Toxic effects of two commercial polybrominated diphenyl ethers on Artemia larvae at three developmental stages

Crustaceana ◽  
2021 ◽  
Vol 94 (2) ◽  
pp. 177-187
Author(s):  
Qingtian Zhang ◽  
Sifan Guo ◽  
Guikun Hu
Keyword(s):  
Developmental Stage ◽  
Polybrominated Diphenyl Ethers ◽  
Developmental Stages ◽  
Experimental Studies ◽  
Mortality Rates ◽  
The Body ◽  
Toxic Effects ◽  
Abnormal Behaviour ◽  
Diphenyl Ethers ◽  
Selection Of

Abstract Toxic effects of two commercial products, penta-BDE (DE-71) and octa-BDE (DE-79), on larvae of the brine shrimp, Artemia, were studied. Results showed that their toxic effects were related not only to the concentration and exposure time, but also to the developmental stage of Artemia. Newly hatched Artemia nauplii showed stronger tolerance than those at metanauplius stage or pseudoadult stage, while DE-71 showed a stronger toxic effect than DE-79 to some extent. Abnormal behaviour of Artemia larvae might occur within 12 h, and sometimes mortality rates increased quickly even if there was no death within 36 h. Both DE-71 and DE-79 showed significant influences on the body length of Artemia larvae within 24 h; the higher the concentration, the stronger the inhibition. As far as a toxic testing standard is concerned, further experimental studies on the selection of Artemia population and developmental stage are essential.

scholarly journals Spatio-temporal selection of reference genes in the two congeneric species of Glycyrrhiza

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuping Li ◽  
Xiaoju Liang ◽  
Xuguo Zhou ◽  
Yu An ◽  
Ming Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Developmental Stage ◽  
Reference Genes ◽  
Developmental Stages ◽  
Individual Factors ◽  
Congeneric Species ◽  
Spatio Temporal ◽  
The Stability ◽  
Different Tissues ◽  
Selection Of

AbstractGlycyrrhiza, a genus of perennial medicinal herbs, has been traditionally used to treat human diseases, including respiratory disorders. Functional analysis of genes involved in the synthesis, accumulation, and degradation of bioactive compounds in these medicinal plants requires accurate measurement of their expression profiles. Reverse transcription quantitative real-time PCR (RT-qPCR) is a primary tool, which requires stably expressed reference genes to serve as the internal references to normalize the target gene expression. In this study, the stability of 14 candidate reference genes from the two congeneric species G. uralensis and G. inflata, including ACT, CAC, CYP, DNAJ, DREB, EF1, RAN, TIF1, TUB, UBC2, ABCC2, COPS3, CS, R3HDM2, were evaluated across different tissues and throughout various developmental stages. More importantly, we investigated the impact of interactions between tissue and developmental stage on the performance of candidate reference genes. Four algorithms, including geNorm, NormFinder, BestKeeper, and Delta Ct, were used to analyze the expression stability and RefFinder, a comprehensive software, provided the final recommendation. Based on previous research and our preliminary data, we hypothesized that internal references for spatio-temporal gene expression are different from the reference genes suited for individual factors. In G. uralensis, the top three most stable reference genes across different tissues were R3HDM2, CAC and TUB, while CAC, CYP and ABCC2 were most suited for different developmental stages. CAC is the only candidate recommended for both biotic factors, which is reflected in the stability ranking for the spatio (tissue)-temporal (developmental stage) interactions (CAC, R3HDM2 and DNAJ). Similarly, in G. inflata, COPS3, R3HDM2 and DREB were selected for tissues, while RAN, COPS3 and CS were recommended for developmental stages. For the tissue-developmental stage interactions, COPS3, DREB and ABCC2 were the most suited reference genes. In both species, only one of the top three candidates was shared between the individual factors and their interactions, specifically, CAC in G. uralensis and COPS3 in G. inflata, which supports our overarching hypothesis. In summary, spatio-temporal selection of reference genes not only lays the foundation for functional genomics research in Glycyrrhiza, but also facilitates these traditional medicinal herbs to reach/maximize their pharmaceutical potential.

Practical Application of the Similarity Law of Structures in the Reconstruction of the Surface Layer of Bricks

2021 ◽  
Vol 1017 ◽  
pp. 21-30
Author(s):  
Victor Danilov ◽  
Arkady Ayzenshtadt ◽  
Maria Frolova
Keyword(s):  
Surface Layer ◽  
Experimental Studies ◽  
Calcium Content ◽  
Degradation Process ◽  
The Body ◽  
Atmospheric Water ◽  
A Value ◽  
Architectural Monument ◽  
Similarity Law ◽  
Selection Of

