Co-occurrence of three types of egg policing in the Norwegian wasp <Emphasis Type="Italic">Dolichovespula norwegica</Emphasis>

In insect societies, workers often try to challenge the reproductive monopoly of the queen by laying their own eggs. Successful worker reproduction, however, is frequently prevented by queen policing or worker policing, whereby either the mother queen or non-reproductive workers selectively kill worker-laid eggs. Recently, a third mechanism—“selfish” worker policing—has also been described in which the workers selectively police worker-laid eggs but also lay eggs themselves. Here, we present results from the monogynous wasp Dolichovespula norwegica, which show that all three kinds of policing—queen policing, worker policing and “selfish” worker policing—co-occur. The net effect of these three kinds of policing collectively favoured the queen’s reproduction, as within 1 day 44% of the worker-laid eggs versus only 8% of the queen-laid eggs were eaten. Of the worker-laid eggs that were killed by workers, approximately two thirds were eaten by the reproductive workers even though these made up only a small proportion, 8%, of the work force. This means that policing workers obtained both direct fitness benefits as well as indirect (inclusive) fitness. In addition, we show that worker policing was carried out by a limited, specialised set of workers that was estimated to constitute approximately one quarter of the whole colony and of which 66% were non-reproductive.     

Modelling dispersion of traffic pollution in a deep street canyon: Application of CFD and operational models

In this study, numerical modelling of the flow and concentration fields has been undertaken for a deep street canyon in Naples (Italy), having aspect ratio (i.e. ratio of the building height H to the street width W) H/W = 5.7. Two different modelling techniques have been employed: computational fluid dynamics (CFD) and operational dispersion modelling. The CFD simulations have been carried out by using the RNG k–? turbulence model included in the commercial suite FLUENT, while operational modelling has been conducted by means of the WinOSPM model. Concentration fields obtained from model simulations have been compared with experimental data of CO concentrations measured at two vertical locations within the canyon. The CFD results are in good agreement with the experimental data, while poor agreement is observed for the WinOSPM results. This is because WinOSPM was originally developed and tested for street canyons with aspect ratio H/W ≌ 1. Large discrepancies in wind profiles simulated within the canyon are observed between CFD and OSPM models. Therefore, a modification of the wind profile within the canyon is introduced in WinOSPM for extending its applicability to deeper canyons, leading to an improved agreement between modelled and experimental data. Further development of the operational dispersion model is required in order to reproduce the distinct air circulation patterns within deep street canyons.     

Unusual products of the aqueous chlorination of atenolol

The reaction of the drug atenolol with hypochlorite under conditions that simulate wastewater disinfection was investigated. The pharmaceutical reacted in 1h yielding three products that were separated by chromatographic techniques and characterized by spectroscopic features. Two unusual products 2-(4-(3-(chloro(2-chloropropan-2-yl)amino)-2-hydroxypropoxy)phenyl) acetamide and 2-(4-(3-formamido-2-hydroxypropoxy)phenyl) acetamide were obtained along with 2-(4-hydroxyphenyl) acetamide. When the reaction was stopped at shorter times only 2-(4-(3-amino-2-hydroxypropoxy)phenyl) acetamide and the dichlorinated product were detected. Tests performed on the seeds of Lactuca sativa show that chlorinated products have phytotoxic activity.     

Low to negligible photoactivity of lake-water matter in the size range from 0.1 to 5 μm

We found that the photochemical generation of reactive transients such as singlet oxygen and triplet states upon irradiation of different lake water samples is mostly accounted for by components smaller than 0.10 μm. Larger components often showed a much lower absorption and/or scattering of radiation compared with the smaller ones, with one exception where the minor to negligible photochemical activity of larger species was associated with significant radiation absorption/scattering. It is also shown that filtration of the lake water samples at 0.10 μm was able to effectively remove the suspended particles, differently from the usually suggested filtration at 0.45 μm.     

Defining Chlorophyll-a Reference Conditions in European Lakes

The concept of “reference conditions” describes the benchmark against which current conditions are compared when assessing the status of water bodies. In this paper we focus on the establishment of reference conditions for European lakes according to a phytoplankton biomass indicator—the concentration of chlorophyll-a. A mostly spatial approach (selection of existing lakes with no or minor human impact) was used to set the reference conditions for chlorophyll-a values, supplemented by historical data, paleolimnological investigations and modelling. The work resulted in definition of reference conditions and the boundary between “high” and “good” status for 15 main lake types and five ecoregions of Europe: Alpine, Atlantic, Central/Baltic, Mediterranean, and Northern. Additionally, empirical models were developed for estimating site-specific reference chlorophyll-a concentrations from a set of potential predictor variables. The results were recently formulated into the EU legislation, marking the first attempt in international water policy to move from chemical quality standards to ecological quality targets.     

