Mirna Velki

Mirna Velki
University of Osijek | UNIOS · Department of Biology

PhD

About

76
Publications
16,435
Reads
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1,893
Citations
Additional affiliations
March 2010 - July 2010
The Czech Academy of Sciences
February 2017 - February 2017
University of Osijek
Position
  • Professor (Assistant)
October 2015 - June 2016
RWTH Aachen University
Position
  • PostDoc Position

Publications

Publications (76)
Article
The present study assessed Cybister lateralimarginalis as a model species for ecotoxicological studies of metal(loid) bioaccumulation in freshwater ecosystems, by optimizing protocols and analysing biomarker activities and metal(loid) concentrations from different sites and investigating their association. To accomplish this, levels of arsenic (As)...
Poster
Full-text available
This research presents a review of the most significant literature describing the Great Cormorant as a suitable model species for monitoring heavy metal bioaccumulation in specific areas. Additionally, this review serves as an introduction to the establishment of monitoring programs for heavy metal bioaccumulation in Great Cormorants in Kopački rit...
Poster
Full-text available
Avian apex predators have proved to be relevant bioindicators for various pollutants. Due to the rapid accumulation of pollutants – heavy metals in the freshwater ecosystem and the sediment, waterbirds are particularly at risk. For that reason, the present study analysed heavy metals cadmium (Cd), mercury (Hg) and lead (Pb) in the blood of the Grea...
Presentation
Fish, as vertebrates, occupy the highest trophic levels within freshwater ecosystems. Their feeding habits impact the accumulation of pollutants in their tissue; therefore, the change in physiological responses reflects the levels of ecosystem pollution. The biggest sources of pollution in freshwater systems are harmful leachates from agricultural...
Article
Full-text available
Chemical pollution resulting from pesticide usage has been a continuous issue since the 1960s, despite comprehensive European Union legislation designed to safeguard human health and the environment from the adverse effects of pesticides. While regulatory risk assessments primarily focus on the active ingredients, recent research indicates ecotoxic...
Article
Grape production is seriously impacted by pests and diseases worldwide. Most producers rely heavily on the application of chemical pesticides to control pests and diseases of grapes and grapevines. With increasing rates of fungicide use, active ingredients may decrease in efficacy or become inefficacious due to the emergence of resistance in the or...
Article
Biofortification aims to increase selenium (Se) concentration and bioavailability in edible parts of crops such as wheat (Triticum aestivum L.), resulting in increased concentration of Se in plants and/or soil. Higher Se concentrations can disturb protein structure and consequently influence glutathione (GSH) metabolism in plants which can affect a...
Poster
Full-text available
White-tailed eagles (Haliaeetus albicilla) is an apex predator, with high trophic position accumulating high concentrations of pollutants throughout their life. Their dietary habits depend on the available prey within their territories and consist mainly of fish, birds, mammals and carrion. White-tailed eagles are territorial, i.e., are resident wi...
Poster
Full-text available
Freshwater ecosystem pollution, primarily from human activities releasing pollutants e.g., pesticides, fertilizers, microplastics, and heavy metals, is a major environmental concern. This pollution may lead to physiological stress subsequently reducing biodiversity. In the present study, conducted in Pannonian Croatia during the 2023 spring–summer...
Article
Full-text available
The goal of the present study was to investigate differences in biomarker responses related to metal(loid)s in white stork Ciconia ciconia) nestling's blood from continental Croatia. To achieve this, a battery of biomarkers that can be affected by environmental pollutants, including metal(loid)s, was assessed (esterase activity, fluorescence-based...
Article
Full-text available
The present study assessed the effect of agricultural practices on biomarker response in white stork (Ciconia ciconia) nestlings from continental Croatia. During the breeding season of 2022, blood was sampled (n = 54) from the landfill Jakuševec and the agricultural areas Baranja and Srijem. Different patterns of biomarker response in regard to the...
Article
Full-text available
Earthworms are key organisms of the soil ecosystem and bioindicators for soil quality. While pesticides are used for the improvement of crop yields, they also present a burden for soil organisms. To understand the complex effects of pesticides on soil organisms, it is important to test these effects in soil exposures to include influences of the so...
Article
Full-text available
The constant increase in the intensity of agricultural production simultaneously increases the risk of negative effects of long-term agricultural practices. By-products of agricultural, forestry, and food production, as well as other types of organic waste, can be used as raw materials in the production of organic fertilizers and substrates for see...
Poster
Full-text available
The present research provides data on the concentrations of metals: lead (Pb), mercury (Hg), cadmium (Cd), and metalloids: arsenic (As), selenium (Se) in the blood of white stork (Ciconia ciconia) nestlings. Blood was sampled (n = 106) during breeding season 2021 in continental Croatia on seven locations: Jakuševec, Lonjsko polje, Crnac polje, Jela...
