1,721,037 research outputs found
Adaptataions of benthic communities to ecopeaking in alpine rivers
Full text linkDaily changes in physical and chemical water parameters (i.e., ecopeaking) can arise seasonally in natural conditions in kryal streams due to the summer daily glacial melt and consequent changes in runoff. Only few and specialized taxa living in such extreme habitats are adapted to such cyclic changes (e.g., Chironomidae Diamesinae and Simuliidae Prosimulinae). In regulated rivers, however, ecopeaking changes are sudden, occur once or more times per day, and span through the entire year, and are related to the releases from hydropower plants fed by high elevation and stratified reservoirs (i.e., the hydropeaking). The entire downstream benthic community is affected and, because large hydropower plants are usually at lower elevation, they affect communities which are not necessarily adapted to naturally-occurring changes. Hence, the effects of ecopeaking is very relevant. Changes in discharge (hydropeaking) and temperature (thermopeaking) have been proved to cause massive drift responses in benthic invertebrates in field and simulated conditions, whereas changes in turbidity, suspended sediments, conductivity and other chemical parameters have been less investigated.
Rapid growth of the human population and economic development are tightly coupled with an increase in global energy demand, which is causing a current boom in hydropower dam construction (Zarfl et al., 2015). The effects on the biota already are, and will be, dramatic, and need to be fully understood. Simuliidae were selected as target taxon to assess the effect of ecopeaking on larval development and emergence. In fact, Simuliidae larvae are filter feeders, sensitive to alterations of solid transport and temperature and they permanently colonize floating substrates. Hence, they are easy to be semi-quantitatively collected upstream and downstream of the alteration source. Furthermore, the larvae have sclerotized head capsules which can be easily measured to assess life cycle parameters, and the pupal cases and exuviae remain fixed on the substrate after adult emergence and allow identification at the species level
Assessment of morphological and ecological conditions of Italian alpine rivers using IQM and Odonata
No full textAssessment of morphological and ecological conditions of Italian alpine rivers using the Morphological Quality Index (IQM) and Odonata
No full textThe Odonate Habitat Index (OHI) revisited: an improved methodology tested in six Alpine Italian rivers
No full textUtilizzo degli Odonati come indicatori dello stato ecologico dei corsi d’acqua e strumento di monitoraggio di interventi di riqualificazione fluviale
No full textEfficacy of Bacillus thuringiensis subsp. israelensis (Bti) for the control of black fly populations, (Simulium spp.) in Mantua province (Italy)
No full text
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
- …
