102,451 research outputs found
A Nucleobase-Centric Coarse-Grained Model for Structure Prediction of RNA Fragments
No full textThe structural characterization of RNA usually poses additional challenges when compared to other biomolecular systems. For example, there is a relatively scarce amount of structural data available, which demands the development of three-dimensional structure prediction tools. In addition, full-resolution simulations can be a hard task not only because of the complexity of the interactions involved, but also due to the limitations of the current force fields. At this point, coarse-grained simulations are a good candidate to fill the gaps in this growing research field. The use of these techniques has rapidly increased in the past decades in the study of biological systems on which the experiments require an additional interpretation or where an atomistic computational approach results difficult or unfeasible. Nevertheless, the development of coarse-grained models involves the understanding of the main structural features of the original system, which can represent a challenge by itself.
In this work, we present a knowledge-base coarse-grained model for RNA structure prediction, representing each nucleotide by a single anisotropic particle. The mapping and the main interactions are designed to reproduce the geometrical distribution of the closest pairs of nucleotides, extracted from a set of ribosomal structures. The model is inspired in the ESCORE function [1], a knowledge-based scoring function that has been shown to perform better compared to fully atomistic techniques in identifying native-like structures from a set of decoys. Its minimalistic nature and successful application on a broad range of structures straightforwardly suggest a representation for a coarse-grained approach. We show the preliminary results of our simulations and discuss the role of pair interactions in the prediction of RNA structures.
[1] S. Bottaro, F. Di Palma and G. Bussi, “The Role of Nucleobase Interactions in RNA Structure and Dynamics”, Nucleic Acids Res., accepted
The clinical pattern of subclinical/silent celiac disease:an analysis on 1026 consecutive cases.
No full textStellar limits on scalars from electron-nucleus bremsstrahlung
No full textWe revisit stellar energy-loss bounds on the Yukawa couplings g B,L of baryophilic and leptophilic scalars φ. The white-dwarf luminosity function yields g B ≲ 7 × 10-13 and g L ≲ 4 × 10-16, based on bremsstrahlung from 12C and 16O collisions with electrons. In models with a Higgs portal, this also implies a bound on the scalar-Higgs mixing angle sinθ ≲ 2 × 10-10. Our new bounds apply for mφ ≲ 1 keV and are among the most restrictive ones, whereas for mφ ≲ 0.5 eV, long-range force measurements dominate. Besides a detailed calculation of the bremsstrahlung rate for degenerate and semi-relativistic electrons, we prove with a simple argument that non-relativistic bremsstrahlung by the heavy partner is suppressed relative to that by the light one by their squared-mass ratio. This large reduction was overlooked in previous much stronger bounds on g B. In an appendix, we provide fitting formulas (few percent precision) for the bremsstrahlung emission of baryophilic and leptophilic scalars as well as axions for white-dwarf conditions, i.e., degenerate, semi-relativistic electrons and ion-ion correlations in the “liquid” phase
Il terzo Piano Nazionale Infanzia e il Garante Nazionale
No full textIl capitolo analizza i due importanti interventi del legislatore italiano e delle altre autorità competenti per dare attuazione ai diritti del fanciullo così come affermati nella Convenzione ONU sui diritti dell'infanzia
L'infanzia "violata": strumenti europei e italiani per il contrasto alla tratta, allo sfruttamento e agli abusi sessuali
No full textLo studio mira all'analisi dei recenti interventi per il contrasto degli abusi sui minori partendo dai dati ufficiali disponibili. Particolare attenzione è posta alla questione delle mutilazioni genitali femminili e al modo in cui essa è stata affrontata dal Comitato sui diritti del fanciullo e dal legislatore italiano che, nel tentativo di tutelare l'integrità del minore, appare trascurare una valutazione complessiva e più complessa del suo interesse superiore
Il ruolo dei media: dagli strumenti internazionali di tutela a quelli locali
No full textLo studio mira ad analizzare gli interventi a livello internazionale ed europeo in materia di media e diritti del fanciullo. Completa il quadro la particolare situazione italiana che si basa sui codici di autoregolamentazione e non su un sistema vincolante ideato per favorire la tutela dell'infanzia. Esempiare il caso della Carta di Treviso
Il diritto al gioco e alle attività ricreative
No full textIl contributo analizza uno degli articoli della Convenzione sui diritti del fanciullo più problematici perché, pur affermato come diritto nel trattato internazionale, è difficilmente riconosciuto come tale a livello interno al di là della complessità circa la sua definizione. Si guarda pertanto all'intepretazione offerta dal Comitato sui diritti del fanciullo per poi verificarne l'attuazione in Italia attraverso dati e normative direttamente e indirettamente collegate. Lo studio si conclude con alcuni dati emersi dalle risposte a un questionario inviato alle amministrazioni locali della Liguria dai quali emerge, innanzitutto, l'assenza di una cultura dell'infanzia nonché la mancanza di formazione sui temi correlati
Multiscale mapping and monitoring of green biodiversity in urban areas
No full textUrban areas are being recognized as ecosystems, where biodiversity is essential for sustaining their functionality. Healthy ecosystems offer numerous services that contribute to the well-being of human populations. The EU Biodiversity Strategy and the Nature Restoration law call for no-net loss of urban green spaces and a minimum 10% tree canopy cover in European cities. This commitment is driving a surge in city tree planting projects, with expectations for further increase in the coming years.
In this context, we present an investigation focused on the multiscale mapping and monitoring of urban green biodiversity, with a primary emphasis on trees. Urban trees, besides providing various ecosystem services, play a crucial role in mitigating the urban heat load during summers, thereby alleviating adverse effects on human health, and reducing energy consumption. Unfortunately, the challenging conditions within urban environments, including increased temperatures and water scarcity due to impervious surfaces, can impact the phenology and physiology of trees, often compromising their health and functionality.
In order to better explore these aspects, we introduce an application based on Google Earth Engine with the aim to extract geospatial data related to tree cover and temperatures across various spatial scales in urban environments. Utilizing machine learning algorithms, the application downscales thermal infrared satellite imagery and classifies vegetation features. Users have the flexibility to investigate the relationship between temperatures and vegetation by selecting specific time windows and areas of interest, along with access to significant spectral indices and correlation coefficients. In a pilot case study on the city of Milan, we use the application to perform a detailed analysis at the tree species level, involving the assessment of individual tree canopy temperature response in different areas of the city.
This application aims to provide researchers, urban planners, green managers, and other professionals with a valuable tool to comprehend the spatial dynamics of vegetation in urban environments, assess the impacts of stressors on their fitness, and in the long run to evaluate the effectiveness of mitigation efforts, such as urban reforestations and tree planting
Il diritto di crescere ed essere educato in ambito familiare
No full textIl saggio approfondisce le linee guida del Comitato delle Nazioni Unite sui diritti del fanciullo in merito alla situazione dei minori fuori famiglia. Partendo dalle indicazioni internazionali, l'autore confronta i dati emersi a livello locale ligure verificando l'adesione o meno agli orientamenti internazionali prevalenti in materia e richiamando esperienze che cercano di tutelare, oltre al diritto di crescere in ambito familiare, anche il diritto ad essere educato nel rispetto della propria identità culturale
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