Winter arsenic pollution in 10 forest ecosystems in the mountainous border regions of the Czech Republic

Environmental Science and Pollution Research - Arsenic (As) concentrations and deposition fluxes were measured in snow and rime at 10 mountain-top sites near the borders between the Czech Republic...     

Land cover change detection in the Turkish coastal zone based on 28-year (1990–2018) Corine data

Environmental Monitoring and Assessment - The present study aims to estimate the effects of PM2.5 on the health and economy of Karaj city from 2012 to 2019. In this study, mortality attributed to...     

Solitary nesting as an alternative breeding tactic in colonial nesting bluegill sunfish (Lepomis macrochirus)

Colonial breeding can evolve in response to benefits afforded by clumped individuals, such as reduced predation and increased ease of assessing potential mates. However, colonial breeding can also impose costs such as increased disease transmission or increased cuckoldry. Here, we investigate solitary nesting as a potential alternative breeding tactic in colonial breeding bluegill sunfish (Lepomis macrochirus). Most male bluegill, termed parentals, compete for nesting sites in colonies and then court and spawn with females and provide sole care of the eggs. Although nesting in a colony results in reduced predation and fungal infection of broods, it comes at a cost of increased parasitism by specialized cuckolder males that do not nest. We found that 4.5% of parentals forgo spawning in a colony and instead construct nests solitarily. Solitary males were of similar size and age to colonial males, but were in significantly better condition. Solitary males obtained as many eggs as males nesting in the center of colonies, and significantly more than males nesting on the periphery of colonies. Thus, females do not appear to discriminate against solitary males. Solitary males had smaller ear tabs, a presumed sexually selected character used by parental males in intrasexual competition, than colonial males. Tracking data revealed consistency in nesting tactic (but not nest position within the colony) between spawning attempts. We suggest that solitary nesting represents either a facultative decision made by parental males in top condition at the onset of breeding, or a life history decision to forgo spawning in colonies.Communicated by K. Lindström     

Phytoremediation of landfill leachate using Pennisetum clandestinum

Landfills are still the most widely used solid waste disposal method used across the world. Leachate generated from landfill areas exerts environmental risks mostly on surface and groundwater, with its high pollutant content, most notably metals, which cause an unbearable lower water quality. During dumping or after the capacity of the landfill has been reached, a decontamination and remediation program should be taken for the area. This study was conducted to assess the capacity and efficiency of Pennisetum clandestinum, a prostrate perennial plant, to accumulate chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), zinc (Zn) and lead (Pb). Leachate, taken from the Sofulu Landfill Site, was given to Pennisetum clandestinum for 180 days, in 3 dilution sets as 1/1, 1/2 and 1/4, in batch configuration. An additional control set was also installed for comparison. Results showed that, even though the metal content of soil had risen, plants accumulated 2 to 8.5 times higher concentrations than the control set. It is important to see, the plant showed almost no stress symptoms even if the set was fed by pure leachate. Pennisetum clandestinum was observed to accumulate metals mostly in the upper bodies, excluding Fe and Cu. 76% of accumulated Cr, 85% of Ni, 66% of Zn and 100% of Pb was observed to accumulate in above-ground parts, where only 20% of Cu and 4% of Fe was accumulated. Due to the high pollution tolerance of Pennisetum clandestinum, makes this plant suitable for decontamination and remediation of landfill sites.     

Studying crop sequences with CarrotAge,a HMM-based data mining software

We have developed a knowledge discovery system based on high-order hidden Markov models for analyzing spatio-temporal data bases. This system, named CarrotAge , takes as input an array of discrete data – the rows represent the spatial sites and the columns the time slots – and builds a partition together with its a posteriori probability. CarrotAge has been developed for studying the cropping patterns of a territory. It uses therefore an agricultural drench database, named Ter-Uti , which records every year the land-use category of a set of sites regularly spaced. The results of CarrotAge are interpreted by agronomists and used in research works linking agricultural land use and water management. Moreover, CarrotAge can be used to find out and study crop sequences in large territories, that is a main question for agricultural and environmental research, as discussed in this paper.     

A Habitat-Based Metapopulation Model of the California Gnatcatcher

We present an analysis of the metapopulation dynamics of the federally threatened coastal California Gnatcatcher (Polioptila c. californica) for an approximately 850 km² region of Orange County, California. We developed and validated a habitat suitability model for this species using data on topography, vegetation, and locations of gnatcatcher pair observations. Using this habitat model, we calculated the spatial structure of the metapopulation, including size and location of habitat patches and the distances among them. We used data based on field studies to estimate parameters such as survival, fecundity, dispersal, and catastrophes, and combined these parameters with the spatial structure to build a stage-structured, stochastic, spatially-explicit metapopulation model. The model predicted a fast decline and high risk of population extinction with most combinations of parameters. Results were most sensitive to density-dependent effects, the probability of weather-related catastrophes, adult survival, and adult fecundity. Based on data used in the model, the greatest difference in results was given when the simulation's time horizon was only a few decades, suggesting that modeling based on longer or shorter time horizons may underestimate the effects of alternative management actions.     

