3,262 research outputs found

    The solvability of groups with nilpotent minimal coverings

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    A covering of a group is a finite set of proper subgroups whose union is the whole group. A covering is minimal if there is no covering of smaller cardinality, and it is nilpotent if all its members are nilpotent subgroups. We complete a proof that every group that has a nilpotent minimal covering is solvable, starting from the previously known result that a minimal counterexample is an almost simple finite group

    Potential Response of Soil-Borne Fungal Pathogens Affecting Crops to a Scenario of Climate Change in Europe

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    A study was carried out on the potential response of soil-borne pathogens causing crop yield losses under a climate change scenario in Europe. A controlled chamber set of experiments was carried out to quantify pathogen response to temperature using pure colonies of three soil-borne fungi, representative of low (Fusarium nivale), medium-high (Athelia rolfsii) and high (Macrophomina phaseolina) temperature requirements. A generic model to simulate fungal growth response to temperature based on these experiments was developed and linked to a soil temperature model component, and to components to simulate soil water content accounting for crop water uptake of potential hosts. Pathogens relative growth was simulated over Europe using the IPCC A1B emission scenario as realization of the Hadley-CM3 global climate model, available from the European Commission and processed for use with biophysical models. The simulations resulting from using the time span centred on 2030 were compared to the baseline, centred on the year 2000, using a sample of 30 years of daily weather. The general trend of soil-borne pathogens response to the scenario of climate change is a relative increase in growth in colder areas of Europe, as a function of their temperature requirements. Projections of F. nivale in the future indicate a relative increase of this winter pathogen of wheat in Northern European countries. A. rolfsii and M. phaseolina, two soil-borne pathogens typical of warmer agricultural areas, could find more favourable conditions in areas of the Central Europe, but they differentiated in Southern Europe where A. rolfsii resulted affected by summer soil temperatures above optimum

    β-blockers : their new life from hypertension to cancer and migraine

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    The pharmacological class of \u3b2-blockers includes a plea of molecules with largely different pharmacokinetic and pharmacodynamic characteristics with a protective effect that may span far beyond the cardiovascular system. Although all these compounds share the pharmacological blockade of the adrenergic receptors, each of them is characterized by specific pharmacological properties, including selectivity of action depending on the adrenergic receptors subtypes, intrinsic sympathomimetic activity (ISA), lipid solubility, pharmacokinetic profile, and also other ancillary properties that impact their clinical effect. Their use in the treatment of hypertension has been extensively debated and at the moment a class indication is not present. However, in specific niche of patients, such as in those young individuals in which hypertension is mainly driven by a sympathetic hyperactivation, strong evidence pose \u3b2-Blockers as a highly reasonable \ufb01rst-line treatment. Lipophilic \u3b2-blockers, specifically propranolol and metoprolol, can cross the Blood Brain Barrier and have a Class A indication for the prophylactic treatment of migraine attacks. Moreover, since \u3b2-adrenergic receptors affect the proliferative process of both cancer and immune cells, their blockade has been associated with metastasis reduction in several epithelial and solid organ tumors posing \u3b2-Blockers as a new attractive, inexpensive and relatively safe therapeutic strategy in patients with several types of cancer. However, further dedicated prospective, randomized, placebo-controlled studies are needed to determine the real efficacy of these compounds

    Chemical Range of Stability for Self-Dusting Ladle Furnace Slags and Destabilizing Effect of Sulfur

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    Ladle furnace slags are characterized by volumetric expansions associated with the transition of dicalcium silicate (C2S) from ÎČ to Îł phase, which generates fine dust during cooling, causing handling and storage issues that further reduce their recycling opportunities. The present work focuses on the effect of slag basicity on dusting and the role of sulfur on slag stability. Seven synthetic ladle slag precursors were made by mixing lime, magnesia, quartz and alumina in different proportions to match effective industrial compositions, increasing the binary basicity and keeping the ternary and quaternary indexes unchanged. Samples were heated to 1500 Â°C for 15 min and monitored during air cooling (< 5 Â°C/s) through thermocouples and camera to characterize the behavior, temperature, and time interval of dusting. The cooled samples were characterized chemically, mineralogically and morphologically. Starting from the chemistry of a self-stabilized slag, five additional slag precursors, characterized by increasing amounts of S, were created and analyzed using the same procedures. Experimental evidence showed the presence of three different dusting behaviors (stable, partial and complete) and stabilization of the slag once an optical basicity of 0.748 or higher was reached. In addition, mayenite was identified as the main phase capable of suppressing the ÎČ to Îł transition by exerting hydrostatic pressure on C2S. Finally, although S can stabilize the ÎČ phase when dissolved in it, after saturation it precipitates as CaS, which can react with mayenite, locally decreasing the optical basicity and allowing dusting. Graphical Abstract: [Figure not available: see fulltext.]

    Niche overlap across landscape variability in summer between two large herbivores using eDNA metabarcoding.

