The Istituto e Museo di Storia della Scienza, Florence, Italy, possesses an astrolabe with five latitude plates that is now attributed to the Duisburg workshop of Gerard Mercator. Although it is known that Mercator made instruments, this is the first surviving example to be identified. Another latitude plate is shown to come from the workshop of the Florentine, Giovan Battista Giusti. A seventh plate, possibly engraved by Rumold Mercator, provides the only known Mercatorian polar stereographic projection. The role of Egnazio (...) Danti, cosmographer to the Grand Duke of Tuscany, in the acquisition of the astrolabe in about 1570 is considered. (shrink)

Background: Although genetic research into Alzheimer disease (AD) is increasing, the ethical aspects of this kind of research and the differences between ethical issues related to genetic and non-genetic research into AD have not yet received much attention. Objectives: (1) To identify and compare the five ethical issues considered most important by surveyed expert panellists in non-genetic and genetic AD research and (2) to compare our empirical findings with ethical issues in genetic research in general as described in the literature. (...) Method: A modified Delphi study in two rounds Results: Genetic and non-genetic research into AD generated an approximately equal number of topics with a considerable overlap. Different priorities in the ethics of both types of research were found. Genetic research raised new topics such as “confidentiality of genetic information” and “implications of research for relatives” which changes the impact and application of existing ethical topics such as “informed consent” and is judged to have more impact on both individuals and society. A difference with the results of more theoretical approaches on ethical aspects related to AD research was also found. Conclusions: Different priorities are given to ethical issues in genetic and non-genetic research. These arise partly because genetic research causes unique and new questions, mostly related to the position of family members and the status of and access to genetic information. Differences found between the results of our empirical study and the more theoretical literature, suggest an additional value for empirical research in medical ethics. (shrink)

With this paper I aim to demonstrate that a look beyond the Aristotelian square of opposition, and a related non-conservative view on logical determiners, contributes to both the understanding of Aristotelian syllogistics as well as to the study of quantificational structures in natural language.

In this paper we generalize the pigeonhole principle by using isols as our fundamental counting tool.

In his note [5] Hausner states a simple combinatorial principle, namely: $$(H)\left\{ {\begin{array}{*{20}c} {if f is a function a non - empty finite set \sigma into itself, p a} \\ {prime, f^p = i_\sigma and \sigma _0 the set of fixed points of f, then } \\ {\left| \sigma \right| \equiv \left| {\sigma _0 } \right|(mod p).} \\\end{array}} \right.$$ .He then shows how this principle can be used to prove:Fermat's little theorem,Cauchy's theorem for finite groups,Lucas' theorem for binomial numbers.Letε=(0,1, ...),ℱ (...) 1−1 the family of all one-to-one functions from a subset ofε intoε andℳ 1−1 the family of all p.r. (i.e., partial recursive) one-to-one functions from a subset ofε intoε. A subsetα of ε is finite, ifα is not equivalent to a proper subset under a function inℱ 1−1. The setα is calledisolated, if it is not equivalent to a proper subset under a function inℳ 1−1. An isolated set can also be defined as a subset ofε which has no infinite r.e. (i.e., recursively enumerable) subset. While every finite set is isolated, there are $c = 2^{\aleph _0 }$ infinite sets which are isolated; these sets are calledimmune. It is the purpose of this paper to generalize (H) to a principle (H*) for isolated sets and to show how (H*) can be used to prove generalizations of Fermat's little theorem and Cauchy's theorem for finite groups. We have been unable to generalize Lucas' theorem in a similar manner. (shrink)

In this paper we discuss the following contributions to recursion theory made by John Myhill: two sets are recursively isomorphic iff they are one-one equivalent; two sets are recursively isomorphic iff they are recursively equivalent and their complements are also recursively equivalent; every two creative sets are recursively isomorphic; the recursive analogue of the Cantor–Bernstein theorem; the notion of a combinatorial function and its use in the theory of recursive equivalence types.

