Fungal spore fragmentation as a function of airflow rates and fungal generation methods

The aim of this study was to characterise and quantify the fungal fragment propagules derived and released from several fungal species (Penicillium, Aspergillus niger and Cladosporium cladosporioides) using different generation methods and different air velocities over the colonies. Real time fungal spore fragmentation was investigated using an Ultraviolet Aerodynamic Particle Sizer (UVASP) and a Scanning Mobility Particle Sizer (SMPS). The study showed that there were significant differences (p < 0.01) in the fragmentation percentage between different air velocities for the three generation methods, namely the direct, the fan and the fungal spore source strength tester (FSSST) methods. The percentage of fragmentation also proved to be dependent on fungal species. The study found that there was no fragmentation for any of the fungal species at an air velocity ≤0.4 m s^?1 for any method of generation. Fluorescent signals, as well as mathematical determination also showed that the fungal fragments were derived from spores. Correlation analysis showed that the number of released fragments measured by the UVAPS under controlled conditions can be predicted on the basis of the number of spores, for Penicillium and A. niger, but not for C. cladosporioides. The fluorescence percentage of fragment samples was found to be significantly different to that of non-fragment samples (p < 0.0001) and the fragment sample fluorescence was always less than that of the non-fragment samples. Size distribution and concentration of fungal fragment particles were investigated qualitatively and quantitatively, by both UVAPS and SMPS, and it was found that the UVAPS was more sensitive than the SMPS for measuring small sample concentrations, whilethe results obtained from the UVAPS and SMAS were not identical for the same samples.     

Land Degradation at the Stara Planina Ski Resort

The environmental impacts of ski resorts in the Balkan region are great and can lead to landscape degradation and loss of land functionality. In this study, we present an example of the negative effects of human activities at the Stara Planina ski resort in southeastern Serbia. The objective of this study is detailed analysis of the characteristics of environmental impacts at the Stara Planina. The management of the ski area and ski slope development caused severe degradation of topsoil and native vegetation. The morphological characteristics of the area, lithological properties of the exposed material and climate conditions resulted in various geomorphic impacts, including rills, deep gullies, solifluctions and debris from rock weathering. Significant changes in land usage altered hydrological conditions, resulting in more frequent torrential floods in the downstream sections of the Zubska River and increased the sediment yield. Environmental impacts were analyzed in the immediate and wider zones of the ski resort in accordance with the specific topography and visual exposure. The restoration and erosion control measures have stopped degradation processes and helped to rehabilitate the appearance and functions of the landscape. The results show the importance of considering lithological (the type and characteristics of minerals present) and hydrological (precipitation, water storage capacity of soil, runoff) factors under the conditions of significant changes in land usage. The results of this investigation can contribute to the improvement of planning processes and the implementation of development projects in ski areas.     

Cadmium and mercury accumulation in European hare (Lepus europaeus): age-dependent relationships in renal and hepatic tissue

A total of 63 European hares have been collected from five Serbian agricultural regions. The hares assayed were divided into four age groups (3–6 months, 12 months, 12–24 months, and 24–36 months) and investigated upon presence at cadmium (Cd) and mercury (Hg) in the kidney and liver. The positive significant correlation (Ps—Pearson’s coefficient) between Cd concentrations in the kidney and liver within age group the 3–6 months was found (Ps?=?0.81, p?p?p?>?0.05). Statistically significant differences were registered between Hg content in the liver of the hares aged 24–36 and 12 months (p?p?>?0.05). The strong statistically significant associations were registered between Cd and Hg content in the liver (Cd L/Hg L) in the age group 3–6 and 12–24 months (Cd L/Hg L, Ps?=?0.94; p?Ps?=?0.91; p?相似文献   

Comparison of light absorption and oxidative potential of biodiesel/diesel and chemicals/diesel blends soot particles

Soot particles,mainly coming from fuel combustion,affect climate forcing through absorbing light and also result in adverse human health outcomes.Though biodiesel or additives blending with diesel was considered environmentally friendly,the understanding on absorbing and oxidative capacity of soot emitted from them are still unclear.The watersoluble organic carbon(WSOC) content,surface chemical structure,light absorption and oxidative potential(OP^DTT) of soot from biodiesel/diesel and...     

Effect of fuel composition and engine operating conditions on polycyclic aromatic hydrocarbon emissions from a fleet of heavy-duty diesel buses

Emissions from 12 in-service heavy-duty buses powered by low- (LSD) and ultra low-sulfur (ULSD) diesel fuels were measured with the aim to characterize the profile of polycyclic aromatic hydrocarbons (PAHs) in the exhaust and to identify the effect of different types of fuels on the emissions. To mimic on-road conditions as much as possible, sampling was conducted on a chassis dynamometer at four driving modes, namely: mode 7 or idle (0% power), mode 11 (25% power), mode 10 (50% power) and mode 8 (100% power). Irrespective of the type of fuel used, naphthalene, acenaphthene, acenaphthylene, anthracene, phenanthrene, fluorene, fluoranthene and pyrene were found to be the dominant PAHs in the exhaust emissions of the buses. However, the PAH composition in the exhausts of ULSD buses were up to 91±6% less than those in the LSD buses. In particular, three- and four-ringed PAHs were more abundant in the later than in the former. Lowering of fuel sulfur content not only reduced PAH emission, but also decreased the benzo(a)pyrene equivalent (BAP_eq) and hence the toxicity of the exhaust. Result from multicriteria decision-making and multivariate data analysis techniques showed that the use of ULSD afforded cleaner exhaust compositions and emissions with characteristics that are distinct from those obtained by the use of LSD.     

