809 research outputs found
Medios alternativos de comunicación y prácticas de Net Activismo
In the following article we will analyse which common elements we can find
in net activism practice, defined as communication digital media use and appropriation in
a social conflict contest. Its starting point will be based on the interviews we carried out
with the net activism member’s experiences that were decisive in popular movement identity
construction and organization during the Oaxaca popular uprising in 2006
Netactivismo en las protestas y procesos de cambio social. Caso de estudio: alzamiento popular en Oaxaca, México
In this paper we propose an analysis of net-activism practices, and how they influence the cultural change process of protestors in the citizen riot of Oaxaca (Mexico) in 2006. The approach adopted in the research is “bottom-up”, hence just analyzing the movement itself. This aspect is both methodological and theoretical. In the analysis of the net-activism’s practice, we focus on the emotive dimension of protestors. The analysis of the emotive components allow us to explicate the initial motivations of collective actions, and how new media are linked with citizen empowerment
Cyberactivism and social appropriation. A case study: Oaxaca popular insurgency
Recuperando la experiencia individual en los medios alternativos que han sido determinantes en la organización y en la construcción de la identidad del movimiento popular en la insurrección de Oaxaca en 2006, en la presente comunicación proponemos un breve análisis de la prácticas de ciberactivismo que se han dado a lo largo de la protesta. Con un enfoque desde abajo en el estudio del movimiento popular mismo, exploraremos los modos en los que las prácticas de ciberactivismo influyen en los procesos de empoderamiento y de acción colectiva, introduciendo el análisis de las emociones y de los procesos emotivos tanto a nivel individual como colectivo.A presente pesquisa analisa a apropriação social da Internet e a utilização de meios alternativos de comunicação por movimentos,
grupos e organizações de resistência em mobilização popular ocorrida em 2006 em Oaxaca, no México.This article analyses common elements found on the internet activism practice, defined as communication digital media use and
appropriation in a social conflict contest. Its starting point is based on interviews carried out through cyberactivism member’s experiences that were decisive in popular movement identity construction and organization during Oaxaca popular uprising in 2006
Emociones, protesta y cambio social. Una propuesta de análisis
Joanna Wood 0 0 2013-04-17T15:48:00Z 2013-05-08T21:41:00Z 1 187 1032 Universidad Pablo de Olavide 8 2 1217 14.0 Normal 0 21 false false false IT JA X-NONE
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El objetivos del artículo es presentar nuestra propuesta de análisis acerca del papel de las emociones en las protesta. Centrando el análisis desde abajo, dedicaremos especial atención a la experiencia de los participantes y a su dimensión emocional. Desde los primeros resultados de nuestra investigación hemos observado que las emociones juegan un papel importante en las prácticas cotidianas de los grupos que hemos analizado e interactúan con la cognición determinando las conductas de las personas. Las emociones no sólo motivan a los individuos, sino que pueden hasta cambiar sus creencias. Concluyendo, hemos comprobado que las emociones juegan un papel importante en la protesta, no sólo influenciando la motivación para la acción y la participación, sino también afectando algunos resultados de la protesta, como el empoderamiento. La metodología empleada en nuestra investigación incluye entrevistas en profundidad, historias de vida y análisis narrativo del material biográfico. Presentaremos algunos resultados basados en el análisis de distintos estudios de casos: la insurrección de Oaxaca, México, 2006, los indignados españoles, #yosoy132 y algunos conflictos ambientales locales en España y México. <!--EndFragment--
Digital Citizen and Collective Action in Latin America : rethinking the social mediation and appropriation by the new social movements
Teniendo como punto de partida el análisis de las experiencias
latinoamericanas, con el presente artículo se pretende contribuir a la discusión que se está dando tanto en la academia
como en los movimientos sociales sobre el mediactivismo,
la acción colectiva y las tecnologías digitales, centrándonos
en los procesos de apropiación y uso de las tecnologías digitales que los movimientos ciudadanos han desarrollado durante este nuevo ciclo de protestas. Con este objetivo proponemos
una reflexión crítica que se centra en la dimensión biográfica y comunitaria de estas experiencias, explicitando cómo el proceso de apropiación de las NTIC está subsumido por el entorno cultural y cotidiano de los protagonistas de tal modo que el uso creador del proceso de apropiación de las NTIC da lugar a espacios productivos en los cuales se repiensa y se reafirma la identidad individual y colectiva de los nuevos actores políticos en la región.In the last two decades, the social movements in Latin America
have experienced new social mediation processes led by new generations of digital citizens willing to challenge the hegemonic place of traditional information media. Regaining from these alternative digital media’s experiences and the critical tradition of participatory communication for social change as it developed in Latin America, in our paper we propose a critical and theoretical framework centred in the biographic and communitarian dimension of the protest. This leads us to focus on how digital media are been appropriated
