The repeatability of avian egg ejection behaviors across different temporal scales,breeding stages,female ages and experiences

An evolutionarily fundamental, yet rarely examined, aspect of host–parasite arms races is the repeatability of individual host responses to parasitism. We examined the repeatability of egg ejection, and the latency to eject, across a time-scale of days (within one breeding attempt), weeks and months (between breeding attempts within one breeding season), and years (across different breeding seasons). The ejection of non-mimetic model eggs by European blackbirds, Turdus merula, showed overall high repeatability (r?~?0.70) and, similar to empirical patterns on most other behavioral traits already studied, showed decreasing repeatability with time. In contrast, latency to ejection showed negligible repeatability overall (r ~0.20) and did not change with time. Ejection rates, latencies to ejection and the repeatability of egg ejection did not differ between young and old females. Previous experience with experimentation (number of model eggs the female received before the focal trial) marginally non-significantly covaried with egg ejection (positively) and with latency to egg ejection (negatively). Repeatability estimates for both egg ejection and latency to egg ejection at the within one breeding attempt time-scale did not statistically differ from those reported in a previous study of a different blackbird population (introduced population in New Zealand). To our knowledge, this is the first comparison of behavioral repeatability between a native vs. introduced population of any animal species.     

Dust from Zambian smelters: mineralogy and contaminant bioaccessibility

Metal smelting is often responsible for local contamination of environmental compartments. Dust materials escaping from the smelting facilities not only settle in the soil, but can also have direct effects on populations living close to these operations (by ingestion or inhalation). In this particular study, we investigate dusts from Cu–Co metal smelters in the Zambian Copperbelt, using a combination of mineralogical techniques (XRD, SEM/EDS, and TEM/EDS), in order to understand the solid speciation of the contaminants, as well as their bioaccessibility using in vitro tests in simulated gastric and lung fluids to assess the exposure risk for humans. The leaching of metals was mainly dependent on the contaminant mineralogy. Based on our results, a potential risk can be recognized, particularly from ingestion of the dust, with bioaccessible fractions ranging from 21 to 89 % of the total contaminant concentrations. In contrast, relatively low bioaccessible fractions were observed for simulated lung fluid extracts, with values ranging from 0.01 % (Pb) up to 16.5 % (Co) of total contaminant concentrations. Daily intakes via oral exposure, calculated for an adult (70 kg, ingestion rate 50 mg dust per day), slightly exceeded the tolerable daily intake limits for Co (1.66× for fly ash and 1.19× for slag dust) and occasionally also for Pb (1.49×, fly ash) and As (1.64×, electrostatic precipitator dust). Cobalt has been suggested as the most important pollutant, and the direct pathways of the population’s exposures to dust particles in the industrial parts of the Zambian Copperbelt should be further studied in interdisciplinary investigations.     

Metal contamination recorded in the sediment of the semi-closed Bakar Bay (Croatia)

This study presents metal levels in the sediments of the Bakar Bay, with its main goal to evaluate recent anthropogenic influence, as well as over previous decades. Sediment profiles at 7 sampling points were taken. Chemical contents in bulk sediment were obtained using ICP, ICP-MS, and AAS methodologies, and 20 most significant elements were presented. Concentrations of selected elements were evaluated by factor statistical analyses to identify their source. Also, metal enrichment factor and geoaccumulation index were calculated, and spatial distribution maps for three sediment layers were constructed. Measured metal concentrations in sediment were compared with concentrations in other sediments from the Adriatic Sea. In addition, a set of sediment quality guidelines were also applied in order to predict the probability of adverse biological effects on the benthic community: This was found not to be very serious. Factor analysis clearly demonstrates the segregation between metals of natural origin resulted from soil and bedrock weathering (Li, Al, Cr, Sc), and with two anthropogenic sources originating from the city of Bakar and bulk cargo terminal (Hg, Pb, Zn, Ag, Sn, and Fe). Mercury (max 0.65 μg g^?1) is found to be the heaviest contaminant, followed by lead (max 71.5 μg g^?1), copper (89.3 μg g^?1), and zinc (156 μg g^?1). However, this study shows that Bakar Bay is considerably less polluted with toxic metals than it was believed.     

