This article argues that personal meaning should be considered important when addressing issues of learning. It is claimed that meaningful learning is not primarily intra-psychological, as suggested by humanistic psychologists and parts of cognitive psychology, but is an integrated part of the person’s participation in various social practices. Inspired by critical psychology and situated learning, it is suggested that in order to comprehend what people in everyday life experience as meaningful, we have to understand the concerns subjects pursue across different (...) contextual settings and the kind of conduct of everyday life they try to realise. A case example from an ongoing research project about how baker apprentices learn their trade is outlined in order to exemplify some of the theoretical considerations. Two baker apprentices, Peter and Charlotte, are presented to illustrate how they orientate their learning activities in the bakeries according to their future participation in the baking trade and in relation to the conduct of everyday life they wish to pursue. (shrink)

This article questions the concept of tacit knowledge as the basis for our conceptual understanding of practice. The first part of the article is a critical introduction to the concept of tacit knowledge. It is emphasized that this concept is situated in various academic practices and not defined and homogeneously but in accordance with issues and intentions significant for these practices. The second part of the article outlines some consequences of conceptualizing practice as basically a matter of tacit knowledge. It (...) is argued that tacit knowledge should be seen in relation to the growth of professions in modern society and to the need to legitimate them. It is further claimed that as a legitimating concept tacit knowledge may bring about various problems leading to a marginalization of specific experiences, to social uniformity, to the reappearance of individualism and to the maintenance of a dualistic view of knowledge. (shrink)

The current study examined the effects of cuing autobiographical memory retrieval in 12 older participants with dementia through immersion into a historically authentic environment that recreated the material and cultural context of the participants’ youth. Participants conversed in either an everyday setting or a museum setting furnished in early twentieth century style while being presented with condition matched cues. Conversations were coded for memory content based on an adapted version of Levine, Svoboda, Hay, Winocur, and Moscovitch coding scheme. More autobiographical (...) memories were recalled in the museum setting, and these memories were more elaborated, more spontaneous and included especially more internal details compared to memories in the control condition. The findings have theoretical and practical implications by showing that the memories retrieved in the museum setting were both quantitatively and qualitatively different from memories retrieved during a control condition. (shrink)

Der Band "Idealismus und Romantik in Jena" nimmt die Jenaer Blütezeit zwischen 1794 und 1807 in den Blick und interpretiert sie als ein Neben- und Gegeneinander der beiden einflussreichsten Geistesströmungen um 1800. In Jena entstehen zwischen 1794 und 1807 zwei geistesgeschichtliche Strömungen von Weltgeltung: der Idealismus und die Romantik. Die rasante Entwicklung immer neuer Ideen ist durch eine beträchtliche Anzahl junger, kreativer Geister geprägt, die in fruchtbarem Austausch und gegenseitiger Kritik um ein neues, angemessenes Verständnis der Moderne ringen. Im Fokus (...) des Bandes stehen Fragen zu einzelnen Autoren genauso wie zum Verhältnis beider Strömungen zueinander. The volume Idealism and Romanticism in Jena focuses on the period between 1794 and 1807 in which creative and original minds developed new ideas for understanding the modern world. The contributions examine the relationship between German Idealism and Early Romanticism: What distinguishes/combines Idealism and Romanticism? What common aspects, synergies and goals arise? And what does the opposition between the two movements means for the question of modernity? (shrink)

We explore the complexity of Sacks’ Splitting Theorem in terms of the mind change functions associated with the members of the splits. We prove that, for any c.e. set A, there are low computably enumerable sets $A_0\sqcup A_1=A$ splitting A with $A_0$ and $A_1$ both totally $\omega ^2$ -c.a. in terms of the Downey–Greenberg hierarchy, and this result cannot be improved to totally $\omega $ -c.a. as shown in [9]. We also show that if cone avoidance is added then there (...) is no level below $\varepsilon _0$ which can be used to characterize the complexity of $A_1$ and $A_2$. (shrink)

Describes the classicall law theory basics. Translaltion from German.

