376 research outputs found

    EXTREME EVENT: HEAVY SNOWFALL ON THE TRENTINO REGION ON 11 MARCH 2004

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    an extreme event of heavy snowfall occurred in the last 11 march 2004 in many regions of the north Italy. It was one of the most important events of snowfall in the winter season 2003-2004 and it was really unusual for the period. The possibility of snowfall at the lower levels was forecasted two days before but the quantity of the precipitation was generally underestimated by the models. This event caused many problems to the civil protection and to the public above all in the traffic and the increasing avalanche risk

    Cesium-Telluride Photocathode No. 166

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    In the CERN photoemission laboratory, a Cs2 Te photocathode has been produced in December 2006. The co-evaporation of Cs and Te onto a copper substrate is observed with two quartz oscillator thickness monitors. The calibration of these monitors and the resulting Cs and Te layer thicknesses are described, and the calculated stoichiometric ratio of the sample is given. The quantum efficiency of cathode No. 166, measured using the cathode in a DC gun, has been found to be 6.2%

    Observation of a Spinning Top in a Bose-Einstein Condensate

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    Boundaries strongly affect the behavior of quantized vortices in Bose-Einstein condensates, a phenomenon particularly evident in elongated cigar-shaped traps where vortices tend to orient along a short direction to minimize energy. Remarkably, contributions to the angular momentum of these vortices are tightly confined to the region surrounding the core, in stark contrast to untrapped condensates where all atoms contribute \hbar. We develop a theoretical model and use this, in combination with numerical simulations, to show that such localized vortices precess in an analogous manner to that of a classical spinning top. We experimentally verify this spinning-top behavior with our real-time imaging technique that allows for the tracking of position and orientation of vortices as they dynamically evolve. Finally, we perform an in-depth numerical investigation of our real-time expansion and imaging method, with the aim of guiding future experimental implementation, as well as outlining directions for its improvement.Comment: 10 pages, 7 figure

    Increase in airborne allergenic pollen in Trentino (North Italy): knowledge to adapt to climate change

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    Pollen allergy affects approximately 25% of adult and 40% of children globally (Nur Husna et al. 2022). Climate change is impacting allergenicity and pollen production, as well as the spread of neophytes that produce allergenic pollen, due to the combined effects of milder weather, air pollution, and elevated CO2 levels (Luschkova et al. 2022). As a result, there is an upward trend in allergic diseases (D’Amato et al. 2015). The study of pollen and its spatio-temporal changes is highly important due to the allergenicity of many airborne pollen taxa. Earlier-onset of pollen, the lengthening of the pollen season, and/or the increase in pollen quantities, can diminish the quality of life of allergic patients. In the "one health" perspective, we examine how climate change impact the ecosystem, affecting human well-being and health. Phenology, the science of natural recurring events, is one of the preferred indicators for observing the impacts of climate change on ecosystems and biological processes (Parmesan 2006). The shift in phenology is a high-temporal resolution signal of this impact and pollen dispersal is often used as a reliable proxy of flowering. This study describes the significant changes that have occurred to the airborne pollen component recorded in San Michele all’Adige, Northern Italy, from 1989 to 2018, analyzing a total of 24 arboreal (AP; trees and shrubs) and non-arboreal pollen taxa (NAP; herbaceous). Airborne pollen was collected using a volumetric Hirst-type aerobiological sampler (Lanzoni VPPS 2000), and the daily concentration of airborne pollen (P*m-3) was calculated for each taxon over a 30-year period from 1989 to 2018. The sampling and analysis of airborne pollen have been performed in accordance with the UNI EN 16868:2019 European standard procedure. The following pollen season descriptors were calculated for each taxon: (i) annual pollen integral (APIn; pollen*day*m-3); (ii) the start and end dates of the main pollen season (MPS), as the day of the year (DOY) when 2.5% and 97.5% of the APIn was reached, respectively; (iii) the length of the MPS, as the difference between the end and start DOY (+1); (iv) peak concentration; and (v) peak date, as the DOY when the maximum concentration was registered. The presence of a monotonic upward or downward temporal trend in pollen season descriptors was verified and changes were analyzed in relation to temperature, precipitation, and land use; in addition, pollen data were analyzed clustered into blocks of one decade each to minimize interannual fluctuations and maximize relevant change signals. The major result is an increase in pollen load (Fig. 1). All arboreal and shrub species (AP) and the majority of herbaceous (NAP) species had an impressive increase in pollen quantities. The extent of the increase in pollen load is evident when analyzing decadic blocks, with a relevant increase in the APIn for the total pollen spectrum, mostly due to AP taxa, with hop hornbeam and cypress family accounting for 49% of the increase (average on the 30-year period). Accordingly, AP shows a significant increase (+31 days) in the number of days with high pollen concentrations (i.e., > 100 pollen grains/m3). Such an increase in pollen quantity is unlikely to be related to changes in land use, given that the increase in forests and semi-natural areas is limited. The finding of an increase in APIn, especially marked for AP taxa, is consistent with previous studies and on a broader scale, from Europe (Ziello et al. 2012) to the entire Northern Hemisphere (Ziska et al. 2019). Moreover, some evidence of early start date for some taxa has been observed (e.g. Poaceae), at the same time as a longer pollen seasons for other taxa (e.g. Cupressaceae). A larger amount of pollen, an increase in the number of days with high pollen concentration, and an early start to the pollen season, which have been occurring since 1990 in the study area, all constitute a worsening situation and a major threat to people with pollen allergies. Thanks to these achievements it is possible to develop proposals for adaptation strategies that include as early stages: (i) development and implementation of risk communication strategies, (ii) implementation of good practices for green management. These proposals will be included in the Climate Change Adaptation Strategy of the Autonomous Province of Trento, which is currently being defined. Figures Fig 1: Increase of total arboreal pollen integral in the 30 years; detail for Ostrya (hop hornbeam) pollen taxonom