Metals in the sediment and liver of four fish species from different trophic levels in Tisza River,Serbia

In aquatic environments metals originate from various natural and anthropogenic sources. The degree of contamination in fish tissues depends on the pollutant, fish species, their mode of feeding, sampling site and trophic level. This study presents concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr and Zn in sediment and liver of four ecologically different fish species: piscivorous northern pike (Esox lucius L.), benthivorous sterlet (Acipenser ruthenus L.) and silver bream (Brama brama L.), and omnivorous common carp (Cyprinus carpio L.). Fish were caught at four sites along the stretch of the River Tisza in Serbia during October 2010. The concentrations of metals have been assessed using the inductively coupled plasma – optical emission spectrometry. Results revealed that metals with the highest values in sediment and fish samples were Al and Fe, respectively and sometimes concentrations of Zn are in the same order of magnitude as Fe concentrations. The highest concentration of metals was recorded in omnivorous common carp.     

Role of the vitamin E model compound Trolox in the prevention of Cr(VI)-induced cellular damage

Given the wide industrial use of chromium (Cr) and its environmental contamination, chromium represents a risk to humans exposed to the metal. Considering that Cr(VI) is a potent oxidizing agent that increases intracellular oxidation and DNA damage, it would be worth considering the pretreatment of cells with antioxidants as a means of preventing Cr(VI)-induced toxicity. The objective of this study was to pretreat yeast cells with the water-soluble vitamin E analogue Trolox in an effort to increase cell tolerance against reactive chromium and reactive oxygen species formed during Cr(VI) reduction. Results revealed a decrease in Cr(VI)-induced cytotoxicity and mitotic gene conversions in Trolox-pretreated cells. The protective effect of Trolox in Cr(VI) induced genotoxicity was confirmed also with the prokaryotic Salmonella typhimurium SOS/umu test. Pretreatment of cells with Trolox (1) increased total Cr bioaccumulation, (2) decreased Cr(VI)-induced intracellular oxidation, (3) decreased Cr(V) persistence and (4) increased OH^? formation in yeast extracts. These findings might be useful in directing future investigations concerning the use of Trolox as a human antioxidant supplement, and in clinical applications related to Cr-induced genotoxicity in occupational and environmental situations where chromium is a problem.     

Microbiological and mycotoxicological contamination in Slovenian primary grain production

This study was aimed at investigating the contamination of grains, which are grown and used for animal diets by Slovene farmers. A total of 107 samples were examined for mesofilic aerobic molds and yeasts. The leading contaminants among molds were from Fusarium spp., detected in 73 samples, mostly in maize (50). In accordance with the European Feed Microbiology Organisation criteria, 68% of all tested samples were of the quality level I, with normal microbiological flora, and 9% of samples were estimated as quality level IV and not suitable for animal feed. Using liquid and gas chromatography methods, the presence of various mycotoxins (expressed as 12% of moisture content) was found in 77% of all samples; mostly deoxynivalenol (71%) in concentration of 150–14,420 µg kg^?1, followed by zearalenone (32%, 20–640 µg kg^?1), fumonisin B1 (31%, 10–4863 µg kg^?1), fumonisin B2 (22%, 10–1629 µg kg^?1), while HT-2 and T-2 toxins were found in low concentration in two samples, and aflatoxin B1 and ochratoxin A in one sample. By statistical evaluation, significant positive correlations were noted between the presence of deoxynivalenol and zearalenone as well as between fumonisin B1 and B2.     

