305,648 research outputs found
The Ca2+/IP3R3/c-Src axis in the regulation of anoikis
No full textLe metastasi sono la principale causa di morte legata al cancro, ma i meccanismi molecolari alla base della diffusione del tumore non sono ancora del tutto noti. Come barriera alla metastasi, le cellule sono solitamente sottoposte a un tipo di morte nota come anoikis, che è un processo apoptotico dovuto alla perdita di contatto con la matrice extracellulare o con le cellule vicine. La resistenza all'anoikis è quindi essenziale nella progressione del cancro e nella colonizzazione metastatica. Sebbene le conoscenze sul riarrangiamento dell'omeostasi del Ca2+ nelle cellule tumorali siano in continuo aumento, manca ancora un collegamento meccanicistico tra Ca2+ e anoikis. L'obiettivo principale di questa tesi è comprendere il ruolo della segnalazione del Ca2+ nell'anoikis e la sua associazione con c-Src, una proteina chinasi non recettoriale coinvolta in diversi segni distintivi del cancro, la cui attività è correlata all'invasione cellulare, alle metastasi e alla resistenza all'anoikis. Abbiamo studiato le alterazioni dell'omeostasi del Ca2+ indotte da c-Src e identificato il bersaglio molecolare dell'attività di c-Src legata al Ca2+. Abbiamo inoltre caratterizzato questa nuova via di segnalazione nel contesto dell'anoikis e della progressione del cancro, fornendo un nuovo paradigma sui meccanismi che regolano la diffusione metastatica.Metastasis is the leading cause of cancer-related death, but the molecular mechanisms underlying cancer dissemination are not yet fully understood. As a barrier to metastasis, cells usually undergo a type of death known as anoikis, which is an apoptotic process due to the loss of contact with the extracellular matrix or neighboring cells. Anoikis resistance is thus essential in cancer progression and metastatic colonization. Although the knowledge about Ca2+ homeostasis rearrangement in cancer cells is continuously increasing, the mechanistic link between Ca2+ and anoikis is still missing. The main goal of this thesis is to comprehend the role of Ca2+ signaling in anoikis and its association with c-Src, a non-receptor protein kinase involved in several cancer hallmarks, whose activity correlates with cell invasion, metastasis, and anoikis resistance. Here, we investigated the alterations of Ca2+ homeostasis induced by c-Src and identified the molecular target of the Ca2+-related c-Src activity. We also characterized this novel signaling pathway in the context of anoikis and cancer progression, providing a new paradigm on the mechanisms that regulate metastatic dissemination
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
No full textThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
ESG ratings explainability through machine learning techniques
No full textEnvironmental, Social, and Governance (ESG) scores are quantitative assessments of companies' commitment to sustainability that have become extremely popular tools in the financial industry. However, transparency in the ESG assessment process is still far from being achieved. In fact there is no full disclosure on how the ratings are computed. As a matter of fact, rating agencies determine ESG ratings (as a function of the E, S and G scores) through proprietary models which public knowledge is limited to what the data provider effectively chooses to disclose, that, in many cases, is restricted only to the main ideas and essential principles of the procedure. The goal of this work is to exploit machine learning techniques to shed light on the ESG ratings issuance process. In particular, we focus on the Refinitiv data provider, widely used both from practitioners and from academics, and we consider white-box and black-box mathematical models to reconstruct the E, S, and G ratings' assessment model. The results show that it is possible to replicate the underlying assessment process with a satisfying level of accuracy, shedding light on the proprietary models employed by the data provider. However, there is evidence of persisting unlearnable noise that even more complex models cannot eliminate. Finally, we consider some interpretability instruments to identify the most important factors explaining the ESG ratings
