The Predictive Mind.Jakob Hohwy -2013 - Oxford, GB: Oxford University Press UK.detailsA new theory is taking hold in neuroscience. It is the theory that the brain is essentially a hypothesis-testing mechanism, one that attempts to minimise the error of its predictions about the sensory input it receives from the world. It is an attractive theory because powerful theoretical arguments support it, and yet it is at heart stunningly simple.Jakob Hohwy explains and explores this theory from the perspective of cognitive science and philosophy. The key argument throughout The Predictive Mind (...) is that the mechanism explains the rich, deep, and multifaceted character of our conscious perception. It also gives a unified account of how perception is sculpted by attention, and how it depends on action. The mind is revealed as having a fragile and indirect relation to the world. Though we are deeply in tune with the world we are also strangely distanced from it. (shrink)
The Self‐Evidencing Brain.Jakob Hohwy -2014 -Noûs 50 (2):259-285.detailsAn exciting theory in neuroscience is that the brain is an organ for prediction error minimization. This theory is rapidly gaining influence and is set to dominate the science of mind and brain in the years to come. PEM has extreme explanatory ambition, and profound philosophical implications. Here, I assume the theory, briefly explain it, and then I argue that PEM implies that the brain is essentially self-evidencing. This means it is imperative to identify an evidentiary boundary between the brain (...) and its environment. This boundary defines the mind-world relation, opens the door to skepticism, and makes the mind transpire as more inferentially secluded and neurocentrically skull-bound than many would nowadays think. Therefore, PEM somewhat deflates contemporary hypotheses that cognition is extended, embodied and enactive; however, it can nevertheless accommodate the kinds of cases that fuel these hypotheses. (shrink)
Derivatives.Jakob Arnoldi -2004 -Theory, Culture and Society 21 (6):23-42.detailsThis article examines the financial technology of derivatives. Derivatives are financial products whose values are based on possible fluctuations in the values of underlying assets. Hence derivatives markets are markets that trade in the risks of other markets. In order for derivatives markets to function, forms of prognostication that can assess the possible future fluctuations of the underlying markets are necessary. What such prognostications do, the article argues, is to create information out of future possibilities. Building upon a notion of (...) virtuality derived from Gilles Deleuze, Ulrich Beck and Niklas Luhmann, the article shows how market risks and uncertainties, by means of prognostications, cease to be mere possibilities and instead come to have virtual existence. Through the technology of derivatives, uncertainty and risk can be rendered virtual and be traded. The article suggests that this technology is an example of a new way in which capitalism is now expanding self-referentially as it creates markets out of markets; and of how it is colonizing the future by developing new technologies for ‘hyper-speculation’, that is, speculation not in the possible developments of a given asset but simply in the risk of such speculation. (shrink)
Niklas Luhmann.Jakob Arnoldi -2001 -Theory, Culture and Society 18 (1):1-13.detailsThe article is an introduction to a special section in TCS on the work of Niklas Luhmann. The first part of the article provides a general introduction to Luhmann's work with an emphasis on the basic elements of Luhmann's general systems theory, in particular Luhmann's notions of autopoiesis and meaning, and the traditions on which it is based. The second part of the text is a presentation of the articles in the special section.