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    Understanding the relationship between a species feeding strategy and its environment (trophic ecology) is critical to assess environmental requirements and improve management policies. However, measuring trophic interactions remains challenging. Among the available methods, quantifying the plant composition of a species' diet indicates how species use their environment and their associated niche overlap. Nevertheless, most studies focusing on herbivore trophic ecology ignore the influence that landscape variability may have. Here, we explored how landscape variability influences diet composition through niche overlap. We used eDNA metabarcoding to quantify the diet composition of two large herbivores of the Bialowieza Forest, red deer (Cervus elaphus) and European bison (Bison bonasus) to investigate how increasing habitat quality (i.e. higher abundance of deciduous forage species) and predation risk (i.e. density of wolf in the area) influence their diet composition and niche partitioning. Our findings indicate diet composition is non-homogeneous across the landscape, both within and between species. Red deer showed greater diet variability and lower niche overlap within species compared to bison. We detected a reduction of niche overlap for red deer with increasing predation risk, leading to more dissimilar diets, suggesting their feeding behaviour is affected by wolf presence. This correlation was not found for bison, which are rarely predated by wolf. Higher habitat quality was associated with higher niche overlap only within bison, probably due to their suboptimal feeding strategy as browsers. These results show the importance of integrating environment-induced diet variation in studies aimed at determining the landscape usage or niche overlap of a species

    Pentraxin 3 in cardiovascular disease

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    The long pentraxin PTX3 is a member of the pentraxin family produced locally by stromal and myeloid cells in response to proinflammatory signals and microbial moieties. The prototype of the pentraxin family is C reactive protein (CRP), a widely-used biomarker in human pathologies with an inflammatory or infectious origin. Data so far describe PTX3 as a multifunctional protein acting as a functional ancestor of antibodies and playing a regulatory role in inflammation. Cardiovascular disease (CVD) is a leading cause of mortality worldwide, and inflammation is crucial in promoting it. Data from animal models indicate that PTX3 can have cardioprotective and atheroprotective roles regulating inflammation. PTX3 has been investigated in several clinical settings as possible biomarker of CVD. Data collected so far indicate that PTX3 plasma levels rise rapidly in acute myocardial infarction, heart failure and cardiac arrest, reflecting the extent of tissue damage and predicting the risk of mortality

    Factors Influencing Greenways Use in Italy: Definition of a Method for Estimation

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    The issue of non-motorized mobility in the last decades has seen increasing attention at the international level. Also in Italy we assisted at the creation of hundreds of miles of trails dedicated to cycling and walking, many of which meet the greenway definition of the European Greenways Association: “Communication routes reserved exclusively for non-motorized journeys, developed in an integrated manner which enhances both the environment and quality of life of the surrounding area. These routes should meet satisfactory standards of width, gradient, and surface condition to ensure that they are both user-friendly and low-risk for users of all abilities. In this respect, canal towpaths and disused railway lines are a highly suitable resource for the development of greenways” (EGWA, 2002). More generally, greenways are green infrastructures that can be planned at different scales and for multiple purposes (ecological, recreational, cultural, non-motorized mobility) (Fabos, 1995; Ahern, 1995). Various methodologies and several studies on greenways planning have been conducted also in Italy (Rovelli et al., 2004; Toccolini et al., 2006; Senes et al., 2010). The growing number of infrastructures built and the related costs, combined with the recent economic crisis, led to an increasing need for public bodies to evaluate each project in terms of its ability to meet the needs of the communities, particularly in terms of attractiveness for users and benefits (not only economic) for local communities. To do this, planners and decision makers need to be provided with: 1) updated and consistent data on greenways and trails users; 2) models, based on the previous data, that can help to predict the number of users on a planned infrastructure. In such a context, the aim of this research was to assess the relationships between the number of users detected along some Italian greenways and the characteristics of the territory crossed (in terms of population and environment), in order to define a model capable of estimating the potential users of a greenway before it is realized. It represents one of the first attempts in Italy

    “Not walled facts, their essence”: Derek Walcott’s Tiepolo’s Hound and Camille Pissarro

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    Life-writing — a genre which goes beyond traditional biography, includes both fact and fiction, and is concerned with either entire lives or days-in-the-lives of individuals, communities, objects, or institutions — has always played an important role in Derek Walcott’s work, from Another Life (1973),Walcott’s autobiography in verse, to his last play O Starry Starry Night (2014), where he re-imagines Paul Gauguin and Vincent Van Gogh’s (often tempestuous) cohabitation in the so-called “Yellow House” in 1888 Arles. In Tiepolo’s Hound (2000), Walcott’s life rhymes with that of the Impressionist painter Jacob Camille Pissarro, who was born in the Caribbean island of St Thomas in 1830. In this work, biographical and autobiographical impulses, fact and fiction, are productively combined, as “creation” (what “might have happened”) shapes Walcott’s life-writing as much as “recreation” (what “actually” happened). Walcott’s Pissarro is an individual immersed in a set of historical networks but also a figure at the centre of a web of imagined relations which illuminate the predicament of present and past artists in the Caribbean region and the ways in which they articulate their vision vis-à-vis the metropolitan centre, their relationship with their social and natural environment, and their individual and collective identity. Tiepolo’s Hound is enriched by the inclusion of twenty-six of Walcott’s own paintings which engage in conversation with the poet’s words and add complexity to his meditation on the nature and purpose of (re)writing and (re)creating lives. Extending the catholicity of life-writing to animals, in this case dogs and, in particular, mongrels, Tiepolo’s Hound also entails a careful, if counterintuitive, evaluation of anonymity
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