scholarly journals Increase in stable isotope ratios driven by metabolic alterations in amphipods exposed to the beta-blocker propranolol

2019 ◽  
Author(s):  
Caroline Ek ◽  
Zhenyang Yu ◽  
Andrius Garbaras ◽  
Hanna Oskarsson ◽  
Ann-Kristin Eriksson Wiklund ◽  
...  
Keyword(s):  
Body Size ◽  
Stable Isotope ◽  
Sublethal Effects ◽  
Isotope Ratios ◽  
Stable Isotope Ratios ◽  
Anthropogenic Pressures ◽  
Contaminant Exposure ◽  
Scope For Growth ◽  
Oxidative Balance ◽  
Stable Isotope Signatures

AbstractAnthropogenic pressures, such as contaminant exposure, may affect stable isotope ratios in biota. These changes are driven by alterations in the nutrient allocation and metabolic pathways induced by specific stressors. In a controlled microcosm study with the amphipod Gammarus spp., we studied effects of the β-blocker propranolol on stable isotope signatures (δ15N and δ13C), elemental composition (%C and %N), and growth (protein content and body size) as well as biomarkers of oxidative status (antioxidant capacity, ORAC; lipid peroxidation, TBARS) and neurological activity (acetylcholinesterase, AChE). Based on the known effects of propranolol exposure on cellular functions, i.e., its mode of action (MOA), we expected to observe a lower scope for growth, accompanied by a decrease in protein deposition, oxidative processes and AChE inhibition, with a resulting increase in the isotopic signatures. The observed responses supported most of these predictions. In particular, %N was positively affected by propranolol, whereas both protein allocation and body size declined. Moreover, both ORAC and TBARS levels decreased with increasing propranolol concentration, with the decrease being more pronounced for TBARS, which indicates the prevalence of the antioxidative processes. These changes resulted in a significant increase of the δ15N and δ13C values in the propranolol-exposed animals compared to the control. These findings suggest that MOA of β-blockers may be used to predict sublethal effects in nontarget species, including inhibited AChE activity, improved oxidative balance, and elevated stable isotope ratios. The latter also indicates that metabolism-driven responses to environmental contaminants can alter stable isotope signatures, which should be taken into account when interpreting trophic interactions in the food webs.

Seasonal differences in foraging and isotopic niche width related to body size in Gulf of Alaska harbor seals

2019 ◽  
Vol 97 (12) ◽  
pp. 1156-1163 ◽  
Author(s):  
Justin Smith ◽  
Shawna Karpovich ◽  
Lara Horstmann ◽  
Julie McIntyre ◽  
Diane M. O’Brien
Keyword(s):  
Body Size ◽  
Stable Isotope ◽  
Isotope Analysis ◽  
Isotope Ratios ◽  
Gulf Of Alaska ◽  
Harbor Seal ◽  
Foraging Strategies ◽  
Stable Isotope Ratios ◽  
Isotopic Niche ◽  
Harbor Seals

Harbor seals (Phoca vitulina Linnaeus, 1758) use different foraging strategies based on body size and sex, but this difference can be difficult to evaluate across seasons. We used stable isotope analysis of harbor seal whiskers from 32 individuals to assess seasonal foraging of seals inhabiting tidewater glacial habitat in Southeast Alaska. We analyzed stable isotope ratios from serial sections of whiskers, estimated deposition date for each section, and used mixed models to determine if sex and body size influence stable isotope ratios. Seals were grouped by size (>1.4 m or ≤1.4 m curvilinear length) as a proxy for sexual maturity to describe isotopic differences between groups using standard ellipse corrected area. Mean carbon and nitrogen isotope ratios differed significantly between size classes (p < 0.005), with no effect of sex. Larger seals exhibited a broader isotopic niche in the fall, winter, and spring relative to smaller seals, but not in the summer. Our results suggest that seals using tidewater glacial habitat share common foraging behavior in the summer, while larger seals exhibit more diverse foraging throughout the rest of the year. These results highlight the importance of tidewater glacial habitat for this population of harbor seals during the summer.

