929 research outputs found

    Vesuvio civil protection exercise MESIMEX: survey on volcanic risk perception.

    Get PDF
    In October 2006 the European Civil Protection Exercise MESIMEX (Somma Vesuvio Mesimex – Major Emergency SIMulation Exercise) on volcanic risk took place at Vesuvio, promoted by Campania Region and coordinated by the Italian Civil Protection Department. The exercise was focused on the preparedness phase for a major volcanic emergency in the area of Vesuvio. An evacuation of a sample of 1800 inhabitants from the Vesuvio Red Zone was also tested during the drill because the emergency plan ensures the complete evacuation of the population from the higher risk zone before the onset of the eruption. During that event a survey on volcanic risk perception was carried out on the evacuated population in order to compare the results with the ones coming from a previous similar survey, using the same questionnaire, carried out on a wider sample of residents in the Vesuvio Red Zone few months before MESIMEX exercise. The aim was to point out any differences in population’s attitude towards volcanic risk after having received detailed information on the emergency plan and on the hazards and risk related to the reactivation of Vesuvio, and experiencing the exercise. 463 questionnaires were distributed to the population evacuated from the 18 municipalities of the Red Zone and participating to the exercise. Main results in comparing data from MESIMEX survey with the Vesuvio previous one, put in evidence how the general level of Vesuvio residents’ trust remains quite low, indicating that a continuous and effective effort has to be done by both scientific community and Civil Protection Department. Particular attention should be paid in education and outreach activities and in involving people in risk mitigation procedures, also through more frequent exercises

    Nucleation Induced Undulative Instability in Thin Films of nCB Liquid Crystals

    Full text link
    A surface instability is reported in thin nematic films of 5CB and 8CB, occurring near the nematic--isotropic phase transition. Although this instability leads to patterns reminiscent of spinodal dewetting, we show that it is actually based on a nucleation mechanism. Its characteristic wavelength does not depend markedly on film thickness, but strongly on the heating rate.Comment: 4 pages, 5 figure

    Chronology of the 2007 eruption of Stromboli and the activity 1 of the Scientific Synthesis Group

    Get PDF
    On 27 February 2007, at 12.49 GMT, a new eruption of Stromboli took place with the effusion of a 15 lava flow from a fracture cutting the flank of the NE cone, which rapidly reached the sea. The eruption 16 had been heralded by an increase in the amplitude of tremor and flank movement since at least the 14th 17 of February. Short-term precursors were an increase in the rate of occurrence of small landslides within 18 the “Sciara del Fuoco” scar on the North-western flank of the volcano. A new effusive vent opened at 19 18.30 GMT on the Sciara del Fuoco at an height of 400 m asl. The new lava emission caused the 20 sudden termination of the summit flow and initiated a period of non-stationary lava outpouring which 21 ended on 2 April, 2007. The eruption has been characterized by a rapid decrease in the eruption rate after the first days and subsequently by episodic pulse increases. On the 15th 22 of March, the increase in 23 lava outpouring, monitored by a thermal camera, heralded by 9 minutes the occurrence of a violent 24 paroxysmal explosion with the formation of an impulsive eruption column and the emission of small 25 pumices mingled with black scoriae. The pumice had a bulk composition similar to that of the lava and 26 of the black scoriae, but with a distinct lower content of phenocrysts. A similar feature has been 27 repeateadly observed during the major explosive paroxysms of Stromboli. Short term precursors of the 28 paroxysm were recorded by strainmeter and tiltmeter stations. The volcano monitoring activity has 29 been made by a joint team of researchers from the INGV sections of Catania, Napoli, Palermo and 30 Rome, along with researchers from the University of Florence, Pisa, Roma Tre, and Palermo. The 31 scientific activity was coordinated by a Synthesis Group made up by the responsibles of the different 32 monitoring techniques of INGV and Universities and by the volcanic experts of Commissione Nazionale Grandi Rischi of the Prime Minister Office (Civil Protection Department). 33 The group made a 34 daily evaluation of the state of the volcano and transmitted its recommendations to the Civil Protection 35 Department (DPC). Several prevention measures were adopted by DPC, the main of which were the 36 evacuation of the coast zone when strong acceleration of the Sciara del Fuoco slope motion (occurred 37 twice) could led to a dangerous tsunami by flank collapse (as last occurred on 30 December 2002) and 38 four days before the 15 March paroxysm when access was prohibited to the part of the volcano above 39 290m as

    Long-term effect of tillage, nitrogen fertilization and cover crops on soil organic carbon and total nitrogen content