This paper deals primarily with countable, simple, connected graphs and the following two conditions which are trivially satisfied if the graphs are finite: (a) there is an edge-recognition algorithm, i.e., an effective procedure which enables us, given two distinct vertices, to decide whether they are adjacent, (b) there is a shortest path algorithm, i.e., an effective procedure which enables us, given two distinct vertices, to find a minimal path joining them. A graph $G = \langle\eta, \eta\rangle$ with η as set (...) of vertices and η as set of edges is an α-graph if it satisfies (a); it is an ω-graph if it satisfies (b). G is called r.e. (isolic) if the sets ν and η are r.e. (isolated). While every ω-graph is an α-graph, the converse is false, even if G is r.e. or isolic. Several basic properties of finite graphs do not generalize to ω-graphs. For example, an ω-tree with more than one vertex need not have two pendant vertices, but may have only one or none, since it may be a 1-way or 2-way infinite path. Nevertheless, some elementary propositions for finite graphs $G = \langle\nu, \eta\rangle$ with $n = \operatorname{card}(\nu), e = \operatorname{card}(\eta)$ , do generalize to isolic ω-graphs, e.g., n - 1 ≤ e ≤ n(n - 1)/2. Let N and E be the recursive equivalence types of ν and η respectively. Then we have for an isolic α-tree $G = \langle\nu, \eta\rangle: N = E + 1$ iff G is an ω-tree. The theorem that every finite graph has a spanning tree has a natural, effective analogue for ω-graphs. The structural difference between isolic α-graphs and isolic ω-graphs will be illustrated by: (i) every infinite graph is isomorphic to some isolic α-graph; (ii) there is an infinite graph which is not isomorphic to any isolic ω-graph. An isolic α-graph is also called a twilight graph. There are c such graphs, c denoting the cardinality of the continuum. (shrink)

A nonnegative interger is called a number, a collection of numbers a set and a collection of sets a class. We write ε for the set of all numbers, o for the empty set, N(α) for the cardinality of $\alpha, \subset$ for inclusion and $\subset_+$ for proper inclusion. Let α, β 1 ,...,β k be subsets of some set ρ. Then α' stands for ρ-α and β 1 ⋯ β k for β 1 ∩ ⋯ ∩ β k . For (...) subsets α 1 ,..., α r of ρ we write: $\alpha_\sigma - \{x \in v \ (\nabla i) \lbrack i \in \sigma \Rightarrow x \in \alpha_i\rbrack\} \text{for} \sigma \subset (1, \ldots, r),\\ s_i = \sum \{N(\alpha_\sigma) \mid \sigma \subset (1,\ldots, r) \& N(\sigma) = i\}, \text{for} 0 \leqq i \leqq r$ . Note that α 0 = v, hence s 0 = N(v). If the set v is finite, the classical inclusion-exclusion principle (abbreviated IEP) states $(a) N(\alpha_1 \cup \cdots \cup \alpha_r) = \sum^r_{t=1} (-1)^{t-1} s_t = \sum_{o \subset_+\sigma \subset (1,\ldots,r)}$ (b) N(α' 1 ⋯ α' r ) = ∑ r t=0 (-1) t s t = ∑ (-1) N(σ) N (α σ ). In this paper we generalize (a) and (b) to the case where α 1 ,⋯, α r are subsets of some countable but isolated set v. Then the role of the cardinality N(α) of the set α is played by the RET (recursive equivalence type) Req α of α. These generalization of (a) and (b) are proved in § 3. Since they involve recursive distinctness, this notion is discussed in § 2. In § 4l we consider a natural extension of "the sum of the elements of a finite set σ" to the case where σ is countable. § 5 deals with valuations, i.e., certain mappings μ from classes of isolated sets into the collection λ of all isols which permit us to further generalize IEP by substituting μ(α) for $\operatorname{Req} \alpha$. (shrink)

In this paper the astronomical explorations of the southern celestial sky by Dutch navigators at the end of the sixteenth century are investigated. It is shown that the main motivation for this scientific enterprise stemmed from Dutch cartographic tradition and interests, represented first and foremost by Petrus Plancius and the competing globemakers Hondius and Blaeu. It is shown, too, that at the time actually two surveys were carried out. We have investigated the results of the two surveys by analysing the (...) data presented on celestial globes by Hondius and Blaeu, and in the star catalogue published by De Houtman in 1603. It appears that only after the first survey was it recognized that the stars of the well-known Southern Cross constellation could be matched with stars already recorded by Ptolemy. (shrink)

