1,721,010 research outputs found
A non-homogeneous Markov model for the definition of climate change scenarios for coastal areas: the case of Agro-Pontina plain
No full textThis study addresses to the possible changes in Agro-Pontino rainfall under different global warming scenarios for the 21st century. The Agro-Pontino-plain is a reclamation region and presents the
typical hydro-geological features of Mediterranean coastal environments. It is densely populated and productive, therefore, climate changes could adversely affect the socio-economic development of
the area. Currently, due to the coarse resolution of Global-Circulation-Models, local climate variables simulations for limited size area are not accurate. Nonetheless, GCMs simulations of large-scale
upper-air fields are generally considered reliable, therefore to bridge the gap between GCMs and local-scale processes different downscaling techniques are carried out. Here, a Hidden Markov Model
and a Non-homogeneous Hidden Markov Model are developed using a 54-years record (1951-2004) of daily rainfall amount at 9 stations in Agro-Pontino-plain and re-analysis fields of atmospheric
variables. In HMM and NHMM runs, we directly consider the entire year, rather than an a priori demarcation of seasons. The idea is to identify, directly using the HMM, the seasonal precipitation
characteristics which may be related to the temporal sequence of ‘hidden states’ of atmosphere, subsequently modeled as dependent on appropriate fields of selected atmospheric variables. Daily
rainfall variability is described in terms of occurrence of 5 ‘hidden weather states’ identified by the HMM and associated to variables representing the main characteristics of large-scale atmospheric
circulation as obtained by re-analysis data, then, using NHMM, calibration and validation tests are made to identify the optimal predictors - GeoPotential Height and Temperature at 1000 hPa,
Meridional & Zonal Wind at 850 hPa and Precipitable Water - to reproduce better the observed rainfall features on Agro-Pontino-plain
Surgical treatment of a peripheral giant cell granuloma of the upper jaw by diode laser
No full textObjectives: The Peripheral Giant Cell Granuloma (PGCG) is a gingival hyperplasia that rises from the mucoperiostium or the periodontal ligament and may occur at gingival edges or alveolar ridges of the oral mucosa. In this paper a case of PGCG treated by a diode laser 808 nm is described. Materials and methods: A case of a 65 years old female patient, in good health, with a PGCG located at the anterior portion of edentulous maxilla, is described. The mass was surgically excised using an 808 nm diode laser (KDL-10, Kavo, Germany) with parameters of 2 W continuous wave and a 320 nm optic fiber. Results: Surgery was performed with no intra- nor post-operative complications. Follow-up at 7 and 21 days showed an increasing secondary intention healing. Histological examination confirmed the clinical diagnosis of peripheral giant cell granuloma. Conclusions: Laser surgery of PGCG offers many intraoperative advantages and reduces postoperative complications, also increasing patient's compliance. For that reason, as well as in light of recent literature studies, it may be considered as the gold standard.Objectives
The Peripheral Giant Cell Granuloma (PGCG) is a gingival hyperplasia that rises from the mucoperiostium or the periodontal ligament and may occur at gingival edges or alveolar ridges of the oral mucosa. In this paper a case of PGCG treated by a diode laser 808 nm is described.
Materials and methods
A case of a 65 years old female patient, in good health, with a PGCG located at the anterior portion of edentulous maxilla, is described. The mass was surgically excised using an 808 nm diode laser (KDL-10, Kavo, Germany) with parameters of 2 W continuous wave and a 320 nm optic fiber.
Results
Surgery was performed with no intra- nor post-operative complications. Follow-up at 7 and 21 days showed an increasing secondary intention healing. Histological examination confirmed the clinical diagnosis of peripheral giant cell granuloma.
Conclusions
Laser surgery of PGCG offers many intraoperative advantages and reduces postoperative complications, also increasing patient's compliance. For that reason, as well as in light of recent literature studies, it may be considered as the gold standard
Un modello markoviano non omogeneo per la definizione di scenari di cambiamento climatico delle aree costiere: il caso della Piana Pontina
No full textQuesto studio è finalizzato alla valutazione dei possibili cambiamenti del regime pluviometrico nella Pianura dell’Agro-Pontino che si determinano nei differenti scenari di riscaldamento globale ipotizzati per il 21°secolo. L’ area oggetto dello studio, fascia costiera compresa fra il Mar Tirreno e la dorsale Lepino-Ausona, ubicata nel Lazio meridionale, costituisce un rilevante esempio di regione di bonifica e presenta le tipiche caratteristiche idro-geologiche degli ambienti costieri del Mediterraneo. È densamente popolata ed è sede di importanti attività agricole e industriali che dipendono in modo determinante dalla disponibilità di acqua da fonti superficiali e sotterranee, quindi le modifiche climatiche e le possibili conseguenti alterazioni del ciclo idrologico hanno una diretta influenza sullo sviluppo socio-economico della zona. Allo stato attuale dell’arte nè i modelli di circolazione generale dell’atmosfera (GCM), nè quelli regionali (RCM), consentono una riproduzione del regime pluviometrico giornaliero sufficientemente accurata per zone di relativamente limitata estensione, quale la regione suddetta. Ciò nonostante, essi riproducono con sufficiente fedeltà i campi alla grande scala delle variabili rappresentanti la circolazione atmosferica globale. Pertanto è necessario ricorrere a tecniche di downscaling per ottenere simulazioni sufficientemente accurate delle precipitazioni locali, basate sull’individuazione di relazioni statistiche fra le suddette variabili alla grande scala e le precipitazioni locali. Nel presente lavoro, sono state applicate le tecniche di downscaling statistico, ‘Hidden Markov Model’ (HMM) e ‘Non-homogeneous Hidden Markov Model’ (NHMM), a 54 anni (1951-2004) di dati delle precipitazioni giornaliere di 9 stazioni dell’Istituto Idrografico e Mareografico di Roma e dell’ Aeronautica Militare ricadenti nell’area di studio. L’HMM e l’NHMM sono utilizzati sull’intero hanno solare piuttosto che su stagioni delineate a-priori per riprodurre le attuali caratteristiche di piovosità giornaliera e quelle future sulla Piana dell’Agro-Pontino, con particolare riferimento alle caratteristiche di stagionalità, che vengono catturate attraverso un’opportuna scelta delle variabili atmosferiche, descriventi le caratteristiche metereologiche e climatiche alla grande scala, influenzanti il regime di precipitazione locale. L’idea consiste nell’identificare, direttamente utilizzando l’HMM, le caratteristiche stagionali di piovosità associate agli ‘stati nascosti’ (HS) e descrivere la variabilità giornaliera delle precipitazioni; successivamente selezionare le variabili atmosferiche (predictors) che più influenzano il regime pluviometrico e analizzare le distribuzioni spaziali associate ai differenti stati piovosi; infine, mediante l’NHMM si sono effettuate prove di calibrazione (1951-1994) e validazione (1995-2004) per individuare l’insieme ottimale di predittori atmosferici (“Mean Sea Level Pressure (MSL)”, “Temperature at 1000 hPa (T)”, “Meridional Wind (MW)” e “Zonal Wind (ZW) at 850 hPa” e “Precipitable Water (P)” (IRI Library – NOAA-NCAR) ) che meglio consentono di riprodurre le caratteristiche stagionali delle precipitazioni osservate.This study addresses to the possible changes in Agro-Pontino rainfall under different global warming scenarios for the 21st century. The Agro-Pontino-plain is a reclamation region and presents the
typical hydro-geological features of Mediterranean coastal environments. It is densely populated and productive, therefore, climate changes could adversely affect the socio-economic development of
the area. Currently, due to the coarse resolution of Global-Circulation-Models, local climate variables simulations for limited size area are not accurate. Nonetheless, GCMs simulations of large-scale
upper-air fields are generally considered reliable, therefore to bridge the gap between GCMs and local-scale processes different downscaling techniques are carried out. Here, a Hidden Markov Model
and a Non-homogeneous Hidden Markov Model are developed using a 54-years record (1951-2004) of daily rainfall amount at 9 stations in Agro-Pontino-plain and re-analysis fields of atmospheric
variables. In HMM and NHMM runs, we directly consider the entire year, rather than an a priori demarcation of seasons. The idea is to identify, directly using the HMM, the seasonal precipitation
characteristics which may be related to the temporal sequence of ‘hidden states’ of atmosphere, subsequently modeled as dependent on appropriate fields of selected atmospheric variables. Daily
rainfall variability is described in terms of occurrence of 5 ‘hidden weather states’ identified by the HMM and associated to variables representing the main characteristics of large-scale atmospheric
circulation as obtained by re-analysis data, then, using NHMM, calibration and validation tests are made to identify the optimal predictors - GeoPotential Height and Temperature at 1000 hPa,
Meridional & Zonal Wind at 850 hPa and Precipitable Water - to reproduce better the observed rainfall features on Agro-Pontino-plain
A sensing and monitoring system for hydrodynamic flow based on imaging and ultrasound
No full textA built environment, that also includes infrastructures, needs to be taken under control to prevent unexpected modifications, otherwise it could react as a loose cannon. Sensing techniques and technologies can come to the rescue of built environments thanks to their capabilities to monitor appropriately. This article illustrates findings related to monitoring a channel hydrodynamic behavior by means of sensors based on imaging and ultrasound. The ultrasound approach is used here to monitor the height of the water with respect to a maximum limit. Imaging treatment is here proposed to understand the flow velocity under the area to be considered. Since these areas can be covered by trash, an enhanced version of the particle image velocimetry technique has been implemented, allowing the discrimination of trash from water flow. Even in the presence of the total area occupied by trash, it is able to detect the velocity of particles underneath. Rainfall and hydraulic levels have been included and processed to strengthen the study
A statistical procedure for analyzing the behavior of air pollutants during temperature extreme events: The case study of emilia‐romagna region (northern italy)
Full text linkMeteorological conditions play a crucial role in air pollution by affecting both directly and indirectly the emissions, transport, formation, and deposition of air pollutants. Extreme weather events can strongly affect surface air quality. Understanding relations between air pollutant concentrations and extreme weather events is a fundamental step toward improving the knowledge of how excessive heat impacts on air quality. In this work, we developed a statistical procedure for investigating the variations in the correlation structure of four air pollutants (NOx, O3, PM10, PM2,5) during extreme temperature events measured in monitoring sites located of Emilia Romagna region, Northern Italy, in summer (June–August) from 2015 to 2017. For the selected stations, Hot Days (HDs) and Heat Waves (HWs) were identified with respect to historical series of maximum temperature measured for a 30‐year period (1971–2000). This method, based on multivariate techniques, allowed us to highlight the variations in air quality of study area due to the occurrence of HWs. The examined data, including PM concentrations, show higher values, whereas NOx and O3 concentrations seem to be not influenced by HWs. This operative procedure can be easily exported in other geographical areas for studying effects of climate change on a local scale
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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