20 research outputs found
Light and Matter, Two Sides of the Same Coin
No full textWith an opinionated and irreverent tone, the author debunks most of the current theories in the field of modern physics, appealing to the scientific method and common sense. At the same time, in strict compliance with the already known experimental evidence, he proposes his own version of the facts, aimed at rationalizing and unifying the various aspects in which the nature that surrounds us manifests itself. The result is a possible model of the universe where events are all connected by a common thread, even if distributed on different scales, ranging from the subatomic to that of galaxies. In this perspective, in the middle, the living cell profits from a substrate and a habitat that have favoured its very existence. Reading of this book does not require any advanced scientific knowledge and is therefore accessible to non-experts, provided they are equipped with the necessary dose of eccentricity that allows them to appreciate these provocative pages
How accurate is an LCD screen version of the Pelli–Robson test?
No full textPurpose: To evaluate the accuracy and repeatability of a computer-generated Pelli–Robson test displayed on liquid crystal display (LCD) systems compared to a standard Pelli–Robson chart. Methods: Two different randomized crossover experiments were carried out for two different LCD systems for 32 subjects: 6 females and 10 males (40.5 ± 13.0 years) and 9 females and 7 males (27.8 ± 12.2 years), respectively, in the first and second experiment. Two repeated measurements were taken with the printed Pelli–Robson test and with the LCDs at 1 and 3 m. To test LCD reliability, measurements were repeated after 1 week. Results: In Experiment 1, contrast sensitivity (CS) measured with LCD1 resulted significantly higher than Pelli–Robson both at 1 and at 3 m of about 0.20 log 1/C in both eyes (p < 0.01). Bland–Altman plots showed a proportional bias for LCD1 measures. LCD1 measurements showed reasonable repeatability: ICC was 0.83 and 0.65 at 1 and 3 m, respectively. In Experiment 2, CS measured with LCD2 resulted significantly lower than Pelli–Robson both at 1 and at 3 m of about 0.10 log 1/C in both eyes (p < 0.01). Bland–Altman plots did not show any proportional bias for LCD2 measures. LCD2 measurements showed sufficient repeatability: ICC resulted 0.51 and 0.65 at 1 and 3 m, respectively. Conclusions: Computer-generated versions of Pelli–Robson test, displayed on LCD systems, do not provide accurate results compared to classic Pelli–Robson printed version. Clinicians should consider that Pelli–Robson computer-generated versions could be non-interchangeable to the printed version
A heuristic algorithm for the electric freight vehicles charge scheduling problem
No full textLAUREA MAGISTRALEL'introduzione dei veicoli elettrici nelle attività logistiche sta affrontando nuove sfide riguardanti in particolare la loro pianificazione operativa quotidiana. Una adeguata gestione di tutte le risorse possibili e una buona pianificazione degli orari sono elementi importanti per espandere l'utilizzo di veicoli elettrici per scopi commerciali. Di conseguenza, l'ottimizzazione di un problema di scheduling è fondamentale per ottenere buoni risultati in termini di costi e organizzazione.
Il lavoro sviluppato in questa tesi è focalizzato sull' “Electric Freight Vehicles Charge Scheduling Problem (EFV-CSP)”, introdotto da Pelletier, Jabali e Laporte 2018. Il paper propone un modello di ottimizzazione finalizzato alla riduzione dei costi legati alla ricarica di una flotta di veicoli elettrici per il trasporto di merci, tenendo conto di un processo di ricarica realistico, delle fasce orarie di consumo, del degrado della batteria, delle restrizioni della rete elettrica e degli oneri di richiesta relativi all’impianto. Lo scopo di questa tesi è sviluppare un algoritmo euristico per la soluzione di EFV-CSP, al fine di trovare risultati quasi ottimali in breve tempo. L'algoritmo euristico finale è il risultato dell'analisi di diversi algoritmi, finalizzati al miglioramento progressivo della soluzione. Tramite dei test, generati variando le caratteristiche dei tragitti percorsi dai veicoli, viene dimostrata l'efficacia dell'algoritmo euristico. Si analizzano inoltre i vari risultati trovati in base alle diverse configurazioni adottate.The introduction of electric vehicles in logistics activities is facing new challenges concerning in particular their daily operational planning. A proper management of all possible resources and a good scheduling procedure are important elements to expand the use of electric vehicles for commercial purposes. As a consequence, the optimization of a scheduling problem is essential to obtain good results in terms of costs and organization.
