130,571 research outputs found
INTEGRATING OPTICAL AND RADAR IMAGERY TO ENHANCE RIVER DROUGHT MONITORING
No full textDrought events are growingly affecting European and Italian territories, hampering local environments and biodiversity, such as the ones relying on rivers for their subsistence. Monitoring of rivers is becoming an important issue to face drought crisis and may be exploited with different tools. Among the most commons, satellite imagery is exploited to map water coverage, basing on optical or radar sources. This work proposes a combination of the two sensors to overcome possible limitations of the single dataset exploitation, reaching a reliable result. The methodology is applied to a stretch of Po River in Lombardy region (Italy). Through Google Earth Engine platform, optical satellite Sentinel-2 and radar satellite Sentinel-1 data are processed. The combination of the radar data and of the optical spectral indices is carried out through a pixel-based supervised classification, with a Random Forest classifier. Maps of water coverage are obtained, numerical outcomes of water surface evaluation are recorded and validated by the mean of reference hydrometric data. A multitemporal analysis is then reported, aiming to prove the efficiency of the procedure. All iterations show reliable accuracies and correlation among water surface estimation and water table measurements in two sections of interest. In perspective, the proposed methodology will be implemented in tools for supporting drought monitoring to be integrated in environmental public administration policies
Towards automation of river water surface detection
No full textEuropean rivers are increasingly impacted by frequent and lasting dry periods, with consequences on jeopardized ecosystems and local economies. Tools for monitoring the evolution of such impacts may be profitable exploited by public administration to assess environmental conditions and draw safeguard policies. This work presents the evolution of a methodology which integrates optical and radar imagery, by Copernicus Sentinel constellations, to map river water surfaces. Despite the base methodology being developed as a man-supervised classification, with necessity for the user to manually define training polygons, the proposed advancements will allow the system to automate training sample extraction. The process is based on the realization of binary masks, originated by processing optical and radar imagery with a BMax Otsu algorithm for image segmentation. The masks are then furtherly refined to obtain a reliable set of classified pixels, from which the training samples are extracted. A sensitivity analysis is performed for assessing the optimal amount of pixels to be considered, with respect to the total area of interest. Furthermore, the performances of several Machine Learning supervised classification algorithms are compared, leading to the selection of the best algorithm to be considered for future developments of the methodology
IO INSEGNO A CASA, IO IMPARO A CASA, IO RESTO A CASA: L’IMPATTO EMOTIVO DELLA DIDATTICA A DISTANZA AI TEMPI DEL COVID-19
No full textIntroduzione
I fattori contestuali sono molto importanti per indurre un'esperienza positiva di vita ed esercitano un'influenza significativa sull'impegno scolastico degli studenti. Lo scenario pandemico prodotto dal Covid-19 ha reso necessarie una serie di misure di distanziamento sociale e l'implementazione della Didattica a Distanza ponendo molte sfide a docenti, genitori e alunni. Questo studio, realizzato nell’ambito del progetto Europeo Interreg INCLUDI, intende fornire un contributo per portare alla luce l’esperienza emotiva che genitori, alunni e docenti hanno vissuto nel periodo in cui l’erogazione della didattica è avvenuto esclusivamente a distanza.
