3,293 research outputs found
Thymic maturation and programmed cell death
No full textThe thymus plays a crucial role in the development and maintenance of the immune system, being the main site of T cell differentiation and maturation throughout life. Associated to dramatic structural changes, its function seems to markedly diminish with time, never the less, there are several data indicating that, despite organ atrophy, at least part of the thymus remains active throughout one's lifetime. In the last decades, several studies, aiming to understand the significance of age-dependent changes in thymic structure and function, highlighted the concept that developmental and maturational stages strongly depend on the balanced and coordinated occurrence of life and death options. In particular, programmed cell death represents a fundamental requirement in order to assure a proper functionality of the immune response and to avoid the formation of uncontrolled and potentially self-damaging lymphocytic clones. By contrast, the time-dependent thymic atrophy is due to progressive replacing of lymphoid with adipose tissue. In the light of the increased knowledge on the factors/mechanisms controlling the process of adipogenesis, it could be suggested that fat accumulation in the thymic stroma might not be considered a passive, deleterious consequence of aging, but instead a potential source of molecules with various biological functions. Therefore, thymus represents a very interesting model in terms of energy expenditure and trade off, tissue homeostasis, immune defence and disease escape. The implications of changes in thymic structure, in the ratio of proliferation and programmed cell death as well as the occurrence of fat involution still represent an open question and will be discussed in the present chapter
Financial literacy, Debt burden and Impulsivity. A mediation analysis
No full textAfter the 2008 crisis, EU regulatory authorities and policy makers started to devote resources to improve households’ financial literacy, considered as a key element of debt decisions. However, the role of another crucial determinant of debt burden has been neglected in such financial education programmes. The present study examines the role of impulsivity and financial literacy as predictors of debt burden in a sample of 445 individuals. An ad-hoc built indicator of financial literacy and scores on the Barratt Impulsiveness Scale were used as regressors. The debt service to income ratio, a proxy of debt burden, served as the dependent variable. Both predictors resulted associated with debt burden; however, impulsivity fully mediated the impact of financial literacy on debt, even after controlling for financial wealth. Findings are discussed in terms of policy implications and means to formulate more effective financial education programmes
Impulsivity and household indebtedness: evidence from real life
No full textUsing a probit model, we estimated the role of emotional factors in determining household participation in the debt market, after controlling for such traditional economic predictors as age, level of education, income, wealth, and work status. A sample of 445 Caucasian subjects selected among fulltime employees at international asset management companies underwent the Barratt Impulsiveness Scale, the Iowa Gambling Task (IGT) while skin conductance was recorded, and a series of questions related to their demographic-socio-economic profile. Aside from confirming the role played by traditional explanatory variables commonly used as determinants of household indebtedness, results revealed the significant influence of individuals' impulsivity in making debt decisions. Impulsivity predicted unsecured debt (i.e. consumer credit), but it was not significantly associated with secured debt (i.e. mortgages). Neither presence of a somatic marker to guide decisions nor performance at the IGT predicted real-life indebtedness decisions in this non-clinical sample. The notion that "non-rational" factors influence debt demand has been largely ignored and raises concerns about the risk of over-indebtedness for impulsive individuals. (C) 2011 Elsevier B.V. All rights reserved
Variations on the Author
No full text“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
Two statistical methods to validate habitat suitability models using presence-only data
No full textPredicting species occurrence using a modelling approach based on a geographic information system (GIS) represents a new methodological tool which can be used to endorse conservation policies, on condition that models are tested for reliability. Habitat suitability models are often used to predict species occurrence through the modelling of proper environmental variables. A major constraint in building large-scale models of species distribution is the availability of data and therefore the deductive approach is adopted. This approach is suitable for bio-diversity assessment as it can be applied to a great number of species, it does however require statistical validation, both to test the accuracy of the input information and to deal with presence data (often affected by high spatial and temporal variability). Available data are, in the large majority, represented by a small sample collected without an ad hoc sampling design and without information on species absence. Reliable information on absence is not easily obtained with animal species due to elusive behaviour, poorly accessible habitats and their activity patterns. Therefore, absence data are to be considered ambiguous. Hence the need to develop statistical tools to deal with presence-only data. Moreover, presence data are rarely geo-referenced with high precision. Often information on species presence is spatially degraded as referred to polygon within which the exact species location cannot be recovered. Consequently, the validation procedure should statistically consider this uncertainty. In this paper we suggest that a compositional procedure be used when presence-only data are affected by strong spatial and temporal variability, and that a multinomial (based) procedure be used when presence-only data are geo-referenced with high precision during an ad hoc field survey. The two procedures have been tested on a large number of deductive models built to represent the distribution of vertebrate species in Italy. Results show that both procedures allow the assessment of the calibration properties of the models. The reliability of the two methods is confirmed by a model rejection pattern, determined by ecological factors, scale issues, spatial accuracy and sample size. Both procedures have a wide range of applications being threshold independent. (C) 2004 Elsevier B.V. All rights reserved
Imparare le lingue per abbracciare il mondo
No full textL’autrice che si colloca, come Daniela Zorzi, tra i fautori di una linguistica “impegnata”, propone in ricordo della studiosa amica, una riflessione sul ruolo cruciale del multilinguismo e delle lingue- culture, per il successo professionale e il benessere sociale, nella società contemporanea. Il multilinguismo appare come un’urgenza educativa che interpella studiosi e formatori a tutti i livelli al fine di promuovere nei giovani un apprendimento consapevole efficace ed autonomo.Multilingualism constitutes an urgent objective for education, which needs to involve teachers and researchers at all levels if we are to promote effective and autonomous learning in the young. Like Daniela Zorzi, the author considers herself a socially engaged linguist, and in memory of her friend’s work, offers a reflection on the key roles of languages and cultures and of multilingualism for professional success and social welfare today
New insights into autophagic cell death in the gypsy moth Lymantria dispar: a proteomic approach
No full textAutophagy is an evolutionary ancient process based on the activity of genes conserved from yeast to metazoan taxa. Whereas its role as a mechanism to provide energy during cell starvation is commonly accepted, debate continues about the occurrence of autophagy as a means specifically activated to achieve cell death. The IPLB-LdFB insect cell line, derived from the larval fat body of the lepidoptera Lymantria dispar, represents a suitable model to address this question, as both autophagic and apoptotic cell death can be induced by various stimuli. Using morphological and functional approaches, we have observed that the culture medium conditioned by IPLB-LdFB cells committed to death by the ATPase inhibitor oligomycin A stimulates autophagic cell death in untreated IPLB-LdFB cells. Moreover, proteomic analysis of the conditioned media suggests that, in IPLB-LdFB cells, oligomycin A promotes a shift towards lipid metabolism, increases oxidative stress and specifically directs the cells towards autophagic activity
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