This paper discusses the results of experimental studies on the selection of the repair mixture compound for recreating the surface layer of the historical brick of the 18th century architectural monument “Commercial Bank” in Arkhangelsk. According to the research results, it was found that the historical brick has a relatively higher density and increased calcium content than the modern one. The characteristics of the surfaces of the analyzed materials based on the component indicators of specific surface energy showed that the brick of 1859, characterized by the highest degree of destruction, has the maximum value of the polar energy component. This fact may indicate a greater hydrophilicity of the surface in relation to atmospheric water and, as a result, a more intensive degradation process. It is established that the composition of the repair mixture with the addition of brick crumbs in the amount of 50 % has a value of the polar part of the surface tension equal to similar parameters for historical bricks (1786 and 1859) after their preliminary priming. The use of this mixture to recreate the surface layer of the brick will allow atmospheric water to pass freely through the repair compound and the body of the brick, without concentrating on the interface and without causing its destruction and detachment when drying.

scholarly journals Energetic constraints on an early developmental stage: a comparative view

2007 ◽  
Vol 4 (1) ◽  
pp. 123-126 ◽  
Author(s):  
James F Gillooly ◽  
Gustavo A Londoño ◽  
Andrew P Allen
Keyword(s):  
Metabolic Rate ◽  
Developmental Stage ◽  
Developmental Stages ◽  
The Body ◽  
Early Developmental Stage ◽  
Time Required ◽  
Taxonomic Groups ◽  
Relationship Of ◽  
The Relationship ◽  
Early Developmental

Biologists have long sought a means by which to quantify similarities and differences in embryonic development across species. Here we present a quantitative approach for predicting the timing of developmental events based on principles of allometry and biochemical kinetics. Data from diverse oviparous species support model predictions that most variation in the time required to reach one early developmental stage—the time to first heartbeat—is explained by the body size and temperature dependence of metabolic rate. Furthermore, comparisons of this stage with later developmental stages suggest that, after correcting for size and temperature, the relationship of metabolic rate to the rate of embryogenesis is approximately invariant across taxonomic groups and stages of ontogeny.

scholarly journals Effects of polybrominated diphenyl ethers on thyroid hormone, neurodevelopment and fertility in rodents and humans

2013 ◽  
Vol 26 (4) ◽  
Author(s):  
Marta Czerska ◽  
Marek Zieliński ◽  
Joanna Kamińska ◽  
Danuta Ligocka
Keyword(s):  
Thyroid Hormone ◽  
Polybrominated Diphenyl Ethers ◽  
Flame Retardants ◽  
Experimental Studies ◽  
Reproductive Organs ◽  
Consumer Products ◽  
Psychomotor Development ◽  
Human Breast Milk ◽  
Postnatal Exposure ◽  
Diphenyl Ethers

AbstractPolybrominated diphenyl ethers (PBDEs) are used as flame retardants. Due to their widespread use in many consumer products, PBDEs can be found in food as well as in the environment. Their presence has also been found in the human serum, human adipose tissue and human breast milk. Results of experimental studies suggest that the presence of PBDE in the environment is not neutral to our health. In rats and mice exposed to PBDE disturbances in thyroid hormone homeostasis and reproductive system such as changes in reproductive organs weight and disorders in sperm motility and motion were found. In rodents, pre- and postnatal exposure to PBDE can cause neurobehavioral effects. Also in humans disturbances in thyroid hormone system, weight of reproductive organs and concentrations of sex hormones associated with PBDEs serum concentrations were found. Exposure to PBDEs during pregnancy may lead to slower mental and psychomotor development in infants. In this paper the results of previous animal and human studies are reviewed.

scholarly journals Brominated Flame Retardants in the Environment: their Sources and Effects (A Review)

2006 ◽  
Vol 75 (4) ◽  
pp. 587-599 ◽  
Author(s):  
P. Mikula ◽  
Z. Svobodová
Keyword(s):  
Polybrominated Diphenyl Ethers ◽  
Hormonal Regulation ◽  
Flame Retardants ◽  
Brominated Flame Retardants ◽  
Toxic Effects ◽  
Potential Health ◽  
Diphenyl Ethers ◽  
Industrial Use ◽  
Living Organisms

Brominated flame retardants (BFRs) are organic substances frequently used in many industries. The most important group within BFRs are polybrominated diphenyl ethers (PBDEs). Because they persist in the environment, accumulate in food chains and have toxic effects, they are a potential health risk both for animals and humans. Polybrominated diphenyl ethers may disrupt processes of hormonal regulation in living organisms by reducing thyroxine concentrations in the plasma of the exposed individuals. In vitro studies have demonstrated the ability of these substances to bind to estrogen and androgen receptors. Tests on rodents have also demonstrated neurotoxicity of some of the PBDEs. Although industrial use of PBDEs is now regulated to a large extent, PBDEs have already been detected in areas with no apparent industrial load, e.g. in Greenland. This article presents an overview of BFRs-related issues with a particular emphasis on PBDEs, describes toxic effects of those substances and their metabolism in living organisms, and discusses issues related to the incidence of PBDEs in the environment.