Medical AI: is trust really the issue?Jakob Thrane Mainz -2024 -Journal of Medical Ethics 50 (5):349-350.detailsI discuss an influential argument put forward by Hatherley in theJournal of Medical Ethics. Drawing on influential philosophical accounts of interpersonal trust, Hatherley claims that medical artificial intelligence is capable of being reliable, but not trustworthy. Furthermore, Hatherley argues that trust generates moral obligations on behalf of the trustee. For instance, when a patient trusts a clinician, it generates certain moral obligations on behalf of the clinician for her to do what she is entrusted to do. I make three objections (...) to Hatherley’s claims: (1) At least one philosophical account of interagent trust implies that medical AI is capable of being trustworthy. (2) Even if this account should ultimately be rejected, it does not matter much because what we care mostly about is that medical AI is reliable. (3) It is false that trust in itself generates moral obligations on behalf of the trustee. (shrink)
The Sense of Self in the Phenomenology of Agency and Perception.Jakob Hohwy -2007 -PSYCHE: An Interdisciplinary Journal of Research On Consciousness 13.detailsThe phenomenology of agency and perception is probably underpinned by a common cognitive system based on generative models and predictive coding. I defend the hypothesis that this cognitive system explains core aspects of the sense of having a self in agency and perception. In particular, this cognitive model explains the phenomenological notion of a minimal self as well as a notion of the narrative self. The proposal is related to some influential studies of overall brain function, and to psychopathology. These (...) elusive notions of the self are shown to be the natural upshots of general cognitive mechanisms whose fundamental purpose is to enable agents to represent the world and act in it. (shrink)
The development of dialectic from Plato to Aristotle.Jakob Leth Fink (ed.) -2012 - Cambridge: Cambridge University Press.detailsThe period from Plato's birth to Aristotle's death (427-322 BC) is one of the most influential and formative in the history of Western philosophy. The developments of logic, metaphysics, epistemology, ethics and science in this period have been investigated, controversies have arisen and many new theories have been produced. But this is the first book to give detailed scholarly attention to the development of dialectic during this decisive period. It includes chapters on topics such as: dialectic as interpersonal debate between (...) a questioner and a respondent; dialectic and the dialogue form; dialectical methodology; the dialectical context of certain forms of arguments; the role of the respondent in guaranteeing good argument; dialectic and presentation of knowledge; the interrelations between written dialogues and spoken dialectic; and definition, induction and refutation from Plato to Aristotle. The book contributes to the history of philosophy and also to the contemporary debate about what philosophy is. (shrink)
How to entrain your evil demon.Jakob Hohwy -2017 -Philosophy and Predictive Processing.detailsThe notion that the brain is a prediction error minimizer entails, via the notion of Markov blankets and self-evidencing, a form of global scepticism — an inability to rule out evil demon scenarios. This type of scepticism is viewed by some as a sign of a fatally flawed conception of mind and cognition. Here I discuss whether this scepticism is ameliorated by acknowledging the role of action in the most ambitious approach to prediction error minimization, namely under the free energy (...) principle. I argue that the scepticism remains but that the role of action in the free energy principle constrains the demon’s work. This yields new insights about the free energy principle, epistemology, and the place of mind in nature. (shrink)
Spinoza and the Possibility of Error.Jakob Zigouras -2007 -Forum Philosophicum: International Journal for Philosophy 12 (1):105-118.detailsIf we consider certain features of Spinoza's metaphysics, it can seem very difficult to see how error, or the having of false ideas, is possible. In this paper I want to give the metaphysical background to the problem, before turning to a more detailed consideration of how Spinoza in fact accounts for error, or the having of false ideas. I will show the importance of the notions of adequacy and inadequacy in Spinoza's account. Having done this I will return to (...) the central problem of accounting for the ontological status of false ideas vis a vis both the Infinite Intellect, and finite minds. (shrink)
Normative Resilience.Henrik Andersson &Jakob Werkmäster -2022 -Utilitas 34 (2):195-208.detailsThis article discusses the phenomenon of normative resilience, with a focus on evaluative resilience. An object can become more or less valuable. In addition to this change in an object's value, the object's value can become more or less resilient. If it is less resilient, it cannot withstand as much evaluative change without its degree of value changing, as compared to an object with more resilient value. The article consists of three parts. First, examples of resilience are presented to give (...) the reader an intuitive understanding of the phenomenon, Second, the Fitting Attitudes Analysis of value is invoked to provide a formal account of evaluative resilience. Third, the theoretical and practical advantages of acknowledging the existence of evaluative resilience are brought to light. (shrink)
El sistema penal normativista en el mundo contemporáneo: libro homenaje al profesor Günther Jakobs en su 70 aniversario.Günther Jakobs,Eduardo Montealegre Lynett,Caro John &José Antonio (eds.) -2008 - Bogotá: Universidad Externado de Colombia.detailsA diferencia de todos los demás sistemas de imputación, Jakobs ubica el acento de la relevancia jurídico-penal del hecho en su significado normativo, como algo que trasciende la mera causalidad exterior y la finalidad del autor, de manera que lo decisivo para la imputación jurídico-penal no es ni lo psíquicoreal querido por el autor, ni la causalidad desplegada por su conducta, sino el significado normativo de esa conducta como la expresión de un sentido objetivo de desautorización de la vigencia de (...) la norma en un determinado contexto social. (shrink)
Being Reduced: New Essays on Reduction, Explanation, and Causation.Jakob Hohwy &Jesper Kallestrup (eds.) -2008 - New York: Oxford University Press.detailsThere are few more unsettling philosophical questions than this: What happens in attempts to reduce some properties to some other more fundamental properties?
