255 research outputs found

    First record of naturalization of Erechtites hieraciifolius (L.) Raf. ex DC. (Asteraceae) in Italy

    Get PDF
    The plant species Erechtites hieraciifolius (Asteraceae) is here reported for the first time in Italy as a naturalized neophyte in the Classical Karst. The species was observed in 2023 in post-fire forest areas burnt by wildfires in the summer 2022. The features of findings suggest for a naturalization of the species with putative invasive character. This novel occurrence highlights the need for additional research to better understand its colonization and expansion, suggesting the need of early eradication actions

    Green roof irrigation management based on substrate water potential assures water saving without affecting plant physiological performance

    Get PDF
    Irrigation management in extensive green roofs (EGRs) is crucial in Mediterranean and semi-arid climates, as it should guarantee efficient water use while ensuring plant survival and vegetation cover. However, benefits of maintaining moderately low substrate water potential (psi(s)) have not been adequately investigated to date. An irrigation control unit based on psi(s) thresholds for irrigation (MediWater Safe [MWS]) was compared to a common irrigation timer maintaining psi(s) similar to 0 MPa (CTR) in shrub-vegetated Mediterranean EGR modules. The effect of the different irrigation regimes on substrate temperature, plant water relations (leaf conductance to water vapour, midday water potential and turgor loss point) and root vulnerability to heat stress via electrolyte leakage was tested in four shrub species. Decreasing psi(s) thresholds to -0.4 MPa reduced irrigation volumes by 68% in 3 summer months. However, the MWS unit neither influenced plant water status and vegetation cover nor induced physiological acclimation responses. Brief irrigation cycles imposed by MWS in the warmest hours reduced substrate surface temperature by 3 degrees C compared to CTR. Plant water status dynamics and root vulnerability to heat were species specific. Progressive stomatal closure and plant decline occurred only in Ceanothus thyrsiflorus and were associated to high root vulnerability to heat. Mortality occurred only in some Ceanothus plants in the CTR module, where higher psi(s) favoured the expansion of Hyperucum x moserianum. The results suggest that selecting proper psi(s) thresholds for irrigation could optimize EGR benefits, guaranteeing substantial water savings and proper plant establishment. Moreover, we claim root resistance to heat as a key parameter for plant selection in Mediterranean EGRs

    The role of psychological flow in adventure tourism: sociodemographic antecedents and consequences on word-of-mouth and life satisfaction

    Get PDF
    While the concept of experience has attracted considerable attention in tourism, the research on psychological flow, as a mental state that tourists may derive from extraordinary experiences, has remained limited, especially in the field of tourism marketing. Yet, this concept might have an important role in promoting sustainable forms of tourism. This paper investigates the sociodemographic antecedents and consequences of psychological flow in the context of adventure tourism, which is a sustainable form of tourism due to its connection with nature and the great potential for assuring extraordinary experiences to tourists by considering mountain biking experiences as a research setting. The empirical results reveal that age is a particularly important sociodemographic antecedent: Indeed, respondents at older ages were more likely to experience psychological flow. Furthermore, reaching this mental state, in turn, increased respondents’ likelihood to disseminate positive information about their experiences and enhanced their satisfaction with life. Theoretical and operational implications are discussed along with main limitations and directions for future research

    Less safety for more efficiency: Water relations and hydraulics of the invasive tree Ailanthus altissima (Mill.) Swingle compared with native Fraxinus ornus L

    Get PDF
    Invasion of natural habitats by alien trees is a threat to forest conservation. Our understanding of fundamental ecophysiological mechanisms promoting plant invasions is still limited, and hydraulic and water relation traits have been only seldom included in studies comparing native and invasive trees. We compared several leaf and wood functional and mechanistic traits in co-occurring Ailanthus altissima (Mill.) Swingle (Aa) and Fraxinus ornus L. (Fo). Aa is one of the most invasive woody species in Europe and North America, currently outcompeting several native trees including Fo. We aimed at quantifying inter-specific differences in terms of: (i) performance in resource use and acquisition; (ii) hydraulic efficiency and safety; (iii) carbon costs associated to leaf and wood construction; and (iv) plasticity of functional and mechanistic traits in response to light availability. Traits related to leaf and wood construction and drought resistance significantly differed between the two species. Fo sustained higher structural costs than Aa, but was more resistant to drought. The lower resistance to drought stress of Aa was counterbalanced by higher water transport efficiency, but possibly required mechanisms of resilience to drought-induced hydraulic damage. Larger phenotypic plasticity of Aa in response to light availability could also promote the invasive potential of the species

    Convexal subarachnoid hemorrhage and acute ischemic stroke: a border zone matter?

    Get PDF
    Background Convexal subarachnoid hemorrhage (c-SAH) is an infrequent condition with variable causes. c-SAH concomitant to acute ischemic stroke (AIS) is even less frequent, and the relationship between the two conditions remains unclear. Methods Between January 2016 and January 2018, we treated four patients who were referred to our stroke unit with ischemic stroke and concomitant nontraumatic c-SAH. The patients underwent an extensive diagnostic workup, including digital subtraction angiography (DSA). Results All four patients developed acute focal neurological symptoms with restricted MRI diffusion in congruent areas. In three of the patients, infarcts were in a border zone between the main cerebral arteries and c-SAH was nearby. The fourth patient showed a small cortical infarct, and c-SAH was in a border zone territory of the contralateral hemisphere. An embolic source was discovered or strongly suspected in all cases. One patient was treated with intravenous thrombolysis, but this treatment was not related to c-SAH. None of the four patients showed microbleeds or further cortical siderosis, thus excluding cerebral amyloid angiopathy. In addition, DSA did not show signs of vasculitis, reversible cerebral vasoconstriction syndrome, or intracranial arterial dissection. Conclusions We proposed the embolism or hemodynamic changes of the border zone arterioles as a unifying pathogenetic hypothesis of coexisting c-SAH and AIS

