Performance of post-processing algorithms for rainfall intensity using measurements from tipping-bucket rain gauges

Abstract. Eight rainfall events recorded from May to September 2013 at Hong Kong International Airport (HKIA) have been selected to investigate the performance of post-processing algorithms used to calculate the rainfall intensity (RI) from tipping-bucket rain gauges (TBRGs). We assumed a drop-counter catching-type gauge as a working reference and compared rainfall intensity measurements with two calibrated TBRGs operated at a time resolution of 1 min. The two TBRGs differ in their internal mechanics, one being a traditional single-layer dual-bucket assembly, while the other has two layers of buckets. The drop-counter gauge operates at a time resolution of 10 s, while the time of tipping is recorded for the two TBRGs. The post-processing algorithms employed for the two TBRGs are based on the assumption that the tip volume is uniformly distributed over the inter-tip period. A series of data of an ideal TBRG is reconstructed using the virtual time of tipping derived from the drop-counter data. From the comparison between the ideal gauge and the measurements from the two real TBRGs, the performances of different post-processing and correction algorithms are statistically evaluated over the set of recorded rain events. The improvement obtained by adopting the inter-tip time algorithm in the calculation of the RI is confirmed. However, by comparing the performance of the real and ideal TBRGs, the beneficial effect of the inter-tip algorithm is shown to be relevant for the mid–low range (6–50 mmh−1) of rainfall intensity values (where the sampling errors prevail), while its role vanishes with increasing RI in the range where the mechanical errors prevail

Thermo-fluid dynamic simulation of the Hotplate precipitation gauge.

The present study addresses the aerodynamic response of the recently developed "Hotplate" liquid/solid precipitation gauge when exposed to the wind. The Hotplate gauge employs two heated thin plates to provide a reliable method of precipitation measurement. The measuring principle is based on an algorithm to associate the latent heat needed to evaporate the snow, or the rain, falling on the instrument and the precipitation rate. However, the presence of the instrument body immersed in a wind field is expected to induce significant deformations of the airflow pattern near the gauge, with an impact on the associated catching efficiency. Indeed, the fall trajectories of the hydrometeors when approaching the gauge can be deviated away from the collecting plate resulting, in general, in some underestimation of the precipitation rate. After an initial analysis of real-world "Hotplate" measurements from a field test site located in Marshall, CO (USA) and the comparison with more traditional measurements obtained from a co-located, shielded reference gauge, the role of wind-induced errors is highlighted. The main approach used in this work is based on the numerical simulation of the airflow field around the gauge, using Computational Fluid Dynamics (CFD) to identify areas where the wind-induced updraft, local acceleration and turbulence are significant. The performed CFD airflow simulations use the URANS SST k - \u3c9 modelling scheme, and are the first modelling step to quantify the associated undercatch. These will be possibly coupled in future developments with particle tracking models to derive suitable correction curves for operational purposes. Due to the specific measurement principle exploited by the "Hotplate" gauge, which measures the heat flux needed to evaporate the collected water amount under a constant plate surface temperature, thermo-fluid dynamic simulations are addressed as well. Dedicated tests have been performed in the wind tunnel facility available at DICCA, University of Genoa to validate simulation results. Results indicate that the presence of wind is a relevant source of systematic bias when using the "Hotplate" gauge for the measurement of precipitation, and its effect must be corrected by adopting suitable correction curves as a function of the wind velocity. The magnitude of the correction can be derived from numerical thermo-fluid dynamic simulations and an assessment of the airflow patterns developing around the gauge at various wind velocity regimes is provided in this work. Wind tunnel tests allowed for a substantial validation of the numerical results, and possible improvements of the model are highlighted and proposed for future developments

Un indice per misurare la accessibilità di prossimità

IAPI (Inclusive Accessibiity by Proximity Index) misura, in ambiente GIS, l'accessibilità a servizi essenziali a partire dalle condizioni che favoriscono/sfavoriscono la pedonalità, la ciclabilità e le interazioni sociali a scala di quartiere. La sua sperimentazione in Bologna ha permesso sia di mappare la qualità dei percorsi ciclo-pedonali, sia di valutare l’accessibilità via mobilità attiva a servizi di quartiere, sia di valutare l’effetto di interventi puntuali di pedonalizzazione sulla qualità dei percorsi e degli spazi pubblici. Grazie alla facilità di calcolo, alla trasferibilità dell’approccio connessa all’uso di dati open source e alle opportunità di aggiornamento degli indicatori e dei coefficienti utilizzati, IAPI può contribuire alla costruzione di politiche multi-settore, a diverse scale

Un indice per misurare la accessibilità di prossimità

IAPI (Inclusive Accessibiity by Proximity Index) misura, in ambiente GIS, l'accessibilità a servizi essenziali a partire dalle condizioni che favoriscono/sfavoriscono la pedonalità, la ciclabilità e le interazioni sociali a scala di quartiere. La sua sperimentazione in Bologna ha permesso sia di mappare la qualità dei percorsi ciclo-pedonali, sia di valutare l’accessibilità via mobilità attiva a servizi di quartiere, sia di valutare l’effetto di interventi puntuali di pedonalizzazione sulla qualità dei percorsi e degli spazi pubblici. Grazie alla facilità di calcolo, alla trasferibilità dell’approccio connessa all’uso di dati open source e alle opportunità di aggiornamento degli indicatori e dei coefficienti utilizzati, IAPI può contribuire alla costruzione di politiche multi-settore, a diverse scale

Long-term insulin independence following repeated islet transplantation in totally pancreatectomized diabetic pigs.