Normative Transmission and Necessary Means.Jakob Green Werkmäster -2019 -Philosophia 47 (2):555-568.detailsThis paper focuses on the interaction of reasons and argues that reasons for an action may transmit to the necessary means of that action. Analyzing exactly how this phenomenon may be captured by principles governing normative transmission has proved an intricate task in recent years. In this paper, I assess three formulations focusing on normative transmission and necessary means: Ought Necessity, Strong Necessity, and Weak Necessity. My focus is on responding to two of the main objections raised against normative transmission (...) for necessary means, in that they seem to give us reasons for buying tickets to plays we have no intention of seeing and that the principles give us the wrong result when the means are necessary but not sufficient. Even though these objections have been discussed previously, the counterarguments have so far relied on rejecting premises that the proponents of these objections are unlikely to concede. In this paper, I show how we may answer the objections in a way more likely to convince proponents of the objections. The result is an argument for a key aspect when it comes to understanding how reasons and ends-means normativity function. Normative transmission from ends to necessary means is not only interesting at the structural level, it is also possible to argue that it has implications for areas as diverse as philosophy of rationality, political philosophy and applied ethics. (shrink)
Cosmopolitanism for Earth Dwellers: Kant on the Right to be Somewhere.Jakob Huber -2017 -Kantian Review 22 (1):1-25.detailsThe paper provides a systematic account of Kant’s ‘right to be somewhere’ as introduced in the Doctrine of Right. My claim is that Kant’s concern with the concurrent existence of a plurality of corporeal agents on the earth’s surface occupies a rarely appreciated conceptual space in his mature political philosophy. In grounding a particular kind of moral relation that is ‘external’ but not property-mediated, it provides us with a fundamentally new perspective on Kant’s cosmopolitanism, which I construe as a cosmopolitanism (...) for ‘earth dwellers’. (shrink)
AI and social theory.Jakob Mökander &Ralph Schroeder -2022 -AI and Society 37 (4):1337-1351.detailsIn this paper, we sketch a programme for AI-driven social theory. We begin by defining what we mean by artificial intelligence (AI) in this context. We then lay out our specification for how AI-based models can draw on the growing availability of digital data to help test the validity of different social theories based on their predictive power. In doing so, we use the work of Randall Collins and his state breakdown model to exemplify that, already today, AI-based models can (...) help synthesise knowledge from a variety of sources, reason about the world, and apply what is known across a wide range of problems in a systematic way. However, we also find that AI-driven social theory remains subject to a range of practical, technical, and epistemological limitations. Most critically, existing AI-systems lack three essential capabilities needed to advance social theory in ways that are cumulative, holistic, open-ended, and purposeful. These are (1) semanticisation, i.e., the ability to develop and operationalize verbal concepts to represent machine-manipulable knowledge; (2) transferability, i.e., the ability to transfer what has been learned in one context to another; and (3) generativity, i.e., the ability to independently create and improve on concepts and models. We argue that if the gaps identified here are addressed by further research, there is no reason why, in the future, the most advanced programme in social theory should not be led by AI-driven cumulative advances. (shrink)
(1 other version)Ethics-based auditing to develop trustworthy AI.Jakob Mökander &Luciano Floridi -2021 -Minds and Machines 31 (2):323–327.detailsA series of recent developments points towards auditing as a promising mechanism to bridge the gap between principles and practice in AI ethics. Building on ongoing discussions concerning ethics-based auditing, we offer three contributions. First, we argue that ethics-based auditing can improve the quality of decision making, increase user satisfaction, unlock growth potential, enable law-making, and relieve human suffering. Second, we highlight current best practices to support the design and implementation of ethics-based auditing: To be feasible and effective, ethics-based auditing (...) should take the form of a continuous and constructive process, approach ethical alignment from a system perspective, and be aligned with public policies and incentives for ethically desirable behaviour. Third, we identify and discuss the constraints associated with ethics-based auditing. Only by understanding and accounting for these constraints can ethics-based auditing facilitate ethical alignment of AI, while enabling society to reap the full economic and social benefits of automation. (shrink)
