189 research outputs found
Buiatti : dalla filosofia della biologia alla filosofia dalla biologia
No full textQuesta raccolta di contributi, realizzata per festeggiare i cinquant'anni d'attività professionale del biologo Marcello Buiatti, va dall'analisi del suo particolare e sintonico modo di pensare e studiare la natura, al suo agire nella politica scientifica italiana, trattare il ruolo delle multinazionali agricole, confrontarsi con i problemi dell'ambientalismo scientifico, ma anche con la storia e l'epistemologia della biologia teorica, affiancando sempre al laboratorio la divulgazione scientifica in scuole di ogni ordine e grado. Il libro documenta a più voci il percorso lavorativo ed esistenziale di un personaggio contemporaneo che è un significativo punto di riferimento scientifico, politico e umano. Un sincero ringraziamento alla Associazione Limonaia Scienza Viva di Pisa per il supporto indispensabile fornito con efficacia e generosità alle attività promosse da Naturalmente Scienza.
Elena Gagliasso, è docente di Filosofia e scienze del vivente presso il Dipartimento di Filosofia dell' Università di Roma "La Sapienza". Dalla filosofia della biologia moderna e contemporanea, al legame tra scienza, filosofia e società, dall'epistemologia dell'evoluzionismo, dell'ecologia, e delle epistemologie naturalizzate, al ruolo delle metafore cognitive e al pensiero di genere, la sua ricerca si situa tra bios e contesti socioculturali, secondo un intreccio di registri che connettono il discorso filosofico, epistemico e storico critico. Segnaliamo i testi più recenti di cui è coautrice e curatrice: Il genere nel paesaggio scientifico (2007); Metafore del vivente (2010); Scienza & Scienziati: colloqui interdisciplinari (2011); Confini aperti. Il rapporto esterno/interno in biologia (2013).
Tommaso Eppesteingher, illustratore e vignettista attivo a Livorno, ha disegnato le tavole interne a due testi e l'illustrazione nella copertina del libr
State Observers for Systems Subject to Bounded Disturbances Using Quadratic Boundedness
No full textQuadratic boundedness is adopted to design state observers for linear, piecewise linear, and Lipschitz nonlinear systems subject to bounded disturbances. Upper bounds on the estimation error are derived by exploiting quadratic boundedness and a design method based on linear matrix inequalities is proposed to minimize such bounds. Simulation results are provided to show the effectiveness of the proposed approach
Elementi per una genetica forense
No full textLo strumento scientifico ha avuto uno sviluppo vertiginoso nel campo delle professioni legali, divenendo fattore sempre più determinante nell'ambito giudiziario, soprattutto in quello penale. È, infatti, ormai impossibile pensare a un processo che non contenga elementi d'indagine caratterizzati in modo scientifico - quali, ad esempio, le impronte digitali, le analisi balistiche, le analisi tossico-chimiche, le analisi relative a tracce o frammenti di sangue, le analisi genetiche -, o che prescinda dalla testimonianza di un esperto in un certo ambito scientifico. Questo volume si propone di introdurre alcuni concetti di genetica e di statistica, ma anche di filosofia della scienza, di cui dovrebbero essere a conoscenza tutte le parti impegnate in un processo, per affrontare il proprio lavoro con maggiore serenità, consapevolezza ed efficacia. Presentazione di Salvatore Scuto e Giovanni Canzio
Distributed Model-Based Fault Diagnosis with Stochastic Uncertainties
No full textThis paper proposes a novel distributed fault detection and isolation approach for the monitoring of non linear large-scale systems. The proposed architecture considers stochastic characterization of the measurement noises and modeling uncertainties, computing at each step stochastic timevarying thresholds with guaranteed false alarms probability
levels. The convergence properties of the distributed estimation are demonstrated. A novel fault isolation method is proposed basing on a Generalized Observer Scheme, providing guaranteed error probabilities of the fault exclusion task. A consensus approach is used for the estimation of variables shared among more than one subsystem; a method is proposed to define the time-varying consensus weights in order to minimize at each step the variance of the uncertainty of the fault detection and isolation thresholds. Detectability and isolability conditions are provided
A MATTER OF STYLE.HOW MAP THINKING AND BIO-ONTOLOGIES SHAPE CONTEMPORARY MOLECULAR RESEARCH
No full textABSTRACT
The aim of this thesis is to provide an epistemic analysis of the transformations occurring in contemporary biological research by considering the relation between molecular biology and computational biology. In particular, I will focus on bio-ontologies, as the tool which incarnates at best the new face of biomedical research. Such a choice is not arbitrary. By appealing to the notion of style of reasoning and way of knowing, I will show that bio-ontologies exemplify the rise and success of map thinking as the signature of a new way of doing molecular biology, while the theoretical tenets, established more than 30 years ago, still maintain their epistemic prominence. This is neither to say that experimentalism will disappear from science, nor that the experiments power will be diminished but rather that experiments will have a new role in the architecture of scientific efforts, precisely because of the increasing importance of classificatory approaches. Therefore, such a transition within biomedical research is indeed radical and profound but it does not involve paradigm shifts but rather a change in the practice. In this sense, it is a matter of style
Masonry elements strengthened through Textile-Reinforced Mortar: application of detailed level modelling with a free open-source Finite-Element code
