1,721,033 research outputs found
CRITICAL-BEHAVIOR IN RANDOM FIELD GAUGE-THEORY
No full textGUIOT C, KEHL E, Satz H, WALTL B. CRITICAL-BEHAVIOR IN RANDOM FIELD GAUGE-THEORY. ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS. 1988;38(3):495-499
A Classification Scheme for Phenomenological Universalities in Growth Problems in Physics and Other Sciences,
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Computer simulations and modeling in oncology: Methods and applications
No full textComputational models and simulations can be powerful tools for gaining an insight into the extremely complex mechanisms governing tumoral growth. In order to be relied upon, however, they must be validated by comparison with sufficiently long strings of experimental or observational data. For obvious ethical reasons it is virtually impossible to obtain such data "in vivo". It may be, therefore, expedient to study the growth of tumoral lines "in vitro" or "ex vivo", i.e. by transplanting them into lab animals (e.g., mice). In fact, experiments with as many as 900 successive transplants into new healthy mice have been performed. Using a recently proposed technique for the analysis of experimental datasets (the Phenomenological Universalities Approach), we have succeeded to reproduce, to an excellent level of reliability, the results of such "multipassage" growth and to explain quantitatively why the growth curves become progressively steeper at each new transplant. We believe that our method could also be applied to study metastatic diffusion and suggest new experiments to further validate our approach and result
Oscillations in growth of multicellular tumour spheroids: a revisited quantitative analysis
No full textObjectives: Multicellular tumour spheroids (MTS) provide an important tool for study of the micro- scopic properties of solid tumours and their responses to therapy. Thus, observation of large-scale volume oscillations in MTS, reported several years ago by two independent groups (1,2), in our opinion repre- sent a remarkable discovery, particularly if this could promote careful investigation of the possible occur- rence of volume oscillations of tumours ‘in vivo’. Materials and methods: Because of high back- ground noise, quantitative analysis of properties of observed oscillations has not been possible in previ- ous studies. Such an analysis can be now performed, thanks to a recently proposed approach, based on for- malism of phenomenological universalities (PUN). Results: Results have provided unambiguous con- firmation of the existence of MTS volume oscilla- tions, and quantitative evaluation of their properties, for two tumour cell lines. Proof is based not only on quality of fitting of the experimental datasets, but also on determination of well-defined values of fre- quency and amplitude of the oscillations for each line investigated, which would not be consistent with ran- dom fluctuation.
Conclusions: Biological mechanisms, which can be directly responsible for observed oscillations, are proposed, which relates also to recent work on related topics. Further investigations, both at experi- mental and at modelling levels, are also suggested. Finally, from a methodological point of view, results obtained represent further confirmation of applicabil- ity and usefulness of the PUN approach
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
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