Probabilistic coherence measures: a psychological study of coherence assessment.Jakob Koscholke &Marc Jekel -2017 -Synthese 194 (4).detailsOver the years several non-equivalent probabilistic measures of coherence have been discussed in the philosophical literature. In this paper we examine these measures with respect to their empirical adequacy. Using test cases from the coherence literature as vignettes for psychological experiments we investigate whether the measures can predict the subjective coherence assessments of the participants. It turns out that the participants’ coherence assessments are best described by Roche’s coherence measure based on Douven and Meijs’ average mutual support approach and the (...) conditional probability. (shrink)
How to tragically deceive yourself.Jakob Ohlhorst -2018 -Les Ateliers de l'Éthique / the Ethics Forum 13 (2):48-69.detailsJakob Ohlhorst | : This paper introduces the concept of tragic self-deception. Taking the basic notion that self-deception is motivated belief against better evidence, I argue that there are extreme cases of self-deception even when the contrary evidence is compelling. These I call cases of tragic self-deception. Such strong evidence could be argued to exclude the possibility of self-deception; it would be a delusion instead. To sidestep this conclusion, I introduce the Wittgensteinian concept of certainties or hinges: acceptances that (...) are beyond evidential justification. One particular type of certainties—iHinges, which are adopted for motivational reasons—explain the phenomenon of tragic self-deception: they warrant the subject’s dismissal of the evidence without loss of rationality from the subject’s point of view. Subsequently, I deal with some objections that can be raised against this account of self-deception. | : Cet article présente le concept d’auto-illusion tragique. En prenant la notion de base selon laquelle l’auto-illusion consiste en une croyance motivée à l’encontre de meilleures preuves, je soutiens qu’il existe des cas extrêmes d’auto-illusion qui persistent même face à des preuves contradictoires incontestables. J’appelle ces cas : auto-illusion tragique. On pourrait soutenir que des preuves d’une telle force excluent la possibilité d’auto-illusion et qu’il s’agirait plutôt de délire. Afin d’éviter cette conclusion, j’introduis le concept wittgensteinien de certitudes ou de propositions charnières : des admissions qui se situent au-delà d’une justification de nature probante. Un type de certitudes en particulier – iHinges, qui sont adoptées pour des raisons d’ordre motivationnel – rend compte du phénomène d’auto-illusion tragique. Ces certitudes justifient que le sujet rejette la preuve sans que cela implique, de son propre point de vue, une perte de rationalité. Subséquemment, je traite de certaines objections qui peuvent être soulevées contre cette explication de l’auto-illusion. (shrink)
Retail Chains’ Corporate Social Responsibility Communication.Jakob Utgård -2018 -Journal of Business Ethics 147 (2):385-400.detailsThis study examines determinants of retail chains’ corporate social responsibility communication on their web pages. The theoretical foundation for the study is signaling theory, which suggests that firms will communicate about their CSR efforts when this is profitable for them and when such communication makes it possible for outsiders to distinguish good from bad performers. Based on this theory, I develop hypotheses about retail chains’ CSR signaling. The hypotheses are tested in a sample of 208 retail chains in the Norwegian (...) market. As hypothesized, I find that foreign chains, chains using private brands, and vertically integrated chains are more likely to signal, but I find no relationship between pricing and signaling. In further analysis using chains’ CSR memberships and certifications as the measure of signals, only the relationship between organizational form and signaling is replicated. In total, the findings give partial support to signaling theory. (shrink)
