Quantitative PCR analysis of house dust can reveal abnormal mold conditions

Indoor mold concentrations were measured in the dust of moldy homes (MH) and reference homes (RH) by quantitative PCR (QPCR) assays for 82 species or related groups of species (assay groups). About 70% of the species and groups were never or only rarely detected. The ratios (MH geometric mean : RH geometric mean) for 6 commonly detected species (Aspergillus ochraceus, A. penicillioides, A. unguis, A. versicolor, Eurotium group, and Cladosporium sphaerospermum) were >1 (Group I). Logistic regression analysis of the sum of the logs of the concentrations of Group I species resulted in a 95% probability for separating MH from RH. These results suggest that it may be possible to evaluate whether a home has an abnormal mold condition by quantifying a limited number of mold species in a dust sample. Also, four common species of Aspergillus were quantified by standard culturing procedures and their concentrations compared to QPCR results. Culturing underestimated the concentrations of these four species by 2 to 3 orders of magnitude compared to QPCR.     

Socio-economic Comparison Between Traditional and Improved Cultivation Methods in Agroforestry Systems, East Usambara Mountains, Tanzania

The East Usambara Mountains, recognized as one of the 25 most important biodiversity hot spots in the world, have a high degree of species diversity and endemism that is threatened by increasing human pressure on resources. Traditional slash and burn cultivation in the area is no longer sustainable. However, it is possible to maintain land productivity, decrease land degradation, and improve rural people’s livelihood by ameliorating cultivation methods. Improved agroforestry seems to be a very convincing and suitable method for buffer zones of conservation areas. Farmers could receive a reasonable net income from their farm with little investment in terms of time, capital, and labor. By increasing the diversity and production of already existing cultivations, the pressure on natural forests can be diminished. The present study shows a significant gap between traditional cultivation methods and improved agroforestry systems in socio-economic terms. Improved agroforestry systems provide approximately double income per capita in comparison to traditional methods. More intensified cash crop cultivation in the highlands of the East Usambara also results in double income compared to that in the lowlands. However, people are sensitive to risks of changing farming practices. Encouraging farmers to apply better land management and practice sustainable cultivation of cash crops in combination with multipurpose trees would be relevant in improving their economic situation in the relatively short term. The markets of most cash crops are already available. Improved agroforestry methods could ameliorate the living conditions of the local population and protect the natural reserves from human disturbance.     

Deposition of gamma emitters from Chernobyl accident and their transfer in lichen–soil columns

Lichen–soil column samples were taken from several locations in the Southern Finland between 1986 and 2006. Columns were divided into three parts, upper lichen, lower lichen and underlying soil, and their gamma emitting radionuclides, ¹³⁴Cs, ¹³⁷Cs, ¹⁰³Ru, ⁹⁵Zr, ¹⁰⁶Ru, ^110mAg, ¹²⁵Sb and ¹⁴⁴Ce, were measured with gamma spectrometry. Deposition values were calculated as Bq/m² for each sampling site. Distribution of various radionuclides in the three compartments as a function of time was determined. Both effective and ecological half-lives of all radionuclides were calculated for upper lichen, whole lichen and whole lichen–soil column. A linear relation was derived between the physical half-lives and effective half-lives for whole lichen and for whole lichen–soil column. Reindeer meat activity concentrations of various radionuclides and ensuing radiation doses to reindeer-herding people were also estimated for a hypothetical case where a similar high radioactive pollution, as was taken place in the Southern Finland, would have occurred in the reindeer-herding areas in the Finnish Lapland.     

Long-term field-scale experiment on using lime filters in an agricultural catchment

The River Yl?neenjoki catchment in southwest Finland is an area with a high agricultural nutrient load. We report here on the nutrient removal performance of three on-site lime-sand filters (F1, F2, and F3), established within or on the edge of the buffer zones. The filters contain burnt lime (CaO) or spent lime [CaO, Ca(OH), and CaCO]. Easily soluble lime results in a high pH level (>11) and leads to an efficient precipitation of soluble phosphorus (P) from the runoff. Water samples were taken from the inflow and outflow of each site in different hydrological situations. The length of the monitoring period was 4 yr for F1, 6 yr for F2, and 1.5 yr for F3. F1 and F2 significantly reduced the suspended solids (SS), total P (PTOT), and dissolved reactive P (DRP) in the treated water. The proportional reduction (%) varied but was usually clearly positive. Filter F3 was divided into two equal parts, one containing burnt lime and the other spent lime. Both filter parts removed PTOT and SS efficiently from the water; the burnt-lime part also removed DRP. The mixed-lime part removed DRP for a year, but then the efficiency decreased. The effect of filters on nitrogen compounds varied. We conclude that sand filters incorporating lime can be used together with buffer zones to reduce both P and SS load to watercourses.     

