1,721,050 research outputs found
Storia di un minuto.Volume 3
No full textI contenuti della Sezione Storia di Un Minuto sono la quintessenza della volontà di superare la logica binaria dell’esposizione di architettura intesa come una raccolta di oggetti materiali, di venerazione quasi religiosa, in un ambito culturale ristretto.
In passato, infatti, la Biennale di Architettura di Venezia è stata il terreno ideale dei demiurghi dell’architettura e dei loro feticci.
Naturalmente non ci sarebbe niente di male nel mettere in scena i modelli in scala, i disegni e le foto degli edifici, oppure il lavoro dei propri maestri, se questi non rappresentassero, soprattutto oggi, un culto esclusivo, ammantato di arcana competenza, incapace di riconoscere la complessità delle crisi ambientali.
In questo contesto, la sezione curata da Alessandro Gaiani, Emilia Giorgi, e Guido Incerti, ha il merito, tra gli altri, di esplorare la crisi di un territorio, con strumenti isotropici come l’arte fotografica e cinematografica.
Da qui emergono le immagini dei luoghi e delle forze potenziali per la ricostruzione di un territorio, a partire dalle comunità, unità minime di coesione sociale.
Le immagini dei tre fotografi descrivono le alterazioni fisiche dell'ambiente e di ogni specie vivente, dagli esseri umani, alle specie animali e vegetali.
Il processo attraverso cui un evento sismico altera un ambiente locale riporta l’architettura verso il suo naturale ruolo di strumento di mediazione e di negoziazione dell’umanità con la troposfera.
E, benché già oltre l’interpretazione primitiva della competenza disciplinare, ci si chiede se anche questa prospettiva non sia controproducente, dato che l’Antropocene si deve all’incapacità di accogliere, all’interno della comunità, ogni presenza vivente e non vivente come parte di un unico organismo.
Dopo il terremoto, infatti, le modifiche dell’habitat, dovute alle componenti tettoniche artificiali, spesso non sono più vantaggiose per i loro abitanti, e, come detriti, possono contribuire al degrado dell’ambiente.
Come nel “principio di costruzione di nicchia”, così ogni presenza sul territorio - gli individui, la collettività, le piante e il vento -, sono un agente attivo del cambiamento, che può contribuire alla resilienza delle comunità.
Coerentemente il luogo fisico dell’esposizione, immaginato dai tre curatori, si espande e diviene un polimorfico spazio pubblico, nel Padiglione Italia, ed un laboratorio nei territori colpiti dal sisma, animato dal coraggio dell’attivismo, grazie al contributo di ActionAid Italia, e dal rigore della ricerca, grazie alle iniziative del Gran Sasso Science Institute.
Con “laboratorio” qui si intende uno spazio inclusivo di creatività come motore del cambiamento, in cui la componenti più marginalizzate delle comunità dimostrano di essere la parte più mobile delle società, quella che, raggiunta la consapevolezza che lo status quo non sia più un’opzione, immagina relazioni adattative inaspettate, e quindi ancora più preziose, tra l’ambiente e le persone
Ecosystem service of air quality improvement provided by urban and natural vegetation in Latium region, Italy
No full textThis report provides a synthesis of current knowledge on the effects of ground-level ozone on ecosystem services and biodiversity. Ecosystems provide an array of services upon which humans depend for food, fresh water, climate regulation, aesthetic enjoyment and spiritual fulfilment. The increased global population along with increased standards of living and other socio-political, economic, technological and societal changes, mean that our interventions can have profound negative effects on the quality of the services provided by ecosystems. As well as having a direct impact on human health, ozone pollution also affects human well-being indirectly via effects on ecosystem services and biodiversity. This report provides a review of current knowledge of the impacts of ozone on biodiversity and supporting, provisioning, regulating and cultural services. Included are effects of ozone on primary production, carbon, nutrient and water cycling, air quality, crop and timber production, flowering and pollination, and aesthetics of the natural environment, together with the interactions with climate change. Approaches for valuing the cost of ozone pollution impacts on ecosystem services are also discussed
Nitrogen transfer in litter mixture enhances decomposition rate, temperature sensitivity, and C quality changes
No full textLitter decomposition is a critical process in terrestrial ecosystems and, since in natural conditions plant litter occurs in mixtures, understanding the interactive effects of mixed litter is of great ecological relevance. In this context, we test the hypothesis that N transfer between high quality litter to N-poor substrates are at the base of synergistic interactions, positively affecting litter decay rate, temperature sensitivity, and changes of organic C quality.
