1,721,514 research outputs found
Measurement of the CP violation parameter Aᴦ in D0 → K+ K־ and D0 → π+π– decays
Get PDF[The math symbols of this abstract has been partly transcripted by the cataloguer] Time-dependent CP asymmetries in the decay rates of the singly Cabibbo-suppressed decays
D(exponentiation)0 → K(exponentiation)+ K(exponentiation)- and D(exponentiation)0 → π(exponentiation)+ π(exponentiation)- are measured in pp collision data at centre-of-mass energies of 7 and 8TeV collected by the LHCb detector during LHC Run I, corresponding to an integrated luminosity of 3 fb(exponentiation)-1. The strong-interaction decay D(exponentiation)*+ → D(exponentiation)*+ -> D(exponentiation)0 π(exponentiation)+ is used to infer the flavour of
the D(exponentiation)0 mesons at production. The asymmetries in effective decay widths between D(exponentiation)0 and (overbar)D(exponentiation)0 decays, sensitive to indirect CP violation, are measured to be
A(p-adic integers)Γ (D(exponentiation)0 → K(exponentiation)+ K (exponentiation)-) = (-0.30 ± 0.32 ± 0.10) x 10(exponentiation)-3,
A(p-adic integers)Γ (D (exponentiation)0 → π (exponentiation)+ π (exponentiation)-) = ( 0.46 ± 0.58 ± 0.12) x 10¡3,
where the first quoted uncertainty is statistical, and the second systematic. These measurements
show no evidence of CP violation and improve on the precisiopn of the previuos best measurements by nearly a factor of two
Feasibility of a tRNA-fragment regulated encapsulated cell therapy approach for epilepsy
No full textBackground: Recenti evidenze suggeriscono un ruolo per i frammenti di tRNA (tRF) nella patogenesi e nella diagnosi di disturbi neurologici come l'epilessia, refrattaria al trattamento medico in un terzo dei pazienti e sovente accompagnata da comorbilità neurologiche e psichiatriche.
Scopi: Valutare la tollerabilità di un nuovo dispositivo impiantabile costituito da cellule incapsulate (ECB) atto a veicolare GDNF nel trattamento delle epilessie farmaco-resistenti e la fattibilità dell'utilizzo di frammenti specifici derivati da 5'tRNA (5'tRF) come molecole segnale per regolare la secrezione del fattore neurotrofico.
Metodi: il progetto ha compreso tre fasi. Innanzitutto, abbiamo testato in modo approfondito la tollerabilità in vivo di un dispositivo a membrana semipermeabile impiantato negli ippocampi di ratti Sprague-Dawley naive. Le indagini comportamentali includevano open field, rotarod e object location task (OLT) per valutare la tollerabilità del dispositivo, l'impatto sulle competenze motorie e sulla funzionalità ippocampale. Sono seguite la valutazione della suscettibilità alle crisi indotte da pentilenetetrazolo (PTZ) e l'analisi istologica dei marcatori di gliosi. In secondo luogo, abbiamo delineato un metodo per la raccolta seriata di campioni di liquido cerebrospinale (CSF) e plasma da ratti epilettici impiantati con elettrodi per la registrazione di tracciato EEG. Abbiamo poi studiato tre 5'tRF (5'AlaTGC, 5'GluCTC e 5'GlyGCC) precedentemente identificati come predittori di crisi in pazienti epilettici. Abbiamo esplorato le loro variazioni in un modello murino di epilessia del lobo temporale (mTLE), sia nel CSF che nel plasma, e le possibili associazioni con l’attività ictale ed interictale.
Risultati: il dispositivo è stato ben tollerato senza effetti significativi sulla funzione motoria o sulla gliosi. Tuttavia, gli animali impiantati hanno mostrato prestazioni ridotte nell’OLT, dato suggestivo di potenziale deterioramento della memoria; e una maggiore suscettibilità alle crisi epilettiche in seguito alla somministrazione di PTZ. L'analisi dei frammenti di tRNA non ha mostrato correlazioni tra i valori di 5'AlaTGC, 5'GluCTC e 5'GlyGCC nel plasma e nel CSF, così come variazioni in relazione a campionamenti a distanza, poco prima o subito dopo una crisi. L’abbondanza dei frammenti non ha mostrato correlazioni con la frequenza delle crisi spontanee, né associazione alla presenza di attività interictale. E’ stata tuttavia notata una tendenza all'aumento di tutti i 5'tRF negli animali epilettici a seguito di un evento critico.
