7 research outputs found
Shedding light on typical species : implications for habitat monitoring
Habitat monitoring in Europe is regulated by Article 17 of the Habitats Directive, which suggests the use of typical species to assess habitat conservation status. Yet, the Directive uses the term “typical” species but does not provide a definition, either for its use in reporting or for its use in impact assessments. To address the issue, an online workshop was organized by the Italian Society for Vegetation Science (SISV) to shed light on the diversity of perspectives regarding the different concepts of typical species, and to discuss the possible implications for habitat monitoring. To this aim, we inquired 73 people with a very different degree of expertise in the field of vegetation science by means of a tailored survey composed of six questions. We analysed the data using Pearson's Chi-squared test to verify that the answers diverged from a random distribution and checked the effect of the degree of experience of the surveyees on the results. We found that most of the surveyees agreed on the use of the phytosociological method for habitat monitoring and of the diagnostic and characteristic species to evaluate the structural and functional conservation status of habitats. With this contribution, we shed light on the meaning of “typical” species in the context of habitat monitoring
Hematocrit and flow rate regulate the adhesion of platelets to von Willebrand factor
Primary hemostasis and blood clotting is known to be influenced by the red blood cell volume fraction (hematocrit) in blood. Depressed or elevated levels of red blood cells can lead to vascular perfusion problems ranging from bleeding to thrombus formation. The early stage of hemostasis and thus blood clotting in all vessel sections from the arterial to the venous system involves the adhesion of platelets to von Willebrand factor. Here we present experimental and theoretical results showing that the adhesion probability of platelets to von Willebrand factor is strongly and nonlinearly dependent on hematocrit and flow rate. Interestingly, the actual binding forces are not markedly different, which suggest that the origin of such behavior is in the distribution of platelets. Using hydrodynamic simulations of a simple model, we explicitly show that the higher the hematocrit and the flow rate, the larger the amount of platelets residing close to the wall. Our simulation results, which are in excellent agreement with the experimental observations, explain why such phenomena occur. We believe that the nonhomogeneous red blood cell distribution as well as the shear dependent hydrodynamic interaction is key for the accumulation of platelets on the vessel wall. The work we present here is an important step forward from our earlier work on single molecules and extends into the collective cellular behavior of whole blood. It sheds new light on the correlation between hematocrit and the initial steps in hemostasis and thrombosis, and outlines advances for the treatment of vascular diseases associated with high levels of red blood cells. These results are not only highly relevant for the field of hemostasis and the physics of blood clotting but are also of powerful impact in applied science most obviously in drug delivery and colloidal science.National Science Foundation (U.S.) (CAREER Award 1054671
Il pubblico di Palazzo Davanzati nei libri dei visitatori. 1910-1924
A pochi mesi dall\u2019apertura di Palazzo Davanzati, Elia Volpi ebbe l\u2019idea di mettere a disposizione dei visitatori del suo museo privato un libro, dalle pagine bianche, sul quale ognuno avrebbe potuto lasciare la propria firma e un commento, seguendo forse l\u2019esempio di altri musei privati come quello di Frederick Stibbert o il milanese Bagatti Valsecchi. I due libri con le firme dei visitatori dal 1910 al 1924 furono poi donati, per volont\ue0 della moglie Marina Volpi, da Mario Vannini Parenti, genero dell\u2019antiquario e sono oggi conservati nel museo. Lo spoglio sistematico dei dati contenuti in questi straordinari documenti ha fatto emergere aspetti molto significativi riguardanti il numero e la provenienza dei visitatori di Palazzo Davanzati, cos\uec come i riflessi della societ\ue0 del tempo e del contesto storico, rappresentando un interessante caso di studio sul pubblico dei musei in un\u2019epoca precedente all\u2019affermazione del turismo di massa. \uc8 il museo visto dalla parte dei suoi visitatori, studenti, educande, persone comuni o aristocratici d\u2019alto lignaggio, turisti stranieri e non con la passione per Firenze e la sua storia, molti dei quali lasciano un commento, una battuta, anche una poesia, o semplicemente la traccia della loro visita. Davvero numerosi, poi, sono i nomi dei personaggi celebri: storici dell\u2019arte (Adolfo e Lionello Venturi, Roberto Longhi), artisti, letterati e intellettuali (Giovanni Boldini, Sibilla Aleramo, Benedetto Croce), mercanti e collezionisti (Salvatore Romano, Georges Wildenstein, Peggy Guggenheim) o personaggi dello spettacolo (Ettore Petrolini, Rodolfo Valentino). La loro presenza, cos\uec come quella di moltissimi architetti e decoratori stranieri e dei tanti visitatori meno noti, restituiscono un feedback importante a tutte quelle iniziative di promozione del museo che Elia Volpi aveva intrapreso sin dal giorno della sua inaugurazione, attraverso campagne fotografiche, pubblicazioni, cartoline illustrate ed eventi a tema
High Shear Dependent von Willebrand Factor Self-assembly Fostered by Platelet Interaction and Controlled by ADAMTS13
Early rehabilitation for severe acquired brain injury in intensive care unit: multicenter observational study
The increased survival after a severe acquired brain injury (sABI) raise the problem of making most effective the treatments in Intensive Care Unit (ICU)/Neurointensive Care Unit (NICU), also integrating rehabilitation care. Despite previous studies reported that early mobilization in ICU was effective in preventing complications and reducing hospital stay, few studies addressed the rehabilitative management of sABI patients in ICU/NICU
An acidic microenvironment sets the humoral pattern recognition molecule PTX3 in a tissue repair mode
Pentraxin 3 (PTX3) is a fluid-phase pattern recognition molecule and a key component of the humoral arm of innate immunity. In four different models of tissue damage in mice, PTX3 deficiency was associated with increased fibrin deposition and persistence, and thicker clots, followed by increased collagen deposition, when compared with controls. Ptx3-deficient macrophages showed defective pericellular fibrinolysis in vitro. PTX3-bound fibrinogen/fibrin and plasminogen at acidic pH and increased plasmin-mediated fibrinolysis. The second exon-encoded N-terminal domain of PTX3 recapitulated the activity of the intact molecule. Thus, a prototypic component of humoral innate immunity, PTX3, plays a nonredundant role in the orchestration of tissue repair and remodeling. Tissue acidification resulting from metabolic adaptation during tissue repair sets PTX3 in a tissue remodeling and repair mode, suggesting that matrix and microbial recognition are common, ancestral features of the humoral arm of innate immunity