We carried out a manipulative experiment using four organic substrates, encompassing a wide range of biochemical quality (Hedera helix and Quercus ilex leaf litter, cellulose strips and woody sticks), each decomposing either separately or in matched pair mixtures for 360 days. Organic substrates were characterized for mass loss, C and N content and by C-13 CPMAS NMR to assess biochemical quality changes.
Litter response to mixing was related to the biochemical quality of the components in the mixture: additive when substrates with similarly high (H. helix and Q. ilex) or low (cellulose and wood) N content were paired, but synergistic when substrates with contrasting N content were associated (either of the two leaf litters with either cellulose or wood). Overall, no antagonist effects were observed in this experiment. Interestingly, decomposition of cellulose and wood showed an higher temperature sensitivity, compared to monospecific substrates, when paired with N rich materials. Significant N transfer was found from N rich litter to N poor substrates and C-13 CPMAS NMR showed rapid changes of C quality of cellulose and wood sticks only when paired with N rich litter.
Our findings support the hypothesis that mixing litters of different quality, with quality expressed in terms of C/N ratio and N content, increases decomposition rate and temperature sensitivity of the lower quality substrates
Biochemical quality of organic amendments affects soil fungistasis
No full textSoilborne plant pathogens are among the most important limiting factors for the productivity of agro-ecosystems. Identifying reliable and effective control methods is crucial for efficient biological control. Soil fungistasis is the capability of soils to inhibit the germination and growth of soil-borne fungi in presence of optimal abiotic conditions. The aim of this study is to clarify the relationships between soil amendments with plant residues spanning a wide variety of biochemical quality and soil fungistasis. Microcosms experiments were performed with 42 different plant residues and the effect on soil fungistasis was assessed by using four different fungi (Aspergillus niger, Botrytis cinerea, Pyrenochaeta lycoperici and Trichoderma harzianum). We measured soil respiration and FDA enzymatic activity and compared classic litter proximate chemical analysis with C-13-CPMAS NMR spectroscopy. Results showed that quality of organic amendments is a major controlling factor of soil fungistasis. The dramatic relief of soil fungistasis when soil was amended with lignin poor, but labile C rich, substrates gives strong support to the competition-based hypothesis. The positive correlation between soil respiration and fungal growth further supports the competition hypothesis. Finally, C-13 NMR results showed a relationship between soil fungistasis and the biochemical quality of plant residues, and provided a quantitative assessment of the time required for fungistasis restoration after organic materials application
Assessing the impact of land abandonment, nitrogen enrichment and fairy-ring fungi on plant diversity of Mediterranean grasslands
No full textSemi-natural calcareous grasslands are of great conservation interest because of their high species richness, but they are threatened by land abandonment and nitrogen eutrophication. These plant communities evolved as a result of a long history of human activity, which generated and maintained these habitats by extensive grazing and mowing. Calcareous grasslands are listed as a priority for conservation in the EC Habitats Directive. However, the effects of different management regimes, nitrogen enrichment, and soil-borne pathogens on plant species diversity are less clear for grasslands of the Mediterranean Basin, compared to meadows in Northern and Central Europe. In this study, we assessed the impact of land abandonment, nitrogen enrichment, and fairy-ring fungi on species diversity in semi-natural grasslands found in the Mediterranean Basin by comparing the available literature with findings from recent studies carried out in Central Italy. In a series of field experiments, the cutting of abandoned grassland consistently reduced the living biomass of the dominant perennial grasses, such as Brachypodium rupestre and Bromus erectus, and promoted a rapid increase in species richness and diversity by allowing the establishment of rare species. There was a similar, but less effective, restoration of species diversity and composition in mowed grassland after litter removal. We also show that nitrogen enrichment at levels comparable to atmospheric deposition depresses species diversity, which also hampers the positive effects of litter removal. Our findings are consistent with previous results achieved in Northern and Central Europe, which however, mainly focused on grasslands with intermediate to high primary productivity levels. The limited availability of data from low-productivity, drought-prone Mediterranean grasslands requires further studies to assess the impact of land abandonment and nitrogen eutrophication in such ecosystems. Finally, we discuss the role of fairy-ring fungi in the maintenance of plant diversity in species-rich grassland. We show that fairy-ring fungi (e.g. Agaricus campestris) critically affect the spatial distribution and diversity of coexisting plant species. By killing the dominant perennial herbs, these radially growing plant pathogens produce empty niches for rare, short-lived species, thus affecting the vegetation pattern. Overall, our results are of interest for environmental managers, as they provide guidelines for the restoration of abandoned areas and the conservation of these species-rich habitats
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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