within the social movements, and how new digital media have contributed to rethink contemporary forms of collective identities and actions
Urban Heat Island (UHI) risk maps as innovative tool for urban regeneration strategies. The case of Parma
For the purposes of regeneration of the consolidated city it is increasingly important
to have the knowledge of the micro-scale distribution of the vulnerability of the population to
the consequences of climate change and increasing urbanization. The work to be presented starts
with the creation of maps of the risk classification induced by the heat islands in the city of
Parma, and aims to investigate which are the most effective strategies that a Public
Administration can adopt. The maps that have been created allow to assess the risk for the fragile
population at the level of the single building. They relate the climatic datum of thermal variation
with the population residing within each building, and verify the causal relationship with the soil
sealing and with the morphology of the urban fabric. The results of the study can help to identify
the thermal hot spot, receivers of specific mitigation actions. The risk map is itself a tool to
develop multilevel actions, designed according to the peculiarities of the sites, where the possible
adaptive solutions are compared with the physical and morphological characteristics of the
places. The positive function of green infrastructures (contrast of overheating, flood mitigation,
creation of places and services with a recreational function) is acquired by research and urban
planning practice. It is equally well known the difficulty faced by Local Authorities in the
maintenance and increase of unbuilt public areas, fundamental for the connection of ecological
networks
Molecular Biomarkers in Sinonasal Cancers: New Frontiers in Diagnosis and Treatment
Purpose of Review: Sinonasal tumors are rare and heterogeneous diseases which pose challenges in diagnosis and treatment. Despite significant progress made in surgical, oncological, and radiotherapy fields, their prognosis still remains poor. Therefore, alternative strategies should be studied in order to refine diagnosis and improve patient care. Recent Findings: In recent years, in-depth molecular studies have identified new biological markers, such as genetic abnormalities and epigenetic variations, which have allowed to refine diagnosis and predict prognosis. As a consequence, new histological entities have been described and specific subgroup stratifications within the well-known histotypes have been made possible. These discoveries have expanded indications for immunotherapy and targeted therapies in order to reduce tumor spread, thus representing a valuable implementation of standard treatments. Summary: Recent findings in molecular biology have paved the way for better understanding and managing such rare and aggressive tumors. Although further efforts need to be made in this direction, expectations are promising
Pancreatic tumors imaging: an update
Currently, ultrasound (US), computed tomography (CT) and Magnetic Resonance imaging (MRI) represent the mainstay in the evaluation of pancreatic solid and cystic tumors affecting pancreas in 80-85% and 10-15% of the cases respectively. Integration of US, CT or MR imaging is essential for an accurate assessment of pancreatic parenchyma, ducts and adjacent soft tissues in order to detect and to stage the tumor, to differentiate solid from cystic lesions and to establish an appropriate treatment. The purpose of this review is to provide an overview of pancreatic tumors and the role of imaging in their diagnosis and management. In order to a prompt and accurate diagnosis and appropriate management of pancreatic lesions, it is crucial for radiologists to know the key findings of the most frequent tumors of the pancreas and the current role of imaging modalities. A multimodality approach is often helpful. If multidetector-row CT (MDCT) is the preferred initial imaging modality in patients with clinical suspicion for pancreatic cancer, multiparametric MRI provides essential information for the detection and characterization of a wide variety of pancreatic lesions and can be used as a problem-solving tool at diagnosis and during follow-up
Synthesis and characterization of new modified metabolites, molecules with strong pharmacological activities
Polyphenols are the most widely distributed class of plant secondary metabolites and several thousand different compounds have been identified. They play many different roles in plant biology and human life, as UV protective agents, defensive compounds against herbivores and pathogens, they contribute to plant colors and to the taste of food and drink. Moreover it is widely known that natural metabolites have played a crucial role in the identification of many of the drugs that are on the market today. Nowadays natural products used pure in pharmacological preparations represent only 5% of the total, but their semi-synthesis derivatives represent more than 50% of the drugs in use.(1)
My PhD project is focused on the chemistry of natural substances, and I developed some strategies to synthetize new silibinin conjugates. Silibinin is the major biologically active component of the seeds extract of the milk thistle (Silybum marianum) also known as silymarin.(2) Structurally, silibinin is a diastereoisomeric mixture of two flavonolignans, silybin A and silybin B in a ratio of approximately 1:1.(3)
Silibinin is a metabolite with multiple biological activities operating at various cell levels.(4) Unfortunately, its therapeutic efficiency is rather limited by its low bioavailability due to its very low water solubility.
