535 research outputs found

    Reconstruction of reflectivity vertical profiles and data quality control for C-band radar rainfall estimation

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    International audienceMicrowave Doppler radars are considered a fairly established technique to retrieve rain rate fields from measured reflectivity volumes. However, in a complex orographic environment radar observations are affected by several impairments which should be carefully evaluated. Together with the enhancement of ground-clutter effects, the major limitation is represented by partial or total beam blocking caused by natural obstructions which very often impose to scan at high-elevation angles. These range-related limitations tend to reduce the potential role of operational weather radars in monitoring precipitation amount at ground within mountainous areas since, if either the nature or intensity of rainfall varies with height (e.g., melting effects during stratiform rain), radar returns at higher altitudes may be not representative of surface rain rate. Therefore, before to use the radar data, it is necessary to reduce, as much as possible, this evaluation errors and to estimate the reliability of the processed data. Near to the quality control, are needed quality indexes, taking into account each correction and elaboration step, that could be useful to retrieve a final quality value. In this work, we analyse the main factors that could be affect the efficiency of a reconstruction methodology of near-surface reflectivity fields from high-elevation reflectivity bins, in presence of complex orography. A climatologic schema is applied to infer near-surface reflectivity at a given range interval. The technique is developed in polar coordinates partially taking into account the antenna beam width degradation at longer ranges and overall computational efficiency for operational purposes. Thereafter, it is applied on a rainfall event observed by a C-band Doppler radar operating in S. Pietro Capofiume (Bologna, Italy) and the relation between the reconstruction error and possible quality indicators is analysed and discussed

    Cadherins as regulators of neuronal polarity

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    A compelling amount of data is accumulating about the polyphonic role of neuronal cadherins during brain development throughout all developmental stages, starting from the involvement of cadherins in the organization of neurulation up to synapse development and plasticity. Recent work has confirmed that specifically N-cadherins play an important role in asymmetrical cellular processes in developing neurons that are at the basis of polarity. In this review we will summarize recent data, which demonstrate how N-cadherin orchestrates distinct processes of polarity establishment in neurons.Peer Reviewe

    Clutter and rainfall discrimination by means of doppler-polarimetric measurements and vertical reflectivity profile analysis

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    The estimation of rainfall rate and other parameters from radar scattering volume is heavily affected by the presence of intense sea and ground clutter and echoes which appears in anomalous propagation condition. To deal with these non meteorological echoes we present a new clutter removal algorithm which combines the results of previous works. The algorithm fully exploits both the Doppler and polarimetric capabilities of the radar used and the analysis of vertical reflectivity profile in order to achieve the better identification of the meteorological and non-meteorological targets. The algorithm has been applied to the C-band radar of Monte Settepani (Savona, Italy), which runs in a high-topography environment. Preliminary results are presented

    Spatial and temporal biochemical variation in the Norther Adriatic Sea during summer 2001

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    Nel giugno e nel settembre del 2001 sono state effettuate due crociere oceanografiche nel nord Adriatico, da Numana (An) a Chioggia (Ve), dall\u27Italia alla Croazia, con misurazioni di temperatura, salinit?, fluorescenza, irradianza, ossigeno disciolto e nutrienti. Nel lavoro vengono posti in relazione tra loro l\u27ossigeno disciolto, la fluorescenza, i nutrienti, l\u27irradianza e le portate del Po, con lo scopo di osservare le loro variazioni biochimiche nello spazio e nel tempo. Dallo studio risulta che gli inputs del Po e l\u27irradianza sono fattori importanti nella distribuzione della clorofilla a e dell\u27ossigeno disciolto in superficie, e che i processi di mineralizzazione determinano una marcata ipossia in un\u27ampia area al largo della foce del Po.Nel giugno e nel settembre del 2001 sono state effettuate due crociere oceanografiche nel nord Adriatico, da Numana (An) a Chioggia (Ve), dall\u27Italia alla Croazia, con misurazioni di temperatura, salinit?, fluorescenza, irradianza, ossigeno disciolto e nutrienti. Nel lavoro vengono posti in relazione tra loro l\u27ossigeno disciolto, la fluorescenza, i nutrienti, l\u27irradianza e le portate del Po, con lo scopo di osservare le loro variazioni biochimiche nello spazio e nel tempo. Dallo studio risulta che gli inputs del Po e l\u27irradianza sono fattori importanti nella distribuzione della clorofilla a e dell\u27ossigeno disciolto in superficie, e che i processi di mineralizzazione determinano una marcata ipossia in un\u27ampia area al largo della foce del Po

