99 research outputs found

    Assessing the solid-liquid discharge and rheological behavior of debris flow. A numerical model of a case study

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    The Friuli Venezia Giulia (FVG) region, located in the northeast of Italy, is characterised by frequent heavy precipitations that recurrently trigger debris flow phenomena. On August 2003, an intense rainfall concentrated in the north-eastern Julian Alps of FVG produced several floods and debris flow events, widespread on the entire basin of the Fella river watershed, with great economic damage and some casualties. In the light of this, forecasting tools for the debris-flow analysis are useful with a view to a territorial planning. The general aim of our research is to develop a hydro-morphodynamical framework to study debris flow phenomena, which includes the hydrological modelling of the rainfall triggering event, the estimate of the solid-liquid discharge of the debris-flow and the hydraulic modelling of its propagation. While previous works have accomplished the hydrological analysis, in the present study we focus on the evaluation of the solid-liquid discharge and the simulation of its propagation down the slope till its stop. Specifically, we considered a sub-basin of the Fella river watershed, the Uque at Ugovizza, and, in particular, a sub-area of the basin from which the debris flow that swept the village of Ugovizza in 2003 came off. The resulting liquid discharge obtained from the previous hydrological analysis was the input data to derive the solid-liquid discharge of the debris flow, which was assessed by using a formulation proposed in literature. In order to study the propagation of the debris flow, we first identified a rheology model suitable to represent this kind of events. This was then implemented into an in-house numerical model, which integrates the bidimensional shallow water equations by means of finite volume techniques. Furthermore, an appropriate runout criterion was also assessed, so that the final stages of the phenomenon can be represented. The first results of the application of the developed hydro-morphodynamic framework to this case study are presented and discussed

    Paternity analyses for the planning of SIT projects against the red palm weevil

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    The red palm weevil Rhynchophorus ferrugineus is an invasive pest from southeastern Asia and Melanesia that has spread widely across the Middle East and the Mediterranean Basin over the last 30 years. Its endophagous larvae cause huge amounts of damage to several palm tree species from the Arecaceae family. Many of these palms are economically important for agricultural and ornamental purposes. Therefore, a lot of attention has recently been focused on studying this species with the aim of identifying sustainable and effective eradication strategies. Sterile insect techniques are biological control strategies that are currently being investigated for their potential to eradicate this pest in selected invasion areas. Mating system features (e.g., polyandry and related features) can affect the success and suitability of these approaches. The main goal of this research was to assess the performance of a previously developed microsatellite panel in terms of the paternity assignment of progeny from laboratory mating experiments. Using a simulation approach, we evaluated the reliability of the microsatellite markers in the paternity tests both in complex laboratory experiment scenarios and on the progeny of wild-caught gravid females to help future studies on the RPW mating system. As a case study of the simulation results, we performed two double-mating experiments, genotyped the progeny and estimated the P2 values to compare to the expected progeny genotypes according to the crossing scheme of each experiment. The results of our simulations on laboratory experiments showed that it was possible to carry out paternity assignments for all progeny with reliable statistical confidence using our 13 microsatellites set. On the contrary the low genetic variability measured in red palm weevil populations in invaded areas made the resolution power of our loci too low to carry out paternity analyses on natural populations. Results of laboratory crossing were completely congruent with the expectations from the Mendelian laws

    Could Hop-derived Bitter Compounds Improve Glucose Homeostasis by Stimulating the Secretion of GLP-1?

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    Hops (Humulus lupulus L.) is by far the greatest contributors to the bitter property of beer. Over the past years, a large body of evidence demonstrated the presence of taste receptors in different locations of the oral cavity. In addition to the taste buds of the tongue, cells expressing these receptors have been identified in olfactory bulbs, respiratory and gastrointestinal tract. In the gut, the attention was mainly directed to sweet Taste Receptor (T1R) and bitter Taste Receptor (T2R) receptors. In particular, T2R has shown to modulate secretion of different gut hormones, mainly Glucagon-like Peptide 1 (GLP-1), which are involved in the regulation of glucose homeostasis and the control of gut motility, thereby increasing the sense of satiety. Scientific interest in the activity of bitter taste receptors emerges because of their wide distribution in the human species and the large range of natural substances that interact with them. Beer, whose alcohol content is lower than in other common alcoholic beverages, contains a considerable amount of bitter compounds and current scientific evidence shows a direct effect of beer compounds on glucose homeostasis. The purpose of this paper is to review the available literature data in order to substantiate the novel hypothesis of a possible direct effect of hop-derived bitter compounds on secretion of GLP-1, through the activation of T2R, with consequent improvement of glucose homeostasis

    Electrocution and containment methods to reduce the activity of red palm weevil (Rhynchophorus ferrugineus, Ol.)

