1,721,145 research outputs found
L'ESPOSIZIONE AD HIV-1 INFLUENZA LA RISPOSTA IMMUNITARIA CD4-MEDIATA ALTERANDO IL PROFILO D'ESPRESSIONE DEI MICRORNA CELLULARI
No full textMicroRNAs (miRNAs) are small single-strand non-coding RNAs that repress gene expression by inhibiting translation. MiRNAs are known to inhibit HIV-1 expression interfering with viral mRNAs. In order to better understand how HIV-related alterations in cellular physiology and immunologic control function, 3 classes of patients (éLTNP, Naive and multiply exposed to HIV-1 uninfected subjects, named MEU) were enrolled, from whom blood CD4+ cells were purified. In this cellular subtype the expression levels of 377 miRNAs were analyzed by TaqMan real-time PCR-based arrays. Only miRNAs expressed in 70% of patients of at least one class and of at least 1 log10 variation from healthy controls were selected. A similar analysis had also been performed in primary culture of CD4+T cells and monocyte-macrophages infected by R5 strains and in CD4+ cells exposed to recombinant and natural gp120 molecules in vitro. In all experiments, expression levels of Dicer and Drosha, two enzymes involved in miRNA biogenesis, were evaluated by real-time PCR.
Similar miRNA profiles were detected in the CD4+ cells from éLTNP and Naive, although these infected patients had different parameters such as viral and proviral loads, infection time and CD4+ T cell number. Moreover, a complex down-regulation of miRNA was observed in the CD4+ cells from MEU subjects. This indicates that the only HIV-1 antigen exposure can modulate cellular programming process of CD4+ cells. Three up-regulated (miR-203, 449a, 502-5p) and five down-regulated (miR-329, 337-5p, 379, 503, 518d-3p) miRNAs, modulated in all patient classes, defined a HIV-1 signature. By hierarchical clustering of the miRNA profile, éLTNP clustered with Naive patients, whereas all MEU subjects grouped together; this suggests that miRNA expression may discriminate between infected and uninfected individuals. By statistical analysis, 16 miRNAs significantly differentiated éLTNP and Naive from MEU, while only the miR-155 discriminated éLTNP from Naive. Of these, 9 were involved in viral replication and/or in immune response.
Computational studies suggested that target genes of altered miRNAs are involved in a lot of cellular processes and in binding/catalytic activity. According to the Dicer and Drosha expression, that was down-regulated in all patient classes, a correlation was observed between miRNA and the two enzymes expression. In contrast, no differences were observed in CD4+ cells infected in vitro or exposed to gp120 molecules. This suggests that there is a complex regulation of miRNA expression after HIV exposure, not only due to the miRNA biogenesis.
The miRNA expression analysis in CD4+ cells exposed to gp120 molecules showed a modulation of 66 miRNAs; only 42% of these showed the same levels of expression, suggesting that the remaining percentage of miRNAs was modulated by other gp120 epitopes. When the gp120 was neutralized with mAbs, only 1/3 of altered miRNAs were reverted to the expression of non exposed controls. This indicates the existence of epitopes (other than the CD4 binding domain) capable of inducing a miRNA modulation. Finally, the miRNA expression analysis highlights that 5 miRNAs (miR-34c-p, 518f, 452, 202 and 487b) could have a role in HIV-CD4+ cell binding.
In conclusion, in light of these results, it can be supposed that the altered miRNA profile is due to the constant HIV exposure of CD4+ cells through a bystander phenomenon rather than a direct effect. Therefore it can be assumed that only the exposure to gp120 molecules can leave a signature in immune cells
Informazione e conoscenza nel settore edilizio
No full textIl saggio affronta questioni operative e conoscitive per
la definizione di un modello originale di CI a supporto
dell’innovazione e del trasferimento tecnologico, in linea con i
bisogni delle piccole e medie imprese del settore edile, ed
esportabile in altri settori
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
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
Fission Fragments Direct Heating for Space Propulsion - Programme Synthesis and Applications to Space Exploration
No full textThe status and the main results achieved by Project 242 are presented. Project 242 is a programme (funded by ASI -1999/2002 from an idea of Carlo Rubbia) that studied a new concept of space propulsion motor by using direct conversion of the kinetic energy of fission fragments into increasing of enthalpy of a propellant gas. Project 242 studied the application of this propulsion system to a manned mission to Mars. Preliminary results were very satisfactory and it has been observed that a propulsion system with these characteristics could make the mission feasible. Results for other unmanned missions to the outer solar system are also presented
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
New Educational itineraries and perspectives for care. The Innovative Caregivers’ Training model as example of strenghtening competences, networking and participation.