In transfinite arithmetic 2n is defined as the cardinality of the family of all subsets of some set v with cardinality n. However, in the arithmetic of recursive equivalence types 2N is defined as the RET of the family of all finite subsets of some set v of nonnegative integers with RET N. Suppose v is a nonempty set. S is a class over v, if S consists of finite subsets of v and has v as its union. Such a (...) class is an intersecting class over v, if every two members of S have a nonempty intersection. An IC over v is called a maximal IC , if it is not properly included in any IC over v. It is known and readily proved that every MIC over a finite set v of cardinality n ≥ 1 has cardinality 2n-1. In order to generalize this result we introduce the notion of an ω-MIC over v. This is an effective analogue ot the notion of an MIC over v such that a class over a finite set v is an ω-MIC iff it is an MIC. We then prove that every ω-MIC over an isolated set v of RET N ≥ 1 has RET 2N-1. This is a generalization, for while there only are χ0 finite sets, there are ϰ isolated sets, where c denotes the cardinality of the continuum, namely all the finite sets and the c immune sets. MSC: 03D50. (shrink)

In the last decade the enterprise of formal semantics has been under attack from several philosophical and linguistic perspectives, and it has certainly suffered from its own scattered state, which hosts quite a variety of paradigms which may seem to be incompatible. It will not do to try and answer the arguments of the critics, because the arguments are often well-taken. The negative conclusions, however, I believe are not. The only adequate reply seems to be a constructive one, which puts (...) several pieces of formal semantics, in particular dynamic semantics, together again.In this paper I will try and sketch an overview of tasks, techniques, and results, which serves to at least suggest that it is possible to develop a coherent overall picture of undeniably important and structural phenomena in the interpretation of natural language. The idea is that the concept of meanings as truth conditions after all provides an excellent start for an integrated study of the meaning and use of natural language, and that an extended notion of goal directed pragmatics naturally complements this picture. None of the results reported here are really new, but we think it is important to re-collect them. (shrink)

Objectives Access to healthcare in most western societies is based on equality. Rapidly rising costs have fuelled debates about differentiation in access to healthcare. We assessed the public's perceptions and attitudes about differentiation in healthcare according to lifestyle behaviour. Methods A vignette study was undertaken in participants in a colorectal cancer screening pilot programme in the Netherlands. Screenees with a negative test result received a questionnaire in which nine hypothetical situations were described: three different healthcare settings (screening, lung cancer, chronic (...) obstructive pulmonary disease) combined with three forms of differentiation each: a difference in premium, waiting list ordering or copayment according to lifestyle. We evaluated the responses using a general hierarchical linear model. Results The percentage of participants in agreement with differentiation varied from 20% to 58% (overall mean of 40%). Significantly more participants were in favour of giving a premium discount to those who do not engage in unhealthy behaviour compared with supporters for higher payments for those who do. More differentiation was supported for non-smoking versus smoking cessation than for participation versus non-participation in screening. We observed in-group favouritism in smokers, but no significant effects of age or disease. There was no support for waiting list ordering based on lifestyle. Conclusions Results of this study show that Dutch citizens eligible for colorectal cancer screening are in favour of some form of financial differentiation in the distribution of healthcare, but that significant differences exist between type of setting and the type of behaviour. Our study can be used in the ongoing discussion about solidarity and behaviour in healthcare. (shrink)

Periodic attacks of uncertain origin, where the clinical presentationresembles epilepsy but there is no evidence of a somatic disease, arecalled Pseudo-Epilepsy or Pseudo-Epileptic Attack Disorder (PEAD). PEADmay be called a `non-disease', i.e. a disorder on the fringes ofestablished disease patterns, because it lacks a rationalpathophysiological explanation. The first aim of this article is tocriticize the idea, common in medical science, that diseases are realentities which exist separately from the patient, waiting to bediscovered by the doctor. We argue that doctor and (...) patient construct adisease, and that the construction of the disease PEAD includes manynormative evaluations. The second aim is to provide insight into thesuffering of patients with PEAD. We focus on three aspects of thepatient, identity, autonomy and responsibility. We present somecharacteristic descriptions of (pseudo-)epileptic attacks by FjodorDostoevsky, Gustave Flaubert and Thomas Mann. We argue that diagnosingPEAD reduces a meaningful life event into an insignificant, thoughintriguing, medical phenomenon, and that the patient will not benefitfrom being diagnosed as having PEAD. (shrink)

