179 research outputs found
Il design per la transizione energetica tra INtuizione e INtenzione
No full textLa transizione energetica rappresenta al contempo una sfida, un’op- portunità e un’urgenza del contemporaneo, che deve confrontarsi con una po- licrisi (Tooze, 2021) dovuta al contesto geopolitico internazionale, alla necessità di indipendenza energetica, alla sempre più diffusa povertà energetica e alla crisi climatica. Nella prospettiva della sostenibilità il saggio esplora vari approcci de- sign-oriented, invitando a spostare l’attenzione tradizionale (prioritariamente tec- nica) dal singolo prodotto a progetti più sistemici (con impatti sociali, comporta- mentali ed economici decisamente maggiori). L’analisi spazia, dunque, dall’idea ormai radicata di comunità energetica a casi più sperimentali che rivoluzionano il modo in cui si può fruire l’energia, semplicemente facendo di più con meno.---The contemporary need for an energy transition simultaneously poses a challenge, an opportunity and an urgency. We are facing a polycrisis (Tooze, 2021) due to the international geopolitical context, the need for energy independence, increasingly widespread energy poverty, and the climate crisis. From a perspective of sustainability, the essay explores various design-oriented approaches, inviting a shift in traditional (primarily technical) focus from individual products to more systemic designs (with significantly greater social, behavioural, and economic impacts). The analysis thus ranges from the now entrenched idea of the energy community to more experimental cases that revolutionise the way energy can be consumed simply by doing more with less
Modelling the population dynamics of Daphnia obtusa (Kurz) in Lake Orta (N. Italy) under pre- and post-liming conditions
No full textA mathematical matrix model was formulated to investigate the response of Daphnia obtusa population dynamics to the changes in the water chemistry of Lake Orta before and after the liming operation. Modelparameters were estimated from experimental laboratory data. Model analysis showed that water chemistry changes induced by liming affected mainly egg survival and predicted the highest population growth at pH 6. Whereas increased egg mortality heavily inhibits population growth rate, the model still predicts a long term tendency of the population to increase in number. However, both before and after the liming operation due to high food availability in the laboratory, egg production was higher under all experimental conditions than in the field. When food limitation is accounted for and more realistic, field based estimates of egg production are used, the model predicts the extinction of D. obtusa population in the lake. This suggests that the effects of water chemistry changes on egg mortality had a critical role in the disappearance of D. obtusa from Lake Orta and may even adequately explain the extinction of this population
Toxicity of hexavalent chromium to the earthworm Eisenia andrei: linking effects at different levlels of biological organization
No full textLiving organisms respond to chemicals at all the levels of biological organization, from molecules to ecosystems. In general, biochemical and physiological responses (molecules, cells, tissues) are triggered at low concentrations and after short exposure times, while ecological responses (life cycle traits, populations, communities, ecosystems) can be evidenced only at higher concentrations and after longer exposures. On the other hand, responses at the higher levels of organization are considered more relevant from an environmental point of view, as they often result in irreversible severe damage to ecological systems. It is important to clarify the relationship between low-level and high-level responses to different toxicants, particularly considering the increasing application of biomarkers as early warning systems to assess environmental pollution.
In accordance with this view, effects of exposure to hexavalent chromium, Cr(VI), on life cycle endpoints were compared to effects on a battery of eight biomarkers in the earthworm Eisenia andrei. In spite of the importance of Cr(VI) as an environmental contaminant, its toxicity to earthworms, a major component of soil fauna, has received little attention; in particular almost no data are available on biochemical and physiological responses.
A natural clayey soil was spiked at six Cr(VI) concentrations, from 6.25 to 200 mg/kg. Adult worms were exposed in laboratory to the spiked soils and to a control treatment (unspiked soil). Two sets of experimental containers were prepared: the first to measure lysosomal membrane stability, lysosomal lipofuscins and neutral lipids accumulation, metallothionein content, Ca2+ ATPase, catalase, glutathione S-transferase and acyl CoA oxydase activities, after 10 d of exposure; the second to asses survival, growth and chromium bioaccumulation after 28 d, and reproduction after 56 d of exposure.
