101,906 research outputs found
Geografia delle risorse idriche
No full textThe Table presents in numerical and cartographic form, the results of a systematic survey of articles concerning water as a resource, published in five international geographic reviews (Annals of the Association of American Geographers, Applied Geography, Political Geography, Transactions of the Institute of British Geographers, L'Espace Géographique), during 10 years (1994-2004). Part 1 pertains to M. Fiori (pp. 561-562); part 2 (pp. 563-564) to G. Galeandro
Doppler ultrasound venous mapping of the lower limbs
No full textBackground: The study aim was to test the accuracy (intra and interobserver variability), sensitivity, and specificity of a simplified noninvasive ultrasound methodology for mapping superficial and deep veins of the lower limbs. Methods: 62 consecutive patients, aged 62 ± 11 years, were enrolled. All underwent US-examinations, performed by two different investigators, of both legs, four anatomical parts, and 17 veins, to assess the interobserver variability of evaluation of superficial and deep veins of the lower limbs. Results: Overall the agreement between the second versus the first operator was very high in detecting reflux (sensitivity 97.9, specificity 99.7, accuracy 99.5; P = 0.80 at McNemar test). The higher CEAP classification stages were significantly associated with reflux (odds ratio: 1.778, 95% confidence interval: 1.552-2.038; P < 0.001) as well as with thrombosis (odds ratio: 2.765, 95% confidence interval: 1.741-4.389; P < 0.001). Thus, our findings show a strict association between the symptoms of venous disorders and ultrasound evaluation results for thrombosis or reflux. Conclusion: This study demonstrated that our venous mapping protocol is a reliable method showing a very low interobserver variability, which makes it accurate and reproducible for the assessment of the morphofunctional status of the lower limb veins. © 2012 Galeandro et al, publisher and licensee Dove Medical Press Ltd
Data driven analysis of the discharge variations at Mercure spring South Italy
No full textMercure Spring collects groundwater from a large catchment on the north-western side of Mount Pollino massif. This spring area is characterized by several small springs in a zone where fluvial and lacustrine deposits overlay the limestone of Pollino Unit. Fluvial-lacustrine deposits of Mercure river are generally impermeable due to the silty clayey fraction and hinder the flow through the limestone with a permeability threshold that force groundwater to come out as spring. Groundwater hydrology of mount Pollino Massif is strictly conditioned by the relative permeability of the geological units and by tectonic structure and karst phenomena and groundwater circulation are quite complex, so there are flow paths of quite different length supplying the spring. The average discharge of the spring is about 1.8 m3/s with a minimum value of 1.10 m3/s and a maximum one of more than 2.50 m3/s. A detailed analysis of hydrograph allows to observe interesting short term variations up to 15-20% of the discharge values, occurring during the year. These variations are related to specific rainfall events or periods, in fact these local peaks are normally during January and February when severe rainfall periods are more common. The available discharge data are not long enough to use a data-driven approach to relate discharge to rainfall for all the annual hydrograph. Anyway available data permit an analysis of short-term variations of discharge in relation to the rainfall. For this purpose it was used a symbolic regression technique namely EPR: Evolutionary Polynomial Regression based on a Genetic Algorithm implemented in the tool EPRMOGA-XL. As input data rainfall measured at Rotonda rain gauge station were used and, as output, data of the spring discharge time-series. Daily data on a period of about 4 years (2007-2010) were used. Data-driven analysis allows to recognize a quite quick flow path of 5-7 days and a longer one of about 15-20 days that determine the short-term discharge variability. In addition, it is possible to try to relate this variation to the geological structure. Anyway, there are long term variations like those occurring during the entire year that cannot be caught by the model, due to the limited set of available data
Modeling environmental bias and computing velocity field from data of Terra Nova Bay GPS network in Antarctica by means of a quasi-observation processing approach
No full textA semi-permanent GPS network of about 30 vertices has been installed at Terra Nova Bay (TNB) near
Ross Sea in Antarctica. A permanent GPS station TNB1 based on an Ashtech Z-XII dual frequency P-code GPS
receiver with ASH700936D_M Choke Ring Antenna has been mounted on a reinforced concrete pillar built on
bedrock since October 1998 and has recorded continuously up to the present. The semi-permanent network has been
routinely surveyed every summer using high quality dual frequency GPS receivers with 24 hour sessions at 15 sec
rate; data, metadata and solutions will be available to the scientific community at (http://www.geodant.unimore.it).
We present the results of a distributed session approach applied to processing GPS data of the TNB GPS network, and
based on Gamit/Globk 10.2-3 GPS analysis software. The results are in good agreement with other authors'
computations and with many of the theoretical models
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Notes on the morphological features of the gorges on southwest bound of Apulia calcareous platform called “Gravine”
No full textThe main morphological elements characterizing the South-West bound of Apulian (South Italy) calcareous platform are deep narrow valleys locally called “Gravine”. There are several of these gorges in this area and some are short while others are really long, sometimes several kilometers and more than 100 m deep. These elements are really relevant for the landscape of this area, in fact they are protected by a Regional Park that is called “Park of the Gravine Land”. Normally, these geomorphic elements are considered related to erosion phenomena. However, they were cut in non-easily erodible rocks in a relatively short period because in the upper part of the banks it outcrops quaternary sandstones. Due to the peculiarity of these landforms, a more detailed study on the geomorphic characters of these gorges is here undertaken for two of the main Gravine on the western part
of the gravine zone: “Gravina di Laterza” and “Gravina di Castellaneta” and a secondary one “Gravina di Montecamplo” that is located between the previous two. The first two gorges (Laterza and Castellaneta) drains catchments of more than 150 km2 upstream of the beginning of the gorge segment. Thus, the catchment upstream the gorge segment is analyzed separately from the gorge. The analyses emphasize that the upstream catchments have characteristics features completely different from those of the gorge segment, that is a singularity of the streams. A stream network quite well hierarchized characterizes the catchments upstream of the gorge and the streams appear in a quite mature stage of evolution. The three gorges share similar characteristics and none of them has characteristics typical of mature streams. The analysis of azimuthal directions of the gorges and of the stream network upstream the gorge segments shows that both gorges and the stream network develop along few clear Apennine and anti-Apennine directions. Therefore, this network is probably strongly conditioned by tectonic fractures. On the base of the analysis, it is here assumed that the origin of gravine may reasonably be related to the final phases of the tectonic uplift of Murgia region. Tectonic tensile stresses on south-west edge of Mesozoic limestone platform brought to the collapse of the lower edge of the platform with separation of limestone blocks, where gravine represent cracks of the carbonate bedrock without relative displacement
Tecnica speditiva di stima del geoide a scala locale
No full textTecnica speditiva di stima del geoide a scala local
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