One in three university students experiences mental health problems during their study. A similar percentage leaves higher education without obtaining the degree for which they enrolled. Research suggests that both mental health problems and academic underperformance could be caused by students lacking control and purpose while they are adjusting to tertiary education. Currently, universities are not designed to cater to all the personal needs and mental health problems of large numbers of students at the start of their studies. Within the (...) literature aimed at preventing mental health problems among students (e.g., anxiety or depression), digital forms of therapy recently have been suggested as potentially scalable solutions to address these problems. Integrative psychological artificial intelligence (AI) in the form of a chatbot, for example, shows great potential as an evidence-based solution. At the same time, within the literature aimed at improving academic success, the online life-crafting intervention in which students write about values and passions, goals, and goal-attainment plans has shown to improve the academic performance and retention rates of students. Because the life-crafting intervention is delivered through the curriculum and doesn’t bear the stigma that is associated with therapy, it can reach larger populations of students. But life-crafting lacks the means for follow-up or the interactiveness that online AI-guided therapy can offer. In this paper, we propose to integrate the current literature on chatbot interventions aimed at the mental health of students with research about a life-crafting intervention that uses an inclusive curriculum-wide approach. When a chatbot asks students to prioritize both academic as well as social and health-related goals and provides personalized follow-up coaching, this can prevent -often interrelated- academic and mental health problems. Right on-time delivery, and personalized follow-up questions enhance the effects of both -originally separated- intervention types. Research on this new combination of interventions should use design principles that increase user-friendliness and monitor the technology acceptance of its participants. (shrink)

This paper explores the ambiguous notion of bodily integrity, focusing on male and female circumcision. In the empirical part of the study we describe and analyse the various meanings that are given to the notion of bodily integrity by people in their daily lives. In the philosophical part we distinguish (1) between a person-oriented and a body-oriented approach and (2) between four levels of interpretation, i.e. bodily integrity conceived of as a biological wholeness, an experiential wholeness, an intact wholeness, and (...) as an inviolable wholeness. We argue that bodily integrity is a prima facie principle in its own right, closely connected with, but still fundamentally different from, the principle of personal autonomy, that is, autonomy over the body. (shrink)

In their 2007 paper, Swierstra and Rip identify characteristic tropes and patterns of moral argumentation in the debate about the ethics of new and emerging science and technologies (or “NEST-ethics”). Taking their NEST-ethics structure as a starting point, we considered the debate about tissue engineering (TE), and argue what aspects we think ought to be a part of a rich and high-quality debate of TE. The debate surrounding TE seems to be predominantly a debate among experts. When considering the NEST-ethics (...) arguments that deal directly with technology, we can generally conclude that consequentialist arguments are by far the most prominently featured in discussions of TE. In addition, many papers discuss principles, rights and duties relevant to aspects of TE, both in a positive and in a critical sense. Justice arguments are only sporadically made, some “good life” arguments are used, others less so (such as the explicit articulation of perceived limits, or the technology as a technological fix for a social problem). Missing topics in the discussion, at least from the perspective of NEST-ethics, are second “level” arguments—those referring to techno-moral change connected to tissue engineering. Currently, the discussion about tissue engineering mostly focuses on its so-called “hard impacts”—quantifiable risks and benefits of the technology. Its “soft impacts”—effects that cannot easily be quantified, such as changes to experience, habits and perceptions, should receive more attention. (shrink)

In their 2007 paper, Swierstra and Rip identify characteristic tropes and patterns of moral argumentation in the debate about the ethics of new and emerging science and technologies (or “NEST-ethics”). Taking their NEST-ethics structure as a starting point, we considered the debate about tissue engineering (TE), and argue what aspects we think ought to be a part of a rich and high-quality debate of TE. The debate surrounding TE seems to be predominantly a debate among experts. When considering the NEST-ethics (...) arguments that deal directly with technology, we can generally conclude that consequentialist arguments are by far the most prominently featured in discussions of TE. In addition, many papers discuss principles, rights and duties relevant to aspects of TE, both in a positive and in a critical sense. Justice arguments are only sporadically made, some “good life” arguments are used, others less so (such as the explicit articulation of perceived limits, or the technology as a technological fix for a social problem). Missing topics in the discussion, at least from the perspective of NEST-ethics, are second “level” arguments—those referring to techno-moral change connected to tissue engineering. Currently, the discussion about tissue engineering mostly focuses on its so-called “hard impacts”—quantifiable risks and benefits of the technology. Its “soft impacts”—effects that cannot easily be quantified, such as changes to experience, habits and perceptions, should receive more attention. (shrink)