    Get PDF
    No-tillage, N fertilization and cover crops are known to play an important role in conserving or increasing SOC and STN but the effects of their interactions are less known. In order to evaluate the single and combined effects of these techniques on SOC and STN content under Mediterranean climate, a long term experiment started in 1993 on a loam soil (Typic Xerofluvent) in Central Italy. The experimental variants are: conventional tillage (CT) and no-tillage (NT), four N fertilization rates (N0, N1, N2 and N3) and four soil cover crop (CC) types (C - no cover crop; NL - non-legume CC; LNL - low nitrogen supply legume CC, and HNL - high nitrogen supply legume CC).The nitrogen fertilization rates (N0, N1, N2 and N3) were: 0, 100, 200, 300kgNha-1 for maize (Zea mays, L.); 0, 60, 120,180kgNa-1 for durum wheat (Triticum durum Desf.); 0, 50, 100, 150kgNha-1 for sunflower (Helianthus annuus L.).From 1993 to 2008, under the NT system the SOC and STN content in the top 30cm soil depth increased by 0.61 and 0.04Mgha-1year-1 respectively. In the same period, the SOC and STN content under the CT system decreased by a rate of 0.06 and 0.04Mgha-1year-1 respectively. During the experimental period, N1, N2 and N3 increased the SOC content in the 0-30cm soil layer at a rate of 0.14, 0.45 and 0.49Mgha-1year-1. Only the higher N fertilization levels (N2 and N3) increased STN content, at a rate of 0.03 and 0.05Mgha-1year-1.NL, LNL and HNL cover crops increased SOC content by 0.17, 0.41 and 0.43MgCha-1year-1 and -0.01, +0.01 and +0.02MgNha-1year-1.Significant interactions among treatments were evident only in the case of the N fertilization by tillage system interaction on SOC and STN concentration in the 0-10. cm soil depth in 2008.The observed SOC and STN variations were correlated to C returned to the soil as crop residues, aboveground cover crop biomass and weeds (C input).We conclude that, under our Mediterranean climate, it is easier to conserve or increase SOC and STN by adopting NT than CT. To reach this objective, the CT system requires higher N fertilization rates and introduction of highly productive cover crops

    Ordered interfaces for dual easy axes in liquid crystals

    Get PDF
    International audienceUsing nCB films adsorbed on MoS 2 substrates studied by x-ray diffraction, optical microscopy and Scanning Tunneling Microscopy, we demonstrate that ordered interfaces with well-defined orientations of adsorbed dipoles induce planar anchoring locked along the adsorbed dipoles or the alkyl chains, which play the role of easy axes. For two alternating orientations of the adsorbed dipoles or dipoles and alkyl chains, bi-stability of anchoring can be obtained. The results are explained using the introduction of fourth order terms in the phenomenological anchoring potential, leading to the demonstration of first order anchoring transition in these systems. Using this phenomenological anchoring potential, we finally show how the nature of anchoring in presence of dual easy axes (inducing bi-stability or average orientation between the two easy axes) can be related to the microscopical nature of the interface. Introduction Understanding the interactions between liquid crystal (LC) and a solid substrate is of clear applied interest, the vast majority of LC displays relying on control of interfaces. However this concerns also fundamental problems like wetting phenomena and all phenomena of orientation of soft matter bulk induced by the presence of an interface. In LCs at interfaces, the so-called easy axes correspond to the favoured orientations of the LC director close to the interface. If one easy axis only is defined for one given interface, the bulk director orients along or close to this axis [1]. It is well known that, in anchoring phenomena, two major effects compete to impose the anchoring directions of a liquid crystal, first, the interactions between molecules and the interface, second, the substrate roughness whose role has been analyzed by Berreman [2]. The influence of adsorbed molecular functional groups at the interface is most often dominant with, for example in carbon substrates, a main influence of unsaturated carbon bonds orientation at the interface [3]. In common LC displays, there is one unique easy axis, but modifications of surfaces have allowed for the discovery of promising new anchoring-related properties. For instance, the first anchoring bi-stability has been established on rough surfaces, associated with electric ordo-polarization [4] and the competition between a stabilizing short-range term and a destabilizing long-range term induced by an external field, can induce a continuous variation of anchoring orientation [5]. More recently, surfaces with several easy axes have been studied extensively. It has been shown that control of a continuous variation of director pretilt, obtained in several systems [6, 7], is associated with the presence of two different easy axes, one perpendicular to the substrate (homeotropic) and one planar [7, 8]. Similar models can explain the continuous evolution of anchoring between two planar orientations observed on some crystalline substrates [9]. However, in the same time, two easy axes can also lead to anchoring bi-stability [10, 11] or discontinuous transitions of anchoring [9], which is not compatible with the model established to interpret observed control of pretilt. In order to be able to predict if bi-stability or continuous combination of the two easy axes occurs for one given system, it becomes necessary to understand the microscopic origin of the easy axes

