1,720,963 research outputs found
Some Notes on the Role of the Identity of Indiscernibles in Metaphysics
No full textThe Principle of the Identity of Indiscernibles (PII) asserts that if putative objects x and y shareall properties P, then they must be one and the same entity. Since the usual formal rendering ofthe PII has the same formal structure as the Leibniz Identity, it may be unclear whether it canbe used to define identity and objectuality. As identity and objectuality are closely related, thisstudy aims to examine their relationship within the framework of formal ontology. Crucialfor the discussion are issues about type and range of quantification and the invariance ofthe identity predicate coourring in the PII. Ultimately, the analysis reveals that the appeal toPII is insufficient for providing both identity and objectuality. Some further considerationsabout how the PII sensitively constrains the range of available ontologies or metaphysics areformulated.Fil: Ferrari, Francesco Maria. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Filosofía "Dr. Alejandro Korn"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Questioni di semantica formale e logica plurale
Full text linkThe present research is a logico-philosophical analysis of the issues concerning the semantics for plural logic, with particular attention to the recent work by A. Oliver and T. Smiley, Plural Logic (OUP).
The first chapter introduces into the model-theoretic semantics for second-order languages. Three versions are presented: standard, Henkin and multi-sorted. All three differ in the definition of the assignment function to the second-order variables. The second chapter analyzes the relationship between model-theoretic semantics and ontology, in particular realism and nominalism. On the one hand, realism relies on the so called referential (or objectual) semantics; on the other hand, nominalism must rely on the so called substitutional semantics, for what concerns second-order variables, in order to avoid any ontological commitment with respect to such variables.
The third chapter introduces plural semantics. W.O. Quine (in 1970), argued that second-order logic is a ‘set theory in sheep’s clothing’ and, so, not a pure logic. Quine’s approach was strongly criticized by G. Boolos, in a series of articles in the 70s and 80s of the last century. He proposed a new sort of referential semantics for (monadic) secon-order variables and quantifiers, the so called plural interpretation based on a (one-many) ralation assignment.
The fourth chapter presents an outline of the more ideas of the work by Oliver and Smiley. In particular, their system 1) recasts predication in terms of plural predication and 2) attempts to capture plural denotation phenomena. In order to extend the category of terms to the plural case, Autors propose a theory of definite descriptions that contrasts with the Russellian one. Plural functional terms, obtained by means of the descriptive apparatus, denote so called multivalued functions – to be added to the usual functions, now singlevalued. In the fifth chapter it is provided an analysis of such function with respect to mathematics and logic. Multivalued functions play also a key role in the semantics of plural logic, modeling the assignment function for plural variables. It is also considered some semantic consequence due to their assumption.
The final chapter concludes the analysis of plural logic. Ø. Linnebo (2003) presented a criterion of logicality. From the application of such a criterion, it emerges that there are no compelling reasons not to define plural logic a pure logic. The only main point against such plural logics is the modal rigidity of the notion of plurality. Such a rigidity reveals that the alleged formalization of some typical features of that fragment of natural language that is related to plural phenomena is not fully adequate in these sort of plural logics
The Nominalist Limit of Kim’s Ontological Physicalism
No full textKim’s Ontological Physicalism (OP) presents itself as a naturalistic and monistic metaphysical framework, aligned with the causal closure of the universe and rejecting causally efficacious “exotic” properties. The foundational ontology is, in turn, monistic and materialistic, positing that the universe is composed solely of material particulars: bits of matter. In this work, we identify a notable tension between OP’s intended model and the one OP specifies. Initially, we show how the theory inevitably becomes entangled with higher-order entities, not just particulars. Kim introduces the Supervenience Argument (SA) to counteract the possibility of higher-order entities being causally efficacious. While SA proves to be a plausible strategy, it is ultimately inadequate: not only SA is a petitio principii against emergence, but it is also unsound and invalid. Therefore, we propose a formal strategy to restore its ontological effectiveness. Unfortunately, at a closer look, even this strategy falls short as it unwarrantedly assumes the logicality and invariance of those equivalence relations (such as identity, similarity, and congruence) which are crucial for specifying the theory’s model as composed of particulars.Fil: Ferrari, Francesco Maria. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Filosofía "Dr. Alejandro Korn"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
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
Quantitative Prediction of Drug Interactions Caused by Cytochrome P450 2B6 Inhibition or Induction
No full textBackground Numerous drugs have the potential to be affected by cytochrome P450 (CYP) 2B6-mediated drug-drug interactions (DDIs). Objectives In this work, we extend a static approach to the prediction of the extent of pharmacokinetics DDIs between substrates and inhibitors or inducers of CYP2B6. Methods This approach is based on the calculation of two parameters (the contribution ratio [CR], representing the fraction of dose of the substrate metabolized via this pathway and the inhibitory or inducing potency of the perpetrator [IR or IC, respectively]) calculated from the area under the concentration-time curve (AUC) ratios obtained in in-vivo DDI studies. Results Forty-eight studies involving 5 substrates, 11 inhibitors and 18 inducers of CYP2B6 (overall 15 inhibition and 33 induction studies) were divided into test and validation sets and considered for estimation of the parameters. The proposed approach demonstrated a fair accuracy for predicting the extent of DDI related to CYP2B6 inhibition and induction, all predictions related to the validation test (N = 18) being 50-200% of the observed ratios. Conclusions This methodology can be used for proposing initial dose adaptations to be adopted, for example in clinical use or for designing DDI studies involving this enzyme
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
A genetic algorithm-based approach for the prediction of metabolic drug-drug interactions involving CYP2C8 or CYP2B6
Full text linkBackground and objectives: A genetic algorithm (GA) approach was developed to predict drug-drug interactions (DDIs) caused by cytochrome P450 2C8 (CYP2C8) inhibition or cytochrome P450 2B6 (CYP2B6) inhibition or induction. Nighty-eight DDIs, obtained from published in vivo studies in healthy volunteers, have been considered using the area under the plasma drug concentration-time curve (AUC) ratios (i.e., ratios of AUC of the drug substrate administered in combination with a DDI perpetrator to AUC of the drug substrate administered alone) to describe the extent of DDI. Methods: The following parameters were estimated in this approach: the contribution ratios (CRCYP2B6 and CRCYP2C8, i.e., the fraction of the dose metabolized via CYP2B6 or CYP2C8, respectively) and the inhibitory or inducing potency of the perpetrator drug (IRCYP2B6, IRCYP2C8 and ICCYP2B6, for inhibition of CYP2B6 and CYP2C8, and induction of CYP2B6, respectively). The workflow consisted of three main phases. First, the initial estimates of the parameters were estimated through GA. Then, the model was validated using an external validation. Finally, the parameter values were refined via a Bayesian orthogonal regression using all data. Results: The AUC ratios of 5 substrates, 11 inhibitors and 19 inducers of CYP2B6, and the AUC ratios of 19 substrates and 23 inhibitors of CYP2C8 were successfully predicted by the developed methodology within 50-200% of observed values. Conclusions: The approach proposed in this work may represent a useful tool for evaluating the suitable doses of a CYP2C8 or CYP2B6 substrates co-administered with perpetrators
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
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