Defoliating insect immune defense interacts with induced plant defense during a population outbreak

During population outbreaks, top-down and bottom-up factors are unable to control defoliator numbers. To our knowledge, details of biotic interactions leading to increased population density have not been studied during real population outbreaks. We experimentally assessed the strength of plant defenses and of insect immunocompetence, assumed to contribute to active insect resistance against parasitoids and pathogens, in the geometrid Epirrita autumnata during a steep increase in population density. We demonstrated rapid (same-season) induced resistance in the foliage of its host, mountain birch. The response was systemic, spreading throughout the tree, and retarded larval growth rate by approximately 10%. On the other hand, no direct delayed carry-over effects were found in the next season in larval growth rate, mortality, or pupal mass. Larval damage to a tree during the previous year, however, significantly (by approximately 13%) accelerated the advance of the immune response (measured as melanization of an implant inserted into the pupal hemocoel). The encapsulation rate correlated positively with larval mortality in trees in which larvae had been introduced the previous year, but not in control trees. Both of these observations suggest that induced plant defense was associated with an increased insect immunocompetence during the population increase.     

Biodeterioration of cardboard-based liquid containers collected for fibre reuse

Liquid packaging board (LPB) collected in Germany is processed in Finland as recycled fibre and as plastic reject for incineration. The chemical, biological and physical changes occurring in recycled LPB bales were monitored during storage of six and 18 months. The moisture content in the core of the bales ranged from 7% to 53%, and pH values varied from 6.0 to 8.5. The average amount of mesophilic bacteria per container was 1.5 x 10(7) - 5 x 10(8), which means that recycled LPB pulp cannot be recommended for sanitary use. The concentration of CO2 inside the bale is an indicator of the activity of aerobic microorganisms and might be suitable for identifying deteriorated bales and removing them from the production line. Insects were found in some bales and the more deteriorated the bale was the more species of insects were found. The results showed the conversion of cellulose into humic acids to be clearly underway in some recycled LPB bales. The bale samples were extracted into hot water and into fulvic acids and humic acid (HA) fractions. The concentration of the humic acid fraction varied in the range 0.3-0.6% of the organic matter in fresh bales and 2.2% in one old bale. During aging nitrogen was enriched in all fractions.     

Means to improve the effect of in situ bioremediation of contaminated soil: an overview of novel approaches

Different aspects of bacterial degradation of organic contaminants in soil, and how to improve the efficiency and reproducibility is discussed in this review. Although bioremediation in principle includes the use of any type of organism in improving the condition of a contaminated site, most commonly bacteria are the degraders and other organisms, such as soil animals or plant roots, play a role in dissemination of bacteria and, indirectly, plasmids between bacteria, and in providing nutrients and co-substrates for the bacteria active in the degradation process. There are a number of different procedures that have been tested more-or-less successfully in attempts to improve reliability, cost efficiency and speed of bioremediation. The methods range from minimal intervention, such as mere monitoring of intrinsic bioremediation, through in situ introduction of nutrients and/or bacterial inocula or improvement of physico-chemical conditions, all the way to excavation followed by on site or ex situ composting in its different varieties. In the past the rule has been that more intervention (leading to higher costs) has been more reliable, but novel ideas are continuously tried out, both as a means to come up with new truly functional applications and also as a line of studies in basic soil microbial ecology. Both approaches generate valuable information needed when predicting outcome of remediation activities, evaluating environmental risks, deciding on cleaning-up approaches, etc. The emphasis of this review is to discuss some of the novel methods for which the value has not been clearly shown, but that in our view merit continued studies and efforts to make them work, separately or in combination.     

Temporal increase in nest defence intensity of the willow tit (Parus montanus): parental investment or methodological artifact?

Summary Nest defence responses of experimentally naive and revisited willow tits (Parus montanus) towards a predator model were studied near Oulu, northern Finland, in 1988–1989. Intensity was measured with three variables in 228 trials at 90 nests. Two hypotheses explaining the temporal changes in the nest defence behavior were examined. In naive birds the nest defence intensity was positively correlated with the brood age, supporting the parental investment hypothesis. The number of previous trials did not cause additional variation in nest defence behavior in comparison between naive and revisited birds. Similarly, experiences in a previous breeding attempt did not affect the nest defence behavior during the course of the subsequent brood. Thus, the temporal increase in multiply visited nests was not due to the birds becoming familiar with the nest threat, i.e., no support was found for the so-called positive reinforcement hypothesis. We think that methodological problems in avian nest defence studies can hide the adaptive significance of the behavior, not explain it. Offprint requests to: S. Rytkönen     

Species- and age-related variation in metal exposure and accumulation of two passerine bird species

We measured the concentration of several elements (arsenic [As], calcium [Ca], cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], selenium [Se] and zinc [Zn]) in adult and nestling pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) at different distances to a Cu-Ni smelter in 2009. Feces of nestlings generally failed to correspond with internal element concentrations but reflected the pollution exposure, indicating an increased stress by removal of excess metals. The uptake of Cu and Ni were regulated, but As, Cd, Pb and Se accumulated in liver tissue. Pied flycatchers had generally higher element concentrations than great tits. The higher accumulation of As and Pb in pied flycatcher livers was explained by a more efficient absorption, whereas the higher Cd concentration was primarily due to different intake of food items. Age-related differences occurred between the two species, though both Cd and Se accumulated with age.