Hvorfor Rosenzweig og Lévinas? -- Rosenzweigs og Lévinas' kritik af Kierkegaard -- Det enkelte, ensomme, sprogløse selv : Rosenzweigs kritik af Kierkegaard -- Subjektivitetens rent egoistiske protest : Lévinas kritik af Kierkegaard -- Kierkegaard syn på religion og etik -- Den kærliges selvtilintetgørelse : analyse af Kierkegaards Kjerlighedens gjerninger -- Det sublime i det pedestre : analyse af de Silentios Frygt og bæven.

A partir de trois positions paradigmatiques du discours bioéthique, il est démontré dans quelle mesure ces positions sont dépendantes de leurs propres concepts porteurs. Ce faisant, aucun point de vue ne doit être exclu du discours bioéthique pour la seule raison qu’il implique un fondement métaphysique. En outre, au niveau philosophico-moral, chaque position doit être jugée d’abord de façon théoriquement immanente pour voir si elle développe ses critères de manière cohérente, à partir des concepts porteurs établis rationnellement. Puis, différents aspects (...) peuvent entrer en dialogue permettant l’apparition de potentielles unilatéralités. Ce n’est que dans un deuxième temps qu’il s’agit d’interpréter du point de vue juridico- éthique et d’entreprendre une correction philosophico-morale selon les critères éthiques si dans le cadre d’un examen juridico-éthique il n’est pas possible d’empêcher le danger de l’instrumentalisation de façon satisfaisante. Ensuite, la tâche consiste à traduire en langue publique les potentiels religieux de l’interprétation censés occulter les aspects laïques. Une éthique du droit devrait certainement refléter ses résultats grâce aux intuitions philosophico-morales pertinentes afin de pouvoir questionner l’approche orientée en priorité vers les intérêts. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:The Entanglement: How Art and Philosophy Make Us What We Are by Alva NoëFrederik M. Bjerregaard-NielsenNOË, Alva. The Entanglement: How Art and Philosophy Make Us What We Are. Princeton, N.J.: Princeton University Press, 2023. 288 pp. Cloth, $27.95In The Entanglement, Alva Noë sets forth a minimal yet meaningful definition of art and philosophy and asks how they make us what we are. Art and philosophy are the modes (...) of practice that disrupt and disorganize our habitual ways of doing things, everything from dancing to language, to philosophy and art themselves. They are the reflection at a distance of what we do. “In this sense, then, art is disruptive. Always: everywhere.” From this basis, he tackles a wide range of phenomena from dancing, seeing, writing, and so forth, to introduce a distinction between these as everyday phenomena and their function as art. This delimitation is not material, nor intrinsic to any of the analyzed phenomena; rather, it depends on each practice’s ability to disrupt, disorganize, and force upon us the question of what dancing, seeing, writing is at all. Noë provides an example: At an art exhibition one is confronted with a painting that is ungraspable, foreign, meaningless. But, through a mediation (pointers from a friend, new knowledge of the era, analyses of the style, and so forth) the painting starts becoming significant; it starts to make sense. The viewer is stopped in her tracks, and a painting that was before closed is now opened up to a new perception, a new way of seeing.But Noë extends this aesthetic domain to experience and perception. In perception, we are actively engaged in achieving the things around us, achieving the world. And, in art, this habitual way of attainment is obstructed, for art presents us with new ways of seeing, listening, feeling, and so forth. Noë thus challenges common (especially neuro-aesthetic) views on perception and experience in favor of a more phenomenological approach by which he accentuates the active engagement in the world by which perception and experience come about. And this aesthetic domain, broadly understood, is the locus of showing how we, through these disruptive practices, create new ways of doing, perceiving, understanding, and, even further, create ourselves. We “all operate in a space of significance held open by art.” In other words, it is through a reassessment of the aesthetic that Noë shows how art and philosophy make us what we are. For what we are, for Noë, is this ability of disruption, development, and creation of ourselves. This is what makes us human. Human nature is therefore essentially cultural, a disruption of habit and new avenues of development, but one that is rooted in our body as a horizon of possibilities. Even though he does not conclude on this phylogenetic question, Noë does seem to suggest that the species’s ability to generate art (exemplified by early cave paintings) and philosophy are foundational [End Page 724] to its development or, more strongly, necessary to it being what it is. He thus proposes an alternative to the traditional schism of the nature/nurture and natural/cultural debate, which takes this wide view of aesthetics as its central term.One might raise the question whether the text would have benefited from more thorough analyses of the thinkers who are at play, sometimes at the margin, sometimes at the foundation of the disruption Noë’s text attempts, notably: Merleau-Ponty, with his extensive analyses of habit and style and their place in our life engaging behavior; Derrida’s deconstruction of phonocentrism, which attacks written language’s subordination to the spoken and asks the fundamental question of the ontology of language as such; or perhaps most present by its absence, Nietzsche’s grandiose thought of the human being and life itself as an aesthetic phenomenon. For Nietzsche thereby incorporated both ontology and critique in the sphere of aesthetics in his revaluation of all values. This, quite like Noë, allowed Nietzsche to set forth the human being as a creature of its own creation. These authors are given brief treatments, relegated to footnotes, or left out entirely.But such a critique might be too... (shrink)