Clinical islet transplantation (Tx) in type I diabetic patients has been successful so far only in a minority of cases, probably because of multiple factors, partly immunologic and partly nonimmunologic in nature. Pre-clinical studies of islet Tx in large animals are still needed to clarify the reasons and find possible solutions. In this study, we tested the feasibility of noninvasive, repeated intrahepatic allo-Tx of porcine pancreatic islets obtained from multiple donors, in pigs rendered diabetic by total pancreatectomy (Pct). In group I Yucatan miniature swine (n = 6), after induction of diabetes by Pct, repeated islet allo-Tx of ≥80% pure islets was performed. Islets obtained from two pigs of the Hanford breed were injected twice a week, half freshly isolated and half 48-h cultured, over a period of 11 days, for a total of 23,647 ± 1617 islet equivalents (IE)/kg recipient body weight (BW). In group II Yucatan miniature swine (n = 3), after Pct, a single allo-Tx of ≥80% pure islets, previously obtained from two donors of the Hanford breed, was performed, using a total of 22,416 ± 1124 IE/kg BW. In group III Yucatan miniature swine (n = 3), auto-Tx of 60–75% pure islets, averaging 2980 ± 424 IE/kg BW, was performed a few hours after Pct. Group IV Yucatan mini pigs (n = 3) underwent Pct and were used as diabetic controls. Group V animals (n = 3) were normal control Yucatan mini pigs. Porcine islets were isolated by a modification of the standard collagenase digestion and Ficoll gradient purification method. Donors and recipients were chosen on the basis of moderate to high mutual alloreactivity in mixed lymphocyte culture (MLC). In groups I and II, cyclosporine A (CsA) was started 4 days before allo-Tx, at the dose of 15 mg/kg IM, and then gradually reduced to 4 mg/kg IM. In all group I animals, normal fasting blood glucose (FBG) was restored within 2–3 weeks. Two normoglycemic pigs died of acute pneumonia at 33 and 112 days, respectively, and one animal became progressively hyperglycemic at 100 days. After 3 months, discontinuation of CsA treatment resulted in FBG increase in two group I animals. In one pig, CsA was stopped after 151 days, and normoglycemia persisted until euthanasia, after 8 months. In group II pigs, normoglycemia lasted 4–20 days, with a progressive increase of insulin requirement thereafter. In group III animals, after islet auto-Tx, normoglycemia lasted 7–10 days, while insulin daily requirement progressively increased thereafter, stabilizing at 0.4 IU/kg/day, corresponding to about one third of the amount required in diabetic controls. The single most important result in this series of experiments is that intraportal allo-Tx of a sufficient islet mass, divided in multiple subtherapeutic doses, produced a better metabolic long-term control in comparison to a single injection of the same amount of islets. The technique of multiple-donor repeated islet Tx may prove useful to overcome the problem of primary nonfunction or early graft failure, currently limiting the success of clinical islet Tx in most cases

Histologic and sonographic features of holmium laser in the treatment of chronic venous disease

A new holmium laser (HOL) has been introduced to the market. The device is able to reduce the great saphenous vein (GSV) caliber in a tumescence-free procedure, favoring an effective sclerotherapy of large vessels. Aim of the present investigation is to provide the first in vivo data about the effect of HOL on GSV histology

