57 research outputs found

    Intraspecific phenotypic variability of plant functional traits in contrasting mountain grasslands habitats

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    Empirical studies that link plants intraspecific variation to environmental conditions are almost lacking, despite their relevance in understanding mechanisms of plant adaptation, in predicting the outcome of environmental change and in conservation. Here, we investigate intraspecific trait variation of four grassland species along with abiotic environmental variation at high spatial resolution (n = 30 samples per species trait and environmental factor per site) in two contrasting grassland habitats in Central Apennines (Italy). We test for phenotypic adaptation between habitats, intraspecific trait-environment relationships within habitats, and the extent of trait and environmental variation. We considered whole plant, clonal, leaf, and seed traits. Differences between habitats were tested using ANOVA and ANCOVA. Trait-environment relationships were assessed using multiple regression models and hierarchical variance partitioning. The extent of variation was calculated using the coefficient of variation. Significant intraspecific differences in trait attributes between the contrasting habitats indicate phenotypic adaptation to in situ environmental conditions. Within habitats, light, soil temperature, and the availability of nitrate, ammonium, magnesium and potassium were the most important factors driving intraspecific trait-environment relationships. Leaf traits and height growth show lower variability than environment being probably more regulated by plants than clonal traits which show much higher variability. We show the adaptive significance of key plant traits leading to intraspecific adaptation of strategies providing insights for conservation of extant grassland communities. We argue that protecting habitats with considerable medium- and small-scale environmental heterogeneity is important to maintain large intraspecific variability within local populations that finally can buffer against uncertainty of future climate and land use scenarios

    Environmental predictors of seed germination in two Halocnemum species from Mediterranean (Balearic, Tyrrenic and Adriatic) and Red Sea coastal salt marshes

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    Reproductive strategies for specific populations are closely related to environmental factors. Consequently, they are fundamental for conservation plans and the management of threatened habitats like salt marshes. From this viewpoint, germination strategy under different temperatures and salt conditions, voltammetric parameters and molecular analysis were performed and compared in six Halocnemum populations (four of H. cruciatum and two of H. strobilaceum) growing on Mediterranean (Balearic, Tyrrenic and Adriatic) and Red Sea coasts to establish the relation to environmental variables. Significant interpopulation differences were found in all the evaluated parameters. The Mediterranean populations showed a variable opportunistic germination strategy that was directly related to the drought period length at the studied sites. Consequently, potential environmental predictors of seed response were identified. The most noteworthy were bioclimate, soil texture, continentality index, winter temperatures and summer precipitations. Additionally, voltammetric parameters were evidenced as indicators of maternal plant stress levels and, thus, as potential determinants of future seed responses. The phylogenetic analyses showed a split into two species that did not correspond to germination response. The phylogeographic analyses showed interpopulation differences in haplotype composition for H. cruciatum, but not for H. strobilaceum. In conclusion, the tight connection between seed responses and the ecological parameters of natural populations as an adaptation for successful seedling emergence was proved regardless of its phylogenetic relations.MICINN Project CTQ2014-53736-C3-2-P and the subsequent PID2020-113022GB-I0

    Results of an Expert Consensus Survey on the Treatment of Pulmonary Arterial Hypertension With Oral Prostacyclin Pathway Agents

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    Background Treatment of pulmonary arterial hypertension (PAH) has evolved substantially over the past two decades and varies according to etiology, functional class (FC), hemodynamic parameters, and other clinical factors. Current guidelines do not provide definitive recommendations regarding the use of oral prostacyclin pathway agents (PPAs) in PAH. To provide guidance on the use of these agents, an expert panel was convened to develop consensus statements for the initiation of oral PPAs in adults with PAH. Methods A systematic literature search was conducted using MEDLINE. The established RAND/University of California Los Angeles appropriateness method, which incorporates the Delphi method and the nominal group technique, was used to create consensus statements. Idiopathic, heritable, repaired congenital heart defect, and drug- or toxin-induced PAH (IPAH+) was considered as one etiologic grouping. The process was focused on the use of oral treprostinil or selexipag in patients with IPAH+ or connective tissue disease-associated PAH and FC II or III symptoms receiving background dual endothelin receptor antagonist/phosphodiesterase type 5 inhibitor therapy. Results The panel developed 14 consensus statements regarding the appropriate use of oral PPAs in the target population. The panel identified 13 clinical scenarios in which selexipag may be considered as a treatment option. Conclusions The paucity of clinical evidence overall, and particularly from randomized trials in this setting, creates a gap in knowledge. These consensus statements are intended to aid physicians in navigating treatment options and using oral PPAs in the most appropriate manner in patients with PAH

    Tissue factor as a potential coagulative/vascular marker in relapsing-remitting multiple sclerosis

