IN SITU LUBRICANT DEGRADATION IN ANTARCTIC MARINE SEDIMENTS. 1. SHORT-TERM CHANGES

2006 ◽  
Vol 25 (2) ◽  
pp. 356 ◽  
Author(s):  
Belinda A.W. Thompson ◽  
Noel W. Davies ◽  
Paul M. Goldsworthy ◽  
Martin J. Riddle ◽  
Ian Snape ◽  
...  
Keyword(s):  
Marine Sediments ◽  
Lubricant Degradation ◽  
Short Term ◽  
Antarctic Marine

scholarly journals “Logrolling” in Antarctic governance: Limits and opportunities

Polar Record ◽  
2020 ◽  
Vol 56 ◽  
Author(s):  
Jeffrey McGee ◽  
Bruno Arpi ◽  
Andrew Jackson
Keyword(s):  
Marine Protected Areas ◽  
International Institutions ◽  
Marine Resources ◽  
International Governance ◽  
Short Term ◽  
Current Case ◽  
Antarctic Marine ◽  
Antarctic Treaty ◽  
Kunlun Station ◽  
The Antarctic

Abstract The Antarctic Treaty System (ATS) is considered a successful example of international governance as it has managed tensions over sovereignty claims, avoided militarisation and dealt with marine resources and environmental protection. Recently, China’s influence and assertiveness in many international institutions have significantly grown. What effect this shift in the international politics will have upon Antarctic governance remains to be seen. However, to further thinking on this issue we explore two current case studies that reveal pressure points within the ATS. First, in the Commission for the Conservation of Antarctic Marine Living Resources, Australia has proposed marine protected areas off East Antarctica, to which China and several other states have objected. Second, in the Antarctic Treaty Consultative Meetings, China has proposed special management arrangements for the area around the “Kunlun” station, to which Australia and several other states have objected. Negotiation theory suggests “logrolling” (i.e. trade of mutual decision-making support across issue areas) can be an effective strategy to avoid diplomatic deadlocks. We therefore consider the merits of a logrolling strategy for the above issues. We find that while a logrolling strategy in the ATS might facilitate short-term diplomatic success, it would carry significant risks, including the weakening of existing norms.

A Candidate Short-Term Toxicity Test Using Ampelisca brevicornis to Assess Sublethal Responses to Pharmaceuticals Bound to Marine Sediments

2014 ◽  
Vol 68 (2) ◽  
pp. 237-258 ◽  
Author(s):  
L. A. Maranho ◽  
L. B. Moreira ◽  
R. M. Baena-Nogueras ◽  
P. A. Lara-Martín ◽  
T. A. DelValls ◽  
...  
Keyword(s):  
Marine Sediments ◽  
Toxicity Test ◽  
Short Term

In situ studies on alginic acid synthesis and other aspects of the metabolism of Laminaria digitata

1972 ◽  
Vol 50 (1) ◽  
pp. 177-184 ◽  
Author(s):  
Johan A. Hellebust ◽  
Arne Haug
Keyword(s):  
Amino Acids ◽  
Time Course ◽  
Alginic Acid ◽  
Acid Synthesis ◽  
Short Term ◽  
Fresh Weight Basis ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
Rate Of Photosynthesis

Amino acids, particularly alanine and aspartate, become more strongly labeled than mannitol in short-term 14C-photoassimilation experiments. The amino acids are the most likely sources of carbon for alginic acid synthesis and respiration in the dark, in contrast to mannitol, which appears to be relatively unavailable. Temperature is very important in determining the rate of loss of recent photoassimilate in L. digitata. The rate of photosynthesis, on a fresh weight basis, is much higher for blades than for stipes.The time course for incorporation of photoassimilated carbon into alginate differs for the stipe and blade both in light and dark periods. Very little 14C enters alginate in blades in the dark, while alginate in stipes acquires considerable amounts of activity during dark periods. Alginate in both blade and stipe acquires 14C predominantly in mannuronic acid residues of their alginate during short-term photoassimilation periods, while guluronic acid residues become relatively more rapidly labeled during dark periods.

In situ infrared attenuated total reflectance spectroelectrochemical study of lubricant degradation

2012 ◽  
Vol 42 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Bushan K. Purushothaman ◽  
Michael Pelsozy ◽  
Philip W. Morrison ◽  
Vadim F. Lvovich ◽  
Heidi B. Martin
Keyword(s):  
Attenuated Total Reflectance ◽  
Lubricant Degradation ◽  
Total Reflectance

A Chloroflexi bacterium dechlorinates polychlorinated biphenyls in marine sediments under in situ-like biogeochemical conditions

2012 ◽  
Vol 209-210 ◽  
pp. 449-457 ◽  
Author(s):  
Giulio Zanaroli ◽  
Annalisa Balloi ◽  
Andrea Negroni ◽  
Luigimaria Borruso ◽  
Daniele Daffonchio ◽  
...  
Keyword(s):  
Polychlorinated Biphenyls ◽  
Marine Sediments

scholarly journals Acetoclastic Methanosaeta are dominant methanogens in organic-rich Antarctic marine sediments

