The COVID-19 pandemic has resulted in more than 524 million cases and 6 million deaths worldwide. Various drug interventions targeting multiple stages of COVID-19 pathogenesis can significantly reduce infection-related mortality. The current within-host mathematical modeling study addresses the optimal drug regimen and efficacy of combination therapies in the treatment of COVID-19. The drugs/interventions considered include Arbidol, Remdesivir, Interferon and Lopinavir/ritonavir. It is concluded that these drugs, when administered singly or in combination, reduce the number of infected cells and viral load. (...) Four scenarios dealing with the administration of a single drug, two drugs, three drugs and all four are discussed. In all these scenarios, the optimal drug regimen is proposed based on two methods. In the first method, these medical interventions are modeled as control interventions and a corresponding objective function and optimal control problem are formulated. In this framework, the optimal drug regimen is derived. Later, using the comparative effectiveness method, the optimal drug regimen is derived based on the basic reproduction number and viral load. The average number of infected cells and viral load decreased the most when all four drugs were used together. On the other hand, the average number of susceptible cells decreased the most when Arbidol was administered alone. The basic reproduction number and viral load decreased the most when all four interventions were used together, confirming the previously obtained finding of the optimal control problem. The results of this study can help physicians make decisions about the treatment of the life-threatening COVID-19 infection. (shrink)

There are various equivalent formulations of the Church-Turing thesis. A common one is that every effective computation can be carried out by a Turing machine. The Church-Turing thesis is often misunderstood, particularly in recent writing in the philosophy of mind.

Presupposing no familiarity with the technical concepts of either philosophy or computing, this clear introduction reviews the progress made in AI since the inception of the field in 1956. Copeland goes on to analyze what those working in AI must achieve before they can claim to have built a thinking machine and appraises their prospects of succeeding.There are clear introductions to connectionism and to the language of thought hypothesis which weave together material from philosophy, artificial intelligence and neuroscience. John Searle's (...) attacks on AI and cognitive science are countered and close attention is given to foundational issues, including the nature of computation, Turing Machines, the Church-Turing Thesis and the difference between classical symbol processing and parallel distributed processing. The book also explores the possibility of machines having free will and consciousness and concludes with a discussion of in what sense the human brain may be a computer. (shrink)

In fourteen scholarly yet delightfully readable essays, Ober solves some ancient mysteries and reveals the secret kinks and passions of famous and obscure historical figures.

Between Saying and Doing aims to reconcile pragmatism with analytic philosophy. It investigates the relations between the meaning of linguistic expressions and their use. Giving due weight both to what one has to do in order to count as saying various things and to what one needs to say in order to specify those doings, makes it possible to shed new light on the relations between semantics and pragmatics. Among the vocabularies whose interrelated use and meaning are considered are: logical, (...) indexical, modal, normative, and intentional vocabulary. As the argument proceeds, new ways of thinking about the classic analytic core programs of empiricism, naturalism, and functionalism are offered, as well as novel insights about the ideas of artificial intelligence, the nature of logic, and intentional relations between subjects and objects. (shrink)

In this book, Yaqub describes a simple conception of truth and shows that it yields a semantical theory that accommodates the whole range of our seemingly conflicting intuitions about truth. This conception takes the Tarskian biconditionals as correctly and completely defining the notion of truth. The semantical theory, which is called the revision theory, that emerges from this conception paints a metaphysical picture of truth as a property whose applicability is given by a revision process rather than by a fixed (...) extension. The main advantage of this revision process is its ability to explain why truth seems in many cases almost redundant, in others substantial, and yet in others paradoxical. Yaub offers a comprehensive defense of the revision theory of truth by developing consistent and adequate formal semantics for languages in which all sorts of problematic sentences can be constructed. Yaqub concludes by introducing a logic of truth that further demonstrates the adequacy of the revision theory. (shrink)

In International Law and World Order, B. S. Chimni articulates an integrated Marxist approach to international law combining the insights of Marxism, socialist feminism and postcolonial theory. The book uses IMAIL to systematically and critically examine the most influential contemporary theories of international law including new, feminist, realist and policy-oriented approaches. In doing so, it discusses a range of themes relating to the history, structure and process of international law. The book also considers crucial world order issues and problems that (...) the international legal process has to contend with, including the welfare of weak groups and nations, the ecological crisis and the role of human rights. This extensively revised second edition provides an invaluable, in-depth and updated review of the key literature and scholarship within this field of study. It will be of particular interest to students and scholars of international law, international relations, international politics and global studies. (shrink)

The study of graph structure has advanced in recent years with great strides: finite graphs can be described algebraically, enabling them to be constructed out of more basic elements. Separately the properties of graphs can be studied in a logical language called monadic second-order logic. In this book, these two features of graph structure are brought together for the first time in a presentation that unifies and synthesizes research over the last 25 years. The author not only provides a thorough (...) description of the theory, but also details its applications, on the one hand to the construction of graph algorithms, and, on the other to the extension of formal language theory to finite graphs. Consequently the book will be of interest to graduate students and researchers in graph theory, finite model theory, formal language theory, and complexity theory. (shrink)

Context: In this empirical and conceptual paper on the historical, philosophical, and epistemological backgrounds of second-order cybernetics, the emergence of a significant pedagogical component to Heinz von Foerster’s work during the last years of the Biological Computer Laboratory is placed against the backdrop of social and intellectual movements on the American landscape. Problem: Previous discussion in this regard has focused largely on the student radicalism of the later 1960s. A wider-angled view of the American intellectual counterculture is needed. However, this (...) historical nexus is complicated and more often dismissed than brought into clear focus. Method: This essay assembles a historical sequence of archival materials for critical analysis, linked to a conceptual argument eliciting from those materials the second-order cybernetic concepts of observation, recursion, and paradox. Results: In this period, von Foerster found the “positive of the negative” in the social and intellectual unrest of that moment and cultivated those insights for the broader constitution of a new cognitive orientation. Implications: As a successful student of his own continuing course on heuristics, von Foerster left the academic mainstream to ally his constructivist epistemology with the systems counterculture. (shrink)

The mathematical genius Alan Turing, well known for his crucial wartime role in breaking the ENIGMA code, was the first to conceive of the fundamental principle of the modern computer. This text contains first hand accounts by Turing and by the pioneers of computing who worked with him on his revolutionary design for an electronic computing machine - his Automatic Computing Engine.