Die besonderen Bedingungen der griechischen Sprache und ihrer langen Geschichte seit den Zeiten Homers haben schon seit der klassischen Epoche und zunehmend im Hellenismus und der Kaiserzeit Probleme der korrekten Akzentuierung und Orthographie aufgeworfen. Zumal die gelehrten hellenistischen und kaiserzeitlichen Editoren und Interpreten der homerischen Gedichte und anderer frühgriechischer und klassischer Poesie mußten zu unzähligen strittigen Fragen des Akzents und der richtigen Schreibung Stellung beziehen. Im 2. Jahrhundert n. Chr. hat der aus Alexandreia gebürtige, in Rom tätige Grammatiker Ailios Herodianos (...) über beide Bereiche umfassende Bücher verfaßt. Auf Aufforderung Kaiser Mark Aurels (und diesem gewidmet) schrieb er sein gewaltiges Hauptwerk in 21 Büchern, die Καθολιϰη πϱοσωδία („Allgemeine Akzentlehre“) und ebenfalls ein umfangreiches Buch Πεϱι οϱθογϱαϕίας. Beide sind wie alle seine anderen Werke bis auf die Schrift Πεϱι μονήϱους λέξεως verloren. Mit geradezu herodianischem Fleiß hat A. Lentz eine Rekonstruktion des Verlorenen unternommen. Man muß leider sagen, daß die Zeit für eine solche Rekonstruktion noch nicht reif war; einerseits mußte Lentz für fast alle Quellschriften auf Editionen zurückgreifen, die auf völlig unzureichender handschriftlicher Basis erstellt waren, andererseits konnte er noch nicht die spektakulären Handschriftenfunde R. Reitzensteins und die daraus resultierenden umstürzenden Ergebnis zur Kenntnis nehmen. „Es liegt eine Tragik darin, daß ein unter den größten Schwierigkeiten geleistetes Lebenswerk durch die Fahrlässigkeit der Herausgeber, deren Leistungen Lentz zugrunde legen mußte, von vornherein auf ungenügendem Fundament ruhte.“ Sowohl für den Bereich der Akzentlehre („Orthoepik“) wie den der Orthographie der Spätantike und der byzantinischen Zeit hat Peter Egenolff in zwei bahnbrechenden Schulprogrammen einen Überblick über die unzähligen Traktate in der Nachfolge Herodians und die sie tradierenden Handschriften geliefert. Egenolffs Arbeiten sind naturgemäß stark veraltet, da zahlreiche Handschriften erst nach ihm bekannt wurden und sehr viele neue Erkenntnisse auf dem Gebiet der griechischen Grammatik und Lexikographie seither erzielt worden sind. Aber Egenolffs Sammlungen und Überblicke sind bisher nicht überholt worden und werden auch für das Gebiet der Orthographien durch das hier zu behandelnde Werk leider nicht wirklich ersetzt. (shrink)

