736 research outputs found
Linking food web functioning and habitat diversity for an ecosystem based management: A Mediterranean lagoon case-study
We propose a modelling approach relating the functioning of a transitional ecosystem with the spatial extension of its habitats. A test case is presented for the lagoon of Venice, discussing the results in the context of the application of current EU directives. The effects on food web functioning due to changes related to manageable and unmanageable drivers were investigated. The modelling procedure involved the use of steady-state food web models and network analysis, respectively applied to estimate the fluxes of energy associated with trophic interactions, and to compute indices of food web functioning. On the long term (hundred years) temporal scale, the model indicated that the expected loss of salt marshes will produce further changes at the system level, with a lagoon showing a decrease in the energy processing efficiency. On the short term scale, simulation results indicated that fishery management accompanied by seagrass restoration measures would produce a slight transition towards a more healthy system, with higher energy cycling, and maintaining a good balance between processing efficiency and resilience. Scenarios presented suggest that the effectiveness of short term management strategies can be better evaluated when contextualized in the long term trends of evolution of a system. We also remark the need for further studying the relationship between habitat diversity and indicators of food web functioning
Household preferences for Socially Responsible Investments
We analyze revealed and stated household preferences for socially responsible investments (SRI). Using a questionnaire specifically designed for this purpose and administered to a Dutch representative household panel, we investigate the actual and latent demand for SRI products. Respondents reported whether they owned SRI products and why or why not, but also answered stated choice questions on traditional investments and hypothetical socially responsible products with an explicit return penalty and/or an in- kind compensation associated with lower return. Our results show that investors attracted by socially responsible financial products are more interested in the social product as such and show little interest in compensation. The magnitude of the penalty for investing in SRI is not diluting their investment intentions
A PRELIMINARY APPROACH TO ASSESS PEACH FRUIT TEXTURE BY TIME-RESOLVED SPECTROSCOPY (TRS)
Most fruits can be modeled for their internal composition as a diffusive medium at visible and near-infrared wavelengths. The low absorption in this spectral range allows exploiting VIS/NIR spectroscopic techniques to probe non-destructively the internal food properties. Time-resolved reflectance spectroscopy (TRS), in particular, allows the separate, but simultaneous estimation of absorption and scattering coefficients. Absorption and scattering properties give very different information about the medium investigated. The possibility of applying TRS to assess the texture type of peach fruit was tested. To this purpose, an instrument for TRS developed at Politecnico di Milano-Department of Physics, was exploited. At least two cultivars for each peach flesh phenotype (melting, non-melting, stony hard and slow melting) and a total of 30 fruits for each cultivar were analyzed over the spectral range 540-940 nm. The absorption spectra exhibit high values around 550 nm due to the anthocyanins' absorption features. Furthermore, an absorption peak is visible at 670 nm, linked to the chlorophyll a content and then gives an idea about the fruit ripeness (a high chlorophyll content corresponds to a less ripe fruit). With the exception of the cultivar 'Iride', particularly rich in anthocyanins, and 'Ghiaccio', anthocyaninless, the absorption spectra of all of the samples were similar. Concerning the scattering properties of peaches, by considering the equivalent density and the scatter power Mie parameters, it was possible to discriminate between three out of four texture types (melting, slow melting and stony hard). Further improvements may lead to a full discrimination in the future
An Iontronic Multiplexer Based on Spatiotemporal Dynamics of Multiterminal Organic Electrochemical Transistors
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