    An Individual's Connection to Nature Can Affect Perceived Restorativeness of Natural Environments : Some Observations about Biophilia

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    This study investigates the relationship between the level to which a person feels connected to Nature and that person's ability to perceive the restorative value of a natural environment. We assume that perceived restorativeness may depend on an individual's connection to Nature and this relationship may also vary with the biophilic quality of the environment, i.e., the functional and aesthetic value of the natural environment which presumably gave an evolutionary advantage to our species. To this end, the level of connection to Nature and the perceived restorativeness of the environment were assessed in individuals visiting three parks characterized by their high level of "naturalness" and high or low biophilic quality. The results show that the perceived level of restorativeness is associated with the sense of connection to Nature, as well as the biophilic quality of the environment: individuals with different degrees of connection to Nature seek settings with different degrees of restorativeness and biophilic quality. This means that perceived restorativeness can also depend on an individual's "inclination" towards Nature

    Analysis of recent meteorological configurations responsible for substantial snowfalls in the Trentine sector of the Adige valley bottom (eastern italian Alps).

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    Aim of this presentation is to analyse the synoptic conditions favourable to snowfall with more than 10 cm fresh snow cover in the bottom of the Trentine sector of the Adige Valley. Following the abundant and reiterated snowfalls in the study area during the 2005-2006 winter season and the many discomforts to the population and mainly to the road traffic, an accurate study of such events resulted necessary for a reliable forecast. The valley orientation in a NNE-SSW direction lets the Mediterranean warm-humid air masses to get in as far as the main headwater divide (Brenner Pass) and to make its climate relatively mild. Moreover, such humid air inflows bring mean annual precipitation of about 800-1000 mm that gradually decreses from the lower valley mouth to the main divide. The precipitation regime consists of rainfalls in spring and autumn whereas a strong absolute minimum occurs between December and Febraury when snowfalls are more likely on the valley floor. In fact, the vally is annually subjected to warm advection snowfalls, though infrequent and scarce, between November and mid April. The study area is about 80 km long with elevation ranging from 130 and 230 m a.s.l. All the snowfall events observed from 1980 to 2006 were analysed by using the data of the Civil Protection Authority of Trento Province, i.e. Trento Roncafort (194 n a.s.l.), Trento Laste (312 m a.s.l.), Rovereto (203 m a.s.l.) and Ala (197 m a.s.l.) meteo stations. Through the study and analysis of ground and at the 500 hPa geopotential meteo maps, satellite images, thermodynamic diagrams of the nearest sounding stations and the data of the nivometeorological stations, the synoptic types that characterised the snowfalls were studied and classified and a clusterisation was made. For each of the synoptic types defined the conditions for a quantification of the mean characteristic meteo parameters were anlysed in order to obtain a reliable forecast of intense snowfalls on the valley bottom

    Clustered superfluids in the one-dimensional Bose-Hubbard model with extended correlated hopping

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    Bosonic lattice systems with nontrivial interactions represent an intriguing platform to study exotic phases of matter. Here, we study the effects of extended correlated hopping processes in a system of bosons trapped in a lattice geometry. The interplay between single particle tunneling terms, correlated hopping processes, and onsite repulsion is studied by means of a combination of exact diagonalization, strong coupling expansion, and cluster mean field theory. We identify a rich ground state phase diagram where, apart from the usual Mott and superfluid states, superfluid phases with interesting clustering properties occur

    Organic Control Of Dioctahedral And Trioctahedral Clay Formation In An Alkaline Soil System In The Pantanal Wetland Of Nhecolandia, Brazil