Metodo
Hanno partecipato alla ricerca i genitori (N = 591), i docenti (N = 228), gli studenti (N = 524) delle scuole del Comune di Gallarate. La raccolta dati è avvenuta nel periodo tra aprile e metà giugno 2020. Tutti i partecipanti hanno compilato alcuni questionari on-line appositamente predisposti, segnalati dai dirigenti scolastici all’interno delle piattaforme informatiche utilizzate dai diversi istituti. Le dimensioni indagate riguardano per tutti gli attori coinvolti: l’indagine personale familiare e lavorativa (per docenti e genitori); il vissuto psico-emotivo, con particolare riferimento all’esperienza emotiva vissuta durante la pandemia e in riferimento a quanto vissuto prima del Covid-19, le preoccupazioni circa la situazione scaturita dalla pandemia, le strategie di coping adottate e la percezione dei rapporti e del supporto familiare. Inoltre, oggetto di indagine è stata la percezione della didattica a distanza: per i genitori in relazione alla difficoltà dei figli e al loro coinvolgimento nella gestione a casa, per gli studenti la fruizione dei dispositivi a disposizione e l’esperienza relativa alla didattica a distanza, così come per i docenti con un approfondimento anche sule metodologie impiegate. Risultati
I risultati principali derivati dalle analisi di regressione mostrano che per quanto riguarda i genitori, il numero dei figli impegnati nella Didattica a Distanza contribuisce all’aumento di vissuti emotivi negativi (ansia, tristezza, irritazione) (R2 = .012, p < .001) e alla diminuzione di vissuti emotivi positivi (allegria e soddisfazione) (R2 = .013, p < .001), ma solo per le mamme. Queste relazioni non sono risultate significative per i papà; per quanto riguarda gli studenti, il percepirsi maggiormente coinvolti nella Didattica a Distanza contribuisce a esperire più vissuti emotivi positivi (R2 = .113, p < .001) e meno vissuti emotivi negativi (R2 = .07, p < .001); per quanto riguarda i docenti, le difficoltà nell’organizzazione della Didattica a Distanza (tempo in più dedicato per la preparazione delle lezioni e verifiche) hanno un effetto significativo sull’incremento di vissuti emotivi negativi (R2 = .066, p < .001) e un effetto significativo sulla riduzione di vissuti emotivi positivi (R2 = -.046, p < .001).
Conclusioni
Questi primi risultati evidenziano come la Didattica a Distanza abbia avuto un significativo impatto emotivo su tutti gli attori coinvolti. In particolare, possono contribuire a individuare quali sono i fattori di rischio e di protezione legati all’erogazione della Didattica a Distanza al fine di favorire il miglioramento della qualità di vita degli studenti, di chi si prende cura di loro a casa e dei docenti
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Supraspinal G beta gamma-dependent stimulation of PLCbeta originating from G inhibitory protein-mu opioid receptor-coupling is necessary for morphine induced acute hyperalgesia
No full textAlthough alterations in micro-opioid receptor (microOR) signaling mediate excitatory effects of opiates in opioid tolerance, the molecular mechanism for the excitatory effect of acute low dose morphine, as it relates to microOR coupling, is presently unknown. A pronounced coupling of microOR to the alpha subunit of G inhibitory protein emerged in periaqueductal gray (PAG) from mice systemically administered with morphine at a dose producing acute thermal hyperalgesia. This coupling was abolished in presence of the selective microOR antagonist d-Phe-Cys-Tyr-d-Trp-Orn-Thr-Pen-Thr-NH(2) administered at the PAG site, showing that the low dose morphine effect is triggered by microOR activated G inhibitory protein at supraspinal level. When Gbetagamma downstream signalling was blocked by intra-PAG co-administration of 2-(3,4,5-trihydroxy-6-oxoxanthen-9-yl)cyclohexane-1-carboxylic acid, a compound that inhibits Gbetagamma dimer-dependent signaling, a complete prevention of low dose morphine induced acute thermal hyperalgesia was obtained. Phospholipase C beta3, an enzyme necessary to morphine hyperalgesia, was revealed to be associated with Gbetagamma in PAG. Although opioid administration induces a shift in microOR-G protein coupling from Gi to Gs after chronic administration, our data support that this condition is not realized in acute treatment providing evidence that a separate molecular mechanism underlies morphine induced acute excitatory effect
A psychometric evaluation of the group environment questionnaire in a sample of professional basketball and soccer players
No full textPsychometric properties of the Group environment Questionnaire were investigated in a large sample of soccer (n = 222) and professional basketball players (n = 375). Confirmatory factor analysis was performed both on the total sample and on the two sub samples through a multi-group approach; associations between cohesion and the duration of belonging to the team were also explored. Results confirmed the four-factor structure proposed by Carron's original model even though some items with low loadings were eliminated. No signifcant associations were found between team cohesion and the duration of belonging to the team
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
A psychometric evaluation of the group environment questionnaire in a sample of professional basketball and soccer players
No full textPsychometric properties of the Group environment Questionnaire were investigated in a large sample of soccer (n = 222) and professional basketball players (n = 375). Confirmatory factor analysis was performed both on the total sample and on the two sub samples through a multi-group approach; associations between cohesion and the duration of belonging to the team were also explored. Results confirmed the four-factor structure proposed by Carron's original model even though some items with low loadings were eliminated. No signifcant associations were found between team cohesion and the duration of belonging to the team. © Perceptual & Motor Skills 2013
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