Poster
Full-text available
Apex bird species, e.g. white stork (Ciconia ciconia), are non-target organisms to pollutant exposure in environments such as wetlands, agricultural ponds, or landfills. Their health status is influenced by their dietary habits, and their body content reflects pollutant levels in the food they forage in the vicinity of the breeding area. In season...
Poster
Composting or vermicomposting of organic residues from agricultural, food-industry, forestry and communal activities can result in products with diff erent degrees of maturity and phytotoxicity. Phytotoxicity due to the presence of organic acids, ammonium form of N, phenols, salts or heavy metals may be consequences of the raw materials properties...
Poster
The constant increase in the intensity of agricultural production, the potentially negative eff ect of intensive mineral fertilization on the environment, the need to manage organic by-products and conserve natural resources, undoubtedly lead to more intensive use of organic fertilizers and substrates. By-products of agricultural, forestry and food...
Article
Microplastics are small plastic fragments that are widely distributed in marine and terrestrial environments. While the soil ecosystem represents a large reservoir for plastic, research so far has focused mainly on the impact on aquatic ecosystems and there is a lack of information on the potentially adverse effects of microplastics on soil biota....
Poster
Full-text available
The white stork (Ciconia ciconia) is an abundant breeding species in continental Croatia, a top predator inhabiting mostly agricultural fields, wetlands, and meadows. White stork nestlings are a good bioindicator species providing information regarding the local environment. Due to environmental transformation and intensive agriculture, white stork...
Article
Full-text available
White stork nestlings can provide quantitative data on the quality of the environment, as they are dependent on their parents that provide locally foraged food. Blood was sampled from the brachial vein (n = 109) and the sampling was performed in parallel with ringing during breeding season 2020 from five areas in eastern Croatia: Lonjsko polje, Jel...
Article
Full-text available
Background The environmental impact of pesticides has been an increasingly discussed issue over the last decades. Constant usage of pesticides presents a burden for soil and causes a decrease in its health, including the negative effects on earthworms which are indicators for soil quality. The objective of this research was the assessment of the ef...
Article
Vitis vinifera (grapevines) can form mutualistic associations with endophytic fungi. However, to date, there is not much information on the influence of endophytic Fusarium isolates on grapevine growth, oenological characteristics or their capabilities to suppress disease. In the present study, it was demonstrated on two grapevine varieties, in a f...
Article
Full-text available
The functioning of soil ecosystems greatly depends on the interactions occurring between soil biota communities. It is well known that earthworms are an important soil component that substantially affects its function, including their meaningful impact on the development of different phytopathogenic soil fungi. Phytopathogenic fungi are responsible...
Poster
Full-text available
Enzyme activities are extensively used biomarkers to assess the response of organisms to various chemicals from the environment. Biomarkers of effect could be used for providing crucial information and identifying harmful effects on non-target avian organisms such as white stork (Ciconia ciconia). Since white stork is an altricial species, the nest...
Article
Full-text available
Industrialization and urbanization have led to an increased accumulation of waste materials that are transformed into a nutrient-rich and high-quality product called vermicompost by the vermicomposting process. Vermicomposting is an ecofriendly and economically favorable biotechnological process that involves the interaction of earthworms and micro...
Article
The assessment of the exposure of aquatic wildlife to complex environmental mixtures of chemicals originating from both point and diffuse sources and evaluating the potential impact thereof constitutes a significant step towards mitigating toxic pressure and the improvement of ecological status. In the current proof-of-concept study, we demonstrate...
Article
Full-text available
White stork (Ciconia ciconia) nestlings can provide quantitative information on the quality of the surrounding environment by indicating the presence of pollutants, as they depend on locally foraged food. This study represents the first comparison of biomarkers in two fractions of white stork nestling blood: plasma and S9 (the post-mitochondrial fr...
Poster
Full-text available
The white stork (Ciconia ciconia) is a breeding species in continental Croatia. It feeds usually close to the breeding site with small mammals, amphibians, snakes, fish, earthworms, large insects and their larvae in the flooded river plains, extensively farmed meadows and pastures or water meadows. White stork nestlings can provide quantitative inf...
Article
This study presents a high-throughput (HTP) micronucleus assay in multi-well plates with an automated evaluation for risk assessment applications. The evaluation of genotoxicity via the micronucleus assays according to international guidelines ISO 21427-2 with Chinese hamster (Cricetulus griseus) V79 cells was the starting point to develop our meth...
