1,720,956 research outputs found
Constructed wetlands as nature-based solution for sustainable wastewater management in urban areas: a critical assessment by experimental studies and literature
No full textIn urban areas, constructed wetland systems (CWS) have been recognized as one of the most valid technologies for sustainable wastewater management. They represent green infrastructure and provide solutions to treatment of wastewaters that cities and peri-urban areas produce in large amount. In particular, CWS offer the advantages of wastewater reuse for parklands irrigation, water storage and peak-flow attenuation, control of stormwater runoff, nutrient cycling and uptake, heavy metals sequestration, removal of organic compounds. In greener cities, these systems have the potential to perform not just hydrological and wastewater treatment functions, but also urban design and ecological aspects as demonstrated by numerous applications around the world. CWS, in fact, can function as urban wildlife sites, educational or recreational facilities, landscape engineering and ecological areas. The aim of this paper was to highlight the potential functionality of CWS in urban areas by a critical assessment of two experimental studies and literature. In particular, the two studies were carried out in Sicily (Italy) in order to evaluate: i) the pollutant removal efficiency of two CWS to treat urban wastewater and first-flush stormwater; ii) the reuse of treated wastewater for irrigation of plants. The results confirm that CWS are efficient in the treatment and reuse of wastewater for irrigation purposes in modern cities. Furthermore, CWS showed very high organic pollutant removal and a good efficiency in reducing excess of nutrients and trace metals, highlighting their important role in the treatment of stormwater in urban areas
Spontaneous urban weeds: a resource against environmental pollution
No full textQuality of the environment and social well-being, both at a collective and individual level, are closely interrelated issues. It is, in fact, a relationship that invests values of primary importance, such as those relating to human health and safety, heritage and resources to be passed on to future generations. Plant growth and survival can be challenged by harsh urban conditions. Many studies show the persistence of endemic species in built-up areas and document the ecosystem services provided. With this research we wanted to investigate the bioaccumulation of heavy metals such as cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), molibden (Mo), cadmium (Cd), lead (Pb) and mercury (Hg), in some spontaneous plants found along Viale Regione Siciliana, the most important thoroughfare of the city of Palermo with high traffic intensity. In two distinct seasons (spring and summer), the most present spontaneous plants were collected: Daucus carota, Verbascum sinuatum, Sorghum halepense and Plantago lanceolata; after, the plants were subjected to drying and analysis for the survey of heavy metals. The results were comforting as the four species all accumulated the metals investigated, albeit with different selectivity. In both seasons, the most present element was Zn, while the other elements, such as Co, Ni, As, Mo, Cd, Cu and Cd, underwent significant fluctuations. Only Hg exceeded the critical values in both seasons and in all the species examined. Furthermore, it had an opposite trend compared to the other elements, finding itself in greater concentration in the tissues of plants during the summer season. The investigation, albeit preliminary, confirmed the ability of some herbaceous plants to accumulate heavy metals, suggesting the use of a set of herbaceous plants for biomonitoring in response to the need for monitoring and verifying environmental sustainability
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
L.) in Sicily
Full text linkAsparagus acutifolius L. and Asparagus albus L. are among the most widespread wild species throughout the Mediterranean basin. In Italy, they find especially favourable growth conditions in the central and southern regions of the peninsula and in the major islands, where they have been used since ancient times for food and medicinal purposes. In view of the high potential interest of wild asparagus for cropping and marketing purposes, numerous botanical surveys were carried out in different Sicilian sites, to determine the presence of these species in natural stands. Small samples of seeds and/or propagation material were taken for each ecotype, further inserted in a collection field for evaluation and ex situ conservation. The main morphological and physiological traits were collected, including number of stems per crown, canopy height, transverse and longitudinal canopy diameter, flowering and fruiting period, and 1000 seed weight. The obtained data were submitted to multivariate statistical analysis. The results showed that morphological characteristics are a suitable tool to discriminate between wild asparagus populations for the evaluation of genetic diversity within a semi-arid Mediterranean area such as Sicily
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
(L.): yield and field performance of 10 genotypes cultivated in a semi-arid environment
No full textAsparagus officinalis (L.) (Asparagaceae) is widely cultivated throughout the world, mostly as a traditional food item but, in recent times, also due to its acknowledged many benefits for human health. In Mediterranean environments, this crop proved able to achieve high spear yields, which in many cases may be marketed earlier than competing products, with a significant advantage for local growers. Although the cropping technique of A. officinalis has already been deepened, there is still scarce knowledge about the year-to-year productive stability of the main commercial cultivars in the pedoclimatic conditions of the southern regions of Italy, potentially suitable to the cultivation of this species. This research aimed to provide local farmers with useful information to facilitate the introduction of this species in their farming systems, also giving information about the major factors affecting yield outcomes in these environments. A 3-year cultivation trial was therefore carried out, comparing the productive performances of 10 genotypes of A. officinalis (‘UC157’, ‘Purple’, ‘Italo’, ‘Darbella’, ‘Giove’, ‘Placoseps’, ‘Grande’, ‘Jaleo’, ‘NJ953’ and ‘Atlas’). For experimental purposes, a randomized complete block design was adopted. The results showed that the farming suitability of A. officinalis in the Mediterranean environment is highly variable among cultivars
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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