [˜1μm] area centered on the same spot. The new system makes it possible to tilt each selected and initially randomly aligned small particle into a zone axis orientation for microdiffraction, or away from it to minimize orientation effects in chemical microanalysis. Tracking of the inevitable specimen movement with tilt is controlled by the operator, with realtime [60Hz] update of the target designation in real space and the diffraction data in reciprocal space. The spot mode micro-DP and images of the surrounding area are displayed continuously. The regular motorized goniometer stage for the HB501STEM is a top entry design but the new control facilities are almost equivalent to having a stage which is eucentric with nanometric precision about both tilt axes.

Influence of increased nutrient supply on Microcystis aeruginosa at cellular and proteomic levels

2020 ◽  
Vol 85 ◽  
pp. 47-58
Author(s):  
Y Jiang ◽  
Y Liu
Keyword(s):  
Microcystis Aeruginosa ◽  
Regulatory Protein ◽  
Acid Synthesis ◽  
Nutrient Supply ◽  
Nitrogen Supply ◽  
Nitrogen And Phosphorus ◽  
Comprehensive Description ◽  
Amino Acid Synthesis ◽  
High Nutrient ◽  
Proteomic Responses

Various studies have observed that increased nutrient supply promotes the growth of bloom-forming cyanobacteria, but only a limited number of studies have investigated the influence of increased nutrient supply on bloom-forming cyanobacteria at the proteomic level. We investigated the cellular and proteomic responses of Microcystis aeruginosa to elevated nitrogen and phosphorus supply. Increased supply of both nutrients significantly promoted the growth of M. aeruginosa and the synthesis of chlorophyll a, protein, and microcystins. The release of microcystins and the synthesis of polysaccharides negatively correlated with the growth of M. aeruginosa under high nutrient levels. Overexpressed proteins related to photosynthesis, and amino acid synthesis, were responsible for the stimulatory effects of increased nutrient supply in M. aeruginosa. Increased nitrogen supply directly promoted cyanobacterial growth by inducing the overexpression of the cell division regulatory protein FtsZ. NtcA, that regulates gene transcription related to both nitrogen assimilation and microcystin synthesis, was overexpressed under the high nitrogen condition, which consequently induced overexpression of 2 microcystin synthetases (McyC and McyF) and promoted microcystin synthesis. Elevated nitrogen supply induced the overexpression of proteins involved in gas vesicle organization (GvpC and GvpW), which may increase the buoyancy of M. aeruginosa. Increased phosphorus level indirectly affected growth and the synthesis of cellular substances in M. aeruginosa through the mediation of differentially expressed proteins related to carbon and phosphorus metabolism. This study provides a comprehensive description of changes in the proteome of M. aeruginosa in response to an increased supply of 2 key nutrients.

Method application of optimal multi-parameter analysis to assess the distribution of water masses as an example of CTD data of the Barents Sea in summer 2017

2019 ◽  
pp. 38-51
Author(s):  
Valeriy G. Yakubenko ◽  
Anna L. Chultsova
Keyword(s):  
Barents Sea ◽  
Field Measurements ◽  
Structural Similarity ◽  
Water Masses ◽  
Parameter Analysis ◽  
Water Dynamics ◽  
Phosphorus Concentration ◽  
Nitrogen And Phosphorus ◽  
The Barents Sea ◽  
Expert Assessments

Identification of water masses in areas with complex water dynamics is a complex task, which is usually solved by the method of expert assessments. In this paper, it is proposed to use a formal procedure based on the application of the method of optimal multiparametric analysis (OMP analysis). The data of field measurements obtained in the 68th cruise of the R/V “Academician Mstislav Keldysh” in the summer of 2017 in the Barents Sea on the distribution of temperature, salinity, oxygen, silicates, nitrogen, and phosphorus concentration are used as a data for research. A comparison of the results with data on the distribution of water masses in literature based on expert assessments (Oziel et al., 2017), allows us to conclude about their close structural similarity. Some differences are related to spatial and temporal shifts of measurements. This indicates the feasibility of using the OMP analysis technique in oceanological studies to obtain quantitative data on the spatial distribution of different water masses.

Sign in / Sign up

Export Citation Format

Share Document