No full textThe paper concerns the modelling of masonry elements strengthened through Textile Reinforced Mortar (TRM), a near surface system made of fiber-based grids or textiles embedded in mortar layers. Recently, the author, focusing on the mechanical characterization of TRM composites, developed a detailed level modelling approach by using the free, open-source Finite-Element code OOFEM, for the simulation of experimental tests on TRM coupons (pull-out tests, tensile tests, shear bond tests and in-plane shear tests). The model was capable to account for the failure of single components (e.g. the fibers tensile failure, the mortar cracking and crushing), as well as of their interactions (the debonding of the fibers from the mortar and of the mortar from the masonry substrate). In this paper, the detailed-level modelling approach is applied to the simulation of TRM strengthened masonry elements subjected to diagonal compression, in-plane and out-of-plane bending tests, investigating on the typical failure modes of masonry. Non-linear static analyses are performed, with nonlinearities of materials and interfaces deduced from experimental evidences. The comparison with some experimental results and a parametric study allowed to evidence the reliability of the models and their sensitivity to the main components characteristics
Model-Based Fault Detection and Estimation for Linear Time Invariant and Piecewise Affine Systems by Using Quadratic Boundedness
No full textQuadratic boundedness is a notion of stability that
is adopted to investigate the design of observers for dynamic systems subject to bounded disturbances. We will show how to exploit such observers for the purpose of fault detection. Toward this end, first of all we present the naive application of quadratic boundedness to construct state observers for linear time-invariant systems with state augmentation, i.e., where additional variables may be introduced to account for the occurrence of a fault. Then a Luenberger observer is designed
to estimate the augmented state variable of the system in such a way to detect the fault by using a convenient threshold selection. Finally, such an approach is extended to piecewise affine systems by presenting a hybrid Luenberger observer and its related design based on quadratic boundedness. The design of all the observers for both linear time-invariant and piecewise affine systems can be done by using linear matrix inequalities.
Simulation results are provided to show the effectiveness of the proposed approaches
Junk or functional DNA? ENCODE and the function controversy
No full textIn its last round of publications in September 2012, the Encyclopedia Of DNA Elements (ENCODE) assigned a biochemical function to most of the human genome, which was taken up by the media as meaning the end of ‘Junk DNA’. This provoked a heated reaction from evolutionary biologists, who among other things claimed that ENCODE adopted a wrong and much too inclusive notion of function, making its dismissal of junk DNA merely rhetorical. We argue that this criticism rests on misunderstandings concerning the nature of the ENCODE project, the relevant notion of function and the claim that most of our genome is junk. We argue that evolutionary accounts of function presuppose functions as ‘causal roles’, and that selection is but a useful proxy for relevant functions, which might well be unsuitable to biomedical research. Taking a closer look at the discovery process in which ENCODE participates, we argue that ENCODE’s strategy of biochemical signatures successfully identified activities of DNA elements with an eye towards causal roles of interest to biomedical research. We argue that ENCODE’s controversial claim of functionality should be interpreted as saying that 80 % of the genome is engaging in relevant biochemical activities and is very likely to have a causal role in phenomena deemed relevant to biomedical research. Finally, we discuss ambiguities in the meaning of junk DNA and in one of the main arguments raised for its prevalence, and we evaluate the impact of ENCODE’s results on the claim that most of our genome is junk
Stratification and biomedicine : how philosophy stems from medicine and biotechnology
No full textRecent advances in molecular biology and biotechnology are drastically changing our perceptions of disease, diagnosis, and therapy. In this reshaping of medical activities, molecular and personalised medicine, with their biotech tools, are emerging as an indispensable bridge between basic research in molecular biology and clinical practice. As usually happens in the history of science, also this innovative turn in medicine has begun spurring new philosophical analyses. In the chapter we will focus on classification, or, more precisely, on stratification of diseases, therapies and patients and on what such a stratification implies from the philosophical point of view. We will start describing the topic of stratification, its novelties and its impact on the way of treating patients in clinical contexts. Then we will move to show how such a stratification turn has relevant philosophical implications. In particular, we will show how it is changing our way of defining and classifying diseases. This is an ontological topic strictly linked with the so-called bio-ontologies, which are a computational approach by means of which we integrate data coming from different sources (in our case, the labs and the clinic)
A Distributed Networked Approach for Fault Detection of Large-scale Systems
No full textNetworked systems present some key new challenges in the development of fault diagnosis architectures. This paper proposes a novel distributed networked fault detection methodology for large-scale interconnected systems. The proposed formulation incorporates a synchronization methodology with a filtering approach in order to reduce the effect of measurement noise and time delays on the fault detection performance. The
proposed approach allows the monitoring of multi-rate systems, where asynchronous and delayed measurements are available.
This is achieved through the development of a virtual sensor scheme with a model-based re-synchronization algorithm and a delay compensation strategy for distributed fault diagnostic units.
The monitoring architecture exploits an adaptive approximator with learning capabilities for handling uncertainties in the interconnection
dynamics. A consensus-based estimator with timevarying weights is introduced, for improving fault detectability in the case of variables shared among more than one subsystem.
Furthermore, time-varying threshold functions are designed to prevent false-positive alarms. Analytical fault detectability sufficient conditions are derived and extensive simulation results are presented to illustrate the effectiveness of the distributed fault detection technique
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