New Hope for Relative Overlap Measures of Coherence.Jakob Koscholke,Michael Schippers &Alexander Stegmann -2019 -Mind 128 (512):1261-1284.detailsRelative overlap measures of coherence have recently been shown to have two devastating properties: according to the plain relative overlap measure, the degree of coherence of any set of propositions cannot be increased by adding further propositions, and according to the refined relative overlap measure, no set can be more coherent than its most coherent two-element subset. This result has been taken to rule out relative overlap as a foundation for a probabilistic explication of coherence. The present paper shows that (...) this view is premature: we propose a relative overlap measure that does not fall victim to the two properties. The guiding idea is to employ a well-established recipe for the construction of coherence measures and to adapt it to the idea of relative overlap. We show that this new measure keeps up with, or even outperforms, former overlap measures in a set of desiderata for coherence measures and a collection of popular test cases. This result re-establishes relative overlap as a candidate for a proper formalization of coherence. (shrink)
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A Teleofunctionalist Solution to the Problem of Deviant Causal Chains of Actions.Jakob Roloff -2022 -Kriterion – Journal of Philosophy (3-4):247-261.detailsDonald Davidson’s causal theory of actions states that actions must be rationalized and caused by a belief-desire-pair. One problem of such a causal theory are cases of deviant causal chains. In these cases, the rationalized action is not caused in the right way but via a deviant causal chain. It therefore intuitively seems to be no action while all conditions of the causal theory are met. I argue that the problem of deviant causal chains can be solved by adding a (...) teleofunctionalist condition. This condition requires that the belief-desire pair that rationalizes an action must cause that action in a selection-historically normal way. I try to show that this additional condition drops counterintuitive cases of deviant causal chains out of the class of actions while being flexible enough to classify such cases as actions in which causal detours are intuitively permissible. (shrink)
Ethics-based auditing of automated decision-making systems: nature, scope, and limitations.Jakob Mökander,Jessica Morley,Mariarosaria Taddeo &Luciano Floridi -2021 -Science and Engineering Ethics 27 (4):1–30.detailsImportant decisions that impact humans lives, livelihoods, and the natural environment are increasingly being automated. Delegating tasks to so-called automated decision-making systems can improve efficiency and enable new solutions. However, these benefits are coupled with ethical challenges. For example, ADMS may produce discriminatory outcomes, violate individual privacy, and undermine human self-determination. New governance mechanisms are thus needed that help organisations design and deploy ADMS in ways that are ethical, while enabling society to reap the full economic and social benefits of (...) automation. In this article, we consider the feasibility and efficacy of ethics-based auditing as a governance mechanism that allows organisations to validate claims made about their ADMS. Building on previous work, we define EBA as a structured process whereby an entity’s present or past behaviour is assessed for consistency with relevant principles or norms. We then offer three contributions to the existing literature. First, we provide a theoretical explanation of how EBA can contribute to good governance by promoting procedural regularity and transparency. Second, we propose seven criteria for how to design and implement EBA procedures successfully. Third, we identify and discuss the conceptual, technical, social, economic, organisational, and institutional constraints associated with EBA. We conclude that EBA should be considered an integral component of multifaced approaches to managing the ethical risks posed by ADMS. (shrink)