The Toxic Effects of Polybrominated Diphenyl Ethers on Rotifer Branchionus plicatilis

2013 ◽  
Vol 807-809 ◽  
pp. 385-391 ◽  
Author(s):  
Jing Zhang ◽  
You Wang ◽  
Xue Xi Tang ◽  
Kuan Fang
Keyword(s):  
Treatment Group ◽  
Life Span ◽  
Polybrominated Diphenyl Ethers ◽  
Brachionus Plicatilis ◽  
Toxic Effects ◽  
Oxygen Species ◽  
Treatment Groups ◽  
Diphenyl Ethers ◽  
All Treatment ◽  
Bde 209

In the current study, two of the most environmentally relevant Polybrominated diphenyl ethers (PBDEs) were individually evaluated for toxic effects on rotifer Brachionus plicatilis. The results showed that the life span declined significantly in all treatment groups (0.05mg/L, 0.1mg/L, 0.2mg/L BDE-47 and BDE-209) compared to the control, and BDE-47 caused significant decrease compared to BDE-209 at 0.2mg/L treatment group. Significant increases of intracellular levels of reactive oxygen species (ROS) occurred in all treatment groups except for 0.05mg/L BDE-209 treatment group compared to the control, and significant increases were observed in all BDE-47 treatment groups compared to the equivalent treatment groups of BDE-209. Meanwhile significant increases of intracellular calcium levels ([Ca2+]in) occurred in 0.1mg/L, 0.2mg/L BDE-47 and 0.2mg/L BDE-209 treatment groups compared to the control, and BDE-47 cause significant increase compared to BDE-209 at 0.2mg/L treatment group. The present study demonstrated that life span, ROS and Ca2+ were involved in PBDEs toxic effects, and toxicities of BDE-47 were higher than BDE-209. Otherwise, the toxic effects in both BDE-47 and BDE-209 were similar, which suggest that the toxic effects of two PBDEs congeners may be caused by the same toxic mechanism of action.

scholarly journals The choice of external morphological characters and developmental stages for tadpole-based anuran taxonomy: a case study in Rana (Sylvirana) nigrovittata (Blyth, 1855) (Amphibia, Anura, Ranidae)

2005 ◽  
Vol 74 (1-2) ◽  
pp. 61-76 ◽  
Author(s):  
S. Grosjean
Keyword(s):  
Developmental Stage ◽  
Developmental Stages ◽  
Model Organism ◽  
Morphological Characters ◽  
The Body ◽  
Morphometric Character ◽  
Morphometric Characters ◽  
Stage Of Development ◽  
Character Variation ◽  
Interspecific Comparisons

The morphology of tadpoles has long received too little attention in taxonomic and phylogenetic contexts, beyond the use of Orton’s general tadpole types, despite the potential of larval characters for resolving problems in systematics. A possible explanation for this neglect is the ontogenetic variation of external morphology. In order to understand the value of larval characters in taxonomy and systematics, it is necessary to determine the developmental stage at which characters reach their definitive size, form and colour before meaningful comparisons can be made within and between species. Here I use the tadpole of Rana (Sylvirana) nigrovittata as a model organism to assess ontogenetic character variation. Morphometric measurements were taken, and external oral and internal buccal characters were assessed separately for each developmental stage from 26 to 38. Coefficients of variation were calculated for each morphometric character at each stage of development to test the character’s efficiency in reflecting the morphology of the tadpole. Most morphometric characters taken from the body described the shape of the animal well and varied little among individuals, whereas those taken from the tail were less reliable and those of the oral disk were quite variable due to contraction during fixation. A developmental 'climax' for most characters was reached by specimens between stages 32-40, indicating that they are best suited for morphological intra- and interspecific comparisons.

The selection of experimental doses and their importance for parasite success in metacercarial infection studies

Parasitology ◽  
2009 ◽  
Vol 137 (5) ◽  
pp. 889-898 ◽  
Author(s):  
R. POULIN
Keyword(s):  
Body Mass ◽  
Definitive Host ◽  
Experimental Studies ◽  
The Body ◽  
Parasite Transmission ◽  
Intermediate Hosts ◽  
Dose Dependent ◽  
Dose Dependent Effect ◽  
Selection Of ◽  
Host Body Mass

SUMMARYExperimental studies of parasite transmission are essential for advances in basic and applied parasitology. A survey of the results of published experiments can identify the determinants of both variation among studies in experimental design and of parasite infection success. Here, analyses are conducted on data compiled from a total of 106 metacercarial infection experiments (35 on Echinostomatidae, 37 on Fasciolidae, 34 on other trematodes) obtained from 83 studies. All of these involved experimental oral infection of individual definitive hosts by a single known dose of metacercariae under controlled conditions. Across these studies, the metacercarial dose used (i) was typically about 10 times higher than the average natural dose that could be acquired by feeding on intermediate hosts (for taxa other than Fasciolidae), and (ii) showed a positive relationship with the body mass of the definitive host, although this relationship was only significant for Fasciolidae. Although the chosen dose was rarely justified, the larger the definitive host, the more metacercariae it received. Among Echinostomatidae and Fasciolidae, there was also a significant dose-dependent effect on infection success: the higher the dose used in an experiment, the smaller the proportion of metacercariae recovered from the host. This effect was mitigated by definitive host body mass, with infection success being generally lower in larger definitive hosts. For Echinostomatidae, the taxonomic identity of the definitive host also mattered, with metacercariae achieving higher infection success in mammals than in birds. The present findings suggest that the design of experimental infection studies requires greater consideration if their results are to yield useful biological insights.

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