27 research outputs found
Intra-guild spatial niche overlap among three small falcon species in an area of recent sympatry
Climate warming and land-use change are reshuffling the distribution of wild organisms on a global scale. Some species may expand their ranges and colonize new regions, which may greatly affect ecological interactions among pre-existing species and colonizers. In the last decades, such processes have originated a unique condition of sympatry among three Eurasian small Falco species (common kestrel F. tinnunculus, lesser kestrel F. naumanni, red-footed falcon F. vespertinus) in the intensively cultivated farmland habitats of the Po Plain (Northern Italy). This provides an excellent opportunity to investigate patterns of spatial niche overlap during the initial phases of the establishment of sympatry. To investigate spatial niche overlap of the three falcon species, we relied on Environmental Niche Models (ENMs) based on widespread breeding occurrence data obtained through field surveys and citizen science programs (during the 2018-2020 period). ENMs were based on bioclimatic and land-use variables in an ensemble modelling framework. We estimated species-specific relative contributions of each climatic and land-use variable and its response curves effect. Eventually, we generated spatial correlation maps of the potential species' distributions to derive spatially-explicit predictions of potential co-occurrence areas among the three species. Overall, eco-climatic determinants of the distribution of lesser kestrel and red-footed falcon were similar, resulting in a strong association with intensive arable lands and dry continental climate. Consistently, we found a high spatial correlation between the suitability maps of the two species, with highly suitable areas located in the Central-Eastern area of the Po Plain, corresponding to the core range of both species. Conversely, the common kestrel emerged as a habitat generalist and was widely distributed throughout the Po Plain. Our findings suggest that the recent sympatry between lesser kestrels and red-footed falcons in the Po Plain may promote ecological interactions and intra-guild competition
Long-Term Effects From A School-Based Trial Comparing Interpersonal Psychotherapy-Adolescent Skills Training To Group Counseling
Adolescence represents a vulnerable developmental period for depression and an opportune time for prevention efforts. In this study, 186 adolescents with elevated depressive symptoms (M age = 14.01, SD = 1.22; 66.7% female; 32.2% racial minority) were randomized to receive either Interpersonal Psychotherapy–Adolescent Skills Training (IPT-AST; n = 95) delivered by research clinicians or group counseling (GC; n = 91) delivered by school counselors. We previously reported the short-term outcomes of this school-based randomized controlled trial: IPT-AST youth experienced significantly greater improvements in depressive symptoms and overall functioning through 6-month follow-up. Here, we present the long-term outcomes through 24 months postintervention. We examined differences in rates of change in depressive symptoms and overall functioning and differences in rates of depression diagnoses. Youth in both conditions showed significant improvements in depressive symptoms and overall functioning from baseline to 24-month follow-up, demonstrating the efficacy of school-based depression prevention programs. However, the two groups did not differ in overall rates of change or in rates of depression diagnoses from baseline to 24-month follow-up. Although IPT-AST demonstrated advantages over GC in the short term, these effects dissipated over long-term follow-up. Specifically, from 6- to 24-month follow-up, GC youth showed continued decreases in depressive symptoms, whereas IPT-AST youth showed a nonsignificant increase in symptoms. GC youth remained relatively stable in overall functioning, whereas IPT-AST youth experienced a small but statistically significant worsening in functioning. This study highlights the potential of school-based depression prevention efforts and the need for further research
Dioxins and furans formation in pilot incineration tests of sewage sludge spiked with organic chlorine
The factors affecting polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) formation were studied in sewage sludge incineration tests carried out on a demonstrative plant. The plant includes a circulating fluidised bed furnace (FBF) and a rotary kiln furnace (RKF), operating alternatively. During the tests sewage sludge was spiked with chlorinated hydrocarbons and the operating parameters of the afterburning chamber were varied. PCDD/F were sampled in each test before the bag filter, thus collecting the above contaminants before abatement systems. From the tests it appeared that PCDD/F were always produced in more abundance in the tests carried out by FBF than by RKF. The higher PCDD/F concentrations in the tests by FBF were reached when sewage sludge was spiked with a high dosage of a surrogate organic mixture of chlorinated hydrocarbons and when the afterburning chamber was used only as transit equipment with the burner off. The distribution of the different PCDD/F homologues was compared. P(5)CDFs were generally the prevalent fraction, with very few exceptions for the tests by RKF at high temperature of the afterburning chamber. As for FBF tests, it was found that the PCDD/F homologue profile depends on the afterburning chamber temperature. (C) 2003 Elsevier Ltd. All rights reserved