TRANSFER EFFICIENCY FROM PRIMARY PRODUCERS TO RUDITAPES PHILIPPINARUM ON AN INTERTIDAL FLAT IN HIROSHIMA BAY, JAPAN

2017 ◽  
Author(s):  
Sosuke Otani ◽  
Sosuke Otani ◽  
Akira Umehara ◽  
Akira Umehara ◽  
Haruka Miyagawa ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Secondary Production ◽  
Isotope Ratios ◽  
Ruditapes Philippinarum ◽  
Transfer Efficiency ◽  
Food Sources ◽  
Stable Isotope Ratios ◽  
Primary Producers ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen

Fish yields of Ruditapes philippinarum have been decreased and the resources have not yet recovered. It needs to clarify food sources of R. philippinarum, and relationship between primary and secondary production of it. The purpose on this study is to reveal transfer efficiency from primary producers to R. philippinarum and food sources of R. philippinarum. The field investigation was carried out to quantify biomass of R. philippinarum and primary producers on intertidal sand flat at Zigozen beach in Hiroshima Bay, Japan. In particular, photosynthetic rates of primary producers such as Zostera marina, Ulva sp. and microphytobenthos were determined in laboratory experiments. The carbon and nitrogen stable isotope ratios for R. philippinarum and 8 potential food sources (microphytobenthos, MPOM etc) growing in the tidal flat were also measured. In summer 2015, the primary productions of Z. marina, Ulva sp. and microphytobenthos were estimated to be 70.4 kgC/day, 43.4 kgC/day and 2.2 kgC/day, respectively. Secondary production of R. philippinarum was 0.4 kgC/day. Contribution of microphytobenthos to R. philippinarum as food source was 56-76% on the basis of those carbon and nitrogen stable isotope ratios. Transfer efficiency from microphytobenthos to R. philippinarum was estimated to be 10-14%. It was suggested that microphytobenthos might sustain the high secondary production of R. philippinarum, though the primary production of microphytobenthos was about 1/10 compared to other algae.

scholarly journals Stable Isotope Ratios of Herbs and Spices Commonly Used as Herbal Infusions in the Italian Market

ACS Omega ◽  
2021 ◽  
Author(s):  
Purna K. Khatri ◽  
Roberto Larcher ◽  
Federica Camin ◽  
Luca Ziller ◽  
Agostino Tonon ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Isotope Ratios ◽  
Stable Isotope Ratios ◽  
Italian Market ◽  
Herbal Infusions ◽  
Herbs And Spices

scholarly journals Elemental and Isotopic Characterization of Tobacco from Umbria

Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 186
Author(s):  
Luana Bontempo ◽  
Daniela Bertoldi ◽  
Pietro Franceschi ◽  
Fabio Rossi ◽  
Roberto Larcher
Keyword(s):  
Stable Isotope ◽  
Economic Value ◽  
Isotope Ratios ◽  
Stable Isotope Ratios ◽  
Umbria Region ◽  
Geographical Regions ◽  
Isotopic Characterization ◽  
First Time ◽  
Micro Elements

Umbrian tobacco of the Virginia Bright variety is one of the most appreciated tobaccos in Europe, and one characterized by an excellent yield. In recent years, the Umbria region and local producers have invested in introducing novel practices (for production and processing) focused on environmental, social, and economic sustainability. Due to this, tobacco from Umbria is a leading commodity in the global tobacco industry, and it claims a high economic value. The aim of this study is then to assess if elemental and isotopic compositions can be used to protect the quality and geographical traceability of this particular tobacco. For the first time the characteristic value ranges of the stable isotope ratios of the bio-elements as a whole (δ2H, δ13C, δ15N, δ18O, and δ34S) and of the concentration of 56 macro- and micro-elements are now available, determined in Virginia Bright tobacco produced in two different areas of Italy (Umbria and Veneto), and from other worldwide geographical regions. The ranges of variability of elements and stable isotope ratios had slightly different results, according to the three geographical origins considered. In particular, Umbria samples presented significantly lower content of metals potentially dangerous for human health. The results of this first exploratory work highlight the possibility of characterizing tobacco from Umbria, and suggest widening the scope of the survey throughout Italy and foreign regions, in order to be used to describe the geographical origin of tobacco in general and verify the origin of the products on the market.

Variations in stable isotope ratios in lamb blood fractions following dietary changes: a preliminary study

2015 ◽  
Vol 30 (1) ◽  
pp. 170-174 ◽  
Author(s):  
L. Bontempo ◽  
F. Camin ◽  
L. Ziller ◽  
L. Biondi ◽  
M. G. D'Urso ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Isotope Ratios ◽  
Stable Isotope Ratios ◽  
Dietary Changes ◽  
Preliminary Study
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