1,721,045 research outputs found
The Counterfactual Challenge:How Machine Learning Can Enhance Policy Evaluation
No full textUnderstanding the impact of public policies and programmed actions is a complex and challenging task that deserves attention and resources. Even if the economic literature on counterfactual methods and identification is well established, conventional methodologies still struggles with holding up the unconfoundedness assumption in complex socio-economic and policy contexts. This paper sets up a ‘counterfactual challenge’, testing the ability of conventional matching versus a novel application of Supervised Machine Learning classification process to identify suitable counterfactuals. Working with high-dimensional data in complex socio-economic and policy contexts, results show that Machine Learning algorithms are better equipped to effectively balance treatment and control groups across a wide range of covariates compared to conventional matching methods. In the context of decision making and policy planning, we show the potential of Machine Learning to drastically improve the reliability and precision of information supporting policymakers in their choices. This is argued to have a positive impact on the effective use of public resources especially in complex and underdeveloped areas and contexts. Improvements in the precision of impact evaluation could result in significant gains in resource efficiency, both by generating realistic expectations of policy outputs, and improving scarce resource allocation we show that the use of Machine Learning algorithms for counterfactual identification consistently provides more precise results and supports policymakers in navigating complex contexts
Selection bias ed incentivi alle imprese nei programmi per lo sviluppo locale: una valutazione ex-post
No full textThis paper focuses on the evaluation of an aid scheme included in a larger local development
program realized in Italy during the 2000-2006 cycle of EU Structural Funds. It follows a
previous analysis (Cusimano, Mazzola, 2014) on the ex-post evaluation of the effects of
the aid schemes included in the so-called territorial integrated projects (tips) and aims
at identifying the possible presence of selection bias in measuring the effectiveness of the
policy. After running an empirical analysis based on several propensity score matching
(psm) methods, we show that, at least partially, the positive results previously obtained
may not be related to an effective success of the policy, but could indicate a distortive effect
of the selection process
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
Antitumor activity of the novel small molecule Akt inhibitor SC66 in hepatocellular carcinoma cells.
No full textHepatocellular carcinoma (HCC) is the fifth most common cancer worldwide characterized by poor and often limited or no response to current drug therapies. The PI3K/Akt/mTOR pathway is a key regulator of cell proliferation and survival. Alterations in this pathway have been reported in many types of human cancer, including HCC. It has become evident that Akt inhibitors have great potential in cancer treatment. SC66 is a new allosteric Akt inhibitor that facilitates ubiquitination of Akt, favoring its degradation via the proteasome, thus inhibiting Akt signaling. In the present study, we investigated the anticancer activity of SC66 in HCC cell lines (HepG2, Huh7, Hep3B, PLC/PRF/5 and HA22T/VGH). Treatment with SC66 reduced cell viability in a dose- and time-dependent manner and inhibited colony formation. At the same time, SC66 induced anoikis, as demonstrated by alterations of cytoskeleton organization and reduction of E-cadherin, -catenin and Snail expression. SC66 induced apoptosis was revealed by flow cytometry analysis, cleavage of PARP, and decreased expression of the anti-apoptotic proteins survivin and Bcl2. In addition, after treatment with SC66 a dose-dependent ROS production was demonstrated by H2DCFDA-based fluorescence staining. Co-treatment with the ROS scavenger NAC prevented the SC66-induced cell growth inhibition and anoikis. In conclusion, our data indicated that the Akt inhibitor SC66 had antitumor effects on HCC cells. This was mediated by ROS production and induction of anoikis-mediated cell death. All together, our results provide a rational basis for the clinical use of SC66 in the treatment of liver cancer
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
Functional Characterization of an Episodic Ataxia Type-1 Mutation Occurring in the S1 Segment of hKv1.1 Channels.
No full textVoltage-gated potassium channels (Kv) play
important roles in neurotransmission, nerve cell excitability
and disease. Several missense mutations in the
Kv1.1 gene have been associated with episodic ataxia
type-1 syndrome (EA-1), which is characterized by
continuous myokymia, episodic attacks of ataxic gait
and spastic contractions of skeletal muscles. In this study
we show that I177N, an EA-1 mutation located in S1
segment, alters the expression and gating properties of the
channel expressed in Xenopus oocytes. In particular, it
reduces ~17-fold the current amplitude, accelerates ~4-
fold the deactivation kinetics of the channel and shifts the
voltage dependence of activation ~60 mV to more
depolarized potentials. Single-channel recordings also
showed that the mean open duration of I177N channels
was ~2.6-fold smaller than the wild-type. These results
demonstrate that both reduced current levels and specific
gating defects are the likely causes of EA-1 symptoms in
patients bearing the I177N mutation. Furthermore, the
data suggest that the I177N substitution may alter the
gating properties of the channel that are specifically
defined by the S1 segment
Functional Properties of Voltage-Gated Potassium Channels Probed with Methanethiosulfonate Reagents
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