Around 1970, high numbers of traffic casualties among cyclists led to the creation of numerous local protest movements in the Netherlands. While activists employed protest strategies, their main interest lie in the way they exemplify a highly successful instance of “lay expertise”; the idea that users of a technology have a fundamentally different and valuable perspective on a technology than experts or system-builders. Specifically, cyclists claimed to be more knowledgeable about cycling conditions and safety than the state-employed engineers and traffic (...) experts who built the roads and cycling path network. A key actor in this story is the Dutch Cyclists’ Union, a national platform of local action groups formed in 1975. These activists used the cycling experience of everyday utilitarian cyclists to compile maps and blacklists of locations where cycling was dangerous, unpleasant, uncomfortable, or otherwise discouraging. In doing so, they successfully claimed legitimacy as a valuable knowledge partner for local engineers and policymakers. As a result, they gained some level of influence within local governments, a relation which in the intervening years has only grown stronger. This case study shows how users can shape socio-technical systems bottom-up, and can therefore to an extent be seen as a successful example of co-construction of technology.ZusammenfassungUm 1970 führte die hohe Zahl von Verkehrsunfällen unter Radfahrern zur Gründung zahlreicher lokaler Protestbewegungen in den Niederlanden. Obwohl die Aktivisten auch Proteststrategien einsetzten, besteht das Hauptinteresse dieses Artikels in der Art und Weise, wie sie ein äußerst erfolgreiches Beispiel für „Laienkompetenz“ darstellen. Die Idee dahinter ist, dass Nutzer eine wertvolle und grundlegend andere Perspektive auf eine Technologie haben als Experten oder Systembauer: Radfahrer gaben in Umfragen an, mehr über die Bedingungen und die Sicherheit von Fahrrädern zu wissen als die staatlich angestellten Ingenieure und Verkehrsexperten, die die Systeme des Straßen- und Radwegenetzes gebaut haben. Ein Hauptakteur dieser Geschichte ist der Fietsersbond [Radfahrerbund], eine nationale Plattform lokaler Aktionsgruppen, die 1975 gegründet wurde. Diese Aktivisten nutzten die Mobilitätserfahrung täglicher Radfahrer, um Karten und Liste von Orten zusammenzustellen, an denen das Radfahren gefährlich und unangenehm oder auf andere Weise beschwerlich war. Damit beanspruchten sie erfolgreich Legitimität als wertvoller Wissenspartner für lokale Ingenieure und politische Entscheidungsträger. Infolgedessen gewannen sie einen gewissen Einfluss auf die Kommunalverwaltung; eine Beziehung, die seitdem immer stärker geworden ist. Diese Fallstudie zeigt, wie Nutzer sozio-technische Systeme „von unten“ gestalten können; sie kann daher in gewissem Maße als erfolgreiches Beispiel für die kooperative Konstruktion von Technik angesehen werden. (shrink)

BackgroundThe interpretation of clinical gait data in children with cerebral palsy (CP) is time-consuming, requires extensive expertise and often lacks transparency. Here we aimed to develop a set of look-up tables to support this process, linking typical gait features as present in CP to their potential underlying impairments.MethodsWe developed an initial core set of gait features and their potential underlying impairments based on biomechanical reasoning, literature and clinical experience. This core set was further specified through a Delphi process in a (...) multidisciplinary group of experts in gait analysis of children with CP and evaluated on 20 patient cases. The likelihood of the listed gait feature–impairment relationships was scored by the expert panel on a five-point scale.ResultsThe final core set included 120 relevant gait feature–impairment relations including likelihood scores. This set was presented in the form of look-up tables in both directions, i.e., sorted by gait features with potential underlying impairment, and sorted by impairments with potential related gait features. The average likelihood score for the relations was 3.5 ± 0.6 (range 2.1–4.6).ConclusionThe developed set of look-up tables linking gait features and impairments, can assist gait analysts and clinicians in standardized biomechanical reasoning, to support treatment decision-making for gait impairments in children with CP. (shrink)