101,954 research outputs found
IL RECUPERO AMBIENTALE E LA PRODUZIONE DI ELEMENTI DI PREGIO DELLA FLORA SPONTANEA: UN NUOVO METODO PER “DIGERIRE” L’INTEGUMENTO DEI SEMI PER LA PROPAGAZIONE DI SPECIE DI BASSA GERMINABILITÀ
No full textIl recupero della vegetazione può essere eseguito utilizzando vari metodi, dalla semina di miscugli per la preservazione, come il fiorume, alla produzione di piante in vaso da trapiantare in natura. Purtroppo l‟esistenza di meccanismi di dormienza dei semi rende difficile la germinazione e la propagazione ex situ di alcune piante spontanee, spesso elementi rari o di pregio della nostra flora. La dormienza può essere associata alla presenza di un integumento rigido e impermeabile costituito per la maggior parte di lignina (legno). I metodi tradizionali per la scarificazione dell‟integumento utilizzano sostanze chimiche corrosive, come l‟acido solforico o l‟ipoclorito di sodio, che possono però danneggiare anche l‟embrione del seme e/o avere effetti collaterali sulla germinazione e lo sviluppo della pianta. Nel presente lavoro viene analizzata l‟ipotesi che enzimi prodotti da funghi per la digestione della lignina (ligninasi), possano essere impiegati per rompere il tegumento del seme e stimolare la germinazione, con particolare riferimento alle orchidee spontanee delle praterie semi-naturali. Una ligninasi è stata somministrata a semi di Himantoglossum adriaticum e Anacamptis morio in condizioni sterili in vitro, utilizzando due metodi: (1) incorporazione dell‟enzima direttamente nel substrato di agarosio; o (2) “bagnatura” dei semi dopo la semina con aggiunta di una soluzione sterile dell‟enzima. In entrambi i casi è stata utilizzata la concentrazione di 1 unità attiva di enzima per lotto di semi/piastra Petri. Dopo sei mesi, il tasso finale di germinazione per entrambe le specie è raddoppiato rispetto al controllo, soltanto quando l‟enzima è stato aggiunto al substrato, nel caso di A. morio da 25 a 50%, mentre per H. adriaticum da 2 a 5%. Per contro, il trattamento con la “bagnatura” di enzima ha significativamente ridotto la germinazione rispetto al controllo, introducendo tra l‟altro contaminazioni. I tassi di germinazione ottenuti possono apparire bassi; tuttavia in specie che producono migliaia di semi per frutto come le orchidee, un modesto incremento nella germinazione può tradursi in un consistente aumento in termini di piante prodotte. L‟utilizzo delle ligninasi nella propagazione di specie rare appare dunque particolarmente promettente, anche perché l‟intervento è mirato all‟integumento, senza il rischio di indurre potenziali complicazioni allo sviluppo dell‟embrione
Correction to: Outcomes on safety and efficacy of left atrial appendage occlusion in end stage renal disease patients undergoing dialysis (Journal of Nephrology, (2021), 34, 1, (63-73), 10.1007/s40620-020-00774-5)
No full textThe article Outcomes on safety and efficacy of left atrial appendage occlusion in end stage renal disease patients undergoing dialysis, written by Simonetta Genovesi, Luca Porcu, Giorgio Slaviero, Gavino Casu, Silvio Bertoli, Antonio Sagone, Monique Buskermolen, Federico Pieruzzi, Giovanni Rovaris, Alberto Montoli, Jacopo Oreglia, Emanuela Piccaluga, Giulio Molon, Mario Gaggiotti, Federica Ettori, Achille Gaspardone, Roberto Palumbo, Francesca Viazzi, Marco Breschi, Maurizio Gallieni, Gina Contaldo, Giuseppe D’Angelo, Pierluigi Merella, Fabio Galli, Paola Rebora, Mariagrazia Valsecchi, and Patrizio Mazzone, was originally published electronically on the publisher’s internet portal on 6 June 2020 without open access. With the author(s)’ decision to opt for Open Choice the copyright of the article changed on 10 July 2020 to © The Author(s) 2020 and this article is licensed under a Creative Commons Attribution 4.0 International License (http://creat iveco mmons .org/licen ses/ by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The original article has been updated
Assessing the effectiveness of the Natura 2000 Special Areas of Conservation strategy: the case of N-Adriatic sandy coastal ecosystem.
No full textCoastal sand dune landscapes hold habitats of high economic, social and ecological value on a global scale.
At the same time, they are among the most threatened ecosystems worldwide, facing escalating anthropogenic pressures, drawing attention to how to achieve trade-offs among society’s needs in land-use allocation and long-term biodiversity conservation. On the European scale, the most important conservation effort being so far implemented is the Natura 2000 Network (N2K) of protected sites.