In this paper which consists of two parts (Teil I and Teil II) we champion Diophantus of Alexandria and Isabella BaÅ¡makova against Norbert Schappacher. In two publications ([Schappacher 1998a] and [Schappacher 1998b]) he puts forward inter alia two propositions: Questioning Diophantus’ originality he considers affirmatively the possibility that the Arithmetica are the joint work of a team of authors like Bourbaki. And he calls BaÅ¡makova’s claim (in [BaÅ¡makova 1972]) that Diophantus uses negative numbers, a nonsense , reproaching her for her (...) thoughtlessness . Teil I: First, we disprove Schappacher’s Bourbaki thesis. Second, we investigate the semantic meaning and historical significance of Diophantus’ keywords $ λvarepsilon tildeιψιζ and ὕπαρξιζ. Next, we discuss Schappacher’s epistemology of the history of mathematics and defend BaÅ¡makova’s methods. Finally we analyse in detail three problems from Diophantus’ Arithmetica (and their solutions) given by Thomas Heath and Helmuth Gericke as proof of the their claim that Diophantus did not use negative numbers. Teil II: In this Part, we give 33 places where Diophantus uses negative quantities as intermediate results; they appear as differences a − b of positive rational numbers, the subtrahend b being bigger than the minuend a; they each represent the (negative) basis ( πλvarepsilonυρacuteα ) of a square number ( τvarepsilonτρacuteαγω ν o ζ ), which is afterwards computed by the formula (a - b) 2 = a 2 + b 2 - 2ab $ . Finally, we report how the topic Diophantus and the negative numbers has been dealt with by translators and commentators from Maximus Planudes onwards. Und er kommt zu dem Ergebnis: ≪Nur ein Traum war das Erlebnis. Weil≫, so schlieβt er messerscharf, ≪nicht sein k a n n, was nicht sein d a r f.≫ CHRISTIAN MORGENSTERN: Palmstrm. (shrink)

La science cognitive moderne ne peut être comprise sans les progrès récents en informatique, intelligence artificielle, robotique, neuroscience, biologie, linguistique et psychologie. La philosophie analytique classique et l’intelligence artificielle traditionnelle présumaient que toutes les sortes de savoir devaient être représentées explicitement par des langages formels ou programmatiques. Cette thèse est en contradiction avec les découvertes récentes en biologie de l’évolution et en psychologie évolutive de l’organisme humain. La majeure partie de notre savoir est implicite et inconsciente. Elle n’est pas représentée (...) formellement, mais constitue un savoir incarné, qui s’acquiert par l’action et se comprend en interaction corporelle avec nos niches écologiques et nos environnements sociaux. Cela n’est pas seulement vrai pour nos aptitudes élémentaires, mais aussi pour nos facultés supérieures de catégorisation, de langage et de pensée abstraite. Science cognitive incarnée, l’intelligence artificielle, ainsi que la robotique, tentent de construire un intellect incarné en évolution artificielle. Du point de vue philosophique, il est admirable de voir à quel point les nouvelles idées d’intellect incarné et de robotique sont ancrées dans la philosophie du XXe siècle. (shrink)

I argue that O'Regan & Noë's (O&N's) theory is in a no better position than any other theory to solve the “hard problem” of consciousness. Getting rid of the explanatory gap by exchanging sensorimotor contingencies for neural representations is an illusion.

Nous étudions l’apparition des monstres en mathématiques (comme, par exemple, le monstre dit de Weierstrass — une fonction continue qui n’est différentiable en aucun point) au XIXe siècle. Nous traitons aussi la question : comment peut-on distinguer les mathématiques normales (ou naturelles) des mathématiques pathologiques?

