1,720,966 research outputs found
Monitoring Ecohydrological Variables in a Peri-Urban Forest and a Non-glacial High-Elevation Grassland Representing Possible Future Conditions in the Alps
No full textMountain environments often suffer from a scarcity of comprehensive environmental data that are the starting point for a better understanding of ecohydrological dynamics and for the validation, or improved conceptualization, of hydrological and land surface models. Recognizing the critical importance of understanding these environments to address the challenges of water resource management under unsettling future climate scenarios, research efforts are underway to address the lack of information. This study focuses on the comprehensive monitoring of ecohydrological variables within two contrasting catchments in Northwestern Italy. The first catchment (Colle del Nivolet, Aosta Valley) is monitored with a station located in a non-glacial high-elevation (2555 m a.s.l.) grassland. The second catchment (Bussoleno Grangia dell’Alpe) is monitored through a station at 650 m a.s.l. in a peri-urban forest. The research employs advanced monitoring techniques such as cosmic ray probes, environmental tracers (such as stable water isotopes in vegetation, soil and streamwater), and the eddy-covariance setup for atmospheric monitoring. In this regard, micrometeorological instruments have been installed on a 5 m-high mast (grassland site) and a 25 m-high mast (forest site). The previously mentioned monitoring techniques lead to the investigation of key ecohydrological variables such as energy, water vapor and carbon dioxide fluxes, 3D wind speed, soil moisture, soil matric potential, 4-component solar radiation, snow water equivalent, and the water isotope content whose integration provides necessary insights of hydrological and ecohydrological processes occurring from the plot to the catchment scale. Continuous monitoring over several years covering a wide range of wetness conditions, including the (probably) worst drought in the past two centuries in Northern Italy, lays the foundations for the identification of trends, anomalies, and potential shifts in these variables, thus providing a picture of the ecosystems' adaptive capacities in the face of evolving environmental conditions
Towards a conceptualization of the hydrological processes behind changes of young water fraction with elevation: A focus on mountainous alpine catchments
Full text linkThe young water fraction (F-yw*), defined as the fraction of catchment outflow with transit times of less than 2-3 months, is increasingly used in hydrological studies that exploit the potential of isotope tracers. The use of this new metric in catchment intercomparison studies is helpful to understand and conceptualize the relevant processes controlling catchment functioning. Previous studies have shown surprising evidence that mountainous catchments worldwide yield low F-yw*. These low values have been partially explained by isolated hydrological processes, including deep vertical infiltration and long groundwater flow paths. However, a thorough framework illustrating the relevant mechanisms leading to a low F-yw* in mountainous catchments is missing.The main aim of this paper is to give an overview of what drives F-yw* variations according to elevation, thus clarifying why it generally decreases at high elevation. For this purpose, we assembled a data set of 27 study catchments, located in both Switzerland and Italy, for which we calculate F-yw*. We assume that this decrease can be explained by the groundwater storage potential, quantified by the areal extent of Quaternary deposits over a catchment (F-qd), and the low-flow duration (LFD) throughout the period of isotope sampling (PoS). In snow-dominated systems, LFD is strictly related to the snowpack persistence, quantified through the mean fractional snow cover area (F-SCA). The drivers are related to the catchment storage contribution to the stream that we quantify by applying a cutting-edge baseflow separation method to the discharge time series of the study sites and by estimating the mean baseflow fraction (F-bf) over the PoS.Our results suggest that Quaternary deposits could play a role in modulating F-yw* elevation gradients via their capacity to store groundwater, but subsequent confirmation with further, more detailed geological information is necessary. LFD indicates the proportion of PoS in which the stream is sustained and dominated by stored water coming from the catchment storage. Accordingly, our results reveal that the increase of LFD at high elevations, to a large extent driven by the persistence of winter snowpacks and the simultaneous lack of a liquid water input to the catchments, results in lower F-yw*. In our data set, F-bf reveals a strong complementarity with F-yw*, suggesting that the latter could be estimated as F-yw*-1-F-bf for catchments without stable water isotope measurements.As a conclusion, we develop a perceptual model that integrates all the results of our analysis into a framework for how hydrological processes control F-yw* according to elevation. This lays the foundations for an improvement of the theory-driven models
Long-Range Low-Power Soil Water Content Monitoring System for Precision Agriculture
Full text linkWorld population growth and desertification are increasing the food demand. Food production must increase to ensure food security in the following years. Smart agriculture tries to improve food production thanks to the adoption of electronic sensors to monitor and control fruit and vegetable crops. Another critical point in agriculture is the use of potable water. Precision irrigation strategies can be implemented to reduce water waste and increase crop production. This paper proposes a long-range, low-power sensor node to monitor soil water content. It is possible to place multiple sensor nodes in the field and use the gathered data to determine the most suitable irrigation strategy. The node communicates thanks to the LoRa protocol and it can also be used in remote areas where it is impossible to have an internet connection
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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