Un'esperienza di teatro scientifico all'elementari

Obiettivo: Facendo seguito a uno studio portato avanti nell’ambito di Miti e Geologia (Lanza & Negrete 2007) si sono volute sperimentare alcune conclusioni di quello studio che caldeggiava l’utilizzo di miti e leggende popolari in ambito scolastico per la diffusione della conoscenza riguardante il nostro pianeta. Il target che era all’inizio rappresentato dai bambini di seconda e quarta elementare (della Scuola primaria Federico Di Donato di Roma) si è poi esteso anche agli insegnanti e persino ai genitori di quegli alunni vedendoli tutti coinvolti come soggetti attivi nell’ambito di questo progetto. Il coinvolgimento e l’entusiasmo partecipativo si è sviluppato anche in seguito alla modalità di realizzazione di questo progetto iniziale. La leggenda del pescatore Colapesce è stata ripresa e riadattata in uno script per celebrare il centenario del terremoto di Messina (1908) ai fini di una vera e propria rappresentazione teatrale fatta dai bambini. Dunque lo script alla fine conteneva non soltanto la favola con i suoi protagonisti classici: un Re, una principessa e un pescatore ma anche una parte più moderna dove i protagonisti erano un gruppetto di sismologi interpretati da alcuni bambini di quarta elementare. L’inserimento di contenuti scientifici all’interno della rappresentazione è stata resa agevolmente possibile con l’introduzione di oggetti, quali una mappa della sismicità in Italia e un sismometro. Oggetti che hanno consentito agli alunni di comprendere non soltanto come si studiano i terremoti ma anche che la prevenzione è il metodo migliore per conviverci. Dopo tre mesi di preparazione ottenuta anche grazie alla collaborazione di un regista di Messina coadiuvato da un esperto in psico-dramma, gli alunni erano pronti per recitare davanti a tutta la scuola nell’ambito della XIX settimana della cultura scientifica (il 27 Marzo 2009). A giudicare dall’entusiasmo generale di tutti, attori, spettatori e organizzatori è stato un successo. Tuttavia se la rappresentazione finale costituisce l’ultima tappa, di fondamentale importanza sarà valutare come si è sviluppato l’apprendimento nel corso dei tre mesi di preparazione a questo evento e quanto rimarrà a qualche mese di distanza soprattutto del contenuto scientifico agito sulla scena. Mentre un altro aspetto assumerà valutare quanto il contenuto favolistico abbia ben disposto gli alunni ad accogliere nozioni nuove e quanto invece li abbia distratti (soprattutto i più piccoli, quelli di seconda elementare). Si può far notare che l’apprendimento ha coinvolto attivamente anche gli insegnanti che non soltanto si sono mostrati piacevolmente disponibili ad approfondire i contenuti scientifici ai fini della rappresentazione, ma hanno utilizzato gli stessi per scegliere gli attori e per suggerire modifiche allo script iniziale. Attualmente sono in corso delle analisi con questionari per alunni e insegnanti al fine di individuarne l’efficacia comunicativa e tirare le conclusioni di questa esperienza

Different patterns of cortical excitability in major depression and vascular depression: a transcranial magnetic stimulation study

BACKGROUND: Clinical and functional studies consider major depression (MD) and vascular depression (VD) as different neurobiological processes. Hypoexcitability of the left frontal cortex to transcranial magnetic stimulation (TMS) is frequently reported in MD, whereas little is known about the effects of TMS in VD. Thus, we aimed to assess and compare motor cortex excitability in patients with VD and MD. METHODS: Eleven VD patients, 11 recurrent drug-resistant MD patients, and 11 healthy controls underwent clinical, neuropsychological and neuroimaging evaluations in addition to bilateral resting motor threshold, cortical silent period, and paired-pulse TMS curves of intracortical excitability. All patients continued on psychotropic drugs, which were unchanged throughout the study. RESULTS: Scores on one of the tests evaluating frontal lobe abilities (Stroop Color-Word interference test) were worse in patients compared with controls. The resting motor threshold in patients with MD was significantly higher in the left hemisphere compared with the right (p < 0.05), and compared with the VD patients and controls. The cortical silent period was bilaterally prolonged in MD patients compared with VD patients and controls, with a statistically significant difference in the left hemisphere (p < 0.01). No differences were observed in the paired-pulse curves between patients and controls. CONCLUSIONS: This study showed distinctive patterns of motor cortex excitability between late-onset depression with subcortical vascular disease and early-onset recurrent drug resistant MD. The data provide a TMS model of the different processes underlying VD and MD. Additionally, our results support the “Vascular depression hypothesis” at the neurophysiological level, and confirm the inter-hemispheric asymmetry to TMS in patients with MD. We were unable to support previous findings of impaired intracortical inhibitory mechanisms to TMS in patients with MD, although a drug-induced effect on our results cannot be excluded. This study may aid the understanding of the pathogenetic differences underlying the clinical spectrum of depressive disorders

Update on intensive motor training in spinocerebellar ataxia: time to move a step forward?:

Some evidence suggests that high-intensity motor training slows down the severity of spinocerebellar ataxia. However, whether all patients might benefit from these activities, and by which activity, and the underlying mechanisms remain unclear. We provide an update on the effect and limitations of different training programmes in patients with spinocerebellar ataxias. Overall, data converge of the finding that intensive training is still based either on conventional rehabilitation protocols or whole-body controlled videogames ("exergames"). Notwithstanding the limitations, short-term improvement is observed, which tends to be lost once the training is stopped. Exergames and virtual reality can ameliorate balance, coordination, and walking abilities, whereas the efficacy of adapted physical activity, gym, and postural exercises depends on the disease duration and severity. In conclusion, although a disease-modifying effect has not been demonstrated, constant, individually tailored, high-intensity motor training might be effective in patients with degenerative ataxia, even in those with severe disease. These approaches may enhance the remaining cerebellar circuitries or plastically induce compensatory networks. Further research is required to identify predictors of training success, such as the type and severity of ataxia and the level of residual functioning