1,721,051 research outputs found
Response of Antarctic soil fungal assemblages to experimental warming and reduction of UV radiation.
No full textAbstract This paper reports the effects of nutrient
availability, UV radiation and temperature on the taxa
composition and abundance of Antarctic soil mycobiota.
Two sites at Edmonson Point were studied: the first
was poor in nutrients, near the glacier, and the second
was close to bird nesting sites. The highest abundance of
soil fungi was recorded at the site adjacent to the bird
nesting sites. Phoma herbarum was the most abundant
taxon. Lecytophora lignicola and Ascotricha erinacea are
new records for continental Antarctica. The fungal
assemblage from the nutrient-deficient site was characterized
by a dominance-diversity curve approaching the
broken-stick model, the assemblage from the soil influenced
by birds was characterized by a lognormal distribution.
Plastic cloches were used in experiments
designed to assess differences in fungal assemblages
subjected to altered temperature and/or UV exposure.
Dominance-diversity curves and diversity values of soil
fungal mycobiota were compared in their natural condition
as compared with manipulated conditions. Under
the walled cloches, at both sites, artificial warming led to
stress on Antarctic soil fungal assemblages. In contrast,
UV protection led to a higher equilibrium in the
assemblage structure. On the basis of the results
obtained, it could be proposed that UV radiation is the
most important limiting ecological factor for soil mycobiota
in continental Antarctica
Characterization of Soil Organic Matter along an elevation gradient at Stelvio Pass (Italian Alps)
Full text linkStudies on Antarctic fungi.
No full textResearch carried out during the last 18 years and still in progress are summarized. They concern investigations on fungal diversity, adaptations, eco-physiological characterization and molecular studies. The main topics of future research are also outline
Extremotolerant rock inhabiting black fungi from Italian monumental sites
No full textA wide sampling for isolating highly destructive and extremotolerant black fungi was performed from Italian monuments in selected historical sites which include the “Cortile della Pigna”, Vatican Museum and the St Peter colonnade (Vatican City State), the monumental cemetery of Bonaria (Cagliari), and other monuments in the city of Cagliari. Thirty out of seventy-four strains isolated were identified basing on ITS Blastn comparison. Based on multilocus phylogeny and morphological data, one new genus and species Lithophila guttulata, five new species Knufia marmoricola, K. vaticanii, K. karalitana, K. mediterranea and Exophiala bonariae, order Chaetothyriales and one new genus and species, Saxophila tyrrhenica, and two new species Vermiconia calcicola and Devriesia sardiniae, order Capnodiales, were proposed. Ecological considerations are put forward
Composition and functioning of the soil microbiome in the highest altitudes of the Italian Alps and potential effects of climate change
No full textAs the European Alps are experiencing a strong climate warming, this study analyzed the soil microbiome at different altitudes and among different vegetation types at the Stelvio Pass (Italian Alps), aiming to (i) characterize the composition and functional potential of the microbiome of soils and their gene expression during the peak vegetative stage; (ii) explore the potential short-term (using open-top chambers) and long-term (space-for-time substitutions) effects of increasing temperature on the alpine soil microbiome. We found that the functional potential of the soil microbiome and its expression differed among vegetation types. Microbial α-diversity increased along the altitudinal gradient. At lower altitude, shrubland had the highest proportion of fungi, which was correlated with higher amounts of CAZymes, specific for degrading fungal biomass and recalcitrant plant biopolymers. Subalpine upward vegetation shift could lead a possible loss of species of alpine soils. Shrub encroachment may accelerate higher recalcitrant C decomposition and reduce total ecosystem C storage, increasing the efflux of CO2 to the atmosphere with a positive feedback to warming. A total of 5 years of warming had no effect on the composition and functioning of microbial communities, indicating that longer-term warming experiments are needed to investigate the effects of temperature increases on the soil microbiome
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
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