Parentage analyses suggest female promiscuity and a disadvantage for athletic males in the colour-polymorphic lizard Podarcis melisellensis

Although laboratory measurements of whole-animal performance have become a standard tool in evolutionary biology, if and how interindividual variation in performance translates into differential fitness remains poorly understood. Particularly rare are studies that have connected performance to mating and reproductive success in the field. In this study, we use DNA microsatellite parentage analyses to study the fitness gradient in a colour-polymorphic lizard, Podarcis melisellensis. We report on two surprising findings. First, contrary to our expectations, individual sprint speed and bite force capacity correlated negatively, not positively, with male mating and reproductive success. Second, we found an unexpected degree of promiscuity in females. Also, contrary to traditional parental investment theory, the variation in mating success and reproductive success was as high in females as in males. Our results call for a better integration of whole-animal performance and life history traits, and for a reconsideration of the ideas on the likeliness of sexual selection acting on female phenotypes.     

Economic,ecological, and health aspects of β-diketonate application in the process of water purification

Environmental Science and Pollution Research - Water pollution is a constant challenge for humanity. Sustainable economic development and environmental protection through a green economy structure...     

Fertilizer source effect on ground and surface water quality in drainage from turfgrass

Nutrients in surface and ground water can affect human and aquatic organisms that rely on water for consumption and habitat. A mass-balance field study was conducted over two years (July 2000-May 2001) to determine the effect of nutrient source on turfgrass runoff and leachate. Treatments were arranged in an incomplete randomized block design on a slope of 7 to 9% of Arkport sandy loam (coarseloamy, mixed, active, mesic Lamellic Hapludalf) and seeded with Kentucky bluegrass (Poa pratensis L.) and perennial ryegrass (Lolium perenne L.). Three natural organic (dairy and swine compost and a biosolid) and two synthetic organic nutrient sources (readily available urea and controlled-release N source sulfur-coated urea) were applied at rates of 50 and 100 kg N ha(-1) per application (200 kg ha(-1) yr(-1)). Runoff water collected from 33 storms and composite monthly leachate samples collected with ion exchange resins were analyzed for nitrate (NO3- -N), phosphate (PO4(3-) -P), and ammonium (NH4+ -N). Nutrient concentrations and losses in both runoff and leachate were highest for the 20-wk period following turfgrass seeding. The NO3- -N and NH4+ -N losses declined significantly once turfgrass cover was established, but PO4(3-) -P levels increased in Year 2. Turf's ability to reduce nutrient runoff and leachate was related to overall plant growth and shoot density. The use of natural organics resulted in greater P loss on a percent applied P basis, while the more soluble synthetic organics resulted in greater N loss.     

Effect of OH/NCO Molar Ratio on Properties of Soy-Based Polyurethane Networks

Polyurethane networks from soybean oil have a number of valuable properties, which are determined by their chemical composition and cross-linking density. Changing the molar ratio of reacting groups can vary the latter. In this work we have varied the NCO/OH molar ratio (isocyanate index) from 1.05 to 0.40 in a soy polyol/MDI system, and tested physical and mechanical properties. The degree of swelling in toluene increased from 52–206% by decreasing isocyanate index from 1.05–0.4. The sol fractions and network densities determined from swelling in toluene were compared with ones obtained using the network formation theory based on branching processes. The comparison of experimental sol fractions and network densities with those predicted by theory of network formation suggest that 5–10% of bonds are lost in cycles and that high entanglement contributions increase the network densities. Polymers prepared with NCO/OH ratios from 1.05–0.8 were glassy while the others were rubbery, and that was reflected in their properties. Glass transition temperature (DSC) of the networks decreased from 64–7°C, tensile strength from 47–0.3 MPa, and elongation at break increased from 7–232%. The activation energy of the glass transition, determined from dielectric spectra, varied from 222–156 kJ/mol as the molar ratio of NCO to OH groups decreased from 1.05–0.4.     

Assessing the estrogenic potency in a Portuguese wastewater treatment plant using an integrated approach

The estrogenic potency of a wastewater treatment plant(WWTP) was evaluated using chemical and biological analyses,which showed that after the station treatment processes some of the selected endocrine disruptor compounds(EDCs) were still present in the treated effuent(e.g.,bisphenol A,alkylphenols,estrone) .Thus,the most common endocrine EDCs were identified and quantified and the overall estrogenicity of the treated effuent assessed by integrating the results.Male goldfish(Carassius auratus) were used as biological indicators in a 28-day experiment.Vitellogenin(Vtg) ,gonadosomatic and hepatosomatic indices,steroids(17β-estradiol and 11-ketotestosterone) and histopathology were biomarkers used in fish to evaluate WWTP treated effuent estrogenicity,in combination with instrumental analyses.The results showed a significant increase(P0.01) in plasma and liver Vtg,which were significantly correlated(r=0.66;P0.01) .The gonadosmatic index was significantly(P0.01) reduced in exposed fish.The steroid analyses revealed significant elevations in 17β-estradiol and depressed 11-ketotestosterone concentrations.The histological examinations show changes in exposed fish gonads,such as regressed testes and in some cases(43%to 75%) the development of ovo-testis in fish exposed to 50% and 100% treated effuent.