From laboratory simulation to scale-up and design of spray barriers mitigating toxic gaseous releases

Simulation of a process by means of physical models at a reduced scale is an essential tool in many application, allowing to perform a large number of experimental runs, so as to obtain a quantitative representation of the involved phenomena, at relatively low cost. Some difficulties can arise when the mathematical model derived from the simulation is applied to a real scale problem, in that the scaling of some empirical coefficients with the system size is not obvious at all. As fluid barrier scaling is a difficult task, still not deeply investigated in the scientific literature, the focus of this study is to translate knowledge from research on this topic into practice for industrial application. Following an extensive and accurate experimental work in wind tunnel, the main parameters determining the effectiveness of containment, absorption and dilution of chlorine releases were determined and a mathematical model is developed. In order to frame proper scale-up strategies, the most important result of this study rests on the explicit formulae giving, as a function of the aforesaid parameters, the single pass efficiency, the global absorption efficiency, and the toxic gas concentration downwind the barrier. In the far field, the gas concentration is practically determined only by the rate of atmospheric dispersion of the mass flow-rate of gas escaping the abatement. The absorption efficiencies are related to the drop size and to the mass transfer coefficients in the gas and liquid phases. The mean drop diameter plays an essential role in the absorption efficiency, since it simultaneously acts on air entrainment, interfacial surface and mass transfer coefficient in the gas phase. The evaluation of the mitigation effect for an industrial installation requires the scaling of the entrainment coefficient experimentally determined from wind tunnel testing. All the scaling criteria needed for adapting the proposed model to the design of a spray curtain suitable for the protection from a chlorine release, are amply discussed presenting some carefully designed simulations. Owing to its rather general structure, the model can be applied to different gaseous releases and/or absorbing solutions, provided that proper values of the parameters related with the chemical and physical absorption of the involved substances be theoretically or experimentally obtained in advance.     

Fluorine in the rocks and sediments of volcanic areas in central Italy: total content, enrichment and leaching processes and a hypothesis on the vulnerability of the related aquifers

Rock, sediment and water samples from areas characterised by hydrothermal alterations in the Sabatini and Vico Volcanic Districts, near Rome and the large city of Viterbo, respectively, were collected and analysed to determine the total fluorine (F) content and to understand the F geochemical background level in the volcanic districts of central Italy. Leaching and alteration processes controlling the high concentration of F in water were also investigated. Fluorine concentrations were directly determined (potentiometrically) by an F selective electrode in water samples, while the procedure for rock samples included preliminary F dissolution through alkaline fusion. F concentrations higher than 800 mg kg(-1) were commonly found in the analysed rocks and sediments; the concentration depended on the lithology and on the distance from the alteration areas. A specific successive sampling campaign was conducted in three areas where the F content in sediments was particularly high; in the same areas, measurements of CO(2) flux were also performed to investigate the possible deep origin of F. To verify the relationships among the high F contents in rocks and sediments, the leaching processes involved and the presence of F in the aquifer, we also collected water samples in the western sector of the Sabatini Volcanic District, where hydrothermal manifestations and mineral springs are common. The data were processed using a GIS system in which the F distribution was combined with morphological and geological observations. The main results of our study are that (1) F concentrations are higher in volcanic and recently formed travertine (especially in hydrothermally altered sediments) than in sedimentary rocks and decrease with distance from hydrothermal alteration areas, (2) F is more easily leached from hydrothermally altered rocks and from travertine and (3) sediments enriched with F may indicate the presence of deep regional fractures that represent direct pathways of hydrothermal fluids from the crust to the surface.     

An Optimization Model for Integrated Coastal Management: Development and a Case Study Using Italy’s Comacchio Municipality

In this paper, I develop an optimization model for integrated coastal management in which decisions arise from an area-based algorithm that minimizes predicted damage caused by beach erosion and inshore flooding, while accounting for economic, social, and environmental losses. The model favors the involvement of stakeholders in coastal management, but does not use complicated assessment procedures for non-economic indicators or relative weights to combine economic, social, and environmental indicators. Instead, the integration between economic activities or properties and the environmental status and landscape is represented objectively and non-linearly by referring to initial and sustainability conditions, combined with budgetary and environmental constraints. The model successfully accounted for both human and environmental dynamics by depicting delayed effects, neighborhood externalities, and feedback effects. It calculated a single optimal value for each integrated coastal management strategy, which permitted the support of future decisions and the evaluation of past decisions. The model’s insights were based on reliable estimates, with reliability determined by calculating the confidence level. The model was successfully applied to Italy’s Comacchio coastal municipality, where it revealed the priorities for optimal beach nourishment, dune fixation, and residential and holiday housing development based on budget constraints, beach losses, flood damage, pollution impacts, and land-use constraints.     

Short-term effects of visitor trampling on macroinvertebrates in karst streams in an ecotourism region

In order to evaluate the potential risks of human visitation on macroinvertebrate communities in streams, we investigated the effect of trampling using two short-term experiments conducted in a Brazilian ecotourism karst region. We asked three questions: (a) Does trampling increase the drift rate of aquatic macroinvertebrates and organic matter? (b) Does trampling change the macroinvertebrate community organization? (c) If trampling alters the community structure, is a short time (5 days, a between weekends interval?-?peaks of tourism activities) sufficient for community restructuring? Analysis of variance of richness, total abundance, abundance of the most abundant genus (e.g., Simothraulopsis and Callibaetis), and community composition showed that trampling immediately affects macroinvertebrate community and that the intervals between the peaks of visitation (5 days) are not sufficient to complete community restructuring. Considering that bathing areas receive thousands of visitors every year and that intervals of time without visitation are nearly nonexistent, we suspect that the negative effects on the macroinvertebrate community occur in a cumulative way. Finally, we discuss some simple procedures that could potentially be used for reducing trampling impacts in lotic environments.