The work developed in this thesis is focused on the "Electric Freight Vehicles Charge Scheduling Problem (EFV-CSP)", introduced by Pelletier, Jabali and Laporte 2018. The paper proposes an optimization model aimed at reducing the costs related to the charging of a fleet of fright electric vehicles, taking into account a realistic charging process, time-dependent energy costs, battery degradation, grid restrictions, and facility-related demand charges. The aim of this thesis is to develop a heuristic algorithm for the solution of EFV-CSP, in order to find near optimal results in a short time. The heuristic algorithm is the result of the analysis of different algorithms, aimed at sequentially improving the solution. The effectiveness of the heuristic algorithm is demonstrated through some tests, generated by varying the characteristics of the routes performed by the vehicles. The different results, obtained from the different configurations adopted, are also analyzed
Adult-onset autosomal recessive ataxia associated with neuronal ceroid lipofuscinosis type 5 gene (CLN5) mutations
No full textAutosomal recessive inherited ataxias are a growing group of genetic disorders. We report two Italian siblings presenting in their mid-50s with difficulty in walking, dysarthria and progressive cognitive decline. Visual loss, ascribed to glaucoma, manifested a few years before the other symptoms. Brain MRI showed severe cerebellar atrophy, prevalent in the vermis, with marked cortical atrophy of both hemispheres. Exome sequencing identified a novel homozygous mutation (c.935G > A;p.Ser312Asn) in the ceroid neuronal lipofuscinosis type 5 gene (CLN5). Bioinformatics predictions and in vitro studies showed that the mutation was deleterious and likely affects ER-lysosome protein trafficking. Our findings support CLN5 hypomorphic mutations cause autosomal recessive cerebellar ataxia, confirming other reports showing CLN mutations are associated with adult-onset neurodegenerative disorders. We suggest CLN genes should be considered in the molecular analyses of patients presenting with adult-onset autosomal recessive cerebellar ataxia
The analysis of social networks in the study of co-authorship and scientific production
No full textSeja por motivos comerciais, seja por motivos acadêmicos, os rankings têm sido largamente utilizados na avaliação acadêmica. Usados na classificação de periódicos no que diz respeito à sua qualidade e de seu material, ou então para mostrar o comportamento acadêmico de um autor quanto à sua produtividade e capacidade de compartilhar conhecimento através de coautorias ou citações, fornecem subsídios às editoras no momento da escolha do material a ser publicado, pensando em termos da visão que a academia tem para com os autores. Neste trabalho, procuramos mostrar a importância, para a Ciência da Informação, da elaboração de um ranking através do uso de três dimensões: as coautorias, formando Redes Sociais com suas métricas próprias, o número de artigos publicados por um autor, o que nos remete à sua produtividade e as citações da comunidade aos textos escritos por um ou mais autores. Considerando que as pesquisas sobre as Redes Sociais se intensificaram a partir dos anos 1990s, escolhemos um período que contemplasse os primórdios do crescimento do interesse pelo tema, até 2019, fase em que apareceram as mídias sociais e parte expressiva da humanidade abandona paradigmas e as adota como elemento substancial na troca de informações, fidedignas ou não. Os acadêmicos não permaneceram à margem desse movimento. As facilidades de se obter um documento, mesmo aqueles escritos em diferentes idiomas - hoje os tradutores já atingiram um grau de excelência aceitável - permitiram, através de um mecanismo de busca ou de uma base de dados, aos pesquisadores ultrapassarem as fronteiras geográficas antes quase intransponíveis: além do idioma, muitas vezes apenas publicações de alto padrão estavam disponíveis para a instituição e para os autores. Nossa proposta de um ranking procura mostrar uma visão, ano a ano, nas três dimensões aplicadas, como cada autor da base ocupou uma determinada posição e a utilizamos como métrica. Também foram considerados o período ativo dos pesquisadores e, neste período de atividade, quantos anos realmente publicou. Nossa meta foi a de propor uma metodologia para avaliar autores sobre um tema que tivesse relação direta com o trabalho, tendo sido escolhido para este caso \"Social Networks\". Necessário enfatizar que o método pode ser aplicado a qualquer outro tema de pesquisa. Através do uso das bases de dados Scopus, levantamos todos os artigos disponíveis sobre o tema, com início em 1990 e término em 2019. Criamos uma base de dados em Microsoft Access com as tabelas e as estruturas necessárias com o uso de programação VBScript pois no ranking proposto a posição relativa de cada autor em cada um dos 30 anos e em cada uma das três dimensões, sempre selecionando aqueles que ficaram no topo da lista, dessa forma limitando a endogenia ou outras distorções advindas de um sucesso momentâneo de um pesquisador e privilegiaríamos seus rendimentos ao longo dos anos.Whether for commercial or academic reasons, rankings have been widely used in academic evaluation. Used in the classification of journals with regard to their quality and material, or else to show the academic behavior of an author regarding their productivity and ability to share knowledge through co-authorship or citations, they provide subsidies to publishers when choosing of the material to be published, thinking in terms of the vision that the academy