Article
The aim of this research was to determine the effect of nine essential oils from the Croatian native flora (Mentha x piperita, Salvia officinalis, Rosmarinus officinalis, Lavandula hybrida, Origanum compactum, Thymus vulgaris, Hiperici oleum, Achillea millefolium and Helichrysum italicum) on the Botrytis cinerea mycelial growth suppression. The res...
Article
Metabolism has to be considered during the toxicological assessment of chemical and environmental samples because it is an important process in the mammalian liver. It can be assessed in vitro via liver homogenates called S9-fractions, an external metabolic activation system. However, the external metabolic activation systems can vary greatly in th...
Article
Full-text available
This study represents the first analysis of heavy metals: lead and cadmium, as well as two metalloids: arsenic and selenium, in the feathers of Grey Herons breeding in Croatia. The Grey Heron was chosen as a model apex predator of the wetland ecosystem due to high trophic level, feeding habits, long lifespan and abundance. Sampling was conducted du...
Poster
Full-text available
Apex predators, especially aquatic bird species, are proven to be relevant biomonitors for various xenobiotics, such as heavy metals due to their abundance, position in the food chain, and chemical exposure through diet. Considering all this, in the present study Grey Heron (Ardea cinerea) was chosen as a model apex predator of the wetland ecosyste...
Chapter
Sediments are a major issue for many scientists and authorities due to their close linkage to the aquatic food web and their potential to accumulate pollutants. In the present chapter, the method of exposure of zebrafish embryos to native sediment samples is described. Such exposure provides an ecologically highly relevant and realistic scenario wh...
Article
Earthworms are often used as model organisms in ecotoxicological research because of their natural habitat where they can be exposed to many different pollutants, including pesticides. Since a number of them has to be sacrificed for sample collection, it would be useful to develop non-invasive methods and techniques suitable for the analysis of tar...
Article
Full-text available
Massive toxic blooms of cyanobacteria represent a major threat to water supplies worldwide. Here, the biological activities of lipopolysaccharide (LPS) isolated from Microcystis aeruginosa, the most prominent cyanobacteria in water bloom, were studied. LPS was isolated from complex environmental water bloom samples dominated by M. aeruginosa, and f...
Article
Hydroxylation of polyaromatic compounds through cytochromes P450 (CYPs) is known to result in potentially estrogenic transformation products. Recently, there has been an increasing awareness of the importance of alternative pathways such as aldehyde oxidases (AOX) or N-methyltransferases (NMT) in bioactivation of small molecules, particularly N-het...
Article
Full-text available
Investigations of deleterious effects on non-target species, including earthworms, have been conducted for a number of pesticides, but there is a need for additional assessments of potential adverse effects. In the present study, the acute toxicity of eight pesticides to the earthworm Eisenia andrei was assessed and compared. The exposures were con...
Article
Full-text available
Background Zebrafish have been increasingly used for monitoring and assessing the effects of different contaminants in the aquatic environments. In the present study, zebrafish embryos and larvae were used to study the effects of the insecticide diazinon and the herbicide diuron in regard to occurrence of oxidative stress-related cellular responses...
Article
Selenium (Se) is an essential element for humans, animals, and certain lower plants, but can be toxic at high concentration. Even though Se is potentially toxic, little information is available about the effects of Se on soil animals. The aim of this study was to assess the impact of different concentrations of two Se forms, selenate and selenite,...
Presentation
The present study highlights the relevance of the assessment of soluble metal levels in gammarid tissue and its implementation as an early indicator of metal exposure in the freshwater habitats. Physico-chemical water properties in the Sutla River, an industrially/agriculturally influenced catchment in North-Western Croatia, indicated a disturbed e...
Article
The usage of pesticides has been steadily increasing over the last decades, and among them herbicides are the most commonly used ones. Despite their main mode of action targeting plant organisms, they can also have adverse effects on non-target animal organisms. In soil ecosystems, earthworms play an important role due to their positive impacts on...
Article
The modes of action of pollutants are diverse, and a common consequences to pollutant exposure is oxidative stress. This phenomenon is caused by an imbalance or disurption in the control of Reactive Oxygen Species (ROS) resulting in an accumulation of free radicals. Oxidative stress may cause damages to the DNA, phospholipids and proteins, and lead...
Article
The zebrafish as a test organism enables the investigation of effects on a wide range of biological levels from molecular level to the whole-organism level. The use of fish embryos represents an attractive model for studies aimed at understanding toxic mechanisms and the environmental risk assessment of chemicals. In the present study, a zebrafish...