All the biological effects were significantly affected by Cr(VI) exposure and showed a clear concentration-effect relationship, except for the content of metallothioneins. Biomarkers showed different trends at increasing Cr(VI) concentrations, that could be classified as typical “increasing responses” (neutral lipids), “decreasing responses” (lysosomal membrane stability, Ca2+-ATPase and acyl Co-A oxydase activities) and “bell-shaped responses” (catalase and glutathione S-transferase activities). Biomarkers were more sensitive to Cr(VI) than life-cycle endpoints; among these, reproduction was the most responsive
Water-Soluble Pyrolysis Products as Novel Urease Inhibitors Safe for Plants and Soil Fauna
No full textWater-soluble pyrolysis products from lignocellulosic biomassare nonphytotoxic urease inhibitors useful for agricultural applications.Water-soluble compounds (WS) obtained from the pyrolysisof threelignocellulosic biomasses (larch, poplar, and switchgrass) were testedas potential inhibitors of the enzyme urease. Thanks to the presenceof an array of phenolic compounds like catechol, methoxy/hydroxy phenols,phenolic acids, and phenolic aldehydes, all the WS samples testedat a catechol concentration of 30 mu M inhibited the activityof jack bean urease (JBU) by 60%-70% and by 80% that of ureasenaturally present in the soil. A 10 times lower dose of WS samples(catechol concentration of 3 mu M) inhibited the activity of JBUby 20%, while that of soil urease by 50%, in line with the known inhibitionof N-(n-butyl) thiophosphoric triamide(NBPT). The germination rate, early growth, and development of oatwere not affected by any WS sample tested at this lower dose, as wellas the cress germination rate, while the development of cress rootsand shoots was lower than the control presumably because of the lowpH of the tested WS solutions. Earthworm survival was not significantlyaffected by any WS sample tested, but an effect was observed on theability of the eggs to develop into viable newborns
Understanding the role of macroalgal complexity and allelochemicals production in invasive and non-invasive macroalgae in the north-western Adriatic Sea: effect on the associated communities
No full textHighly diverse microphyto and meiobenthic communities are associated with large-sized marine macroalgae. Both morphological traits and allelochemical responses of macroalgae affect the composition of these communities, but the relative importance of these factors remains incompletely understood. In this study we investigated the microphytobenthic and meiobenthic communities associated with some native macroalgae and a non-indigenous species (Sargassum muticum) of the north-western Adriatic Sea. These seaweeds were sampled in two coastal sites subjected to different impacts. The possible effects of the structural complexity of the macroalgae and the potential role of allelochemicals (specifically polyunsaturated aldehydes, PUAs) on the associated communities were examined using univariate and multivariate analyses. The results indicate that distinct assemblages were associated with the macroalgae collected at the two different sites. Differences in microphytobenthic communities could be ascribed to differences in the macroalgal morphological traits and in their PUAs production. Conversely, variation of the meiobenthic community seemed to be related mainly to differences in the macroalgal communities at the two sites. This apparent inconsistency between the two analyzed communities suggests that microphytobenthos and meiofauna were differently shaped by the environmental habitat provided by macroalgae in the two sites, that are subjected to different environmental conditions and human activities. Overall, these results indicate that interactions between organisms belonging to different trophic groups (e.g., microphytobenthos and meiofauna) should be investigated in detail to better understand the global role of macroalgae as habitat formers on coastal ecosystems, especially in the case of large-sized introduced species
The effect factor for nano TiO2: preliminary toxicity tests on Daphnia magna and future developments
No full textNanotechnologies are being developed for application in a large variety of sectors, from food industry to environmental remediation technology. However, numerous uncertainties exist regarding their possible impacts on the environment and human health. The Life Cycle Assessment (LCA) methodology could be a tool to evaluate, analyze and manage the environmental and health effects for the emerging technologies. The evaluation of the environmental performance of nanotechnologies trough LCA is not always possible due to the lack of data regarding the environmental pathway of NPs. The focus of the present research is to evaluate the freshwater ecotoxicological Effect Factor (EF) for TiO2 nanoparticles (which are widely used in different applications as sunscreens, solar cells, ecc.), following the framework of the USEtox model. This model is used for the Life Cycle Impact Assessment (LCIA) phase and is aimed to provide the Characterization Factor (CF) for the ecotoxicity impact category. The CF is quantified trough the evaluation of the Fate Factor (FF) and Effect Factor (EF). The latter is based on chronic or acute toxicity value as EC50. In order to establish the acute EC50 for nano TiO2, two preliminary toxicity tests on Daphnia magna (72h) have been performed. The particles were prepared following two different treatments. In the first case the nano TiO2 suspensions were stirred for 24 h only before the test; in the second case the particles were maintained in agitation also for the whole duration of the bioassay. No adverse effects have been observed for the concentration applied, this contrasts with the findings of other studies that reported effects of nano TiO2 on D. magna. The future developments of our research are to conduct other toxicity tests on D. magna, following different treatments of the sample (example: irradiation with UV-A, filtration etc), and to conduct toxicity test on different trophic level (algae, crustaceans, fish) as suggested by USEtox framework. The research is intended to identify suitable treatments for nanoparticles to be used in toxicity test, taking into account their tendency to aggregate and precipitate and that this could influence the results of the tests. The suitable treatment should also reproduce the actual exposure modality of the organisms in the field
Survey of microarthropods and biological quality of soils of San Vitale pinewood (Ravenna, Italy): first results / Etude sur les microarthropodes et sur la qualite biologique des sols de la pinede de San Vitale (Ravenna, Italie): premiers resultats / Indagine sui microartropodi e sulla qualità biologica dei suoli della pineta di San Vitale (Ravenna, Italia): primi risultati
No full textSono riportati i primi risultati di uno studio condotto nella Pineta di San Vitale (Ravenna). L'obiettivo è valutare la qualità biologica dei suoli mediante l’analisi del popolamento dei microartropodi edafici, in relazione al pedotipo ed in particolare alla salinizzazione. La Qualità Biologica del Suolo è valutata con l’indice QBS-ar.
