79 research outputs found

    Biological invasions are a population-level rather than a species-level phenomenon.

    Get PDF
    Biological invasions pose a rapidly expanding threat to the persistence, functioning and service provisioning of ecosystems globally, and to socio-economic interests. The stages of successful invasions are driven by the same mechanism that underlies adaptive changes across species in general-via natural selection on intraspecific variation in traits that influence survival and reproductive performance (i.e., fitness). Surprisingly, however, the rapid progress in the field of invasion science has resulted in a predominance of species-level approaches (such as deny lists), often irrespective of natural selection theory, local adaptation and other population-level processes that govern successful invasions. To address these issues, we analyse non-native species dynamics at the population level by employing a database of European freshwater macroinvertebrate time series, to investigate spreading speed, abundance dynamics and impact assessments among populations. Our findings reveal substantial variability in spreading speed and abundance trends within and between macroinvertebrate species across biogeographic regions, indicating that levels of invasiveness and impact differ markedly. Discrepancies and inconsistencies among species-level risk screenings and real population-level data were also identified, highlighting the inherent challenges in accurately assessing population-level effects through species-level assessments. In recognition of the importance of population-level assessments, we urge a shift in invasive species management frameworks, which should account for the dynamics of different populations and their environmental context. Adopting an adaptive, region-specific and population-focused approach is imperative, considering the diverse ecological contexts and varying degrees of susceptibility. Such an approach could improve and refine risk assessments while promoting mechanistic understandings of risks and impacts, thereby enabling the development of more effective conservation and management strategies

    Recent advances in hydrothermal carbonisation:from tailored carbon materials and biochemicals to applications and bioenergy

    Get PDF
    Introduced in the literature in 1913 by Bergius, who at the time was studying biomass coalification, hydrothermal carbonisation, as many other technologies based on renewables, was forgotten during the "industrial revolution". It was rediscovered back in 2005, on the one hand, to follow the trend set by Bergius of biomass to coal conversion for decentralised energy generation, and on the other hand as a novel green method to prepare advanced carbon materials and chemicals from biomass in water, at mild temperature, for energy storage and conversion and environmental protection. In this review, we will present an overview on the latest trends in hydrothermal carbonisation including biomass to bioenergy conversion, upgrading of hydrothermal carbons to fuels over heterogeneous catalysts, advanced carbon materials and their applications in batteries, electrocatalysis and heterogeneous catalysis and finally an analysis of the chemicals in the liquid phase as well as a new family of fluorescent nanomaterials formed at the interface between the liquid and solid phases, known as hydrothermal carbon nanodots

    On the principles of B-smooth discontinuous flows

    Get PDF
    In this paper, we define B − smooth discontinuous dynamical systems which can be used as models of various processes in mechanics, electronics, biology and medicine. We find sufficient conditions to guarantee the existence of such systems. These conditions are easy to verify. Appropriate examples are constructed.

    Role of cited-1 and caspase-6 expression in HELLP syndrome

    Get PDF
    OBJECTIVE: In this study, we investigated the immunohistochemical staining of cited-1 and caspase-6 expression in the placentas of pregnant women with HELLP syndrome. PATIENTS AND METHODS: Placentas of 20 normotensive patients and 20 women with HELLP syndrome were processed for routine histological tissue processing. The biochemical and clinical parameters of patients were recorded. Placentas were stained with hematoxylin-eosin and cited-1 and caspase-6 immunostaining. RESULTS: Placentas of normotensive patients showed normal histology. Placentas of women with HELLP syndrome showed degenerated cells, hyalinization and vacuolization. Cited-1 expression was negative in normotensive group; however, it was increased in HELLP group, especially in decidual cells, endothelial cells and other placental cells. Caspase-6 expression was negative in placental structures of normotensive groups. However, it was intense in decidual cells, vacuolar and hyalinized areas, inflammatory cells and connective tissue cells in HELLP group. CONCLUSIONS: Cited-1 and caspase-6 are a marker in determining the severity of HELLP syndrome
    corecore