scholarly journals Effects of Tissue Preservation on Carbon and Nitrogen Stable Isotope Signatures in Syngnathid Fishes and Prey

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2301
Author(s):  
Miquel Planas ◽  
Alex Paltrinieri ◽  
Mario Davi Dias Carneiro ◽  
Jorge Hernández-Urcera

Isotopic stable analysis (SIA) is a powerful tool in the assessment of different types of ecological and physiological studies. For that, different preservation methods for sampled materials are commonly used prior to isotopic analysis. The effects of various preservation methods (freezing, ethanol and formaldehyde) were analyzed for C:N, and δ13C and δ15N signals on a variety of tissues including dorsal fins (three seahorse and two pipefish species), seahorse newborns (three seahorses species), and prey (copepods and different stages of Artemia) commonly used to feed the fishes under rearing conditions. The aims of the study were: (i) to evaluate isotopic effects of chemical preservation methods across different types of organisms and tissues, using frozen samples as controls, and (ii) to construct the first conversion models available in syngnathid fishes. The chemical preservation in ethanol and, to a lesser extent, in formaldehyde significantly affected δ13C values, whereas the effects on δ15N signatures were negligible. Due to their low lipid content, the isotopic signals in fish fins was almost unaffected, supporting the suitability of dorsal fins as the most convenient material in isotopic studies on vulnerable species such as syngnathids. The regression equations provided resulted convenient for the successful conversion of δ13C between preservation treatments. Our results indicate that the normalization of δ15N signatures in preserved samples is unnecessary. The conversion models should be applicable in isotopic field studies, laboratory experiments, and specimens of historical collections.

Author(s):  
Miquel Planas ◽  
Alex Paltrinieri ◽  
Mario Davi Dias Carneiro ◽  
Jorge Hernández-Urcera

Isotopic stable analysis (SIA) is a powerful tool in the assessment of different types of ecological and physiological studies. For that, different preservative methods for the samples are commonly used prior to isotopic analysis. The effects of various preservative methods (drying, freezing, ethanol and formaldehyde) have been analyzed for C:N ratio, δ13C and δ15N on a variety of tissues including dorsal fins (three seahorse and two pipefish species), seahorse newborns (three seahorses species), and prey (copepods and different stages of Artemia) commonly used to feed the fishes in rearing conditions. The aims of the study were to: (i) evaluate isotopic effects of preservation methods across tissues; and (ii) construct the first conversion models available in syngnathid fishes. The preservation in ethanol and to a lesser extend in formaldehyde significantly affected δ13C values, whereas δ15N signatures were not affected significantly. Due to their low lipid content, the isotopic signals in fish fins were almost unaffected, supporting the suitability of dorsal fins as a convenient tool in isotopic studies on vulnerable species such as syngnathids. The regression equations provided permit the successful conversion of δ13C and δ15N values between preservative treatments. The conversion models can be applied to isotopic studies in the field and in the laboratory.


Soil Research ◽  
2018 ◽  
Vol 56 (6) ◽  
pp. 632 ◽  
Author(s):  
Kathryn Conrad ◽  
Ram C. Dalal ◽  
Ryosuke Fujinuma ◽  
Neal W. Menzies

Stabilisation and protection of soil organic carbon (SOC) in macroaggregates and microaggregates represents an important mechanism for the sequestration of SOC. Legume-based grass pastures have the potential to contribute to aggregate formation and stabilisation, thereby leading to SOC sequestration. However, there is limited research on the C and N dynamics of soil organic matter (SOM) fractions in deep-rooted legume leucaena (Leucaena leucocephala)–grass pastures. We assessed the potential of leucaena to sequester carbon (C) and nitrogen (N) in soil aggregates by estimating the origin, quantity and distribution in the soil profile. We utilised a chronosequence (0–40 years) of seasonally grazed leucaena stands (3–6 m rows), which were sampled to a depth of 0.3 m at 0.1-m intervals. The soil was wet-sieved for different aggregate sizes (large macroaggregates, >2000 µm; small macroaggregates, 250–2000 µm; microaggregates, 53–250 µm; and <53 µm), including occluded particulate organic matter (oPOM) within macroaggregates (>250 µm), and then analysed for organic C, N and δ13C and δ15N. Leucaena promoted aggregation, which increased with the age of the leucaena stands, and in particular the formation of large macroaggregates compared with grass in the upper 0.2 m. Macroaggregates contained a greater SOC stock than microaggregates, principally as a function of the soil mass distribution. The oPOM-C and -N concentrations were highest in macroaggregates at all depths. The acid nonhydrolysable C and N distribution (recalcitrant SOM) provided no clear distinction in stabilisation of SOM between pastures. Leucaena- and possibly other legume-based grass pastures have potential to sequester SOC through stabilisation and protection of oPOM within macroaggregates in soil.


2015 ◽  
Vol 74 (3) ◽  
Author(s):  
S. M. Zain ◽  
N. L. Ching ◽  
S. Jusoh ◽  
S. Y. Yunus

The aim of this study is to identify the relationship between the rate of electricity generation and the rate of carbon and nitrogen removal from wastewater using different MFC processes.  Determining whether the generation of electricity using MFC process could be related to the rate of pollutant removal from wastewater is noteworthy. Three types of MFC process configurations include the batch mode (SS), a continuous flow of influent with ferricyanide (PF) as the oxidizing agent and a continuous flow of influent with oxygen (PU) as the oxidizing agent. The highest quantity of electricity generation was achieved using the continuous flow mode with ferricyanide (0.833 V), followed by the continuous flow mode with oxygen (0.589 V) and the batch mode (0.352 V). The highest efficiency of carbon removal is also achieved by the continuous flow mode with ferricyanide (87%), followed by the continuous flow mode with oxygen (51%) and the batch mode (46%). Moreover, the continuous flow mode with ferricyanide produced the highest efficiency for nitrogen removal (63%), followed by the continuous flow mode with oxygen (54%) and the batch mode (27%).


