828 research outputs found

    Structural Properties of the Disordered Spherical and other Mean Field Spin Models

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    We extend the approach of Aizenman, Sims and Starr for the SK-type models to their spherical versions. Such an extension has already been performed for diluted spin glasses. The factorization property of the optimal structures found by Guerra for the SK model, which holds for diluted models as well, is verified also in the case of spherical systems, with the due modifications. Hence we show that there are some common structural features in various mean field spin models. These similarities seem to be quite paradigmatic, and we summarize the various techniques typically used to prove the structural analogies and to tackle the computation of the free energy per spin in the thermodynamic limit.Comment: 24 page

    Metriche citazionali e mutazioni strategiche della ricerca scientifica: narrative ed evidenze

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    Following the diffusion of the management model promoted by the New Public Management also within universities, sectors until then endowed with particular protection, such as the academic one, were progressively subjected to new controls and constraints, which gradually took the form of quantitative surveys, with a growing role of citation metrics. These evaluation processes have given rise to various important critical positions at an international level. If it is true that, according to Goodhart's law, "when a measure becomes an objective it ceases to be a good measure‚ÄĚ, it is even more significant to note that when a measure becomes an objective, what is measured ceases to be what it was before. The quantitative measurement of academic performance has in fact triggered forms of gaming such as to alter the very game of scientific research, its purposes and the forms of its sharing. In the article we will carry out a comparison between the forms of mutation and the narratives that accompany them to see to what extent we are legitimate today to talk about the transformation of scientific research into strategic scientific research

    Metriche citazionali e mutazioni strategiche della ricerca scientifica: narrative ed evidenze

    Get PDF
    Following the diffusion of the management model promoted by the New Public Management also within universities, sectors until then endowed with particular protection, such as the academic one, were progressively subjected to new controls and constraints, which gradually took the form of quantitative surveys, with a growing role of citation metrics. These evaluation processes have given rise to various important critical positions at an international level. If it is true that, according to Goodhart's law, "when a measure becomes an objective it ceases to be a good measure‚ÄĚ, it is even more significant to note that when a measure becomes an objective, what is measured ceases to be what it was before. The quantitative measurement of academic performance has in fact triggered forms of gaming such as to alter the very game of scientific research, its purposes and the forms of its sharing. In the article we will carry out a comparison between the forms of mutation and the narratives that accompany them to see to what extent we are legitimate today to talk about the transformation of scientific research into strategic scientific research

    Citation metrics and strategic mutations of scientific research: narratives and evidence

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    Following the diffusion of the management model promoted by the New Public Management also within universities, sectors until then endowed with particular protection, such as the academic one, were progressively subjected to new controls and constraints, which gradually took the form of quantitative surveys, with a growing role of citation metrics. These evaluation processes have given rise to various important critical positions at an international level. If it is true that, according to Goodhart's law, "when a measure becomes an objective it ceases to be a good measure‚ÄĚ, it is even more significant to note that when a measure becomes an objective, what is measured ceases to be what it was before. The quantitative measurement of academic performance has in fact triggered forms of gaming such as to alter the very game of scientific research, its purposes and the forms of its sharing. In the article we will carry out a comparison between the forms of mutation and the narratives that accompany them to see to what extent we are legitimate today to talk about the transformation of scientific research into strategic scientific research

    The influence of a new clinical motion for endodontic instruments on the incidence of postoperative pain

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    Previous studies showed that motor motions play an important role in determining apical extrusion of debris. Therefore a new clinical motion (MIMERACI) has been proposed. The basic idea is to progress slowly (1mm advancement), and after each 1mm, to remove the instrument from the canal, clean flutes and irrigate. The aim of the study was to prove whether the clinical use of MIMERACI technique would influence or not postoperative pain.MATERIALS AND METHODS: 100 teeth requesting endodontic treatment were selected for the study and divided into two similar groups based on anatomy, pre-operative symptoms and vitality, presence or absence of periapical lesion. All teeth were shaped, cleaned and obturated by the same operator, using the same NiTi instruments. The only difference between the two groups was the instrumentation technique: tradional (group A) vs MIMERACI (group B). Assessment of postoperative pain was performed 3 days after treatment. Presence, absence and degree of pain were recorded with a visual analogue scale (VAS), validated in previous studies. Collected data statistically analyzed using one-way ANOVA post hoc Tukey test. RESULTS: For VAS pain scores MIMERACI technique showed significantly better results than group A (p=0,031). Overall, both incidence and intensity of symptoms were significantly lower. Flare ups occurred in 3 patients, but none treated with the MIMERACI Technique. CONCLUSIONS: Since extruded debris can elicit more postoperative pain, results obtained by using MIMERACI technique are probably due to many factors: better mechanical removal and less production of debris and more efficient irrigation during instrumentation

    Zebra-Sphinx: Modeling Sphingolipidoses in Zebrafish

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    Sphingolipidoses are inborn errors of metabolism due to the pathogenic mutation of genes that encode for lysosomal enzymes, transporters, or enzyme cofactors that participate in the sphingolipid catabolism. They represent a subgroup of lysosomal storage diseases characterized by the gradual lysosomal accumulation of the substrate(s) of the defective proteins. The clinical presentation of patients affected by sphingolipid storage disorders ranges from a mild progression for some juvenile- or adult-onset forms to severe/fatal infantile forms. Despite significant therapeutic achievements, novel strategies are required at basic, clinical, and translational levels to improve patient outcomes. On these bases, the development of in vivo models is crucial for a better understanding of the pathogenesis of sphingolipidoses and for the development of efficacious therapeutic strategies. The teleost zebrafish (Danio rerio) has emerged as a useful platform to model several human genetic diseases owing to the high grade of genome conservation between human and zebrafish, combined with precise genome editing and the ease of manipulation. In addition, lipidomic studies have allowed the identification in zebrafish of all of the main classes of lipids present in mammals, supporting the possibility to model diseases of the lipidic metabolism in this animal species with the advantage of using mammalian lipid databases for data processing. This review highlights the use of zebrafish as an innovative model system to gain novel insights into the pathogenesis of sphingolipidoses, with possible implications for the identification of more efficacious therapeutic approaches

    Systematic Characterization of High-Power Short-Duration Ablation: Insight From an Advanced Virtual Model

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    High-power short-duration (HPSD) recently emerged as a new approach to radiofrequency (RF) catheter ablation. However, basic and clinical data supporting its effectiveness and safety is still scarc

    Mean field dilute ferromagnet I. High temperature and zero temperature behavior

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    We study the mean field dilute model of a ferromagnet. We find and prove an expression for the free energy density at high temperature, and at temperature zero. We find the critical line of the model, separating the phase with zero magnetization from the phase with symmetry breaking. We also compute exactly the entropy at temperature zero, which is strictly positive. The physical behavior at temperature zero is very interesting and related to infinite dimensional percolation, and suggests possible behaviors at generic low temperatures. Lastly, we provide a complete solution for the annealed model. Our results hold both for the Poisson and the Bernoulli versions of the model.Comment: 38 page
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