Chapter
Considering the importance of the soil in the food production and constant input of diverse chemicals (from industrial activities, urban waste, agrochemicals) that present serious threat to soil quality, there is a growing concern regarding the soil pollution and the adverse effects on soil ecosystems. Earthworms are naturally in contact with the s...
Article
The use of zebrafish for aquatic vertebrate (eco)toxicity testing allows the assessment of effects on a wide range of biological levels – from enzymes to sensory organs and behavioral endpoints. The present study investigated the effects of the insecticide diazinon and the herbicide diuron regarding the acute toxicity and behavior of zebrafish embr...
Article
Selenium (Se) is an essential micronutrient for humans, animals, and certain lower plants, but at higher concentrations Se becomes toxic to organisms. The boundary between the Se beneficial effect and its toxicity is narrow and depends on its chemical form, applied concentration, and other environmentally regulating factors. Due to the potential ri...
Article
This study investigated the direct and indirect toxic effects of microplastics and nanoplastics toward zebrafish (Danio rerio) larvae locomotor activity. Results showed that microplastics alone exhibited no significant effects except for the upregulated zfrho visual gene expression; whereas nanoplastics inhibited the larval locomotion by 22% during...
Chapter
The importance and beneficial effects of earthworms on soil structure and quality is well-established. In addition, earthworms have proved to be important model organisms for investigation of pollutant effects on soil ecosystems. In ecotoxicological investigations effects of various pollutants on earthworms were assessed. But some important issues...
Chapter
Full-text available
Several studies showed that insect endocrine system, especially anti-stress neuropeptides, could be used as a potential target for the pest control. The main role of those neuropeptides is to eliminate or at least to reduce the impact of various stressors on insect organism. This defense response is primarily operated by neurohormones from adipokin...
Article
Full-text available
The present study investigated effects of different river flow rates on basal activities of selected biomarkers and the occurrence of oxidative stress in the common carp (Cyprinus carpio). Juvenile carp were exposed to different river flow rates (5–120 cm/s) by caging for 3 weeks. After this period, one half of the fish were sacrificed and used for...
Article
Tribolium castaneum, the red flour beetle, is one of the major pests of cereal grains and their products. Infestation of raw food products by T. castaneum can be tackled by use of insecticides which offer a rapid and effective control method for different insect pests. In the present study, toxicity and repellency of three widely used insecticides...
Article
Full-text available
Earthworms from different ecological categories—epigeic Eisenia andrei and Lumbricus rubellus, endogeic Octolasion lacteum and anecic Lumbricus terrestris—were exposed in a microcosmic system to three commonly used insecticides. The effects of the insecticides were evaluated by measuring the following molecular biomarkers—the activities of AChE, CE...
Article
Full-text available
In many studies that investigate the toxic effects of pollutants on earthworms, experiments are performed using only one species of earthworms, most commonly the Eisenia species. However, the differences in sensitivities of different earthworm species could potentially lead to an underestimation of environmental aspects of pollutants. Therefore, th...
Article
Full-text available
Acetylcholinesterase, glutathione-S-transferase and catalase activities were determined in earthworms Eisenia andrei exposed to insecticides (endosulfan, temephos, malathion, pirimiphos-methyl) alone and in a binary combination with the herbicide metolachlor. Metolachlor individually was not acutely toxic, even at high concentrations applied; howev...
Article
The effects of two widely used insecticides - organophosphate pirimiphos-methyl and pyrethroid deltamethrin - were investigated under laboratory conditions following OECD guidelines using the epigeic earthworm Eisenia andrei as the test organism. The overall aim of this study was to evaluate the effects of these pesticides on molecular biomarkers o...
Article
Full-text available
This study examined the impact of oxidative stress indicated by thiobarbituric acid reactive substances (TBARS) and protein carbonyl (PC), induced by intensive exercise and cadmium chloride (CdCl2) on ethoxyresorufin-O-deethylase (EROD) activity in juvenile carp (Cyprinus carpio). In the first experiment, fish were divided into three groups: (1) co...
Article
Efflux pumps are transport proteins involved in the extrusion of toxic substrates from cells to the external environment. Activities of efflux pumps have been found in many organisms, however such activity has not been evidenced in earthworms. Adult Eisenia andrei earthworms were exposed to efflux modulators - verapamil (a known inhibitor of efflux...
Article
Adipokinetic hormones (AKHs) are insect neuropeptides responding to stress situations including oxidative stress. Two insecticides - endosulfan and malathion - were used to elicit oxidative stress conditions in the firebug Pyrrhocoris apterus, and the physiological functions of AKHs and their ability to activate protective antioxidative reactions w...

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