Estudio del impacto ambiental en la fábrica de fideos Don Vitto
No full textCAPITULO I: GENERALIDADES. PLANTEAMIENTO DEL PROBLEMA. IMPORTANCIA. OBJETIVOS. IDEA A DEFENDER. VARIABLES E INDICADORES. METODOLOGIA. MARCO CONCEPTUAL. CAPITULO II: MARCO TEORICO. PLANTEAMIENTO PARA ABORDAR LOS IMPACTOS SOCIOECONOMICOS. APLICACION DE LOS CRITERIOS DE IDENTIFICACION. DE IMPACTOS. CRITERIO DE VALORACION. MARCO LEGAL. GESTION AMBIENTAL. CAPITULO III: DIAGNOSTICO DE LA EMPRESA. UBICACION DE LA EMPRESA. ANTECEDENTES DE LA EMPRESA. ESTRUCTURA FISICA DE LAS INSTALACIONES DE LA FABRICA DON VITTO. DESCRIPCION DEL PROCESO. DATOS DE PRODUCCION. SISTEMA DE CONTROL DE CALIDAD. SISTEMA DE TRATAMIENTO DE EFLUENTE. CAPITULO IV: PROPUESTA DE ESTUDIO. IDENTIFICACION DE LAS CARACTERISTICAS DEL MEDIO AMBIENTE SUSCEPTIBLES DE SER AFECATADAS POR LA OPERACION. DE LA FABRICA DE FIDEOS DON VITTO. IDENTIFICACION DE LAS ACTIVIDADES DE LA PLANTA QUE PROVOCAN IMPACTOS AMBIENTALES. IDENTIFICACION DE LAS INTERACCIONES ENTRE: ACCIONES DEL PROYECTO Y ELEMENTOS DEL AMBIENTE QUE SON OBJETO DEL IMPACTO. DETERMINACION DE LOS INDICADORES QUE CUANTIFICAN LA MAGNITUD DE LOS IMPACTOS PROVOCADOS. CUMPLIMIENTO DE LAS NORMAS Y EL PLAN DE MANEJO AMBIENTAL. IDENTIFICACION DE IMPACTOS AMBIENTALES NO PREVISTOS EN LA EVALUACION DEL IMPACTO AMBIENTAL. IDENTIFICACION DE IMPACTOS AMBIENTALES NO PREVISTOS EN LA EVALUACION DEL IMPACTO AMBIENTAL. PLAN DE MANEJO AMBIENTAL PROPUESTO PARA LA FABRICA DE FIDEOS DON VITTO. CAPITULO V: CONCLUSIONES Y RECOMENDACIONES. CAPITULO VI: ANEXOS
Senecio hualtaranensis Petenatti, Ariza & Del Vitto
No full textSierra de Las Quijadas, El Mirador, aprox. 8 km al W de HualtaránpublishedVersio
Present Status of Mixed Plastic Waste Pyrolysis: Plant Simulation through Aspen Hysys
No full textThe widespread use of plastics results in plastic waste generation. After reuse, recycling is the preferred pathway to reduce the need for virgin feedstock. Concerning mechanical recycling, pyrolysis, consisting of heating the feedstock to promote the thermal degradation of polymers, allows to process Mixed Plastic Wastes (MPW) which cannot be easily sorted. Nowadays, chemical recycling through pyrolysis has reached the demonstration scale, but it is still challenging its further scale-up. In this work, a simulation of a MPW pyrolysis plant coherent with the present technology status is presented. The simulation was performed on Aspen Hysys v11. Unit operations composing the system were chosen according to literature and patent reviews. The process flow diagram of the system is composed of 4 lines in parallel, each one constituted by a reactor, one or more condensation (flash) steps, and a water scrubber (ex-situ dehalogenation) for incondensable gases before their combustion to sustain the reactor energy demand. Each line processes 5000 t/y, representing current scalability limits. The MPW feedstock mass composition assumed is the following: 45 % for both polypropylene (PP) and polyethylene (PE), 8 % for polystyrene (PS), and 1 % each for polymethylmethacrylate (PMMA) and polyvinylchloride (PVC). The reactor has been modeled as a conversion reactor which satisfies the conservation of atoms yielding gaseous, liquid, and solid products of 20, 70, and 10 % of the feedstock mass respectively. After the condensing units, a single distillation column collects the oil produced by each line. The influence of changing the number of condensation (i.e., flash) steps has been investigated. The maximum condensate production was observed for one flash unit. Employing fewer flash units allows to obtain more condensate, paying a slightly larger reboiler duty
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
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