130,527 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
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
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
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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
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