    Using spectral diversity and heterogeneity measures to map habitat mosaics: An example from the Classical Karst

    Get PDF
    Questions: Can we map complex habitat mosaics from remote-­sensing data? In doing this, are measures of spectral heterogeneity useful to improve image classification performance? Which measures are the most important? How can multitemporal data be integrated in a robust framework? Location: Classical Karst (NE Italy). Methods: First, a habitat map was produced from field surveys. Then, a collection of 12 monthly Sentinel-­2 images was retrieved. Vegetation and spectral heterogeneity (SH) indices were computed and aggregated in four combinations: (1) monthly layers of vegetation and SH indices; (2) seasonal layers of vegetation and SH indices; (3) yearly layers of SH indices computed across the months; and (4) yearly layers of SH indices computed across the seasons. For each combination, a Random Forest clas- sification was performed, first with the complete set of input layers and then with a subset obtained by recursive feature elimination. Training and validation points were independently extracted from field data. Results: The maximum overall accuracy (0.72) was achieved by using seasonally ag- gregated vegetation and SH indices, after the number of vegetation types was re- duced by aggregation from 26 to 11. The use of SH measures significantly increased the overall accuracy of the classification. The spectral β-­diversity was the most im- portant variable in most cases, while the spectral α-­diversity and Rao's Q had a low relative importance, possibly because some habitat patches were small compared to the window used to compute the indices. Conclusions: The results are promising and suggest that image classification frame- works could benefit from the inclusion of SH measures, rarely included before. Habitat mapping in complex landscapes can thus be improved in a cost-­and time-­effective way, suitable for monitoring applications

    Stem photosynthesis contributes to non-structural carbohydrate pool and modulates xylem vulnerability to embolism in Fraxinus ornus L

    Get PDF
    Stem photosynthesis can significantly contribute to the carbon budget of woody plants, providing an extra carbon gain that might be crucial under drought stress causing leaf photosynthesis impairment and/or a reduced phloem transport.Stems of Fraxinus ornus L. saplings were covered with aluminum foil to test the impact of inhibition of stem photosynthesis on plant vulnerability to drought. Plants were water-stressed to target xylem water potential of-3.5 MPa and were then re-irrigated to field capacity to quantify their recovery capacity. Vulnerability to xylem embolism was assessed in light-exposed and stem-shaded saplings with both the hydraulic method and in vivo with X-ray phase contrast micro-computed tomography. We also measured non-structural carbohydrate (NSC) concentration and osmotic potential in bark and wood, separately.Stem shading increased xylem vulnerability to embolism formation under drought but did not influence the recovery phase. This difference was coupled with modification of the NSC pool and impaired osmoregulation, in particular in the wood of stem-shaded saplings compared to control ones.Our results indicate stem photosynthesis as an important source of local NSCs, directly or indirectly involved in osmoregulation processes, which could be crucial to enhance the hydraulic resistance to embolism formation and to endure drought

    The Role of Allogeneic Transplantation in Chronic Myeloid Leukemia in 2023: A Case-Based Concise Review

    Get PDF
    Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of chronic myeloid leukemia (CML), granting patients a life expectancy close to that of the normal population and, in a subset of patients, the possibility to discontinue therapy. Nonetheless, for a not negligible minority of patients, TKIs are not able to control CML. Allogeneic hematopoietic cell transplantation (HCT) has long been a pivotal therapy for CML. At present, allogeneic HCT is considered an option in CML patients diagnosed or progressing to blast phase (BP), for those in chronic phase (CP) resistant to multiple lines of TKI therapy or for those experiencing severe toxicity, mostly hematologic, under TKIs. Moving from real-world cases, we reviewed the results of allogeneic HCT in the setting of advanced-phase CML or failure of TKIs, with a focus on the progresses in transplant technology that has extended transplant options in elderly CML patients and in those lacking a sibling donor, and on the post-HCT strategies for prevention and treatment of disease relapse

    Projections of leaf turgor loss point shifts under future climate change scenarios

    Get PDF
    Predicting the consequences of climate change is of utmost importance to mitigate impacts on vulnerable ecosystems; plant hydraulic traits are particularly useful proxies for predicting functional disruptions potentially occurring in the near future. This study assessed the current and future regional patterns of leaf water potential at turgor loss point (Ψtlp) by measuring and projecting the Ψtlp of 166 vascular plant species (159 angiosperms and 7 gymnosperms) across a large climatic range spanning from alpine to Mediterranean areas in NE Italy. For angiosperms, random forest models predicted a consistent shift toward more negative values in low-elevation areas, whereas for gymnosperms the pattern was more variable, particularly in the alpine sector (i.e., Alps and Prealps). Simulations were also developed to evaluate the number of threatened species under two Ψtlp plasticity scenarios (low vs. high plasticity), and it was found that in the worst-case scenario approximately 72% of the angiosperm species and 68% of gymnosperms within a location were at risk to exceed their physiological plasticity. The different responses to climate change by specific clades might produce reassembly in natural communities, undermining the resilience of natural ecosystems to climate change
    • …
    corecore