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    ObjectivesRecent studies supported coagulation involvement in multiple sclerosis, an inflammatory-demyelinating and degenerative disease of the central nervous system. The main objectives of this observational study were to identify the most specific pro-coagulative/vascular factors for multiple sclerosis pathogenesis and to correlate them with brain hemodynamic abnormalities.MethodsWe compared i) serum/plasma levels of complement(C)/coagulation/vascular factors, viral/microbiological assays, fat-soluble vitamins and lymphocyte count among people with multiple sclerosis sampled in a clinical remission (n=30; 23F/7M, 40 ± 8.14 years) or a relapse (n=30; 24F/6M, age 41 ± 10.74 years) and age/sex-matched controls (n=30; 23F/7M, 40 ± 8.38 years); ii) brain hemodynamic metrics at dynamic susceptibility contrast-enhanced 3T-MRI during relapse and remission, and iii) laboratory data with MRI perfusion metrics and clinical features of people with multiple sclerosis. Two models by Partial Least Squares Discriminant Analysis were performed using two groups as input: (1) multiple sclerosis vs. controls, and (2) relapsing vs. remitting multiple sclerosis.ResultsCompared to controls, multiple sclerosis patients had a higher Body-Mass-Index, Protein-C and activated-C9; and a lower activated-C4. Levels of Tissue-Factor, Tie-2 and P-Selectin/CD62P were lower in relapse compared to remission and HC, whereas Angiopoietin-I was higher in relapsing vs. remitting multiple sclerosis. A lower number of total lymphocytes was found in relapsing multiple sclerosis vs. remitting multiple sclerosis and controls. Cerebral-Blood-Volume was lower in normal-appearing white matter and left caudatum while Cerebral-Blood-Flow was inferior in bilateral putamen in relapsing versus remitting multiple sclerosis. The mean-transit-time of gadolinium-enhancing lesions negatively correlated with Tissue-Factor. The top-5 discriminating variables for model (1) were: EBV-EBNA-1 IgG, Body-Mass-Index, Protein-C, activated-C4 and Tissue-Factor whereas for model (2) were: Tissue-Factor, Angiopoietin-I, MCHC, Vitamin A and T-CD3.ConclusionTissue-factor was one of the top-5 variables in the models discriminating either multiple sclerosis from controls or multiple sclerosis relapse from remission and correlated with mean-transit-time of gadolinium-enhancing lesions. Tissue-factor appears a promising pro-coagulative/vascular biomarker and a possible therapeutic target in relapsing-remitting multiple sclerosis.Clinical trial registrationClinicalTrials.gov, identifier NCT04380220

    Supporting ecological restoration of Italian mountain grasslands: an investigation of intra- and inter-species variation in seed germination behaviour in native grasses

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    Il presente studio risponde alla necessità di acquisire maggiori conoscenze riguardo il possibile impiego di germoplasma autoctono nel restauro delle praterie secondarie, specialmente di quelle protette dalla Direttiva Habitat (92/43/CEE) e riconducibili all’habitat 6210 “Formazioni erbose secche seminaturali e facies coperte da cespugli su substrato calcareo (Festuco-Brometalia)”. I semi trattati in questo studio possono essere usati anche in altri ambienti, quali fossi e margini stradali, o nel restauro di praterie all’interno di HNVf, al posto delle sementi commerciali. Ciò ridurrebbe l’inquinamento genetico della flora autoctona, dovuto all’uso di sementi alloctone, e pertanto la perdita di biodiversità. A questo scopo, sono state realizzate raccolte di semi in varie località dell’Appennino Centro-Orientale. Successivamente, i semi sono stati trattati e conservati seguendo i protocolli internazionali in materia. Prove di laboratorio sono state condotte al fine di acquisire informazioni riguardanti la germinazione delle specie e per verificare l’idoneità dei semi all’uso nelle opere di ripristino. Precisamente, questa ricerca è stata finalizzata a studiare l’influenza dei seguenti fattori sulla germinazione: volume e peso dei semi, temperatura, luce, strutture esterne al seme e stoccaggio. Ognuno dei fattori menzionati interessa aspetti tecnici delle opere di ripristino. I risultati dei test hanno suggerito che i semi studiati dovrebbero essere idonei per i progetti di ripristino. Infatti, essi germinano massicciamente in un ampio range di temperature ed in diverse condizioni, almeno dopo la disidratazione. Quanto dimostrato in questa ricerca costituisce una base scientifica e tecnica per la moltiplicazione dei semi e per le opere di ripristino ambientale. Inoltre, le graminacee studiate sono presenti anche in altri habitat italiani protetti dalla UE, oltre al 6210, quali il 6230*, il 62A0, il 6420, il 6510 e il 6520. Pertanto, i risultati di questa ricerca potranno essere utili anche nella realizzazione di progetti di ripristino riguardanti questi habitat

    Pulmonary hypertension in left heart disease

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    Pulmonary hypertension (PH) is a frequent complication of left heart disease arising from a wide range of cardiac disorders. In the clinical classification, PH associated with left heart disease is classified as Group 2, which includes left heart systolic dysfunction, left heart diastolic dysfunction and left heart valvular disease. In the past, rheumatic mitral valve disease was the most common cause of PH in left heart disease; however, today it is more likely to be associated with hypertensive and/or ischaemic heart disease. As the incidence of these conditions is increasing, the number of patients presenting with PH is also increasing and, today, left heart disease represents the most frequent cause of PH. The development of PH in patients with left heart disease is associated with poor prognosis. However, despite the increasingly large number of patients affected and the impact of PH on outcome, there are currently no specific treatment options for these patients. This review gives an overview of the pathophysiology and epidemiology of PH associated with left heart disease, and discusses the challenges associated with its management and treatment

    The study of risk in pulmonary arterial hypertension

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    A growing body of published evidence exists on the risk factors for disease progression in pulmonary arterial hypertension (PAH). The Scientific Steering Committee for the Study of Risk in PAH was established to bring together leading clinical and statistical experts in PAH and risk modelling, for the purpose of advancing the understanding of the risk of development and progression of PAH. Herein, we discuss the impact of this information on three key areas: 1) clinical decision-making; 2) policy and reimbursement; and 3) future trials and research
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