Nitrogen and oxygen isotopic compositions of water-soluble nitrate in Taihu Lake water system, China: implication for nitrate sources and biogeochemical process

2013 ◽  
Vol 71 (1) ◽  
pp. 217-223 ◽  
Author(s):  
Zi-Xiang Chen ◽  
Lei Yu ◽  
Wei-Guo Liu ◽  
Michael H. W. Lam ◽  
Gui-Jian Liu ◽  
...  
Keyword(s):  
Lake Water ◽  
Taihu Lake ◽  
Water System ◽  
Water Soluble ◽  
Biogeochemical Process ◽  
Nitrate Sources ◽  
Isotopic Compositions ◽  
Oxygen Isotopic

Reconstructing Terrestrial Environments Using Stable Isotopes in Fossil Teeth and Paleosol Carbonates

2012 ◽  
Vol 18 ◽  
pp. 167-194 ◽  
Author(s):  
Benjamin H. Passey
Keyword(s):  
Isotopic Composition ◽  
Soil Temperature ◽  
Carbon Isotopes ◽  
Oxygen Isotopes ◽  
Precipitation Amount ◽  
Radiative Heating ◽  
Mammal Species ◽  
Isotopic Compositions ◽  
Heat Effects ◽  
Oxygen Isotopic

Carbon isotopes in Neogene-age fossil teeth and paleosol carbonates are commonly interpreted in the context of past distributions of C3 and C4 vegetation. These two plant types have very different distributions in relation to climate and ecology, and provide a robust basis for reconstructing terrestrial paleoclimates and paleoenvironments during the Neogene. Carbon isotopes in pre-Neogene fossil teeth are usually interpreted in the context of changes in the δ13C value of atmospheric CO2, and variable climate-dependent carbon-isotope discrimination in C3 plants. Carbon isotopes in pre-Neogene soil carbonates can be used to estimate past levels of atmospheric CO2. Oxygen isotopes in fossil teeth and paleosol carbonates primarily are influenced by the oxygen isotopic compositions of ancient rainfall and surface waters. The oxygen isotopic composition of rainfall is has a complex, but tractable, relationship with climate, and variably relates to temperature, elevation, precipitation amount, and other factors. Mammal species that rely on moisture in dietary plant tissues to satisfy their water requirements (rather than surface drinking water) may have oxygen isotopic compositions that track aridity. Thus, oxygen isotopes of fossil mammals can place broad constraints on paleoaridity. Carbonate clumped isotope thermometry allows for reconstruction of soil temperatures at the time of pedogenic carbonate mineralization. The method is unique because it is the only thermodynamically based isotopic paleothermometer that does not require assumptions about the isotopic composition of the fluid in which the archive mineral formed. Soil temperature reflects a complex interplay of air temperature, solar radiative heating, latent heat effects, soil thermal diffusivity, and seasonal variations of these parameters. Because plants and most animals live in and/or near the soil, soil temperature is an important aspect of terrestrial (paleo)climate.

scholarly journals Water intake of pigs consuming tiamulin during the nursery phase1

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Kimberly A Vonnahme ◽  
Adam Mueller ◽  
Daniel A Nelson ◽  
Manuel Alexander Vasquez-Hidalgo ◽  
Deborah Amodie ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Intake ◽  
Feed Intake ◽  
Animal Health ◽  
Average Daily Gain ◽  
Water System ◽  
Water Soluble ◽  
Daily Water Intake ◽  
Original Product ◽  
Effect Of Treatment

