Search results for "c space"
showing 10 items of 552 documents
Optimisation des requêtes de similarité dans les espaces métriques répondant aux besoins des usagers
2012
The complexity of data stored in large databases has increased at very fast paces. Hence, operations more elaborated than traditional queries are essential in order to extract all required information from the database. Therefore, the interest of the database community in similarity search has increased significantly. Two of the well-known types of similarity search are the Range (Rq) and the k-Nearest Neighbor (kNNq) queries, which, as any of the traditional ones, can be sped up by indexing structures of the Database Management System (DBMS). Another way of speeding up queries is to perform query optimization. In this process, metrics about data are collected and employed to adjust the par…
Cover Crop Impact on Soil Organic Carbon, Nitrogen Dynamics and Microbial Diversity in a Mediterranean Semiarid Vineyard
2020
Cover crop (CC) management in vineyards increases sustainability by improving soil chemical and biological fertility, but knowledge on its effects in semiarid soils is lacking. This study evaluated the effect of leguminous CC management on soil organic carbon (SOC) sequestration, soil nitrate content and microbial diversity in a semiarid vineyard, in comparison to conventional tillage (CT). SOC and nitrate were monitored during vine-growing season
Studies on the response of soil microflora to the application of the fungicide fenhexamid
2007
The aim of this work was to evaluate the impact of the fungicide fenhexamid (FEX) on the genetic structure of soil bacterial communities using the Ribosomal Intergenic Spacer Analysis molecular technique. Using real-time PCR, we also tried to quantify the pcaH sequences which encode the dioxygenases involved in the degradation process of a variety of aromatic compounds. Soil taken from a vineyard in the Etna Park (Sicily, Italy) was treated with FEX in the ratio 2 µg g-1 soil every 7 days, the process being repeated four times. The analyses were carried out before treatment and 7 days after each further application of FEX. At the same time, the degradation rate was evaluated. The use of FEX…
Sampling strategy in molecular microbial ecology: influence of soil sample size on DNA fingerprinting analysis of fungal and bacterial communities.
2003
Assessing soil microbial community structure by the use of molecular techniques requires a satisfactory sampling strategy that takes into account the high microbial diversity and the heterogeneous distribution of microorganisms in the soil matrix. The influence of the sample size of three different soil types (sand, silt and clay soils) on the DNA yield and analysis of bacterial and fungal community structure were investigated. Six sample sizes from 0.125 g to 4 g were evaluated. The genetic community structure was assessed by automated ribosomal intergenic spacer analysis (A-RISA fingerprint). Variations between bacterial (B-ARISA) and fungal (F-ARISA) community structure were quantified b…
Accelerated mineralisation of atrazine in maize rhizosphere soil
2002
International audience; The mineralisation rate of atrazine measured in soil pre-treated with this herbicide, was significantly higher in the maize rhizosphere than in bulk soil. Maize rhizosphere was also shown to significantly increase microbial biomass C as compared with bulk soil. Ribosomal intergenic spacer analysis conducted on nucleic acids extracted directly from soil samples revealed that the structure of microbial communities observed in the rhizosphere was slightly different from that of bulk soil. The quantification of the relative amount of the gene atzC, which encodes an enzyme involved in atrazine mineralisation, was carried out on soil nucleic acids by using quantitative-com…
The shopping mall as an emergent public space in Palermo
2017
<p>As Doreen Massey (2005) pointed out, space matters. Does public space still matter today? Since the early seventies, several studies have explored public space as an emerging, and in many ways innovative, universe of actors, spatiality and socio-territorial practices which invaded the public spheres of our cities (Habermas, 1979; Rossi, 2008). However, ‘public space’ may have a wide variety of interpretations which relate to a semantic overlapping between a sensitive material sphere -The Space- and an intangible metaphorical sphere -The Public- (Bianchini, 1990; Crosta, 2000; Hajer and Reijndorp, 2002; Harvey, 2006; Low and Smith, 2006; Rossi, 2008). As Crosta (2000) reveals, a new…
Per un ripensamento dello standard in chiave prestazionale: un caso studio a Palermo
2017
Il contributo nasce dallo studio dell’esperienza di Parco Uditore, un'area verde di Palermo, diventata nel 2012 parco pubblico in seguito a una mobilitazione civica. L'apertura del parco in una circoscrizione che, parimenti alle altre a Palermo, risulta carente di aree attrezzate ha indotto un ragionamento sull'ipotesi di stabilire dei parametri prestazionali, oltre che di superficie, per gli spazi pubblici verdi. Seguendo una metodologia induttiva e comparativa, rispetto a modelli sperimentati in altri contesti, il contributo si propone di verificare se dall’osservazione del caso di Parco Uditore sia possibile estrapolare parametri prestazionali da affiancare alla dotazione minima dello st…
Spazi pubblici e luoghi condivisi. Progetti architettonici per le città europee
2016
Sotto la responsabilità intellettuale e supervisione diretta dell'autore, il volume raccoglie i contributi scritti dai relatori che hanno partecipato al ciclo di conferenze Spazi pubblici e luoghi condivisi. Progetti architettonici per le città europee, ideato da Guya Bertelli e coordinato dal sottoscritto. Il symposium è stato promosso dal Dipartimento di Architettura e Studi Urbani (DAStU) e le conferenze hanno avuto luogo, tra il 2012 e il 2013, presso la sede centrale del Politecnico di Milano e presso il Campus Arata del Polo Territoriale di Piacenza. Le quattro giornate di studio sono state organizzate in modo tale che il dibattito prendesse in esame, nell’ambito della stessa giornata…
Hierarchical Structure in Financial Markets
1998
I find a topological arrangement of stocks traded in a financial market which has associated a meaningful economic taxonomy. The topological space is a graph connecting the stocks of the portfolio analyzed. The graph is obtained starting from the matrix of correlation coefficient computed between all pairs of stocks of the portfolio by considering the synchronous time evolution of the difference of the logarithm of daily stock price. The hierarchical tree of the subdominant ultrametric space associated with the graph provides information useful to investigate the number and nature of the common economic factors affecting the time evolution of logarithm of price of well defined groups of sto…
(φ, ψ)-weak contractions in intuitionistic fuzzy metric spaces
2014
The purpose of this paper is to extend the notion of (phi,psi)-weak contraction to intuitionistic fuzzy metric spaces, by using an altering distance function. We obtain common fixed point results in intuitionistic fuzzy metric spaces, which generalize several known results from the literature.