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Diversity and biomass of soil fungal community related to experimental fires in Mediterranean maquis (Southern Italy)
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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
Diversity, activity and biomass of soil microbial community of Mediterranean environment as affected by plant cover
No full textSoil microbial community plays a fundamental role in the ecosystem functioning, be cause it decomposes organic matter, determining the release of mineral nutrients in the soil and, consequently, influencing primary productivity and nutrient cycling. On the other hand, soil microorganisms may be affected by plant cover that influences chemical-physical properties of the soil. Plant cover changes are frequent in Mediter ranean areas and mainlyduetorecurring fires andvegetation cutting, linked to land use changes or not. Aim of this research was to evaluate diversity, activity and biomass of soil microbial community in Mediterranean areas with different plant cover. The study was carried out in the Castel Volturno Nature Reserve (Southern Italy) dominated by dense high maquis (2.5-3 m-high) with gaps (probably due to recent fire or vegeta tion cutting) covered by scattered low shrubs (30-40 cm-high) or by herbaceous plant community. Soil was collected, in spring and autumn 2004, in near areas covered by three different plant cover types, i.e. high maquis, low shrubs and herbaceous plant community (dominated by leguminous species). Microbial diversity was evaluated as functional diversity and assayed as catabolic response profiles, obtained from short term respiration responses to addition of several simple organic compounds to the soils. Data from catabolic response profiles were also used to calculate soil catabolic evenness by Simpson-Yule index. Microbial activity was evaluated as CO2 evolution from soil samples incubated in standard conditions (25◦C, 55% of water holding ca pacity). Microbial biomass was evaluated as microbial C (Cmic). Moreover, because fungi are particularly sensitive to changes of ecological factors, fungal mycelium (to tal and active), fungal fraction of microbial carbon and fungal colonies forming units (CFUs) were also determined. Data showed that soil microbial community was af fected by plant cover but also by sampling season. Soil covered by high maquis gen erally showed higher values of microbial activity, total and active fungal mycelium as well as of fungal fraction of microbial carbon, than other soils; whereas, soil from herbaceous plant community was characterized by the lowest values of total and ac tive fungal mycelium and fungal fraction of microbial carbon. By contrast, the studied soils did not differ for total microbial biomass, functional diversity (catabolic response profiles and catabolic evenness) and fungal CFUs. Moreover, a decrease of total micro bial biomass, fungal CFUs and microbial activity was generally observed in autumn, when the soil water content was lower, than in spring. A change in catabolic response profiles was also observed in autumn, compared to spring. On the contrary, fungal mycelium and catabolic evenness were similar in the two seasons and fungal fraction of microbial carbon was lightly higher in autumn than in spring. The results sug gest that both spatial heterogeneity of plant cover and temporal changes of ecological factors influence microbial community composition, with fungal or bacterial compo nent dominating in different microhabitats and in different times. However, changes in catabolic response profiles, that may indicate changes in community composition, were observed in the different seasons, but not in the different plant cover type
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
Diversity, activity and biomass of microbial community of Mediterranean environment as affected by plant cover
No full textChanges in microfungi and fauna of burned and unburned soils in a Mediterranean area of southern Italy
No full textThe effect of experimental fires on fungi and fungivorous microarthropods was investigated in a coastal area of southern Italy. In particular, in burned soils affected by different severity fires (low and high) the following parameters were determined at 245 (March 2001), 364 (July 2001) and 728
(July 2002) days after fire: total and active fungal mycelium, abundance and species density of total, xerotolerant and heatstimulated fungi as well as abundance and species density of oribatid mites and springtails, which are the main groups of mesofauna. Fungal mycelium decreased in burned soils, compared to unburned soils, during the whole study period (active mycelium) or only at 728 days after fire (total mycelium), with significant effect of fire severity only at 245 days after fire. Similarly, species density of total mycobiota tend to be reduced in burned soils; by contrast, total mycobiota abundance increased in burned soils, reflecting the increase in abundance of xerotolerant and heat-stimulated fungi. To some
extent total fungal decrease could be responsible for reduction in abundance and species density of oribatid mites and springtails often occurred in this study (with the exception for July 2002), particularly in soils affected by high-severity fire. In fact, positive correlations between faunal and fungal
parameters were often observed. However, the effect of other factors on soil fauna cannot be excluded. A clear temporal dynamics of considered biological parameters was generally evident, with the lowest values in the first summer after fire (July 2001), characterized by the lowest soil water content. In fact, positive correlations with soil water content were found for fungal mycelium and abundance as well as for springtail species density. Different organism groups showed the highest abundance and species density in different times (at March 2001 or July 2002). Data suggest that changes due to fire together with seasonal variation of climatic factors (probably emphasized by fire) raise the survival probability of several
species, also providing temporary refuges to species (such as heat-stimulated fungi) that are unable to compete in undisturbed soils, so that different groups were favoured in different microhabitats and/or in different times
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
Bio-phytoremediation of organic pollutants in soils from organic farms: current situation in Poland and challenges
No full textContamination of soils with persistent organic pollutants (POPs), particularly DDT, is very common in the natural environment, and their removal from the soil has become a serious problem. Results of a monitoring program showed that about 30% of the soil samples collected from eight Voivodeships contained DDT residues. We have thus started a research program aiming at: (i) assessing the presence of DDT contamination in different Polish soils; (ii) evaluate the risk of DDT contamination for different horticultural crops; (ii) evaluating the efficacy of different crops for phytoremediation; (iii) isolating and selecting soil microbial organisms able to metabolize DDT; (iv) assess the efficacy of a bio-rhizoremediation method to reduce the soil contamination with DDT. The consortia utilized in the bioremediation trials showed to favor DDT uptake by the plants and its translocation to above ground organs. Cucurbita pepo L. resulted the most efficient in DDT uptake. A rhizoremediation strategy, using C. pepo plants inoculated with specific microbial strains, seems to better sustain the uptake and accumulation by plants of DDT residues reducing the risk of residue presence in food
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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