Like It or Not: When Corporate Social Responsibility Does Not Attract Potential Applicants.Eva AlexandraJakob,Holger Steinmetz,Marius Claus Wehner,Christina Engelhardt &Rüdiger Kabst -2022 -Journal of Business Ethics 178 (1):105-127.detailsCompanies increasingly recognize the importance of communicating corporate social responsibility including their engagement toward employees, the community, the environment and other stakeholder groups to attract applicants. The positive findings on the effect of CSR on applicants’ reactions are commonly based on the assumption that companies send a clear signal about their commitment to CSR. However, communication is always contextualized and has become more ambiguous through the increased availability of information online. External stakeholders including actual and potential applicants are confronted with (...) inconsistencies between the way companies communicate CSR activities and their overall CSR performance. Drawing on signaling theory, this article raises the question of how the interaction between strong CSR communication and low CSR performance influences organizational attractiveness. We propose that low CSR performance dampens the effect of CSR communication on organizational attractiveness. Hence, the inconsistency between CSR communication and CSR performance decreases organizational attractiveness. To test our hypotheses, we scraped 67,189 posts published on corporate Facebook career pages by 58 Fortune 500 companies from the time they began their respective career page until June 2018. Surprisingly, our results show that a low CSR performance strengthens the effect of CSR communication on organizational attractiveness. Thus, inconsistencies between CSR communication and CSR performance seem to lead to positive evaluations among applicants. (shrink)
Artificial virtuous agents in a multi-agent tragedy of the commons.Jakob Stenseke -2022 -AI and Society:1-18.detailsAlthough virtue ethics has repeatedly been proposed as a suitable framework for the development of artificial moral agents, it has been proven difficult to approach from a computational perspective. In this work, we present the first technical implementation of artificial virtuous agents in moral simulations. First, we review previous conceptual and technical work in artificial virtue ethics and describe a functionalistic path to AVAs based on dispositional virtues, bottom-up learning, and top-down eudaimonic reward. We then provide the details of a (...) technical implementation in a moral simulation based on a tragedy of the commons scenario. The experimental results show how the AVAs learn to tackle cooperation problems while exhibiting core features of their theoretical counterpart, including moral character, dispositional virtues, learning from experience, and the pursuit of eudaimonia. Ultimately, we argue that virtue ethics provides a compelling path toward morally excellent machines and that our work provides an important starting point for such endeavors. (shrink)
The neural correlates of consciousness: New experimental approaches needed?Jakob Hohwy -2009 -Consciousness and Cognition 18 (2):428-438.detailsIt appears that consciousness science is progressing soundly, in particular in its search for the neural correlates of consciousness. There are two main approaches to this search, one is content-based (focusing on the contrast between conscious perception of, e.g., faces vs. houses), the other is state-based (focusing on overall conscious states, e.g., the contrast between dreamless sleep vs. the awake state). Methodological and conceptual considerations of a number of concrete studies show that both approaches are problematic: the content-based approach seems (...) to set aside crucial aspects of consciousness; and the state-based approach seems over-inclusive in a way that is hard to rectify without losing sight of the crucial conscious-unconscious contrast. Consequently, the search for the neural correlates of consciousness is in need of new experimental paradigms. (shrink)
(1 other version)Artificial virtuous agents: from theory to machine implementation.Jakob Stenseke -2021 -AI and Society:1-20.detailsVirtue ethics has many times been suggested as a promising recipe for the construction of artificial moral agents due to its emphasis on moral character and learning. However, given the complex nature of the theory, hardly any work has de facto attempted to implement the core tenets of virtue ethics in moral machines. The main goal of this paper is to demonstrate how virtue ethics can be taken all the way from theory to machine implementation. To achieve this goal, we (...) critically explore the possibilities and challenges for virtue ethics from a computational perspective. Drawing on previous conceptual and technical work, we outline a version of artificial virtue based on moral functionalism, connectionist bottom–up learning, and eudaimonic reward. We then describe how core features of the outlined theory can be interpreted in terms of functionality, which in turn informs the design of components necessary for virtuous cognition. Finally, we present a comprehensive framework for the technical development of artificial virtuous agents and discuss how they can be implemented in moral environments. (shrink)