Urinary level of homovanillic acid and mercury in autistic children

Catecholamines and their metabolites affect children's nervous system. Dopamine is an important neurotransmitter in the brain. In the routine analysis for diagnostics of diseases, the dopamine metabolite homovanillic acid (HVA) is determined. Mercury is a neurotoxic agent and can cause different undesirable effects on the brain. In the present work a putative correlation between HVA, the main metabolite of dopamine, and mercury in urine of healthy and autistic children was studied. The level of HVA was higher in the urine of autistic children (14.5 ± 8.3 mg L^?1) compared to generally healthy children (4.4 ± 0.5 mg L^?1). The level of mercury in the urine of autistic children was lower (0.36 ± 0.24 µg L^?1) than in the urine of healthy children (2.1 ± 1.0 µg L^?1) showing that there is no correlation between HVA and mercury.     

Environmental human silver exposure

Environmental exposure to silver (Ag) was assessed in occupationally non-exposed adult human population by analyzing Ag in the hair (H?·?Ag) and whole blood (WB?·?Ag). H?·?Ag was analyzed in 311 (123 men, M; 188 women, W); while WB?·?Ag was determined in 235 of these individuals (90 M, 145 W). Women had more H?·?Ag than men (M 0.05 vs. W 0.076), whereas WB?·?Ag concentrations in men and women were not significantly different. A natural distribution of the median derivatives was utilized to generate the dataset to fit the logistic sigmoid curve to assess the current human body burden of environmental Ag population exposure for M and W separately. The H?·?Ag (µg?g^?1) below 0.0105 for M and 0.0145 for W, reflects low level of environmental Ag exposure. The adaptive physiological saturation phase followed where H?·?Ag rose rapidly, first for M and then for W in parallel with biological assay. Both parallel saturation curves converged and plateaued at 0.215 for M and 0.965 for W (µg?g^?1). The current level of human environmental Ag exposure is low, but cases of high Ag exposure occurred sporadically. In conjunction with the medical histories overt clinical neural toxicity may be expected for H?·?Ag at 4?µg?g^?1and higher. There were no significant correlation between the H?·?Ag and WB?·?Ag.     

Project tocoen. The fate of selected organic pollutants in the environment—iv. soil,earthworms and vegetation 1988

The samples of soils, earthworms and vegetation (needles, lichens, mosses) were collected for the realization of Project TOCOEN (Toxic Organic Compounds in the ENvironment). The samples were collected from three TOCOEN model areas in Czechoslovakia—one city and two rural areas. The samples were analyzed for polycyclic aromatic hydrocarbons (PAHs), chlorinated pesticides (C1‐PEST) and polychlorinated biphenyls (PCBs).     

Possible health impacts of naturally occurring uptake of aristolochic acids by maize and cucumber roots: links to the etiology of endemic (Balkan) nephropathy

Aristolochic acids (AAs) are nephrotoxic and carcinogenic derivatives found in several Aristolochia species. To date, the toxicity of AAs has been inferred only from the effects observed in patients suffering from a kidney disease called “aristolochic acid nephropathy” (AAN, formerly known as “Chinese herbs nephropathy”). More recently, the chronic poisoning with Aristolochia seeds has been considered to be the main cause of Balkan endemic nephropathy, another form of chronic renal failure resembling AAN. So far, it was assumed that AAs can enter the human food chain only through ethnobotanical use (intentional or accidental) of herbs containing self-produced AAs. We hypothesized that the roots of some crops growing in fields where Aristolochia species grew over several seasons may take up certain amounts of AAs from the soil, and thus become a secondary source of food poisoning. To verify this possibility, maize plant (Zea mays) and cucumber (Cucumis sativus) were used as a model to substantiate the possible significance of naturally occurring AAs’ root uptake in food chain contamination. This study showed that the roots of maize plant and cucumber are capable of absorbing AAs from nutrient solution, consequently producing strong peaks on ultraviolet HPLC chromatograms of plant extracts. This uptake resulted in even higher concentrations of AAs in the roots compared to the nutrient solutions. To further validate the measurement of AA content in the root material, we also measured their concentrations in nutrient solutions before and after the plant treatment. Decreased concentrations of both AAI and AAII were found in nutrient solutions after plant growth. During this short-term experiment, there were much lower concentrations of AAs in the leaves than in the roots. The question is whether these plants are capable of transferring significant amounts of AAs from the roots into edible parts of the plant during prolonged experiments.