Comparison between the carbon-14 and oxygen consumption method for the determination of the activity of heterotrophic bacterial populations

The activity of the heterotrophic microbial population in the saline Lake Grevelingen (The Netherlands) and the Mediterranean Etang Salses Leucate (France) was determined by measuring the oxygen consumption rate, and the uptake of ¹⁴C-labelled glycollate, pyruvate and an amino acid mixture. The maximum uptake rate of the applied organic compounds in Lake Grevelingen was generally less than 10% of the carbon mineralization rate calculated from the oxygen consumption experiments. Only for pyruvate and glycollate higher values were found of about 30 to 40% with one exceptionally high value for pyruvate of 149%. However, these higher percentages were found in winter, when the activity of the heterotrophic microbial population was very low. In Etang Salses Leucate higher maximum uptake rates of the ¹⁴C-labelled compounds were found, relating this uptake to the oxygen consumption rate. Yet the maximum uptake rate is still always lower than 35% of the carbon mineralization calculated from the oxygen uptake rate. Taking into account that maximum uptake rates were considered, the results demonstrate that the uptake of ¹⁴C-labelled organic compounds represents a serious underestimation of the activity of the bacterial population in situ. The extent of the underestimation depends on the water type. It was concluded that the determination of the heterotrophic activity by measuring oxygen consumption rates offers a better insight into the carbon mineralization process in natural waters than the uptake experiments with ¹⁴C-labelled substrates.Communication no. 228 of the Delta Institute for Hydrobiological Research, Yerseke, The Netherlands     

Self-monitoring of reproductive success: nest switching in the redlip blenny (Pisces: Blenniidae)

Summary In the redlip blenny Ophioblennius atlanticus, commonly found on Caribbean reefs, eggs are laid in a male's nest and are guarded by the male until they hatch as planktonic larvae. Male reproductive success, defined as the number of egg batches hatched per reproductive period, was positively correlated with male size and with the inner surface area of the male's nest. Male blennies often switch nests between reproductive periods. Most nest switching (83%) occurred following periods of low reproductive success. Moreover, a male having low reproductive success was more likely to switch if the inner surface area of his nest was small. Most nest switching (72–80%) was to a nest of larger surface area than the previous nest. In 72% of all switches, males had higher reproductive success in the period following the switch than in the one preceding it. The results suggest that male redlip blennies monitor their current reproductive success and the characteristics of their current nests, switch to better nests if their reproductive success is low, and typically benefit from the decision to do so. These capabilities have seldom been demonstrated in any phylum.     

First trimester prenatal diagnosis of haemophilia A: Two years' experience

We evaluated the feasibility, reliability, and acceptability of prenatal diagnosis of haemophilia A by DNA analysis of chorionic villi. Twenty-two women at risk to transmit the abnormal gene were referred for prenatal diagnosis, two of them twice. Two of the 22 women appeared to be non-carriers by DNA analysis. In one of these women, the results were known only after chorionic villus sampling had been carried out. Thirteen of the twenty carriers were heterozygous for an intragenic (Bell or Xbal) marker; six women were only heterozygous for the extragenic DXS52 (Stl4) locus. One of the women was homozygous for all the presently known DNA markers within or closely linked with the factor VIII locus. Twelve of the 22 fetuses at risk were male, ten were female. Seven of the 12 male fetuses were shown to be affected and were subsequently aborted. Four male fetuses appeared to be not affected. In one case, the diagnosis was made by use of an extragenic marker. The woman rejected fetal blood sampling to confirm the diagnosis. After birth, a normal factor VIII level was found in three of the four cases. The fourth pregnancy is still continuing. In one of the 12 male fetuses, no diagnosis at the gene level was possible. DNA analysis is expected to provide maximum certainty as to the phenotype of the fetus for approximately 60 per cent of the women; for another 37 per cent a rate of misdiagnosis of 4–5 per cent applies. In only 3 per cent of the cases will no diagnosis at the gene level be possible as yet. The new possibility of a prenatal diagnosis in the first trimester of pregnancy enabled some of these women to have a family of their own and was appreciated in particular by the women who underwent fetoscopy in an earlier pregnancy.     

Application of response surface methodology for the optimization of biodiesel production from yellow mustard (Sinapis alba L.) seed oil

In the present study, response surface methodology (RSM) involving central composite design (CCD) was applied to optimize the reaction parameters of biodiesel production from yellow mustard (Sinapis alba L.) seed oil during the single-step transesterification process. A total of 30 experiments were designed and performed to determine under the effects of variables on the biodiesel yield such as methanol to oil molar ratio (2:1–10:1), catalyst concentration (0.2–1.0 wt.% NaOH), reaction temperature (50–70°C), and reaction time (30–90 min). The second order polynomial model was used to predict the biodiesel yield and coefficient of determination (R²) was found to be at 0.9818. The optimum biodiesel yield was calculated as 96.695% from the model with the following reaction conditions: 7.41:1 of methanol to oil molar ratio, 0.63 wt. % NaOH of catalyst concentration, 61.84°C of reaction temperature, and 62.12 min of reaction time. It is seen that the regression model results were in agreement with the experimental data. The results showed that RSM is a suitable statistical technique for optimizing the reaction parameters in the transesterification process in order to maximize the biodiesel yield.