2017 ◽  
Vol 12 (2) ◽  
pp. 330-342 ◽  
Author(s):  
Stephanie A Carr ◽  
Florence Schubotz ◽  
Robert B Dunbar ◽  
Christopher T Mills ◽  
Robert Dias ◽  
...  
Keyword(s):  
Marine Sediments ◽  
Antarctic Marine

Structural basis of muscle O2 diffusing capacity: evidence from muscle function in situ

2000 ◽  
Vol 88 (2) ◽  
pp. 560-566 ◽  
Author(s):  
Russell T. Hepple ◽  
Michael C. Hogan ◽  
Creed Stary ◽  
Donald E. Bebout ◽  
Odile Mathieu-Costello ◽  
...  
Keyword(s):  
Gastrocnemius Muscle ◽  
Capillary Density ◽  
Structural Basis ◽  
Diffusing Capacity ◽  
Diffusion Distance ◽  
Short Term ◽  
Cross Sectional ◽  
Intact Organism ◽  
Minimal Reduction

Although evidence for muscle O2 diffusion limitation of maximal O2 uptake has been found in the intact organism and isolated muscle, its relationship to diffusion distance has not been examined. Thus we studied six sets of three purpose-bred littermate dogs (aged 10–12 mo), with 1 dog per litter allocated to each of three groups: control (C), exercise trained for 8 wk (T), or left leg immobilized for 3 wk (I). The left gastrocnemius muscle from each animal was surgically isolated, pump-perfused, and electrically stimulated to peak O2 uptake at three randomly applied levels of arterial oxygenation [normoxia, arterial[Formula: see text]([Formula: see text]) 77 ± 2 (SE) Torr; moderate hypoxia, [Formula: see text]: 33 ± 1 Torr; and severe hypoxia, [Formula: see text]: 22 ± 1 Torr]. O2 delivery (ml ⋅ min−1 ⋅ 100 g− 1) was kept constant among groups for each level of oxygenation, with O2 delivery decreasing with decreasing [Formula: see text]. O2extraction (%) was lower in I than T or C for each condition, but calculated muscle O2 diffusing capacity (Dm[Formula: see text]) per 100 grams of muscle was not different among groups. After the experiment, the muscle was perfusion fixed in situ, and a sample from the midbelly was processed for microscopy. Immobilized muscle showed a 45% reduction of muscle fiber cross-sectional area ( P < 0.05), and a resulting 59% increase in capillary density ( P < 0.05) but minimal reduction in capillary-to-fiber ratio (not significant). In contrast, capillarity was not significantly different in T vs. C muscle. The results show that a dramatically increased capillary density (and reduced diffusion distance) after short-term immobilization does not improve Dm[Formula: see text] in heavily working skeletal muscle.

scholarly journals Temporal Variation of Chlorophyll-a Concentrations in Highly Dynamic Waters from Unattended Sensors and Remote Sensing Observations

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2699 ◽  
Author(s):  
Jian Li ◽  
Liqiao Tian ◽  
Qingjun Song ◽  
Zhaohua Sun ◽  
Hongjing Yu ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Chlorophyll Fluorescence ◽  
Chlorophyll A ◽  
Temporal Variations ◽  
Lake Area ◽  
Short Term ◽  
Chl A ◽  
Spatio Temporal

Monitoring of water quality changes in highly dynamic inland lakes is frequently impeded by insufficient spatial and temporal coverage, for both field surveys and remote sensing methods. To track short-term variations of chlorophyll fluorescence and chlorophyll-a concentrations in Poyang Lake, the largest freshwater lake in China, high-frequency, in-situ, measurements were collected from two fixed stations. The K-mean clustering method was also applied to identify clusters with similar spatio-temporal variations, using remote sensing Chl-a data products from the MERIS satellite, taken from 2003 to 2012. Four lake area classes were obtained with distinct spatio-temporal patterns, two of which were selected for in situ measurement. Distinct daily periodic variations were observed, with peaks at approximately 3:00 PM and troughs at night or early morning. Short-term variations of chlorophyll fluorescence and Chl-a levels were revealed, with a maximum intra-diurnal ratio of 5.1 and inter-diurnal ratio of 7.4, respectively. Using geostatistical analysis, the temporal range of chlorophyll fluorescence and corresponding Chl-a variations was determined to be 9.6 h, which indicates that there is a temporal discrepancy between Chl-a variations and the sampling frequency of current satellite missions. An analysis of the optimal sampling strategies demonstrated that the influence of the sampling time on the mean Chl-a concentrations observed was higher than 25%, and the uncertainty of any single Terra/MODIS or Aqua/MODIS observation was approximately 15%. Therefore, sampling twice a day is essential to resolve Chl-a variations with a bias level of 10% or less. The results highlight short-term variations of critical water quality parameters in freshwater, and they help identify specific design requirements for geostationary earth observation missions, so that they can better address the challenges of monitoring complex coastal and inland environments around the world.

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