Aiming to improve the solubility, during the first year of my PhD project, we have developed an efficient synthetic procedure to obtain new 9”-phosphodiester silibinin conjugates with different mono- and di-saccharide labels through the anomeric hydroxyl group.(5)
In our approach 9’’-phosphoramidite has been used as silibinin substrate and 1-OH full protected mono- and disaccharide derivatives as sugar starting materials. We initially converted full acetylated mono and di-saccharides into 1-OH derivatives and these compounds were coupled with 9’’-phosphoramidite silibinin. The oxidation and the deprotection treatments led to the desired phosphodiester derivatives in good yields. The crude materials were then subjected to the purification by reverse phase analysis (RP-18 HPLC), using a variety of columns and elution conditions, but unfortunately it was too difficult to purify the mixture of diastereoisomers. In the end new silibinin analogues were obtained as a mixture of diastereoisomers, observed by 31P NMR analysis. The NMR analysis has proved to be very complex, in fact 1H and 31P NMR spectra of all compounds showed a dramatic complexity, due to the presence of a lot of diastereoisomers. This drawback has not allowed a complete and detailed NMR characterization of the new derivatives. The structures were confirmed by 31P NMR and ESI-MS mass spectra signals. In preliminary study, new derivatives were subjected to DPPH free radical scavenging and Xanthine Oxidase inhibition assays to evaluate their antioxidant activities. Independently of the sugar moiety present, all compounds exhibited a radical scavenging activities slightly higher than that of the silibinin, and Xanthine Oxidase inhibition at least as that of the silibinin. On the other hand the new derivatives showed a water solubility well above that of silibinin, in fact it was possible to prepare solutions of about 70 mg/mL in water.
These two data encouraged our studies during my second year of PhD to improve this synthetic strategy and to realize libraries of optically pure glyco-conjugated silibinins.
The 9''-phosphoramidite has been used as silibinin substrate and fully protected 6-OH mono- and di-saccharide derivatives as sugar starting materials.(6)
We initially converted opportunely protected mono- and di-saccharides (Glucose, Mannose, Galactose, N- Acetylglucosamine, Trehalose and Lactose) into 6-OH derivatives and then they were coupled with 9"-phosphoramidite silibinin following typical phosphoramidite chemistry procedure. The crude materials were purified by reverse phase chromatography (RP-18 HPLC) and characterized by NMR and MALDI- TOF/TOF-MS analyses. All compounds were obtained in good yields and as a mixture of two silibinin diastereoisomers (A and B). Finally new phosphodiester derivatives were converted into the corresponding sodium salt by cation exchange resin carrying crystalline samples. New derivatives showed water solubility well above that of silibinin, with the possibility to prepare solutions of about 70 mg/mL in water. The stability of new glyco-conjugates was investigated in human serum by HPLC analyses and the 50% disappearance of the peak corresponding to the intact glyco-conjugate was observed after ca. 40-68 hours. All derivatives were subjected to DPPH free radical scavenging assay and they exhibited radical scavenging activities slightly higher than that of the silibinin. In order to verify the potential biological properties of these derivatives, a biological assay was used to evaluate the cytotoxicity of the new glyco-conjugates, compared with that of the silibinin, on human liver cancer cell line (Hep G2). No significant changes in the viability of treated cells were observed when they were subjected to the action of glyco-conjugates, also considering the longest incubation (72 hours) at the maximum dose taken (30 µM). Also, in order to investigate the role of the different OH groups in the antioxidant activity of new glyco-conjugates in comparison with silibinin, their acidity and redox capacity have been evaluated. A redox-deep characterization was carried out in collaboration with Prof. Mauro Iuliano and Dr Gaetano De Tommaso of our Department, using potentiometric and voltammetric techniques. The determination of the acidity constants was conducted by potentiometric titrations measuring the concentration of hydrogen ions with a glass electrode. By processing data, it was possible to define three equilibrium constants. Analysis of the data shows that the conjugation in position 9" does not affect the redox behaviour of the silibinin scaffold.