    Assessing seismic efficiency from scalar Moment-rates: an application to Mt. Etna volcano (Italy)

    Get PDF
    Here we propose an improved estimation of the scalar seismic (from instrumental and historical catalogues), geodetic and geologic moment-rates for the eastern flank of Mt. Etna. The estimated moment-rates have been compared in terms of seismic efficiency. Results show that all the calculated efficiency values are lower than 40%, i.e., the geodetic moment-rate estimations are generally larger than the seismic and the geologic ones. Although a number of reasons may account for the observed discrepancy, we are confident that a large amount of the deformation affecting the eastern flank occurs aseismically

    Organic vs conventional stockless arable systems: a multidisciplinary approach to soil quality evaluation

    Get PDF
    Soil quality in Mediterranean conventional and organic stockless arable systems was assessed by a multidisciplinary approach. At the end of the first cycle of a 5-year crop rotation (2002–2006) in the Mediterranean Arable Systems Comparison Trial (MASCOT) long-term experiment, the effects of organic and conventional management systems were evaluated by using soil chemical, biochemical and biological parameters. Chemical and biochemical parameters linked to soil C cycle, arbuscular mycorrhizal fungi (AMF) and microarthropod communities were analysed according to a comparative approach. Results suggested a higher soil carbon sequestration in the organic respect to the conventional system, as shown by the values of total organic C (9.5 and 7.8 g kg1, for organic and conventional system, respectively) and potentially mineralisable C (277 and 254 mg kg1, for organic and conventional system, respectively). AMF population, AMF root colonisation and diversity of microarthropod population were slightly influenced by management system. On the other hand, mites/collembolans ratio was higher in conventionally than in organically managed soil (2.67 and 1.30, respectively), indicating as organic managed soils were more disturbed than conventional ones, probably as the consequence of the more frequent soil tillage performed for mechanical weeds control. The overall results demonstrated that, even in the short-term, the implementation of organically managed stockless systems in Mediterranean areas determined significant changes of some attributes for soil quality evaluation

    Potential association of specific Candida parapsilosis genotypes, bloodstream infections and colonization of health workers' hands

    Get PDF
    Fungal nosocomial infections continue to be a serious problem among hospitalized patients, decreasing quality of life and adding millions of euros to healthcare costs. The aim of this study was to describe the pattern of fungi associated with the hands of healthcare workers and to genotype Candida parapsilosis isolates in order to understand whether their high clinical prevalence stems from endemic nosocomial genotypes or from the real emergence of epidemiologically-unrelated strains. Approximately 39% (50/129) of healthcare workers were positive for yeasts and among 77 different fungal isolates recovered, C. parapsilosis was the most frequent (44/77; 57%). Twenty-seven diverse genotypes were obtained by microsatellite analysis of 42 selected blood and hand isolates. Most of the isolates from hands showed a new, unrelated, genotype, whereas a particular group of closely related genotypes prevailed in blood samples. Some of the latter genotypes were also found on the hands of healthcare workers, indicating a persistence of these clones within our hospital. C. parapsilosis genotypes from the hands were much more heterogeneous than clinical ones, thus reflecting a high genetic diversity among isolates, which is notably unusual and unexpected for this species

    Nutritional management and follow up of infants and children with food allergy: Italian Society of Pediatric Nutrition/Italian Society of Pediatric Allergy and Immunology Task Force Position Statement.

    Get PDF
    Although the guidelines on the diagnosis and treatment of food allergy recognize the role of nutrition, there is few literature on the practical issues concerning the nutritional management of children with food allergies. This Consensus Position Statement focuses on the nutritional management and follow-up of infants and children with food allergy.It provides practical advices for the management of children on exclusion diet and it represents an evidence-based consensus on nutritional intervention and follow-up of infants and children with food allergy. Children with food allergies have poor growth compared to non-affected subjects directly proportional to the quantity of foods excluded and the duration of the diet. Nutritional intervention, if properly planned and properly monitored, has proven to be an effective mean to substantiate a recovery in growth. Nutritional intervention depends on the subject's nutritional status at the time of the diagnosis. The assessment of the nutritional status of children with food allergies should follow a diagnostic pathway that involves a series of successive steps, beginning from the collection of a detailed diet-history. It is essential that children following an exclusion diet are followed up regularly. The periodic re-evaluation of the child is needed to assess the nutritional needs, changing with the age, and the compliance to the diet. The follow- up plan should be established on the basis of the age of the child and following the growth pattern
    • …
    corecore