In this paper we consider the classes of all continuous $\mathcal {L}$ -(pre-)structures for a continuous first-order signature $\mathcal {L}$. We characterize the moduli of continuity for which the classes of finite, countable, or all continuous $\mathcal {L}$ -(pre-)structures have the amalgamation property. We also characterize when Urysohn continuous $\mathcal {L}$ -(pre)-structures exist, establish that certain classes of finite continuous $\mathcal {L}$ -structures are countable Fraïssé classes, prove the coherent EPPA for these classes of finite continuous $\mathcal {L}$ -structures, and (...) show that actions by automorphisms on finite $\mathcal {L}$ -structures also form a Fraïssé class. As consequences, we have that the automorphism group of the Urysohn continuous $\mathcal {L}$ -structure is a universal Polish group and that Hall’s universal locally finite group is contained in the automorphism group of the Urysohn continuous $\mathcal {L}$ -structure as a dense subgroup. (shrink)

Kvantory kak vtoropori︠a︡dkovye predikaty: ot Frege k abstraktnym logikam -- Kvantory kak funkt︠s︡ii vybora: ot Pirsa k IF-logikam -- Kvantifikat︠s︡ii︠a︡ i ėkzistent︠s︡ii︠a︡ -- Ėkzistent︠s︡ii︠a︡ i negat︠s︡ii︠a︡.

Before Euro-American settlement, many Native American nations intercropped maize (_Zea mays_), beans (_Phaseolus vulgaris_), and squash (_Cucurbita pepo_) in what is colloquially called the “Three Sisters.” Here we review the historic importance and consequences of rejuvenation of Three Sisters intercropping (3SI), outline a framework to engage Native growers in community science with positive feedbacks to university research, and present preliminary findings from ethnography and a randomized, replicated 3SI experiment. We developed mutually beneficial collaborative research agendas with four Midwestern US Native (...) American nations. Ethnographic data highlighted a culturally based respect for 3SI as living beings, the importance it holds for all cultural facets of these Native nations, and the critical impact the practice has on environmental sustainability. One concern expressed by Native growers during ethnographic research was improving soil health—part of the rationale for establishing the 3SI agronomic experiment. To address this, we collaboratively designed a 3SI experiment. After 1 year, 3SI increased short-term soil respiration by 24%, decreased salt-extractable nitrate by 54%, had no effect on soil microbial biomass (but increased its carbon-to-nitrogen ratio by 32%) compared to the average of monoculture crops. The overarching purpose of this collaborative project is to develop a deeper understanding of 3SI, its cultural importance to Native communities, and how reinvigorating the practice—and intercropping in general—can make agroecosystems more sustainable for people and the environment. (shrink)

Taking a set of central issues from ancient Greek medicine and biology, this book studies firstly, the interaction between scientific theorising and folklore or popular assumptions; secondly, the ideological character of scientific inquiry. Topics of interest in the philosphy and sociology of science illuminated here include the relationship between primitive thought and early science, the roles of the consensus on the scientific community, tradition and the authority of the written text, in the development of science.

The usual representation of quantum algorithms is limited to the process of solving the problem. We extend it to the process of setting the problem. Bob, the problem setter, selects a problem-setting by the initial measurement. Alice, the problem solver, unitarily computes the corresponding solution and reads it by the final measurement. This simple extension creates a new perspective from which to see the quantum algorithm. First, it highlights the relevance of time-symmetric quantum mechanics to quantum computation: the problem-setting and (...) problem solution, in their quantum version, constitute pre- and post-selection, hence the process as a whole is bound to be affected by both boundary conditions. Second, it forces us to enter into relational quantum mechanics. There must be a representation of the quantum algorithm with respect to Bob, and another one with respect to Alice, from whom the outcome of the initial measurement, specifying the setting and thus the solution of the problem, must be concealed. Time-symmetrizing the quantum algorithm to take into account both boundary conditions leaves the representation to Bob unaltered. It shows that the representation to Alice is a sum over histories in each of which she remains shielded from the information coming to her from the initial measurement, not from that coming to her backwards in time from the final measurement. In retrospect, all is as if she knew in advance, before performing her problem-solving action, half of the information that specifies the solution of the problem she will read in the future and could use this information to reach the solution with fewer computation steps. This elucidates the quantum computational speedup in all the quantum algorithms examined. (shrink)

