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Il tabù della separazione in psicoterapia: Una Grounded Theory del punto di vista dei pazienti sulla conclusione dell'esperienza psicoterapeutica
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High redshift cosmography: new results and implication for dark energy
No full textThe explanation of the accelerated expansion of the Universe poses one of the most
fundamental questions in physics and cosmology today. If the acceleration is driven
by some form of dark energy, and in the absence of a well-based theory to interpret
the observations, one can try to constrain the parameters describing the kinematical
state of the universe using a cosmographic approach, which is fundamental in that it
requires only a minimal set of assumptions, namely to specify the metric, and it does
not rely on the dynamical equations for gravity. Our high-redshift analysis allows us
to put constraints on the cosmographic expansion up to the fifth order. It is based
on the Union2 Type Ia Supernovae (SNIa) data set, the Hubble diagram constructed
from some Gamma Ray Bursts luminosity distance indicators, and gaussian priors on
the distance from the Baryon Acoustic Oscillations (BAO), and the Hubble constant
h (these priors have been included in order to help break the degeneracies among
model parameters). To perform our statistical analysis and to explore the probability
distributions of the cosmographic parameters we use the Markov Chain Monte Carlo
Method (MCMC). We finally investigate implications of our results for the dark en-
ergy, in particular, we focus on the parametrization of the dark energy equation of state
(EOS). Actually, a possibility to investigate the nature of dark energy lies in measuring
the dark energy equation of state, w, and its time (or redshift) dependence at high ac-
curacy. However, since w(z) is not directly accessible to measurement, reconstruction
methods are needed to extract it reliably from observations. Here we investigate differ-
ent models of dark energy, described through several parametrizations of the equation
of state, by comparing the cosmographic and the EOS series. The main results are:
a) even if relying on a mathematical approximate assumption such as the scale factor
series expansion in terms of time, cosmography can be extremely useful in assessing
dynamical properties of the Universe; b) the deceleration parameter clearly confirms
the present acceleration phase; c) the MCMC method provides stronger constraints
for parameter estimation, in particular for higher order cosmographic parameters (the
jerk and the snap), with respect to those presented in the literature; d) both the esti-
mation of the jerk and the DE parameters, reflect the possibility of a deviation from
the LambdaCDM cosmological model; e) there are indications that the dark energy equa-
tion of state is evolving for all the parametrizations that we considered; f) the q(z)
reconstruction provided by our cosmographic analysis allows a transient acceleration
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
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