No full textIn associating the word education with “carer”, considering the related representations that it holds, we immediately fall in contradiction. The reason for this contradiction is located in the ambiguous state, both social and professional, of this role, that despite being a consolidate reality (EUROFAMCARE 2011) in some European countries (Switzerland, Italy), in terms of people that play the role and of services related to it, and last but not least, the services given to the citizens they care for, they can be considered as a hidden portion of welfare. There are various levels of ambiguity, the first one can be identified in the professional mandate that those people respond to (essentially women), which are formally hired for domestic-economy related duties, but that end up doing a purely healthcare job too, for which they are not trained at all and sometimes not even aware of. A second level of ambiguity, that generates the first one, is located in the contractual formula that sets their work, which, compared to the general regulations of the Swiss labor market (D’Angelo, Bignami, Kunz 2013), it’s quite lacunose concerning this category of people, since the actual job relationship is set directly with the hiring family, in fact in Ticino one is working to find solutions to this situation. This leads to a situation in which the quality of the working conditions is strongly dependent on the hiring family attitude, which often shows these characteristics: the carers live in the patient’s house, availability during 24 hours, even if during night they can sleep depending on the patient’s health conditions and requests, during the day at afternoon they have a 2 hours break (generally between 14.00 and 16.00), on Sunday they have a day off but without private spaces (regarding the dwelling) for their private life, the patients usually suffer from chronic degenerative polypathologies. These peculiarities summarize and effectively express the degree of precariousness from the professional side and the difficulties connected with it from the personal and social side, which often configure a state of isolation, from this point of view. Connected to previous emerges a third level of ambiguity, which refers to the relationship between "carer" and the family context where she works. The employer should generally be the direct patient of the carer, but the family members often play this role, sometimes because of the problems of health of the person that needs assistance. In some cases the assisted person is not an active part in the decision of being cared by someone, or is clearly against it, and reluctantly accepts the presence of a stranger in his house, somehow imposed by family members. Another aspect concerns the role of the family members that may, indeed, be employers for the "caretaker" but are also considered, especially by formal services, part of the patient’s care network. This creates a triangular situation full of potential conflict sources.
A fourth level of ambiguity can be ascribed to the institutions, that don’t seem to be inclined to regulate clearly the position of these people, held back by the difficulty in dealing with a relatively new social phenomenon that don’t lends itself to classic solutions derivable from labor law.
If you were for example to apply the rule of 8 daily working hours, every family would need three carers, that would make the costs for families hardly sustainable, this situation would need the involvement of the welfare state with consequent increases in social costs and related doubts about the appropriateness of similar solutions. The state tries quietly to avoid breaking a mechanism that has found its way to function in response to a need, ignoring the precarious conditions of "carers".
Recently, just to try to respond in an structural way at these issues, started the project of training for "family collaborators", (involving several local educational institutions and the public authority ) that is definitely a decisive and concrete progress towards the professional qualification and the social and civic integration of these people. A first step has been taken will be to assess developments and impacts.
Direct consequence of this is the carer’s social status ambiguity; they seem to be a community of people living in the social fabric’s interstices. From a juridical point of view they are stranger citizens, whose rights and duties are set by the law and are summed in their residence permit.
But in fact, given their life conditions, they remember the figure of the Metic, whom in ancient Greece, was a stranger, sitting between non-free people and citizens. In conclusion, the carer job seems to be lived as a forced choice for own and family subsistence, apparently open to all but complex and difficult, incardinated in a twosome action/relation scene basically closed, with no recognition and self-realization, apparently low-specialized, exposed to risks of illegal hiring harassment and exploitation, related to the separation from the loved ones and from one’s own culture, lived almost like a suspended time
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