Nous étudions l’apparition des monstres en mathématiques (comme, par exemple, le monstre dit de Weierstrass — une fonction continue qui n’est différentiable en aucun point) au XIXe siècle. Nous traitons aussi la question : comment peut-on distinguer les mathématiques normales (ou naturelles) des mathématiques pathologiques?

On the 4th of December 1967, Hans Kamp sent his UCLA seminar notes on the logic of ‘now’ to Arthur N. Prior. Kamp’s two-dimensional analysis stimulated Prior to an intense burst of creativity in which he sought to integrate Kamp’s work into tense logic using a one-dimensional approach. Prior’s search led him through the work of Castañeda, and back to his own work on hybrid logic: the first made temporal reference philosophically respectable, the second made it technically feasible in a (...) modal framework. With the aid of hybrid logic, Prior built a bridge from a two-dimensional UT calculus to a one-dimensional tense logic containing the ‘now’ operator J. Drawing on material from the Prior archive, and the paper “‘Now”’ that detailed Prior’s findings, we retell this story. We focus on Prior’s completeness conjecture for the hybrid system and the role played by temporal reference. (shrink)

This book focuses on the gradual formation of the concept of ‘light quanta’ or ‘photons’, as they have usually been called in English since 1926. The great number of synonyms that have been used by physicists to denote this concept indicates that there are many different mental models of what ‘light quanta’ are: simply finite, ‘quantized packages of energy’ or ‘bullets of light’? ‘Atoms of light’ or ‘molecules of light’? ‘Light corpuscles’ or ‘quantized waves’? Singularities of the field or spatially (...) extended structures able to interfere? ‘Photons’ in G.N. Lewis’s sense, or as defined by QED, i.e. virtual exchange particles transmitting the electromagnetic force? The term ‘light quantum’ made its first appearance in Albert Einstein’s 1905 paper on a “heuristic point of view” to cope with the photoelectric effect and other forms of interaction of light and matter, but the mental model associated with it has a rich history both before and after 1905. Some of its semantic layers go as far back as Newton and Kepler, some are only fully expressed several decades later, while others initially increased in importance then diminished and finally vanished. In conjunction with these various terms, several mental models of light quanta were developed—six of them are explored more closely in this book. It discusses two historiographic approaches to the problem of concept formation: the author’s own model of conceptual development as a series of semantic accretions and Mark Turner’s model of ‘conceptual blending’. Both of these models are shown to be useful and should be explored further. This is the first historiographically sophisticated history of the fully fledged concept and all of its twelve semantic layers. It systematically combines the history of science with the history of terms and a philosophically inspired history of ideas in conjunction with insights from cognitive science. (shrink)

A real number x is computable iff it is the limit of an effectively converging computable sequence of rational numbers, and x is left computable iff it is the supremum of a computable sequence of rational numbers. By applying the operations “sup” and “inf” alternately n times to computable sequences of rational numbers we introduce a non-collapsing hierarchy {Σn, Πn, Δn : n ∈ ℕ} of real numbers. We characterize the classes Σ2, Π2 and Δ2 in various ways and give (...) several interesting examples. (shrink)

A fragment with the same provably recursive functions as n iterated inductive definitions is obtained by restricting second order arithmetic in the following way. The underlying language allows only up to n + 1 nested second order quantifications and those are in such a way, that no second order variable occurs free in the scope of another second order quantifier. The amount of induction on arithmetical formulae only affects the arithmetical consequences of these theories, whereas adding induction for arbitrary formulae (...) increases the strength by one inductive definition. (shrink)

En la crítica platónica al relativismo de Protágoras en el Teeteto se pueden distinguir dos ámbitos: el plano del aparecer conforme a la percepción y el plano del aparecer que dirige la acción. Held reconstruye los argumentos de dicha crítica, al tiempo que intenta mostrar cómo Platón proyecta superar ambas formas de relativismo, descubriendo que la base de la crítica es el pensamiento de las Ideas. En contraste, Held sugiere dos perspectivas distintas desde las cuales podría intentar superarse la tesis (...) de Protágoras: Heráclito y Aristóteles. Finalmente, se llama la atención sobre el camino que deja abierto el diálogo respecto al vínculo existente entre filosofia práctica y teórica, pues ambas tienen como raíz común el aparecer. (shrink)