According to Article 11 of the Habitats Directive, EU member states are asked to provide monitoring, management and impact assessment aiming at the maintenance of the natural habitats and species referred to in Article 2 with particular concern to priority habitat types and species.
To date, monitoring has primarily been tackled at wide scale, and a vast number of indicators are being established to provide bases for national and EU level biodiversity conservation assessment as well as for the implementation and evaluation of efficacy of the EC Biodiversity Strategy and Action Plans.
However, Article 6 also requires member states to take all the necessary measures to ensure a “favourable conservation status” (FCS) on individual N2K site level. As referred to in the Article 1, a sound assessment of FCS requires information on habitats’ structure and function, which reflect patterns and processes at local scale.
Therefore, the assessment of the conservation status of habitats’ structure and function necessarily claims for lower level, habitat-and site-based monitoring, as these variables are difficult to measure at coarser scales.
The study was undertaken on the North-Adriatic coastal landscape, which suffers from a severe and complex human utilization meanwhile holding high landscape, faunal and floral values.
As plant communities, because of their specific nature, are considered good indicators of overall biodiversity and of ecosystem integrity of coastal dune environments, effects of both human and natural disturbance have been analysed through a comparison between real and potential coastal vegetation.
To provide a comprehensive framework for sustainable coastal management and development, a multiscale method for the assessment of the conservation status of sandy coastal environment has been applied.
The assessing methodology focused first on floristic, vegetational and structural aspects of plant communities that were analyzed along the main environmental gradient, which develops moving inland from the sea edge.
At site level, analyses were carried out by means of structural and compositional indicators.
At a broader scale, that is, landscape level, we tried to apply some “Resource Use”
Indicators to characterise the pressures on coastal N2K sites.
Conservation status of N-Adriatic coastal zonation resulted fairly good at only few sites along the coast, mostly located where urban development and tourism are limited by legislation or simply because of the difficulty in reaching them.
Elsewhere, real vegetation is deeply different from the potential zonation erosion and tourism pressures truncate the first elements of the zonation, while towns and villages, coastal roads, pines plantations and agriculture truncate the last stages and sandy systems are trapped between erosion on the sea side and human settlements inlands, with no space for natural sediment dynamics and communities development
The use of plant community attributes to detect habitat quality in coastal environments
No full textThe monitoring of biodiversity has mainly focused on the species level. However, researchers and land managers are making increasing use of complementary assessment tools that address higher levels of biological organization, i.e. communities, habitats and ecosystems. Recently, a variety of frameworks have been proposed for assessing the conservation status of communities or ecosystems. Among the various criteria proposed, all the protocols suggest considering (i) spatial aspects (range and area), and (ii) qualitative aspects of specific structures and functions. However, changes to ecological function are difficult to quantify and many protocols end up by using qualitative criteria. The aim of this work was to test the efficacy of some plant community attributes for the detection of vegetation quality in sand dune plant communities. We chose plant community attributes that either help to distinguish a habitat from others (diagnostic components) or play a significant role in habitat function and persistence over time. We used a diachronic approach by contrasting up-to-date vegetation data with data from previous studies carried out within the same areas. Changes in species composition were detected through detrended correspondence analyses (detrended correspondence analyses), Multi-Response Permutation Procedures and Indicator Species Analysis, while structural changes were analyzed by comparing species richness, total species cover, ecological groups of species and growth forms through null models. Ecological groups such as native focal species and aliens, and growth forms proved their efficacy in discriminating between habitat types and in describing their changes over time. The approach used in this study may provide an instrument for the assessment of plant community quality that can be applied to other coastal ecosystems
Actions for plant biodiversity improvement and recovery in lowland ancient woods and artificial forest stands
No full textItalian forest ecosystems, characterized by a long tradition of forestry and agro-pastoral practices that have guided their evolution, have ensured the preservation over time of significant aspects of naturalness to which important landscape,ecological (carbon stock) and recreational values are associated.
These functions have become increasingly important leading to the implementation of several reforestation projects. Nevertheless, the new forest stands, born on lands subject to agricultural use for a long time, evolve into ecologically sustainable ecosystems only in a very long time.
One of the main findings of this process is represented both by the structure of biological communities and their complexity, which remain greatly simplified for a long time.
In particular, nemoral herbaceous species, which represent the most valuable and ecologically significant component of a forest habitat, remain confined to the ―ancient forests‖. These species, closely habitat-specific and substantially unable to adapt to the environmental changes (Buffa and Villani in pubbl.; Eckert, 2002; Honnay et al., 1999), are in risk of local extinction due to the small size and isolation of their populations.