Polycyclic aromatic hydrocarbons formation in sludge incineration by fluidised bed and rotary kiln furnace
Polycyclic Aromatic Hydrocarbons (PAHs) are typical pollutants arising from incineration. They are produced in any incomplete combustion principally due to inhomogeneities in a combustion chamber. The effects of the afterburning temperature on PAHs formation during sewage sludge incineration are discussed in this paper. Tests were performed inside the area of the wastewater treatment plant of 'Bari Ovest' on a demonstrative plant (maximum throughput 250 kg hr(-1) of dewatered sludge at 20% solids concentration) equipped with a fluidised bed furnace (FBF) and a rotary kiln furnace (RKF) where sewage sludge was fed, either as it was taken from the dewatering section of the wastewater treatment plant, or previously spiked by different dosages of chlorinated hydrocarbons. Exhaust gases were sampled before the bag filter, where the pollutants can be considered representative of those arising from the process. Parallel sampling of flue gas at the stack was also carried out. In the FBF tests with sludge spiked with high dosages of chlorinated hydrocarbons highest values of PAHs concentrations (> 3.9 mug Nm(-3)) were detected before filtration, when the afterburning chamber was not in use. The operation of the afterburning chamber, at a temperature higher than 900degreesC, allows to partially suppress PAHs formation up to values of 0.9 - 3.2 mug Nm(-3). PAHs removal efficiency of the exhaust gas treatment was calculated with a mean value for all the test of 72%. In RKF tests PAHs displayed much lower values before filtration ( range 0.04 - 2.98 mug Nm(-3), mean value 0.51 mug Nm(-3)) probably due to the longer gas residence time in the furnace (> 6 s in comparison with values < 2 s in fluidised bed furnace). Surprisingly, for RKF tests PAHs removal efficiency of gas treatment appeared quite unstable: some tests evidenced PAHs stripping in the scrubber, where the effluent of the wastewater treatment plant was used. No correlation was observed in RKF tests between PAHs concentration before the bag filter and the temperature of the afterburning chamber
Microorganic pollutants in the outskirts of Rome
A short field campaign was performed in the outskirts of Rome at. four sites located pretty along the four rose wind directions to city centre. Both chlorinated (PCB and PCDD/F) and non-chlorinated (n-alkanes, PAH, nitrated-PAH, n-alkanoic acids) organic micropollutants were investigated for their contents in the atmosphere. Concentrations reached by these pollutants in the outskirts were compared to those found in downtown Rome, both inside and outside of its largest city garden. Although concentrations of organic pollutants found in the outskirts were quite low, however they seemed enough high to, induce some health risk in humans. Rural sites were less affected than industrial and waste disposal/treatment areas.A short field campaign was performed in the outskirts of Rome at. four sites located pretty along the four rose wind directions to city centre. Both chlorinated (PCB and PCDD/F) and non-chlorinated (n-alkanes, PAH, nitrated-PAH, n-alkanoic acids) organic micropollutants were investigated for their contents in the atmosphere. Concentrations reached by these pollutants in the outskirts were compared to those found in downtown Rome, both inside and outside of its largest city garden. Although concentrations of organic pollutants found in the outskirts were quite low, however they seemed enough high to, induce some health risk in humans. Rural sites were less affected than industrial and waste disposal/treatment areas
Mass and energy balances of sludge processing in reference and upgraded wastewater treatment plants
This paper describes the preliminary assessment of a platform of innovative upgrading solutions aimed at improving sludge management and resource recovery in wastewater treatment plants. The effectiveness of the upgrading solutions and the impacts of their integration in model reference plants have been evaluated by means of mass and energy balances on the whole treatment plant. Attention has been also paid to the fate of nitrogen and phosphorus in sludge processing and to their recycle back to the water line. Most of the upgrading options resulted in reduced production of dewatered sludge, which decreased from 45 to 56 g SS/(PE × day) in reference plants to 14-49 g SS/(PE × day) in the upgraded ones, with reduction up to 79% when wet oxidation was applied to the whole sludge production. The innovative upgrades generally entail an increased demand of electric energy from the grid, but energy recovery from biogas allowed to minimize the net energy consumption below 10 kWh/(PE × year) in the two most efficient solutions. In all other cases the net energy consumption was in the range of -11% and +28% of the reference scenarios