As a part of our continuing research effort towards the synthesis of new natural product analogues exploiting the phosphoramidite chemistry, in the last year of my PhD project the attention was focused on the development of synthetic methods to obtain oligoflavonoids based on silibinin, and to investigate their anti-radical activity. Exploiting the selective protection to hydroxyl groups of the silibinin we have developed an efficient strategy for the synthesis of new 3-9", 3-3 and 9"-9" dimers of silibinin in good yields.(7)
In order to obtain suitable building blocks for the dimers synthesis, we have developed a selective protective reaction for the different hydroxyl groups with isobutyric anhydride. The building blocks obtained were coupled in the three different provisions with 3- and 9”-silibinin phosphoramidite using the well known phosphoramidite chemistry. After oxidation, deprotection and RP-18 HPLC purification the products were converted into the corresponding sodium salts by cation exchange on a DOWEX (Na+ form) resin, leading to the desired phosphodiester dimers derivatives in good yields. The structures of new analogues were confirmed by 31P NMR and MALDI-TOF/TOF-MS analyses. The stability of new silibinin dimers was investigated in human serum by HPLC analysis and the 50% disappearance of the peak corresponding to the intact molecule (t1/2) was observed after ca. 80 hours. All derivatives were subjected to DPPH free radical scavenging assay and they exhibited activities quite higher than silibinin.
Moreover, the solubility in water of silibinin and its dimers as well as their ability to react with reactive oxygen species (ROS) were determined by estimating their second order rate constant with singlet oxygen (1O2) and hydroxyl radical (HO∙) in solution. This data were obtained in the laboratories of Prof. Marcello Brigante during my experience work in his research team at the University Blaise Pascal, Institute of Chemistry of Clermont-Ferrand (France). Solubility experiments indicate that dimers were completely dissolved (0.1 mg in 10 mL) in water and solubility can be estimated to be ≥ 19.5 µM corresponding to > 20 mg/L.
Reactivity between silibinin and dimers with 1O2 and HO∙ was determined by use of Rose Bengal (RB) and hydrogen peroxide as respective ROS sources. For this purpose, 545 nm centered excitation of RB and laser flash photolysis (LFP) experiments were coupled with a kinetic competition approach. Dimers reactivity toward singlet oxygen results to be close to the value determined for silibinin, or about 35% lower. Second order rate constant fare in the same order of magnitude reported in literature for molecules with similar structure. Morales and co-workers8 reported a reactivity ranging from 2.4 to 13.4 × 107 M-1s-1 for flavonoid derivative such as quercetin and morin. Estimation of second order rate constant reactivity with HO∙ indicates that some dimers showed a second order rate constant ≥ 1.5 × 1010 M–1s–1. Wang and co-workers (9) investigated the reactivity of hydroxyl radical with phenolic compounds in order to estimate their anti-oxidative ability using aqueous pulse radiolysis. The value of 1.5 × 1010 M–1s–1 was found for quercetin that is close to those estimates for green tea polyphenols. Interestingly, Husain at al.10 reported that reactivity of flavonoids toward photo-generated hydroxyl radical increases with the number of hydroxyl groups in the aromatic ring.
References
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3 Napolitano, J. G.; Lankin, D. C.; Graf, T. N.; Friesen, J. B.; Chen, S-N.; McAlpine, J. B.; Oberlies, N. H.; Pauli, G. F. J. Org. Chem. 2013, 78, 2827.
4 Zhan, T.; Digel, M.; Küch, E.-M. J. Cell. Biochem. 2011, 112, 849 and references therein.
5 Zarrelli, A.; Romanucci, V.; Tuccillo, C.; Federico, A.; Loguercio, C.; Gravante, R.; Di Fabio, G. Bioorg. Med. Chem. Lett. 2014, 24, 5147.
6 Romanucci, V.; Gravante, R.; Di Marino, C.; Iuliano, M.; De Tommaso, G.; Caruso, T.; Zarrelli, A.; Di Fabio, G. submitted for publication.
7 Gravante, R .; Romanucci, V.; Cimafonte, M.; Di Marino, C.; Mailhot, G.; Brigante, M.; Zarrelli, A.; Di Fabio, G. submitted for publication.
8 Morales, J.; Günther, G.; Zanocco, A. L.; Lemp, E. PLoS One 2012, 7, e40548.
9 Wang, W. F.; Luo, J. S.; Yao, D.; Lian, Z. R.; Zhang, J. S.; Lin, N. Y. Radiat. Phys. Chem. 1993, 42, 985.
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