Abstract Mass medication to manage population health can be achieved by providing therapeutics in the drinking water. Young nursery pigs are highly sensitive to the flavor and smell of water. Medications that reduce water palatability often lead to an interruption in water and feed intake. With the availability of several generic water-soluble antimicrobials for pigs, questions have arisen about their palatability compared with the original product. In this study, we compared the intake of water containing tiamulin hydrogen fumarate from two different manufacturers with the intake of unmedicated water. The hypothesis was that the intake of tiamulin-containing water would be similar to unmedicated water. Water intake was monitored upon entry into the nursery and just prior to leaving the nursery. Also, average daily gain (ADG) and feed efficiency (FE) were determined. A total of 300 pigs were individually weighed (4.2–10.9 kg; avg = 6.8 kg) for randomization to pen (n = 30 pens). The experiment had two time points: 1) early nursery (periods 1–3) and 2) late nursery (period 4). Pens were randomly assigned to a sequence (period 1–3) in a crossover experimental design containing three 10-d periods, with 5 d for the resetting of baseline where unmedicated water was provided followed by 5 d on tiamulin source addition [i.e., TriamuloxTM (Zoetis, Parsippany, NJ); Denagard (Elanco Animal Health, Greenfield, IN)] or unmedicated water. After period 3 was concluded, all pens were given unmedicated water (via nipple waterers) and the number of pigs per pen was reduced to six pigs to maintain adequate space per pig. Ten days prior to pigs leaving the nursery, a fourth period was performed. After a 5-d water baseline was achieved, pens were treated with either unmedicated water or Triamulox- or Denagard-containing water. Pigs had ad libitum access to water and feed. During the testing periods, daily water intake was measured by a cup water system in each pen. Feed intake was measured every 5 d. There was no effect of treatment on initial body weights or weights at the beginning or end of each period (P ≥ 0.51). Therefore, there was no effect of treatment on ADG (P ≥ 0.23). Water intake (P ≥ 0.16) and FE (P ≥ 0.35) were not affected by treatment. Water consumption was similar among all treatments in each of the four periods. There appears to be no aversion to water intake when tiamulin hydrogen fumarate is added to the drinking water.

scholarly journals Seasonal variations of triple oxygen isotopic compositions of atmospheric sulfate, nitrate and ozone at Dumont d'Urville, coastal Antarctica

2016 ◽  
Author(s):  
Sakiko Ishino ◽  
Shohei Hattori ◽  
Joel Savarino ◽  
Bruno Jourdain ◽  
Susanne Preunkert ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Ice Cores ◽  
Oxidative Capacity ◽  
So2 Oxidation ◽  
Mixing Ratios ◽  
Isotopic Compositions ◽  
Oxygen Isotopic ◽  
Low Sensitivity ◽  
Complex Chemistry ◽  
Oxidation Chemistry

Abstract. Reconstruction of the oxidative capacity of the atmosphere is of great importance to understanding climate change, because of its key role in determining the life times of trace gases. Triple oxygen isotopic compositions (Δ17O = δ17O − 0.52 × δ18O) of atmospheric sulfate (SO42−) and nitrate (NO3−) in the Antarctic ice cores have shown potential as stable proxies, because they reflect the oxidation chemistry involved in their formation processes. However, observations of Δ17O values of SO42−, NO3− and ozone in the present-day Antarctic atmosphere are very limited, and their complex chemistry is not fully understood in this region. We present the first simultaneous measurement of Δ17O values of atmospheric sulfate, nitrate, and ozone collected at Dumont d'Urville station (66°40' S, 140°01' E) throughout 2011. Δ17O values of sulfate and nitrate exhibited seasonal variation characterized by summer minima and winter maxima, within the ranges of 0.9–3.4 ‰ and 23.0–41.9 ‰, respectively. In contrast, Δ17O values of ozone showed no significant seasonal variation, with values of 26 ± 1 ‰ through the year. These contrasting seasonal trends suggest that Δ17O(O3) is not the major factor determining seasonal changes in Δ17O(SO42−) and Δ17O(NO3−) values. The summer/winter trends for Δ17O(SO42−) and Δ17O(NO3−) values are caused by sunlight-driven changes in O3/ROX ratios, which decrease in summer through ozone destruction and photo-oxidants production, resulting in co-variation between ozone mixing ratios and Δ17O(SO42−) and Δ17O(NO3−) values. However, despite similar ranges of ozone mixing ratios in spring (September to November) and fall (March to May), Δ17O(SO42−) values observed in spring were lower than in fall. The relatively low sensitivity of Δ17O(SO42−) values to the ozone mixing ratio in spring is possibly explained by (i) lower O3/ROX ratios caused by NOX emission from snowpack and/or (ii) SO2 oxidation by hypohalous acids (HOX = HOCl + HOBr) in the aqueous phase.

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