Reconstruimos la teoría central de las redes bayesianas n-dimensionales de forma clara y completa en el marco estructuralista. Nuestra formulación también incluye los n espacios de probabilidad unidimensionales y un espacio de probabilidad n-dimensional. Explicamos los sistemas previstos y la afirmación empírica de la teoría de las redes bayesianas n-dimensionales. En nuestra formulación, se destaca el concepto de dimensión, y discutimos si los eventos o las oraciones (enunciados, proposiciones) podrían usarse como bloques de construcción básicos.

Simulation studies in the context of Robert Axelrod’s research on iterative prisoner’s dilemma games focus nearly exclusively on the two-player- version of the game. In contrast, this article reports results of a simulation with an iterated N-prisoners’ dilemma where group size N varies between 2 and 30. The simulation investigates the relative performance of conditional cooperative strategies with increasing group size. Results show that some ‘nice’ strategies like ‘tit-for-tat’ are relatively successful and robust even in larger groups and non-nice environments. (...) However, this does not solve the cooperation problem. On the contrary, the relative success of some ‘nice’ conditional cooperative strategies is paralleled by a rapid decline of cooperation in large groups. (shrink)

La puerta de entrada a la fenomenología es, según su fundador, Edmund Husserl, la "epojé", la suspensión de todas las proposiciones con las que se afirma ser a un evento en el mundo. Esta actitud es la que se presupone para abstenerse de prejuicios como lo procuran la filosofía y la ciencia desde sus inicios. Cuando se introdujo la actitud de la epojé en la época del helenismo por los escépticos y estoicos, ésta se basaba a su vez en un (...) prejuicio no controlado: en asumir que entre el ser de los sucesos y su aparecer al hombre hay un abismo que debe ser superado gracias a decisiones de la voluntad. De este voluntarismo se desarrolló más tarde el subjetivismo moderno, cuyas consecuencias ecológicas y políticas preocupan hoy en día a toda la humanidad. El pensamiento griego antes del helenismo se basaba en la equiparación de ser y aparecer sin que interviniera para nada la voluntad. Pero también esto era un prejuicio sin controlar. La nueva forma de epojé de la "fenomenología" ("doctrina del aparecer'') es la suspensión de ambos prejuicios acerca de la relación de ser y aparecer. Aparecer significa fenomenológicamente: manifestarse en el contexto de sentido de horizontes, de "mundos". Todos los mundos sean los horizontes de hombres singulares o de culturas globales pertenecen a un singular específico, el mundo en cuanto tal, lo que llamamos "el mundo-uno". El mundo-uno como horizonte universal es la dimensión del aparecer. Pero como se hizo claro en la continuación de la fenomenología por Martín Heidegger, la esencia del mundo no consiste en su carácter de horizonte. La fenomenología como apertura del camino de una filosofía después del subjetivismo tiene la tarea histórica de clarificar en qué sentido el mundo-uno es "más" que horizonte y qué significa esto para los muchos mundos. Sólo con esto se aclara la relación de ser y aparecer y el significado futuro de la voluntad para la posición del hombre en el mundo. (shrink)

This paper initiates the study of sets in Euclidean spaces ℝn that are defined in terms of the dimensions of their elements. Specifically, given an interval I ⊆ [0, n ], we are interested in the connectivity properties of the set DIMI, consisting of all points in ℝn whose dimensions lie in I, and of its dual DIMIstr, consisting of all points whose strong dimensions lie in I. If I is [0, 1) or.

