Antagonistic effects of seawalls and urban sedimentation on epilithic algal matrix (EAM)-feeding fishes

2021 ◽  
Vol 173 ◽  
pp. 113098
Author(s):  
Dillen Ng ◽  
Daisuke Taira ◽  
Eliza C. Heery ◽  
Peter A. Todd
2007 ◽  
Vol 40 (05) ◽  
Author(s):  
C Schüle ◽  
AK Schmidt ◽  
TC Baghai ◽  
D Eser ◽  
S Wenninger ◽  
...  

Author(s):  
N. A. Ilyushina ◽  
Yu. A. Revazova

In order to overcome resistance to individual pesticides and improve their effectiveness, formulations containing two or more active substances are constantly being developed and put on the market over recent years. Mixtures of residual amounts of pesticides can be present in water and food and enter the human and animal bodies. However, the combined effect of pesticides on living organisms, including genetic structures in cells, has not been studied enough and it is not yet possible to predict the genotoxic effects of their mixtures based on available data. The purpose of this review was to collect and summarize literature information on the genotoxicity of pesticide combinations obtained at different objects. The results of studies conducted in different countries of the world are discussed, examples of detected synergistic, additive and antagonistic effects are given, indicating the need for testing the genotoxicity of preparative forms of pesticides containing several active substances, as well as mixtures of jointly used pesticides in order to ensure the safe use of pesticides for public health.


2018 ◽  
Vol 68 (12) ◽  
pp. 2747-2751
Author(s):  
Marioara Nicula ◽  
Nicolae Pacala ◽  
Lavinia Stef ◽  
Ioan Pet ◽  
Dorel Dronca ◽  
...  

Living organisms take nutrients from the environment, and together with them, substances with toxic potential � such as heavy metals. Lead is one common metal pollutant especially in aquatic environment, from where the fish can be intoxicated very easily. Bioavailability, distribution, toxic action, synergistic and antagonistic effects are characteristics which can alter the fish health. Our experimental study followed the effects of lead overload in water on iron distribution, in different tissues sample Carassius gibelio Bloch fish. We performed the experiment in four different fish groups: control C; lead � Pb (administration of lead in water 0.075mg/mL of water, as Pb(NO3)2 x � H2O); lead (the same dose) and 2% of freeze-dry garlic incorporated into fishes� food � Pb+garlic; lead (the same dose) and 2% chlorella incorporated into fishes� food � Pb+chlorella, for 21 consecutive days. The iron concentration was analysed with AAS (Atomic Absorption Spectroscopy) from gills, muscle, skin (and scales), intestine, liver, heart, brain, ovary, testicles, and kidney. The obtained data presented a significantly decrease of iron content in all tested tissue samples that demonstrated, alteration of iron homeostasis, explained by a strong antagonistic effect of lead on iron. Our experiment showed that biologic active principles from garlic and chlorella act like natural protectors, and potentiate the iron deficiency even in the case of lead overload in aquatic environment, for fish.


2012 ◽  
Vol 9 (4) ◽  
pp. 1746-1752 ◽  
Author(s):  
J. Wilson Sahayaraj ◽  
A. John Amalraj ◽  
Susai Rajendran ◽  
N. Vijaya

The inhibition efficiency (IE) of sodium molybdate (SM) in controlling corrosion of carbon steel in an aqueous solution containing 120 ppm of Cl-, in the absence and presence of Zn2+has been evaluated by weight-loss method. A synergistic effect exists between SM and Zn2+when the concentration of Zn2+is 25 ppm and above. Inhibition efficiencies obtained are greater than 85%. Antagonistic effect exists between SM and Zn2+when the concentration of Zn2+is 10 ppm and below. The SM-Zn2+system shows excellent IE up to third day. Above third day IE decreases. Acceleration of corrosion takes place. Excellent IE is shown at pH 5,7 and 12. At pH 9, IE decreases since Zn2+is precipitated as Zn(OH)2in the bulk of the solution. Polarization study reveals that SM-Zn2+system functions as a mixed inhibitor. FTIR spectra reveal that the protective film consists of Fe2+-SM complex and Zn(OH)2.


Author(s):  
Richard P Meisel

Abstract In species with polygenic sex determination, multiple male- and female-determining loci on different proto-sex chromosomes segregate as polymorphisms within populations. The extent to which these polymorphisms are at stable equilibria is not yet resolved. Previous work demonstrated that polygenic sex determination is most likely to be maintained as a stable polymorphism when the proto-sex chromosomes have opposite (sexually antagonistic) fitness effects in males and females. However, these models usually consider polygenic sex determination systems with only two proto-sex chromosomes, or they do not broadly consider the dominance of the alleles under selection. To address these shortcomings, I used forward population genetic simulations to identify selection pressures that can maintain polygenic sex determination under different dominance scenarios in a system with more than two proto-sex chromosomes (modeled after the house fly). I found that overdominant fitness effects of male-determining proto-Y chromosomes are more likely to maintain polygenic sex determination than dominant, recessive, or additive fitness effects. The overdominant fitness effects that maintain polygenic sex determination tend to have proto-Y chromosomes with sexually antagonistic effects (male-beneficial and female-detrimental). In contrast, dominant fitness effects that maintain polygenic sex determination tend to have sexually antagonistic multi-chromosomal genotypes, but the individual proto-sex chromosomes do not have sexually antagonistic effects. These results demonstrate that sexual antagonism can be an emergent property of the multi-chromosome genotype without individual sexually antagonistic chromosomes. My results further illustrate how the dominance of fitness effects has consequences for both the likelihood that polygenic sex determination will be maintained as well as the role sexually antagonistic selection is expected to play in maintaining the polymorphism.


1997 ◽  
Vol 109 (2) ◽  
pp. 158-162 ◽  
Author(s):  
Hervé Serpier ◽  
Philippe Gillery ◽  
Véronique Salmon-Ehr ◽  
Roselyne Garnotel ◽  
Nadine Georges ◽  
...  

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