ABSTRACTThis article, which summarises some of the main arguments of Analogical Investigations [Lloyd 2015], undertakes a comparative cross-cultural critique of the dominant Western view that downgrades analogy especially when that is contrasted unfavourably with a notion of axiomatic-deductive demonstration aiming to secure incontrovertible conclusions. It draws on materials from ancient Greece, ancient China and modern social anthropology and philosophy of science to explore the problems of translation and mutual intelligibility. It develops the idea of semantic stretch to qualify the literal/metaphorical (...) dichotomy and the notion of the multidimensionality of reality to clarify aspects of the controversy between realism and relativism. (shrink)

This book is a study of the origins and development of Greek science, focusing especially on the interactions of scientific and traditional patterns of thought from the sixth to the fourth centuries BC. The starting point is an examination of how certain Greek authors deployed the category of 'magic' and attacked magical beliefs and practices, and these attacks are related to their complex background in Greek medicine and speculative thought. In his second chapter Dr Lloyd outlines the development, and assesses (...) the significance, of the theory and practice of argument in early Greek science, and he follows this with a study of the development of empirical research. Finally the author confronts the question of why the Greeks invented science: what precisely was their contribution to science, and what social, economic, ideological and political factors had a bearing on the growth of science in Greece. (shrink)

Originally published in 1965. This is a textbook of modern deductive logic, designed for beginners but leading further into the heart of the subject than most other books of the kind. The fields covered are the Propositional Calculus, the more elementary parts of the Predicate Calculus, and Syllogistic Logic treated from a modern point of view. In each of the systems discussed the main emphases are on Decision Procedures and Axiomatisation, and the material is presented with as much formal rigour (...) as is compatible with clarity of exposition. The techniques used are not only described but given a theoretical justification. Proofs of Consistency, Completeness and Independence are set out in detail. The fundamental characteristics of the various systems studies, and their relations to each other are established by meta-logical proofs, which are used freely in all sections of the book. Exercises are appended to most of the chapters, and answers are provided. (shrink)

The purpose of this article is to illustrate moral learning in persons with a psychiatric disability who participated in a nursing intervention, called the photo-instrument. This intervention is a form of hermeneutic photography. The findings are based on a multiple case study of 42 patients and additional interviews with eight of them. Photo groups were organized within three settings of psychiatric services: ambulatory as well as clinical, all situated in the Netherlands. Data were analysed according to hermeneutic and semiotic principles. (...) Two cases are presented. Findings show that voice and face are concepts that help to identify elements of moral learning in the rehabilitation process of persons with a psychiatric disability. During the process patients become more aware of their responsibilities towards themselves and others. (shrink)

ObjectivesTo describe reporting of informed consent in pragmatic trials, justifications for waivers of consent and reporting of alternative approaches to standard written consent. To identify factors associated with (1) not reporting and (2) not obtaining consent.MethodsSurvey of primary trial reports, published 2014–2019, identified using an electronic search filter for pragmatic trials implemented in MEDLINE, and registered in ClinicalTrials.gov.ResultsAmong 1988 trials, 132 (6.6%) did not include a statement about participant consent, 1691 (85.0%) reported consent had been obtained, 139 (7.0%) reported a (...) waiver and 26 (1.3%) reported consent for one aspect (eg, data collection) but a waiver for another (eg, intervention). Of the 165 trials reporting a waiver, 76 (46.1%) provided a justification. Few (53, 2.9%) explicitly reported use of alternative approaches to consent. In multivariable logistic regression analyses, lower journal impact factor (p=0.001) and cluster randomisation (p<0.0001) were significantly associated with not reporting on consent, while trial recency, cluster randomisation, higher-income country settings, health services research and explicit labelling as pragmatic were significantly associated with not obtaining consent (all p<0.0001).DiscussionNot obtaining consent seems to be increasing and is associated with the use of cluster randomisation and pragmatic aims, but neither cluster randomisation nor pragmatism are currently accepted justifications for waivers of consent. Rather than considering either standard written informed consent or waivers of consent, researchers and research ethics committees could consider alternative consent approaches that may facilitate the conduct of pragmatic trials while preserving patient autonomy and the public’s trust in research. (shrink)

Dr Lloyd writes for those who want to discover and explore Aristotle's work for themselves. He acts as mediator between Aristotle and the modern reader. The book is divided into two parts. The first tells the story of Aristotle's intellectual development as far as it can be reconstructed; the second presents the fundamentals of his thought in the main fields of inquiry which interested him: logic and metaphysics, physics, psychology, ethics, politics, and literary criticism. The final chapter considers the unity (...) and coherence of Aristotle's philosophy, and records briefly his later influence on European thought. This is a concise and lucid account of the work of a difficult and profound thinker. Dr Lloyd's business is only with the essentials; but he does not shirk the difficulties which arise in their interpretation, nor does he invest Aristotle with a spurious modernity. (shrink)