1,721,163 research outputs found
A Conceptual Framework for Measuring the Impact of LARG Practices on Logistics Performance
No full textThe performance of industrial activities is being challenged by the complexity, uncertainty, and volatility of economic-industrial contexts. Moreover, organizations are increasingly compelled to address environmental issues by adopting more sustainable practices that reduce resource usage and waste. Within this context, logistics is also undergoing a strategic review to enable efficient, effective, flexible, and environmentally friendly physical flows. To achieve these objectives, the integration of Lean, Agile, Resilient, and Green (LARG) paradigms is proposed as a solution, offering specific problem-solving capabilities. While the evaluation of LARG practices has been discussed in various industrial contexts, such as supply chain management and manufacturing, its application to logistics remains understudied. Therefore, the purpose of this paper is to investigate the individual contributions of LARG practices and their relationship with logistics activities by assessing their level of integration. Based on this analysis, we propose a conceptual framework to evaluate the impact of LARG practices on logistics performance. The research findings can serve as a preliminary tool for measuring lean, agile, resilient, and green indicators within logistics activities and the transport sector
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
Integration of fuzzy reliability analysis and consequence simulation to conduct risk assessment
No full textLosses of containment within the natural gas network, located in most populated areas, could cause environmental damage, injuries, or even death. Accordingly, it is pivotal to adopt proper approaches to assess and mitigate the risk arising from potential losses. Within this context, it is required to exploit solid reliability and consequence analysis techniques. To this end, this paper presents a methodology established on the integration of a Fuzzy Bayesian Network and consequence simulation. The Bayesian Network is more flexible and realistic than classic approaches because it can consider conditional probabilities and prior information. Furthermore, Leaky Noisy-OR Gates are exploited to allow an easier filling of the Conditional Probability Tables. This task is performed through expert elicitation, adopting Intuitionistic Fuzzy Set Theory and Similarity Aggregation Method. Finally, the severity analysis is performed via a software, named Safeti, which provides an accurate evaluation of the consequences. To show the applicability of the framework, a pressure regulator of a Natural Gas Regulating and Metering Station is considered as case study. The proposed approach can assist asset managers in evaluating the risk arising from the operations, and, accordingly, it can guide them in making maintenance-related decisions to assure the safety of the operations
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
Effetto dei campi elettromagnetici a frequenza estremamente bassa sul differenziamento neuronale di cellule AtT20 e NTera-2
Full text linkIl primo obiettivo di questa tesi è stato quello di determinare se l’esposizione ad un campo elettromagnetico a frequenza estremamente bassa (ELF-EMF) di 50Hz ed intensità di flusso magnetico di 2milli Tesla (mT) fosse in grado di influenza la biologia cellulare e molecolare della linea cellulare AtT20/D16V. Le cellule corticotrope pituitarie di topo AtT20/D16V differenziano spontaneamente dopo 5 giorni di coltura in neuroni simil-peptidergici. I valori della concentrazione dello ione calcio ([Ca2+]i) ed il pH (pHi) intracellulari sono stati monitorati tramite sonde raziometriche fluorescenti Indo-1 e SNARF. L’analisi di fluorescenza su singola cellula ha messo in evidenza che l’esposizione al campo ELF-EMF determina un aumento di [Ca2+]i seguito da una diminuzione del pHi. Le analisi effettuate al microscopio elettronica a scansione (SEM) e a trasmissione (TEM) mostrano come l’esposizione ad un campo magnetico di 50Hz, 2mT di 24 ore determini cambiamenti morfologici nella membrana plasmatica e variazioni nella distribuzione della actina citoscheletrica rispetto ai controlli. Inoltre si osserva l’insorgenza delle caratteristiche dei neuroni peptidergici quali un aumento del marcatore delle vescicole sinaptiche, la sinaptofisina, e dei granuli elettron densi nel citosol. La rilevazione della proteina dei neurofilamenti NF-200 mediante marcatura con anticorpo monoclonale e l’analisi tramite PCR hanno ulteriormente evidenziato che le cellule esposte si trovano in una fase più avanzata del differenziamento rispetto ai controlli. Il pretrattamento con uno specifico bloccante dei canali del calcio di tipo L, la Nifedipina, previene l’espressione di NF-200 nelle cellule esposte. Questi risultati mostrano che l’esposizione ad un campo ELF-EMF di 50Hz, 2mT determina un precoce differenziamento delle cellule della linea AtT20/D16V.
