1,720,995 research outputs found
Hydro-chemical anomalies in clay-rich landslides: evidences from case studies in the northern Apennines (Italy)
Full text linkThe presence of deep faults can affect the groundwater circulation. They can control the rising of deep fluids to
the ground surface. Normally, deep fluids have a chemical composition completely different from the shallow
groundwater; depending on the travel depth, temperature and pressure conditions, mineral composition of the
rocks crossed and time of interaction.
This can affect the hydro-chemical characteristics of near-surface groundwater. Eventually, it can change the
fingerprint of groundwater circulating in landslides and it can influence long-term pore-pressure fluctuations,
playing a role on slope stability.
In the northern Apennines of Italy, several large-scale earth slides – earth flows affecting faulted clayey formations
are believed to be somehow influenced by deep fluids. The study was aimed at detecting hydro-chemical anomalies
in groundwater circulating in 3 landslides that have resumed activity several times in the last decades, and that
are occurring in areas of potential deep-fluid influence (Silla, Ca’ Lita, Vedriano). More than 30 water-samples
were collected at different depth in the landslide body and in the underlying bedrock, owing to the presence
of several piezometers. Physical and chemical analyses comprised determination of temperature, conductibility,
pH, main cations and anions (K+, Na+, Cl, Ca2+, Mg2+, SO42 and HCO). Isotopic analyses (oxygen and
deuterium) are still ongoing. Results allowed discriminating between a Ca-Carbonate hydrotype (400-600 μS/cm),
that is interpreted as being directly connected with rainfall infiltration, and a Na-sulfate-rich hydrotype, that is
interpreted as the evidence of deep fluids upflow. This would actually be the result of the mixing between two
extreme hydrotypes: Na-bicarbonate water and Ca-sulfate waters, both characterized by high salinity, over 4000
μS/cm. The first is typical of geothermal water in the Apennines and is linked to the infiltration at great depth of
rain water and the subsequent long term interaction between water and rock masses that allows to degradation of
the Na-silicate. The second hydrotype, Ca-sulfate water, might be related to the presence of gypsum deposits in
the stratigraphic sequence of the Apennines chain
Meniett therapy may avoid vestibular neurectomy in disabling Meniere's disease
No full textConclusion. In those patients for whom vestibular neurectomy has been selected due to the disabling recurrence of vertigo spells, Meniett((R)) therapy has been shown to allow avoidance of this surgical procedure in a fairly high percentage of patients with Meniere's disease (MD). Our data would also support a better result when pressure treatment is acting on MD of short duration. Objective. To test the possibility that low pressure treatment (Meniett((R))) could avoid vestibular neurectomy in patients with MD that was refractory to medical treatment. Patients and methods. The setting was a tertiary referral centre in a university hospital. Thirty-six MD patients, for whom vestibular neurectomy was indicated, underwent Meniett((R)) treatment and composed a group in which a long-term (>2 years) follow-up was achieved. Additionally, different durations of MD('young' and 'old' MD) were distinguished and analysed separately. Results. Twenty-five patients (69.4%) were treated satisfactorily by using Meniett((R)) treatment and therefore avoided vestibular neurectomy. In half of them only one cycle of treatment was necessary
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
Hydrological and chemical characterization of an earth slide-flow
Full text linkTo understand the origin of instability and the evolution of large and deep earth slide-flows, it is important to define
the origin and path of groundwater and the role of the groundwater on the landslide deposit rheology. To achieve
these goals it is important characterize, physically and chemically, the bedrock and slope deposits and the groundwater system.
This study deals with the hydrological and geochemical characterization of a reactivated earth slide-flow affecting
Cretaceous flysch, located in the northern Apennines of Italy. In situ permeability and pumping test, continuous
monitoring of groundwater levels, electrical conductivity, temperature, furthermore, hydrochemical and isotope
analysis were the adopted prospecting methods. In detail, oxygen, deuterium and tritium isotopes, the major cations
and anions and the Boron content have been analyzed. To investigate the relation between the groundwater chemical elements, the total dissolved solids and the changing in the landslide behavior some geotechnical tests have
been conducted.
Groundwater levels were monitored for more than 5 years by means of transducers in 5 standpipe piezometers,
fissured above or below the sliding surface. Results showed that two overlaying aquifers exist at the slope scale:
an unconfined one, in the fractured flysch of the rock slide; a semi-confined one, in the undisturbed flysch below
sliding surface.
Pore pressure in the unconfined aquifer is controlled by rainfall, with fluctuation of several meters occurring hours
or days from onset of precipitation. On the contrary, pore pressure in the semi-confined aquifer shows little response to precipitation events, has fluctuations of few meters related to seasonal trends, and maintains pressure
head higher than that in the unconfined one. This makes it a relevant factor for the stability of the slide. Storage
coefficient of 10-3 and hydraulic transmissivity of 1E-5 m2/s were estimated for the unconfined aquifer with a
pumping test carried out with several control piezometers.
The geochemical characterization obtained by sampling and lab analysis highlighted two groundwater types in
the landslide area. One shallow, directly connected with rainfall, that can be classified as cold (13 C) and Cacarbonate rich with electric conductivity around 800 S/cm and which is characterized by 6.5 Unit Tritium. The
second consists of deep-fluids, rich in Na-sulfate and Boron. This deep-fluids are characterized by cold temperature
(13 C) and high salinity, over 4000S/cm and which is characterized by 3.5 Unit Tritium. Both groundwater have
an oxygen and deuterium composition similar to the local rainfall.
The results obtained in Ca’ Lita show a high complexity of the groundwater flow due to high heterogeneity and
anisotropy of the hydraulic characteristics inside the landslide deposit and in the underlying fractured bedrock.
Moreover, the hydrogeological study has individuated a rising of deep fluids in the landslide area, which can have
a negative effect on the stability of the whole slope. The research results will be used to design and implement deep
drainage systems for risk mitigation purposes
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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