323,881 research outputs found
Introduction. Vegetation science and the habitats directive. Approaches and methodologies of a never-ending story
No full textRendiconti Lincei has dedicated a Special Issue to present a number of case studies highlighting the role played by the European Vegetation Survey Working Group established by Sandro Pignatti and his colleagues in support to the implementation of the Habitats Directive. Studies include theoretical analyses as well as researches conducted at different spatial and temporal scales focused on the assessment and monitoring of the conservation status of habitats and target plant species, identification of new habitats and subtypes, and their diagnostic species
Geological history and the phytogeography of the Mediterranean region.
No full textManoscritto accettato per la stampa
Edaphic characteristics of Quercus suber woods in Latium.
No full textIn this paper the results are reported of a soil survey done in selected sites of Latium under the most significant Quercus suber woods (Cytiso-Quercetum suberis Testi, Pignatti and Lucattini 1994) previously studied from a phytosociological point of view. After describing the dominant soil type of each area, physical-chemical characteristics have been analysed in order to point out the significance of edaphic factors in the distribution and floristic composition of the Quercus suber coenoses. Bioclimatic, structural and edaphic features of this vegetation showed a great convergence; among all the parameters examined, AWC resulted to be the most effective one in conditioning the mesophilous character of Quercus suber coenoses growing in Latium. In this respect this type of vegetation shows rather strong affinities with mixed Quercus cerris woods, both in the floristic composition and in the edaphic requirements, as already suggested in the most recent phytosociological studies
Diversitas and Biodiversity: the roots of a 21st century myth
No full textThe first on conceptualization of what we now term “biodiversity” was given by Federico Cesi about 400 yrs ago. By the light of the first formulation of this concept, the historical changes in the human approach to “biodiversity” are discussed. The popularity of this term shifted from scientific to socio-political contexts and its significance became progressively blurred by eco-social implications. Biodiversity, today, is perceived by most as an ideal container of the remains of a vanishing traditional landscape, where man and nature lived together harmoniously. This is in contrast with the man’s desire for self-assertion, which has accompanied the civilisation process from its origins up to the birth of the ecology movements. While the present need to promote research on biodiversity arises from the desire to help organisms and ecosystems threatened by man, Federico Cesi and the first Linceans were inspired by the desire to “acquire knowledge and wisdom” in order to improve man’s condition. Between the Cesian view of diversitas and the modern perception of biodiversity, there is the same gap that marked the transition from a “traditional” world, longed for by modern man as an Edenic state, to a “modern” world, probably dreamt by the first Linceans as the point of arrival of a strongly innovative scientific ascent, which was taking its first steps during their time. The strong connecting element between diversitas and biodiversity is represented by a common epistemological approach, i.e. to delineate an exhaustive and shareable bulk of knowledge on living organisms, according to how they appear in the light of a collection of empirical data
11. OROBANCHE L.
No full textTrattamento del genere Orobanche s.l. per la seconda edizione delle Flora d'Italia di Sandro Pignatti
Can the surgical tourniquet be used in patients with sickle cell disease or trait? A review of the literature.
No full textIntroduction: In patients with sickle cell disease, circulatory stasis, acidosis, and hypoxemia induce red cell deoxygenation and consequent sickling. Tourniquets are an important adjunct in limb surgery to obtain a bloodless field. Many local and systemic effects, due to the inflation and deflation of the tourniquet, can develop. These effects may have severe consequences if comorbidities are present. The use of a tourniquet in sickle cell patients is controversial because it may provoke vaso-occlusive complications.
Areas covered: We reviewed the literature to detect reports of the use of tourniquet in sickle cell disease or sickle trait. We found only three case reports and five case series, three of which controlled, none randomized, on the complications of tourniquet.
Expert commentary: From what we could find in the literature and contrary to what is suggested by most guidelines it appears that complications are rare. However, caution must be applied and the risk/ benefit ratio carefully considered
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