Artificial intelligence is an oxymoron.Jakob Svensson -2023 -AI and Society 38 (1):363-372.detailsDeparting from popular imaginations around artificial intelligence (AI), this article engages in the I in the AI acronym but from perspectives outside of mathematics, computer science and machine learning. When intelligence is attended to here, it most often refers to narrow calculating tasks. This connotation to calculation provides AI an image of scientificity and objectivity, particularly attractive in societies with a pervasive desire for numbers. However, as is increasingly apparent today, when employed in more general areas of our messy socio-cultural (...) realities, AI- powered automated systems often fail or have unintended consequences. This article will contribute to this critique of AI by attending to Nicholas of Cusa and his treatment of intelligence. According to him, intelligence is equally dependent on an ability to handle the unknown as it unfolds in the present moment. This suggests that intelligence is organic which ties Cusa to more contemporary discussions in tech philosophy, neurology, evolutionary biology, and cognitive sciences in which it is argued that intelligence is dependent on having—and acting through—an organic body. Understanding intelligence as organic thus suggests an oxymoronic relationship to artificial. (shrink)
New directions in predictive processing.Jakob Hohwy -2020 -Mind and Language 35 (2):209-223.detailsPredictive processing (PP) is now a prominent theoretical framework in the philosophy of mind and cognitive science. This review focuses on PP research with a relatively philosophical focus, taking stock of the framework and discussing new directions. The review contains an introduction that describes the full PP toolbox; an exploration of areas where PP has advanced understanding of perceptual and cognitive phenomena; a discussion of PP's impact on foundational issues in cognitive science; and a consideration of the philosophy of science (...) of PP. The overall picture is that PP is a fruitful framework, with exciting new directions awaiting exploration. (shrink)
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Decisive creatures and large continuum.Jakob Kellner &Saharon Shelah -2009 -Journal of Symbolic Logic 74 (1):73-104.detailsFor f, g $ \in \omega ^\omega $ let $c_{f,g}^\forall $ be the minimal number of uniform g-splitting trees (or: Slaloms) to cover the uniform f-splitting tree, i.e., for every branch v of the f-tree, one of the g-trees contains v. $c_{f,g}^\exists $ is the dual notion: For every branch v, one of the g-trees guesses v(m) infinitely often. It is consistent that $c_{f \in ,g \in }^\exists = c_{f \in ,g \in }^\forall = k_ \in $ for N₁ many (...) pairwise different cardinals $k_ \in $ and suitable pairs $(f_{ \in ,g \in } ).$ For the proof we use creatures with sufficient bigness and halving. We show that the lim-inf creature forcing satisfies fusion and pure decision. We introduce decisiveness and use it to construct a variant of the countable support iteration of such forcings, which still satisfies fusion and pure decision. (shrink)
Looping in on Ndc80 – How does a protein loop at the kinetochore control chromosome segregation?Jakob Nilsson -2012 -Bioessays 34 (12):1070-1077.detailsSegregation of chromosomes during mitosis requires the interaction of dynamic microtubules with the kinetochore, a large protein structure established on the centromere region of sister chromatids. The core microtubule‐binding activity of the kinetochore resides in the KMN network, an outer kinetochore complex. As part of the KMN network, the Ndc80 complex, which is composed of Ndc80, Nuf2, Spc24, and Spc25, is able to bind directly to microtubules and has the ability to track with depolymerizing microtubules to produce chromosome movement. The (...) Ndc80 complex binds directly to microtubules through a calponin homology domain and an unstructured tail in the N terminus of the Ndc80 protein. A recent flurry of papers has highlighted the importance of an internal loop region in Ndc80 in establishing end‐on attachment to microtubules. Here I discuss these recent findings that suggest that the Ndc80 internal loop functions as a binding site for proteins required for kinetochore‐microtubule interactions. (shrink)