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    Aim of study: To evaluate the susceptibility of the Rhynchophorus ferrugineus to electric discharges, to eventually use this application in synergy with other methods as part of an integrated control strategy.Area of study: Worldwide.Material and methods: Three different electric voltage intensities were applied to R. ferrugineus to investigate the insect’s susceptibility in both adult and larval stages. The transmission and diffusion of electricity within a portion of the palm tree was tested. In addition, the suitability of containment materials for handling and transportation of plant residues was tested.Main results: The results of adult test showed that the total number of eggs laid per mating couple and the number of larvae born were about 1.5 times higher in the control compared to the electrified samples. The duration of the electric discharge on larvae had a small impact on the mortality rate, while the electric voltage showed a strong impact on mortality (87% for 10 V and 99% for 15 V). The presence of a significant electric current was observed in a viable portion of stem (distance from the source of electricity 10 cm) providing a direct current with 250 V tension. Among the materials tested for the transportation of palm residues, the aluminium net sheet showed the best results in the containment of both larval and adult individuals.Research highlights: Electrocution has proven to be a system which can help in the control of red palm weevil reducing the use of synthetic chemicals

    Miglioramento delle abilità linguistiche e dell'assertività nei disturbi del comportamento alimentare: studio randomizzato controllato di un'attività di laboratorio letterario [Improving linguistic skills and assertiveness in eating disorders: A randomized controlled trial on a literary workshop activity]

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    Objectives: To assess the effectiveness of a literary workshop activity for increasing linguistic skills and assertiveness in patients with eating disorders (ED). Methods: Twenty-four patients consequently admitted to the ED in-patient unit at the private clinic "Villa Maria Luigia" (Parma, Northern Italy) were enrolled in the study. Of these, 8 were randomly assigned to treatment and 16 to care as usual (the only difference between treatment and care as usual was the literary workshop activity). The literary workshop consisted in 15 weekly 60-minute group sessions. Linguistic and expressive skills were provided and tested during the sessions. The Rathus Assertiveness Schedule and the Verbal Fluency Test (phonemic and semantic) were administered to all patients at the beginning and end of hospitalization. Results: A significant improvement of semantic skills, phonetic skills and assertiveness (p < 0.01) was registered in the treatment group. A positive correlation was also found between variations of linguistic skills and assertiveness in the treatment group, but not in the control group. Conclusions: The results of this study suggest that a literary workshop activity within a rehabilitation program for patients suffering from ED can aid in improving communication and language skills that might have a positive and significant impact on levels of assertiveness

    Active DNA demethylation of developmental cis-regulatory regions predates vertebrate origins

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    DNA methylation [5-methylcytosine (5mC)] is a repressive gene-regulatory mark required for vertebrate embryogenesis. Genomic 5mC is tightly regulated through the action of DNA methyltransferases, which deposit 5mC, and ten-eleven translocation (TET) enzymes, which participate in its active removal through the formation of 5-hydroxymethylcytosine (5hmC). TET enzymes are essential for mammalian gastrulation and activation of vertebrate developmental enhancers; however, to date, a clear picture of 5hmC function, abundance, and genomic distribution in nonvertebrate lineages is lacking. By using base-resolution 5mC and 5hmC quantification during sea urchin and lancelet embryogenesis, we shed light on the roles of nonvertebrate 5hmC and TET enzymes. We find that these invertebrate deuterostomes use TET enzymes for targeted demethylation of regulatory regions associated with developmental genes and show that the complement of identified 5hmC-regulated genes is conserved to vertebrates. This work demonstrates that active 5mC removal from regulatory regions is a common feature of deuterostome embryogenesis suggestive of an unexpected deep conservation of a major gene-regulatory module

    Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects

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    The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E2^{-2} shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E2^{-2} be able to explain the observations
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