In order to preserve the venetian lowland ecotypes, some experiments were started in 2010 with the aim of producing some target species (Arum maculatum L., Allium ursinum L., Asparagus tenuifolius Lam., Carex remota L., Colchicum autumnale L., Mercurialis perennis L., Lamium orvala L., Leucojum vernum L., Loncomelos pyrenaicum (L.) Hrouda ex J. Holub s.l., Paris quadrifolia L., Ranunculus auricomus L., Viola reichenbachiana Jordan ex Boureau).
The peculiarities of the environment in which these species are adapted impose a continuous integration of autoecology knowledge with plant nursery techniques. Thus in situ (ancient forest) and ex situ (germination room and outdoors cultivation tunnel) germination tests were carried out to understand how soil variables (texture, pH, organic C, N, P), physical environment variables (quantity and quality of light radiation in the undergrowth) and microclimatic variables (soil T at 0 cm) allow to break dormancy, induce germination and promote seedlings recruitment.
The comparison of in situ and ex situ tests showed that for the majority of the species germinating output is significantly higher in natural conditions or artificial conditions that simulate more accurately the natural ones than in germination room.
Seeds of some species kept at 20 ° C in dry storage (eg. Leucojum vernum L., Mercurialis perennis L.) showed a reduction of viability even more than 80% in 6 months since the collection date, proving potential recalcitrance, and explaining the negative results for their germination tests.
The first results encourage further tests in order to implement the knowledge on the production of these species, which is desirable both in terms of biodiversity conservation, and for the reinforcement of existing populations or for the naturalization of artificial forests. A new frontier, finally, may be offered by their use in private gardens (for aesthetic and naturalistic reasons, in a sort of transposition of the bird-gardening practice within the conservation of nemoral species), with the activation of a production chain giving also employment benefits
Antiseptics for burns: a review of the evidence
No full textThe burn patient is easily subject to colonization by microorganisms and infection, due to reduced defence capabilities and immune dysfunction. Moreover, burn units and intensive care units are characterized by a selection of resistant bacterial strains. If the burn patient is not adequately cared for in terms of infection prevention and control, sepsis is inevitable. Nowadays, several different antiseptics and antiseptic dressings are used in the topical treatment of burns, each with positive and negative effects. Topical antiseptics allow control of bacterial load, but they can also cause cytotoxicity and reduce healing rate. Choosing the most effective antiseptic is crucial to preventing infection from compromising wound healing. The present study aims to review the available literature in order to highlight evidence on the use of topical antiseptics in burns
Long-term outcome of patients who require renal replacement therapy after cardiac surgery
No full textBackground and objective: Acute renal failure is a serious complication of cardiac surgery. We studied the long-term survival and quality of life of patients requiring renal replacement therapy after cardiac surgery, since they represent a heavy burden on hospital resources and their outcome has never been adequately evaluated. Methods: Out of 7846 consecutive cardiac surgical patients, 126 (1.6%) required postoperative renal replacement therapy: their preoperative status and hospital course was compared with patients who had no need of postoperative renal replacement therapy. A multivariate analysis identified predictors of renal replacement therapy. Longterm survival and quality of life was collected in patients who had renal replacement therapy and in casematched controls. Results: Hospital mortality in the study group was 84/126 (66.7%) vs. 118/7720 (1.5%) in the control population (P < 0.001). Patients who underwent renal replacement therapy and were discharged from the hospital (42 patients) had a reasonable long-term outcome: at 42 +/- 23 months, 30 out of 42 patients were alive, with only 3 patients complaining of limitations in daily activities. Predictors of in-hospital renal replacement therapy were: emergency surgery, preoperative renal Impairment, intra-aortic balloon pumping, reoperation for bleeding, previous cardiac surgery, female gender, low ejection fraction, bleeding &rt; 1000 mL, chronic obstructive pulmonary disease and age. Conclusions: This study confirms that the in-hospital mortality of patients requiring renal replacement therapy is high and shows a low long-term mortality with reasonable quality of life in patients discharged from hospital alive
Designing fin structure by topology optimization for maximizing heat transfer efficiency of latent thermal energy storage
No full textThe theory of topology optimization was integrated into the field of solid-liquid phase transition thermal energy storage. A novel fin structure was developed considering the laminar flow of liquid phase change materials, which establishes a robust design method for fin optimization in shell-and-tube latent thermal energy storage unit. In the two-dimensional latent thermal energy storage unit, convection topology optimization was used to design and optimize the topological fin structure. The influences of penalty factor and filter radius on the evolution of topology fins were clarified, meanwhile the effects of natural convection, the volume fraction of high thermal conductivity material, on the fin structure were analyzed. Natural convection is a sufficient condition for the topological fin structure to be asymmetrical along the vertical direction. When natural convection is considered, the distribution of the fin structure along the gravity direction is asymmetrical and uneven, and t..
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