Conclusioni: l'impianto bilaterale di dispositivi ECB può essere ben tollerato in un modello murino di mTLE, ma il potenziale deterioramento della memoria e la maggiore suscettibilità alle crisi richiedono ulteriori indagini e ottimizzazioni. Per valutare l'applicabilità clinica dei frammenti di tRNA come biomarcatori dell'epilessia, sono necessarie ulteriori conferme in modelli animali. Studi futuri dovrebbero concentrarsi sul miglioramento della risoluzione temporale delle misurazioni di 5'tRF, sull'espansione delle dimensioni del campione e sull'esplorazione di una gamma più ampia di 5'tRF come potenziali biomarcatori nell'epilessia.Background: Emerging evidence suggests a role for tRNA fragments (tRFs) in both the develop-ment and diagnosis of neurological disorders like epilepsy, which is refractory to medical treat-ment in a third of patients, often accompanied by underreported neurological and psychiatric comorbidities.
Aims: We investigated the tolerability of a novel intracerebral device for encapsulated cell bio-delivery (ECB) of GDNF in refractory epilepsies’ treatment. We also evaluated the feasibility of using specific 5'tRNA-derived fragments (5'tRFs) as signal molecules to regulate neurotrophic factor secretion.
Methods: This project encompassed three stages. First, we in depth tested the in-vivo tolerability of a semipermeable membrane device implanted in the hippocampi of naïve Sprague-Dawley rats. Behavioral investigations included open field, rotarod and object location task (OLT) to assess device tolerability and impact on motor and hippocampal specific function. Pentylenetetrazol (PTZ) -induced seizure susceptibility evaluation and histological analysis of gliosis markers fol-lowed. Second, we established a robust method for repeatedly collecting combined cerebrospinal fluid (CSF) and plasma samples from EEG-implanted epileptic rats. We further investigated three 5'tRFs (5'AlaTGC, 5'GluCTC, and 5'GlyGCC) previously identified as seizure predictors in epilep-tic humans. We explored their dynamics in CSF and plasma of a murine model of temporal lobe epilepsy (mTLE) and possible associations with ictal and interictal activity.
Results: Device was well-tolerated with no significant effects on motor function or gliosis. How-ever, implanted animals displayed reduced performance in the OLT, suggesting potential memory impairment, and increased seizure susceptibility following PTZ administration. tRNA fragment analysis showed no correlations of 5'AlaTGC, 5'GluCTC and 5'GlyGCC values in plasma and CSF. No differences were observed in median 5’tRFs values in either CSF or plasma when comparing baseline, pre-seizure, and post-seizure samples. Fragments readings did not correlate with spon-taneous seizures frequency, nor were they associated with interictal activity presence. Neverthe-less, a tendency towards post-seizure increase for all 5’tRFs was noted in epileptic animals.
Conclusions: Bilateral implantation of ECB devices may be well tolerated in a murine model of mTLE, but potential memory impairment and increased seizure susceptibility require further in-vestigation and optimization. To assess the clinical applicability of tRNA fragments as epilepsy biomarkers, further validation in animal models is necessary. Future studies should focus on en-hancing temporal resolution of 5'tRF measurements, expanding sample size, and exploring a broader range of 5'tRFs as potential biomarkers in epilepsy
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
NPY and Gene Therapy for Epilepsy: How, When,... and Y
No full textNeuropeptide Y (NPY) is a neuropeptide abundantly expressed in the mammalian central and peripheral nervous system. NPY is a pleiotropic molecule, which influences cell proliferation, cardiovascular and metabolic function, pain and neuronal excitability. In the central nervous system, NPY acts as a neuromodulator, affecting pathways that range from cellular (excitability, neurogenesis) to circuit level (food intake, stress response, pain perception). NPY has a broad repertoire of receptor subtypes, each activating specific signaling pathways in different tissues and cellular sub-regions. In the context of epilepsy, NPY is thought to act as an endogenous anticonvulsant that performs its action through Y2 and Y5 receptors. In fact, its overexpression in the brain with the aid of viral vectors can suppress seizures in animal models of epilepsy. Therefore, NPY-based gene therapy may represent a novel approach for the treatment of epilepsy patients, particularly for pharmaco-resistant and genetic forms of the disease. Nonetheless, considering all the aforementioned aspects of NPY signaling, the study of possible NPY applications as a therapeutic molecule is not devoid of critical aspects. The present review will summarize data related to NPY biology, focusing on its anti-epileptic effects, with a critical appraisal of key elements that could be exploited to improve the already existing NPY-based gene therapy approaches for epilepsy
Environmental Pollution and Peripheral Artery Disease
Get PDFPeripheral artery disease (PAD) of the lower limbs represents one of the most important clinical conditions among vascular disease and can negatively impact quality of life of affected patients, representing also an important socioeconomic burden. Several risk factors predispose to PAD and its complications. Nevertheless, the role of pollution in this context has not been fully evaluated and this article explored the most updated information on epidemiology and environmental pollution in order to hypothesize the possible contribution of air pollution in the onset of PAD. Pollution is an important problem for the global community and has harmful effects on human health and cardiovascular system, and, specifically, particulate matter 10 (PM10) was found significantly associated with PAD
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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