169,910 research outputs found
Il Mondo degli Elli: un nuovo modello di potenziamento delle Funzioni Esecutive per la scuola primaria
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Variations in the foliar nutrient content of mire plants: effects of growth-form based grouping and habitat
No full textWe determined concentrations of major nutrients in the vegetation of six habitat types (hummock, scrub, lawn, fen meadow, hollow and marginal stream), spanning a broad range of environmental conditions as regards water-table depth and water chemistry, in five mires on the southern Alps of Italy. Our study was based on chemical analyses of living tissues of plant species, grouped into growth-form based plant functional types (PFTs). We aimed at assessing to what extent the observed differences in tissue nutrient content were accounted for by community composition (both in terms of species and PFTs) and by habitat. Nutrient concentrations were overall lowest in Sphagnum mosses and highest in forbs, although the latter showed large variations presumably due to heterogeneity in mechanisms and adaptations for acquiring nutrients among species within this PFT. Nutrient content patterns in the other three PFTs varied greatly in relation to individual nutrients, with evergreen shrubs showing low nitrogen (N) concentrations, graminoids showing high N concentrations but low potassium (K) and magnesium (Mg) concentrations and deciduous shrubs showing rather high phosphorus (P) concentrations. Habitat accounted for a modest fraction of variation in tissue concentration of all nutrients except P. We concluded that the nutrient status of mire vegetation is primarily controlled by community composition and structure although habitat does exert a direct control on P concentration in the vegetation, presumably through P availability for plant uptake
Il Mondo Degli Elli. Un viaggio nelle Funzioni Esecutive per capirle, provarle e accrescerle
No full textAboveground production and nutrient status of the vegetation of different mire types in the South-eastern Alps (Italy).
No full textWe determined aboveground net primary production
(ANPP) in five mires in the South-eastern Alps of
Italy. The mires differed considerably from each other with
regard to pore-water chemistry, ranging from bog to rich fen.
In different habitat types (hummock, scrub, lawn, fenmeadow,
hollow and marginal stream) within each mire type we
assessed nutrient status based on measurements of nutrient
concentrations and nutrient ratios in the plant biomass in order
to test whether ANPP patterns along the poor-rich gradient
could be related to the limiting effects of one or several
nutrients for biomass production. Vegetation composition
varied considerably both among mire sites and among habitat
types in terms of individual species and plant functional types
(PFTs). Nonetheless, mean ANPP was similar in the five
mires. However, ANPP showed a positive correlation with
total P concentration and negative correlations with the N:P
ratio andwith theK:P ratio of the vegetation.Weconclude that
plant biomass production is limited by P, rather than by other
nutrients, across a broad range of mire types in this region
Manipulating snow cover in an alpine bog: effects on ecosystem respiration and nutrient content in soil and microbes
No full textSnow amount is expected to decline in the Northern hemisphere as an effect of climate warming. However, snow amount in alpine regions will probably undergo stronger interannual fluctuations than elsewhere. We set up a short-term (1 year) experiment in which we manipulated snow cover in an alpine bog, with the following protocol: snow removal at the end of winter; snow removal in spring; snow addition in spring; removal of all aboveground plant tissues with no snow manipulation; no manipulation at all. We measured, at different dates from late spring to early autumn: ecosystem respiration (ER), and concentrations of carbon (C), nitrogen (N) and phosphorus (P) in the soil and in microbes. We hypothesized that longer duration of snow cover will lead to: i) higher ER rates associated with increased microbial biomass; and ii) decreased soil nutrient availability. Contrary to our first hypothesis, ER and microbial C content were unaffected by the snow cover manipulations, probably because ER was decoupled from microbial biomass especially in summer, when CO 2 efflux was dominated by autotrophic respiration. Our second hypothesis also was partially contradicted because nutrient content in the soil and in plants did not vary in relation to snow cover. However, we observed unexpected effects of snow cover manipulations on the N : P ratio in the microbial biomass, which declined after increasing snow cover. This probably depended on stimulation of microbial activity, which enhanced absorption of P, rather than N, by microbes. This may eventually reduce P availability for plant uptake
Dermoscopy of Lymphomas and Pseudolymphomas
No full textPrimary cutaneous lymphomas are a heterogeneous group that includes 2 main groups of primary T- and B-cell lymphomas, which can involve the skin with distinct variability in clinical presentation, histopathology, immunophenotypes, molecular signature, and prognosis. We sought to describe the clinical and dermoscopic features of the most frequent clinical forms of cutaneous lymphomas. The diagnosis of these entities is still based on a cellular level and there are very few reports in literature about dermoscopy of cutaneous lymphomas. Nevertheless, we think that their dermoscopic features can be useful for helping in clinical diagnosis
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