2010 ◽  
Vol 12 (1) ◽  
pp. 13-20 ◽  
Author(s):  
RP Oliveira ◽  
C Ducatti ◽  
AC Pezzato ◽  
JC Denadai ◽  
VC Cruz ◽  
...  

Author(s):  
Xuan Lu ◽  
Fengxia Zhou ◽  
Fajin Chen ◽  
Qibin Lao ◽  
Qingmei Zhu ◽  
...  

Elemental (total organic carbon (TOC) and total nitrogen (TN)) and stable carbon and nitrogen isotope compositions (δ13C and δ15N, respectively) in the surface sediment of Zhanjiang Bay (ZJB) in spring and summer were measured to study the spatial and seasonal changes of organic matter (OM) and assess the human-induced and environment-induced changes in the area. The OM in the surface sediment of ZJB was a mixture of terrestrial and marine sources, and was dominated by marine OM (54.9% ± 15.2%). Compared to the central ZJB, the channel and coastal ZJB areas had higher δ13C and δ15N values, higher TOC and TN concentrations, and lower TOC/TN ratios, indicating higher primary productivity and higher percentages of marine OM in the latter two subregions. Mariculture activities, sewage inputs, and dredging were responsible for these phenomena. Clear seasonal variations in OM were observed in ZJB. The average proportions of terrestrial OM in summer increased by 10.2% in the ZJB channel and 26.0% in the coastal ZJB area compared with those in spring. Heavy rainfall brought a large amount of terrestrial OM into the channel and coastal ZJB areas, leading to the increase of the terrestrial OM fraction in these two subregions in summer. In summary, anthropogenic influences had a significant influence on the spatial and seasonal variations of sedimentary OM in ZJB.


2011 ◽  
pp. 218-239 ◽  
Author(s):  
Heinz K. Klein ◽  
Michael D. Myers

Given the increase in the number of interpretive research articles being published in IS today, we believe it is timely to develop and explain a classification scheme of the literature. Such a classification scheme draws attention to the tremendous variety and breadth of interpretive research today, from the most abstract and general philosophical foundations to the most in-depth, detailed field studies. The explicit consideration of different types may contribute to a more effective division of labor among scholars with different research interests. It should also help interpretive researchers to better focus their work and to identify their research priorities.


2020 ◽  
pp. 097215091988645
Author(s):  
Saikat Chatterjee ◽  
Amit Shukla

Workplace stress has always been considered as a potential source of job dissatisfaction and many psychosomatic disorders in employees the world over. The IT sector has emerged as a major contributor to work stress in India over the last 2 decades. Still there is lack of sector-specific studies, and most of the existing studies treat work stress as an umbrella term. Against this background, the objective of this article is twofold: one, to identify different types of stressors, and the other, to rate them according to their severity. The outcome should be helpful in devising proper mitigation strategies. On the basis of findings from the two field studies, the article identifies major stressors among junior level Indian IT professionals ( n1 = 38), and then furnishes a risk profile of these stressors on the basis of their frequency and impact ( n2 = 234). At the end, 21 stressors are identified in the given context, and their ‘riskiness’ is presented in a descending order in terms of risk scores. Implications of findings are discussed at the end. All the stressors were assigned a score in terms of their frequency, impact and risk. At the end, techno-stress emerged as the most serious stressor in both in terms of its frequency of occurrence and impact. The results serve as a guide to the management in the IT firms in addressing the prevalent high levels of stress at workplace. The risk scores will help them in allocating resources and, setting and prioritizing their HR strategies to this end. Amid few studies conducted in the context of stress in the Indian IT sector, this article offers useful and practical insights while deploying a novel approach of risk profiling.


2012 ◽  
Vol 12 (4) ◽  
pp. 585-596 ◽  
Author(s):  
Dariusz Lisiak ◽  
Karol Borzuta ◽  
Piotr Janiszewski ◽  
Fabian Magda ◽  
Eugenia Grześkowiak ◽  
...  

AbstractFour manual classification devices for estimating pork carcass meat content, i.e. CGM, Fat-OMeat’er II, IM-03 and UltraFom 300 were tested. The experiment was carried out with properly selected raw material (n=141 pigs) from current deliveries for pig slaughter at the Meat Plant SKIBA S.A. in Chojnice. Pork raw material was derived from three different Polish regions and represented different types of fatness, different carcass weights (from 60 to 120 kg) and different sexes (half were gilts and half were barrows). The applied testing procedure was consistent with European Union regulations. The research resulted in the development of regression equations for estimating pork carcass meat content in Poland. These equations are of rectilinear type and use four (in the case of UltraFom 300) or two (in the case of other devices) measurements of backfat and longissimus dorsi muscle thickness located at a distance of 6 cm (CGM, IM-03) or 7 cm (Fat-OMeat’er II, UltraFom 300) from the backfat edge at the section between 3rd and 4th rib, counting ribs from the end (CGM, IM-03, Fat-O-Meat’er II) and also at the height of the last rib section (UltraFom 300). The prediction error does not exceed the termination value of 2.50% established by EU regulations and amounts to 2.16% for CGM, 2.18% for Fat-O-Meat’er II, 1.89% for IM-03 and 2.07% for UltraFom 300. New regression equations have been applied in the meat industry since 12 December 2011.


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