    Clutter and rainfall discrimination by means of doppler-polarimetric measurements and vertical reflectivity profile analysis

    No full text
    International audienceThe estimation of rainfall rate and other parameters from radar scattering volume is heavily affected by the presence of intense sea and ground clutter and echoes which appears in anomalous propagation condition. To deal with these non meteorological echoes we present a new clutter removal algorithm which combines the results of previous works. The algorithm fully exploits both the Doppler and polarimetric capabilities of the radar used and the analysis of vertical reflectivity profile in order to achieve the better identification of the meteorological and non-meteorological targets. The algorithm has been applied to the C-band radar of Monte Settepani (Savona, Italy), which runs in a high-topography environment. Preliminary results are presented

    The middle-southern Adriatic basin in February 1999: the chemical and physical characteristics of the water column.

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    In the Southern Adriatic depression nitrogen and phosphorous salts are concentrated in the bottom water. The Redfield ratio, same 29, is higher at Pomo and D transect, mostly on the bottom, because phosphorous is limiting and nitrogen is abundant. Northern waters influence this southern area, together with surface and intermediate waters coming from Ionian sea, and western shelf waters which tend to sink to the bottom. Key-words: Adriatic Sea, thermohaline characteristics, nutrient salts, Redfield rati

    Synapsins contribute to the dynamic spatial organization of synaptic vesicles in an activity-dependent manner.

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    The precise subcellular organization of synaptic vesicles (SVs) at presynaptic sites allows for rapid and spatially restricted exocytotic release of neurotransmitter. The synapsins (Syns) are a family of presynaptic proteins that control the availability of SVs for exocytosis by reversibly tethering them to each other and to the actin cytoskeleton in a phosphorylation-dependent manner. Syn ablation leads to reduction in the density of SV proteins in nerve terminals and increased synaptic fatigue under high-frequency stimulation, accompanied by the development of an epileptic phenotype. We analyzed cultured neurons from wild-type and Syn I,II,III(-/-) triple knock-out (TKO) mice and found that SVs were severely dispersed in the absence of Syns. Vesicle dispersion did not affect the readily releasable pool of SVs, whereas the total number of SVs was considerably reduced at synapses of TKO mice. Interestingly, dispersion apparently involved exocytosis-competent SVs as well; it was not affected by stimulation but was reversed by chronic neuronal activity blockade. Altogether, these findings indicate that Syns are essential to maintain the dynamic structural organization of synapses and the size of the reserve pool of SVs during intense SV recycling, whereas an additional Syn-independent mechanism, whose molecular substrate remains to be clarified, targets SVs to synaptic boutons at rest and might be outpaced by activity

    Influenza vaccination and absenteeism among healthy working adults: a cost-benefit analysis

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    Seasonal influenza is a highly contagious infection that might lead to serious clinical complications and incurs a conspicuous socio-economic impact. Influenza vaccination is currently recommended only for specific groups of healthy adults (such as healthcare workers) even though it was demonstrated to be effective in reducing absenteeism and decreased workers' productivity during flu epidemic period. The main purpose of this study is to analyse the extent of absences due to illness following a voluntary flu immunization program among the Komatsu Italia Manufacturing company's personnel during the flu season 2017-2018. Secondly, we aimed at performing a cost-benefit analysis of the vaccination campaign from the company's perspective
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