La Pineta è stata campionata nella zona Est, maggiormente influenzata dall’ingressione salina e nella zona Ovest, dove tale fenomeno è meno rilevante. Il campionamento è stato svolto in primavera e in estate. I risultati del campionamento primaverile, confermano che le caratteristiche chimiche e fisiche variano secondo il gradiente sommità dunali - bassure interdunali. Per quanto riguarda la struttura del popolamento di microartropodi e il QBS-ar, si riconoscono alcune caratteristiche comuni alla maggior parte delle stazioni con il medesimo pedotipo. Non si evidenzia uno stress sul popolamento attribuibile alla salinizzazione. Il QBS-ar è nel complesso abbastanza elevato
Linking responses at different levels of biological organization: The effect on biomarkers and life cycle traits in the earthworm Eisenia andrei exposed to copper-spiked soils
No full textLiving organisms respond to chemicals at all the levels of biological organization, from molecules to ecosystems. In general, biochemical and physiological responses (molecules, cells, tissues) are triggered at low concentrations and after short exposure times, while ecological responses (life cycle traits, populations, communities, ecosystems) can be evidenced only at higher concentrations and after longer exposures. On the other hand, responses at the higher levels of organization are considered more relevant from an environmental point of view, as they often result in irreversible, severe damage to ecological systems. It is important to clarify the relationship between low-level and high-level responses to toxicants, particularly considering the increasing application of biomarkers as early warning systems to assess environmental pollution. In accordance with this view, effects of exposure to copper-spiked soils on life cycle endpoints were compared to effects on a battery of biomarkers in the earthworm Eisenia andrei.
A natural clayey soil was spiked at seven copper concentrations, from 25 to 1600 mg/kg. Adult worms were exposed in laboratory to the spiked soils and to a control treatment (unspiked soil). Two sets of experimental container were prepared: the first to measure lisosomial stability, Ca2+ATP-ase activity, lipofuscin storage and metallotionein storage, after 10 d of exposure; the second to assess survival, growth and copper bioaccumulation after 28 d, and reproduction after 56 d of exposure. All the biological responses showed a clear concentration-effect relationship. EC50 was in the range 30–60 mg/kg of extractable copper for the physiological biomarkers (120–260 mg/kg total copper). EC50 for life cycle endpoints were noticeably higher, reproduction being the most sensitive
Introduction of oxygenated side chain into imidazolium ionic liquids:Evaluation of the effects at different biological organization levels
No full textThe biological effects of a class of oxygenated imidazolium ionic liquids were studied in comparison with alkyl imidazolium salts (BMIM BF4 and BMIM N(CN)2).The cellular and subcellular effects were evaluated on rat pheochromocytoma PC12 cell lines, through MTT test, lactate dehydrogenase release and acetylcholinesterase inhibition; the eco-toxicological responses were assessed through the acute toxicity tests towards Daphnia magna and Vibrio fischeri. The introduction of ethoxy moieties in the lateral chain of imidazolium cations reduced the biological effects in all the tests. The acute toxicity towards D. magna was not affected by the number of ethoxy units, but the crustacean seemed to be sensitive to the type of anion; on the contrary, a further addition of ethoxy moieties increased the toxicity towards V. fischeri, M(OE)4MIM N(CN)2 being the most toxic oxygenated ionic liquid. In the cytotoxicity assays the salts with oxygenated cations resulted ineffective compared to BMIMs, independently from the anion and the number of ethoxy units in the lateral chain.
In order to estimate the influence on membrane fluidity, an analysis of fluorescence anisotropy was done and it indicated that BMIM BF4, the most toxic ionic liquid among the tested ones, led to a
destabilization of the model membranes at any molarity
- …