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Recent studies have focused on the formation of authigenic clays in an alkaline soil system surrounding lakes of the Nhecolandia region, Pantanal wetland. The presence of trioctahedral Mg-smectites (stevensite and saponite types), which requires low Al and Fe contents in the soil solution for its formation, contrasts with the neoformation of dioctahedral Fe-mica (glauconite, and Fe-illite), which instead requires solutions relatively enriched in Al and Fe. This study aims to understand the conditions of co-existence of both, Mg-smectite and Fe-mica a common clay association in former or modern alkaline soil systems and sediments. The study was carried out along an alkaline soil catena representative of the region. The soil organization revealed that Mg-smectite occur in top soil close to the lake, whereas Fe-mica dominate in the clay fraction of deeper greenish horizons a few meters apart. We propose here that this spatial distribution is controlled by the lateral transfer of Fe and Al with organic ligands. Alkaline organic rich solutions (DOC up to 738 mg L-1) collected in the watertable were centrifuged and filtered through membranes of decreasing pore size (0.45 mu m, 0.2 mu m, 30 KDa, 10 KDa, 3 KDa) to separate colloidal and dissolved fractions. Fe, Al, Si, Mg and K were analysed for each fraction. Although the filtration had no influence on Si and K contents, almost 90% of Fe (up to 2.3 mg L-1) and Al (up to 7 mg L-1) are retained at the first cutoff threshold of 0.45 mu m. The treatment of the same solutions by oxygen peroxide before filtration shows that a large proportion of Fe and Al were bonded to organic colloids in alkaline soil solution at the immediate lake border, allowing Mg-smectite precipitation. The fast mineralization of the organic matter a few meters apart from the lake favors the release of Fe and Al necessary for Fe-mica neoformation. In comparison with chemical and mineralogical characteristics of alkaline environments described in the literature, the study suggests that the co-existence of trioctahedral Mg-smectite and dioctahedral Fe-mica should be regarded as a standard occurrence in alkaline soil systems with organic rich waters.117Sao Paulo State Research Foundation (FAPESP) [2011/12770-0, 2013/09192-0]National Council for Scientific and Technological Development (CNPq) [405898/2012-6, 443030/2015-4]National Institute of Sciences of the Universe (INSU-Ec2co)Federal Agency for the Support and Evaluation of Graduate Education (CAPES)Consulate of France in Sao PauloSao Paulo UniversityCampinas State UniversityFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Prediction of minimum temperatures in an alpine region by linear and non-linear post-processing of meteorological models

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    International audienceModel Output Statistics (MOS) refers to a method of post-processing the direct outputs of numerical weather prediction (NWP) models in order to reduce the biases introduced by a coarse horizontal resolution. This technique is especially useful in orographically complex regions, where large differences can be found between the NWP elevation model and the true orography. This study carries out a comparison of linear and non-linear MOS methods, aimed at the prediction of minimum temperatures in a fruit-growing region of the Italian Alps, based on the output of two different NWPs (ECMWF T511?L60 and LAMI-3). Temperature, of course, is a particularly important NWP output; among other roles it drives the local frost forecast, which is of great interest to agriculture. The mechanisms of cold air drainage, a distinctive aspect of mountain environments, are often unsatisfactorily captured by global circulation models. The simplest post-processing technique applied in this work was a correction for the mean bias, assessed at individual model grid points. We also implemented a multivariate linear regression on the output at the grid points surrounding the target area, and two non-linear models based on machine learning techniques: Neural Networks and Random Forest. We compare the performance of all these techniques on four different NWP data sets. Downscaling the temperatures clearly improved the temperature forecasts with respect to the raw NWP output, and also with respect to the basic mean bias correction. Multivariate methods generally yielded better results, but the advantage of using non-linear algorithms was small if not negligible. RF, the best performing method, was implemented on ECMWF prognostic output at 06:00 UTC over the 9 grid points surrounding the target area. Mean absolute errors in the prediction of 2 m temperature at 06:00 UTC were approximately 1.2°C, close to the natural variability inside the area itself

    Frustrated extended Bose-Hubbard model and deconfined quantum critical points with optical lattices at the anti-magic wavelength

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    The study of geometrically frustrated many-body quantum systems is of central importance to uncover novel quantum mechanical effects. We design a scheme where ultracold bosons trapped in a one-dimensional state-dependent optical lattice are modeled by a frustrated Bose-Hubbard Hamiltonian. A derivation of the Hamiltonian parameters based on Cesium atoms, further show large tunability of contact and nearest-neighbour interactions. For pure contact repulsion, we discover the presence of two phases peculiar to frustrated quantum magnets: the bond-order-wave insulator with broken inversion symmetry and a chiral superfluid. When the nearest-neighbour repulsion becomes sizeable, a further density-wave insulator with broken translational symmetry can appear. We show that the phase transition between the two spontaneously-symmetry-broken phases is continuous, thus representing a one-dimensional deconfined quantum critical point not captured by the Landau-Ginzburg-Wilson symmetry-breaking paradigm. Our results provide a solid ground to unveil the novel quantum physics induced by the interplay of non-local interactions, geometrical frustration, and quantum fluctuations.Comment: 7+3 pages, 3+3 figure
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