has towards the authors. In this work, we try to show the importance, for Information Science, of creating a ranking through the use of three dimensions: co-authorships, forming social networks with their own metrics, the number of articles published by an author, which brings us productivity and community citations to texts written by one or more authors. Considering that research on Social Networks intensified from the 1990s onwards, we chose a period that contemplated the beginnings of the growth of interest in the subject, until 2019, a phase in which social media appeared and a significant part of humanity abandons paradigms and adopts as a substantial element in the exchange of information, reliable or not. Academics have not remained on the sidelines of this movement. The ease of obtaining a document, even those written in different languages - today translators have already reached an acceptable degree of excellence - enabled, through a search engine or a database, researchers to overcome geographic borders that were almost insurmountable before: in addition to language, often only high standard publications were available to the institution and authors. Our proposal for a ranking seeks to show a view, year by year, in the three dimensions applied how each author in the base occupied a certain position and we use it as a metric. The researchers\' active period and, in this period of activity, how many years actually published were also considered. Our goal was to propose a methodology to evaluate authors on a theme that was directly related to the work, having chosen for this case \"Social Networks\". It is necessary to emphasize that the method can be applied to any other research topic. Through the use of Scopus databases, we surveyed all available files on the subject, starting in 1990 and ending in 2019. We created a database in Microsoft Access with the necessary tables and structures using VBScript programming because in the proposed ranking the relative position of each author in each of the 30 years and in each of the three dimensions, always selecting those who were at the top of the list, thus limiting endogeny or other distortions arising from a momentary success of a researcher and we would privilege their income over the years
Development of dosimeters with selective materials to high frequency radiation
No full text2011 - 2012The clinical use of ionizing radiation to obtain a necrosing or cytotoxic radiobiological effect on tumoral lesions requires wide and complex physical and dosimetrical procedures. In particular, it is necessary to calculate accurately the absorbed dose optimizing its delivery in order to treat the tumor, without affecting the surrounding healthy tissues. Moreover, the technological development of the last few years has led to an evolution in the field of radiotherapy, in the sense of an always bigger conformation of the dose distribution to the volumes to be irradiated, through the use of very complex dose release techniques. For this reason, priority target in radiotherapy is the research and the tuning of suitable systems for dosimetrical measurements. In this context, the research activity presented in this PhD thesis has regarded not only the use and development of conventional dosimeters but mainly the development of new radiation detectors based on nanomaterials. Different nanomaterials have been prepared and tested under photon radiation, such as precursors of silver nanoparticles, manganese doped zinc sulphate nanoparticles, multiwall carbon nanotubes and graphene. This work demonstrates that these nanomaterials, interesting for their fascinating physical and chemical properties, are also very promising to realize dosimeters of new generation. [edited by Author]L’utilizzo clinico di radiazioni ionizzanti per ottenere un effetto radiobiologico necrotizzante o citotossico su lesioni tumorali comporta ampie e complesse procedure fisico-dosimetriche. In particolare, è necessario calcolare accuratamente la dose assorbita, ottimizzando il suo rilascio, al fine di trattare il tumore senza danneggiare i circostanti organi sani. Inoltre, lo sviluppo tecnologico degli ultimi anni ha condotto ad un’evoluzione nel campo della radioterapia, con il raggiungimento di una sempre più grande conformazione delle distribuzione di dose ai volumi da irradiare, attraverso l’uso di tecniche di rilascio della dose molto complesse. Per questo motivo l’obiettivo prioritario in radioterapia è la ricerca e messa a punto di adeguati sistemi per effettuare misure dosimetriche. In tale contesto, l’attività di ricerca, presentata in questa tesi di dottorato, ha riguardato non solo l’uso e lo sviluppo di dosimetri convenzionali ma, principalmente, la realizzazione di nuovi rilevatori di radiazione basati su nanomateriali. Diversi nanomateriali sono stati preparati e testati alla radiazione di fotoni, quali precursori di nanoparticelle di argento, nanoparticelle di solfuro di zinco drogate con manganese, nanotubi di carbonio a parete multipla e grafene. Da questo lavoro si evince che questi nanomateriali, interessanti per le loro proprietà fisiche e chimiche, sono anche molto promettenti per realizzare dosimetri di nuova generazione. [a cura dell'Autore]XI n.s
A NOVEL GENE FOR SPINOCEREBELLAR ATAXIA (SCA) LINKED TO CHROMOSOME 6 AND INVOLVED IN FATTY ACID METABOLISM
No full textA NOVEL GENE FOR SPINOCEREBELLAR ATAXIA (SCA) LINKED TO CHROMOSOME 6 AND FATTY ACID METABOLISM
No full textAdult-onset autosomal recessive ataxia associated with neuronal ceroid lipofuscinosis type 5 gene (CLN5) mutations.
No full text