Inoltre sono stati riportati i risultati preliminari sugli effetti dell’esposizione ad un campo di 29Hz, 1mT su una linea di teratocarcinoma umano. Quando le cellule NTera2 cl.D1 vengono fatte aggregare in neurosfere possono essere indotte a differenziare in neuroni del sistema nervoso centrale in soli 14 giorni mediante trattamento con Acido Retinoico 1μM (RA). Gli aggregati sono stati piastrati su matrigel in presenza di AraC e analizzati a contrasto di fase. Le cellule differenziate in RA assumono la tipica morfologia dei neuroni, piccoli corpi cellulari con due o più prolungamenti. Il campo ELF-EMF di 29Hz 1mT è in grado di indurre un parziale differenziamento delle cellule esposte e questo è visibile dalla crescita di neuriti non presenti invece nei controlli. L’analisi del ciclo cellulare mediante marcatura con Ioduro di Propidio mostra nei campioni esposti, in maniera simile ai campioni trattati con RA, un aumento della percentuale delle cellule nella fase G1/G0. L’analisi mediante Real Time PCR di marcatori del differenziamento neuronale precoci (NeuroD, Nestin) e tardivi (NR1, TAU) offre evidenze aggiuntive sull’effetto del campo ELF-EMF sul differenziamento delle NT2. Tutti i marcatori analizzati sono risultati essere up regolati in seguito all’esposizione al campo rispetto ai controlli e l’andamento dell’espressione, ad eccezione di NeuroD, segue quello delle cellule trattate con RA. L’aumento graduale dell’mRNA di NeuroD insieme ai risultati sopra illustrati porta ad ipotizzare che un campo ELF-EMF di 29Hz, 1mT sia in grado di indurre il differenziamento delle cellule NT2 in maniera più lenta ma costante rispetto al trattamento chimico con Acido Retinoico.The first aim of this thesis was to establish whether exposure to an extremely low frequency electromagnetic field (ELF-EMF) at a frequency of 50Hz and magnetic flux density of 2 milli Tesla (mT) could affect the cellular and molecular biology of AtT20/D16V cell line. The mouse pituitary corticotrope-derived AtT20 cells spontaneously differentiate after 5 days of culture in peptidergic-like neurons. Intracellular calcium ([Ca2+]i) and pH (pHi) were monitored by ratiometric fluorescent probes Indo-1 and SNARF respectively. Single-cell fluorescence microscopy showed a statistically significant increase in [Ca2+]i followed by a drop in pHi in exposed cells. Both scanning (SEM) and transmission (TEM) electron microscopy analysis of 24 hours exposed cells showed morphological changes in plasma membrane compared to control ones. These modifications came with a rearrangement in actin distribution and the emergence of peptidergic neurons features like the increase in synaptic vesicles marker, synaptophysin, and electron-dense granules in the cytosol. Neurofilament protein NF-200 immunostaining and PCR analysis gave additional evidences that exposed cells were in a more advanced stage of differentiation compared to control. Pre-treatment with a specific L-type Ca2+ channel blocker, Nifedipine, prevented NF-200 expression in the exposed cells. The above findings demonstrate that exposure to 50Hz, 2mT ELF-EMF is responsible for the precocious differentiation of AtT20 cells.
Moreover I reported the preliminary results about the exposure effects of a human teratocarcinoma cell line to a 29Hz, 1mT extremely low frequency electromagnetic field. When NTera2 cl.D1 cells were allowed to form neurospheres they differentiated in (central nervous system) neurons after 14 days of Retinoic Acid (RA) treatment (1μM). Afterwards the aggregated cells were plated on matrigel in AraC and analysed by phase contrast microscopy. The RA differentiated cells had a typical neuronal morphology, small cell bodies with two or more elongated processes. The 29Hz, 1mT ELF-EMF is able to induce to a certain extent the differentiation of NT2 exposed cells visible as growth of neurites respect to control ones. Cell Cycle Analysis by Propidium Iodide staining showed, in the same way as in RA treated neurospheres, an increase in cells percentage in G1/G0 phase in exposed NT2 at 14th and 21st days. Real Time PCR analysis on early (NeuroD, Nestin) and late (NR1, TAU) neuronal development genes gave additional evidences about the ELF-EMF effect on NT2 differentiation. All neuronal markers were up regulated in exposed cells compared to control and, except for NeuroD, the expression trends followed the same pattern found in RA treated cells. The gradual increase in NeuroD mRNA together with the previous results made hypothesize that a 29Hz, 1mT ELF-EMF induce neuronal differentiation in NT2 cells in a different way in respect to the chemical treatment by Retinoic Acid suggesting a slower and continuous effect
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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