La recherche d’une définition de la raison droite ( orthos logos ) au livre VI de l’ Éthique à Nicomaque d’Aristote n’est pas une recherche des “raisons droites” ou du “raisonnement droit” que produit l’expert – il ne tente pas de caractériser (et moins encore de “définir”) le type de justification ou de délibération qu’un médecin ou un phronimos produisent avant de choisir la bonne façon de procéder. A fortiori, il ne recherche pas des règles de conduite. Il recherche plutôt (...) les propriétés qui caractérisent l’âme d’une personne qui est capable de raisonner correctement: la “raison droite” comprise comme perfection de la partie rationnelle de l’âme. Dans cet article, j’examine la description aristotélicienne de la phronēsis, la vertu de la pensée ( dianoētikē aretē ) qui a rapport à l’action, et l’ euboulia, en tant qu’elle en est l’excellence caractéristique. (shrink)

Pericytes, like vascular smooth muscle cells, are perivascular cells closely associated with blood vessels throughout the body. Pericytes are necessary for vascular development and homeostasis, with particularly critical roles in the brain, where they are involved in regulating cerebral blood flow and establishing the blood-brain barrier. A role for pericytes during neurovascular disease pathogenesis is less clear—while some studies associate decreased pericyte coverage with select neurovascular diseases, others suggest increased pericyte infiltration in response to hypoxia or traumatic brain injury. Here, (...) we used an endothelial loss-of-function Recombination signal binding protein for immunoglobulin kappa J region (Rbpj)/Notch mediated mouse model of brain arteriovenous malformation (AVM) to investigate effects on pericytes during neurovascular disease pathogenesis. We tested the hypothesis that pericyte expansion, via morphological changes, and Platelet-derived growth factor B/Platelet-derived growth factor receptor β (Pdgf-B/Pdgfrβ)-dependent endothelial cell-pericyte communication are affected, during the pathogenesis of Rbpj mediated brain AVM in mice. Our data show that pericyte coverage of vascular endothelium expanded pathologically, to maintain coverage of vascular abnormalities in brain and retina, following endothelial deletion of Rbpj. In Rbpj-mutant brain, pericyte expansion was likely attributed to cytoplasmic process extension and not to increased pericyte proliferation. Despite expanding overall area of vessel coverage, pericytes from Rbpj-mutant brains showed decreased expression of Pdgfrβ, Neural (N)-cadherin, and cluster of differentiation (CD)146, as compared to controls, which likely affected Pdgf-B/Pdgfrβ-dependent communication and appositional associations between endothelial cells and pericytes in Rbpj-mutant brain microvessels. By contrast, and perhaps by compensatory mechanism, endothelial cells showed increased expression of N-cadherin. Our data identify cellular and molecular effects on brain pericytes, following endothelial deletion of Rbpj, and suggest pericytes as potential therapeutic targets for Rbpj/Notch related brain AVM. (shrink)

AimRapid eye movement (REM) sleep, non-rapid eye movement (NREM) sleep, and sleep spindles are all implicated in the consolidation of procedural memories. Relative contributions of sleep stages and sleep spindles were previously shown to depend on individual differences in task processing. However, no studies to our knowledge have focused on individual differences in experience with Vipassana meditation as related to sleep. Vipassana meditation is a form of mental training that enhances proprioceptive and somatic awareness and alters attentional style. The goal (...) of this study was to examine a potential role for Vipassana meditation experience in sleep-dependent procedural memory consolidation.MethodsGroups of Vipassana meditation practitioners (N = 22) and matched meditation-naïve controls (N = 20) slept for a daytime nap in the laboratory. Before and after the nap they completed a procedural task on the Wii Fit balance platform.ResultsMeditators performed slightly better on the task before the nap, but the two groups improved similarly after sleep. The groups showed different patterns of sleep-dependent procedural memory consolidation: in meditators, task learning was positively correlated with density of slow occipital spindles, while in controls task improvement was positively associated with time in REM sleep. Sleep efficiency and sleep architecture did not differ between groups. Meditation practitioners, however, had a lower density of occipital slow sleep spindles tha... (shrink)