Since its development about 15 years ago, functional magnetic resonance imaging (fMRI) has become the leading research tool for mapping brain activity. The technique works by detecting the levels of oxygen in the blood, point by point, throughout the brain. In other words, it relies on a surrogate signal, resulting from changes in oxygenation, blood volume and flow, and does not directly measure neural activity. Although a relationship between changes in brain activity and blood flow has long been speculated, indirectly (...) examined and suggested and surely anticipated and expected, the neural basis of the fMRI signal was only recently demonstrated directly in experiments using combined imaging and intracortical recordings. In the present paper, we discuss the results obtained from such combined experiments. We also discuss our current knowledge of the extracellularly measured signals of the neural processes that they represent and of the structural and functional neurovascular coupling, which links such processes with the hemodynamic changes that offer the surrogate signal that we use to map brain activity. We conclude by considering applications of invasive MRI, including injections of paramagnetic tracers for the study of connectivity in the living animal and simultaneous imaging and electrical microstimulation. D 2004 Elsevier Inc. All rights reserved. (shrink)

In this project, a spiral fast imaging sequence was implemented on a Bruker Avance MR system. Acquisition and processing schemes were developed to measure the experimental k-space trajectories. Since errors in k-space are reflected as errors in the corresponding image, we used different strategies to measure and calculate corrections for deviation of the experimental k-space trajectory from the theoretical one. Even if the k-space trajectories deviate from the theoretical ones, an experimentally measured trajectory can be incorporated in the spiral reconstruction (...) and a reduction of image artifacts can be obtained. (shrink)

Calcium plays an important role in regulating a great variety of neuronal processes, and many efforts are made to generate gadolinium complexes that can act as calcium-dependent MRI contrast agents. A series of gadolinium chelate complexes based on DO3A were developed, bearing phosphonate groups as an additional coordination sites, which is hypothesized to change relaxivity in magnetic resonance experiments dynamically with Ca2+ concentration. Different lengths of the phosphonate side chains are expected to lead to different binding constants of the phosphonate (...) - gadolinium bonds. The latter property can be exploited for fine-tuning the sensitivity of the agent to calcium ion concentration. (shrink)

The ability of non-invasively observing changes in the Ca2+ concentrations is important in the understanding of a great variety of neuronal processes. Several compounds were designed (Fig.1) to take advantage of the different binding abilities of carboxylates and phosphonates to gadolinium. Furthermore the different affinities of the two functional groups to Ca2+ permit to obtain free coordination sites at gadolinium. The generation of these coordination sites, which are mandatory for water relaxivity, depends on the structure of the complexes and the (...) Ca2+ concentration. Gadolinium complexes 1 and 2 were synthesized and relaxivity studies were performed. (shrink)

Functionally distinct anatomic subdivisions of the brain can often be only a few millimeters in one or more dimensions. The study of metabolic differences in such structures by means of localized in vivo MR spectroscopy is therefore challenging, if not impossible. In fact, the spatial resolution of chemical shift imaging (CSI) in humans is typically in the range of centimeters. The aim of the present study was to optimize 1H CSI in monkeys and demonstrate the feasibility of high spatial resolutions (...) up to 1.4 ؋ 2 ؋ 1.4 mm3. The obtained spatial resolution permitted the segregation of gray and white matter in the visual cortex based on the concentration of different metabolites and neurotrans- mitters like N-acetylaspartate, glutamate, and creatine. Con- centration ratios of white matter versus gray matter tissue as well as between metabolites matched those reported in the literature from healthy human brain, demonstrating the consis- tency and reliability of the procedure. Magn Reson Med 54: 1541–1546, 2005. © 2005 Wiley-Liss, Inc. Key words: in vivo 1H NMR spectroscopy; spectroscopic imag- ing; chemical shift imaging; spatial resolution; monkey visual cortex.. (shrink)

‘Smart’ contrast agents (CA) exhibit dynamic and reversible modulation of their relaxivity by specific physiological or biochemical triggers such as changes in pH, Ca2+ concentration or enzymatic activity (1-3). The extracellular concentration of Ca2+ plays important role in physiological and pathological processes in the nervous system. This led to the designing of a chelating system in which relaxivity is influenced as a function of Ca2+ concentration by changing coordination number around the paramagnetic metal ion. We synthesized a novel bifunctional bismacrocycle (...) [Gd-(DO3A-DTPA- DO3A); Fig.] based on DO3A-EA [{4,7-Bis-carboxymethyl-10-(2-aminoethyl)-1,4,7,10-tetraazacyclododec-1-yl}-acetic acid] coupled to DTPA-bis-anhydride via a flexible alkyl spacer to form the.. (shrink)

Smart MR contrast agents exhibit modulation of their relaxivity by specific physiological or biochemical trigger-events, while targeted MR contrast agents are envisioned to deliver the large gadolinium chelates into the target tissue. In an effort to develop novel smart and targeted MR contrast agents, the series of the DO3A based multifunctional chelating agents with the variable length of the side chain has been synthesized. They serve as valuable multipurpose precursors for contrast agents based on gadolinium chelates in the design of (...) relaxometric MR probes. The presence of the amino group in the side chain of the macrocycle allows for conversion into various functional groups (aminophosponates, aminocarboxylates, etc.) or for conjugation with different biomolecules, dyes, and polymers. Choice of the functional groups depends on the.. (shrink)

1. Matter and form -- 2. Maimonides' theory of the parable -- 3. The parable of adamic perfection -- 4. Physical matter and its limitations on intellects -- 5. Maimonidean skepticism I -- 6. Maimonidean skepticism II -- 7. In the inner chamber of the ruler's palace: the critique of the theory of separate intellects -- 8. The embodied life of an intellect -- 9. Excrement and exegesis, or shame over matter.

An eminent part of Wittgenstein's work is his bequest.The present volume launches a discussion aboutthe significance of the so-called Kringel-Buch, as well as about the constitution of the text, and about Wittgenstein's cultural and moral philosophy.

Today, most liberal states are torn between attempts to accommodate different religions within floating limits of tolerance, and at the same time trying to uphold a sense of national identity. The traditionally liberal way to negotiate this dilemma has, put bluntly, been to address religion as a generic category, relegate it to the private sphere, and to make religion an object of tolerance. This idea of a strict separation between religion and the secular rests on an Enlightenment notion of a (...) secular reason disembodied from tradition. Against such an understanding post-secular philosophers have sought to make tacit assumptions about the nature of reality explicit, and consequently, to make metaphysics relevant. This book explores the metaphysical assumptions that underlie different interpretations of the relationship between religion and the secular, faith and reason, and transcendence and immanence. Questioning the notion of secular reason as a neutral and ultimate adjudicator of religious difference, different answers to how people of diverse religious and cultural identities can live together peacefully are explored. (shrink)

The proposal of a semantics for quotations using explanatory notions drawn from philosophical theories of pictures. In Quotations as Pictures, Josef Stern develops a semantics for quotations using explanatory notions drawn from philosophical theories of pictures. He offers the first sustained analysis of the practice of quotation proper, as opposed to mentioning. Unlike other accounts that treat quotation as mentioning, Quotations as Pictures argues that the two practices have independent histories, that they behave differently semantically, that the inverted commas (...) employed in both mentioning and quotation are homonymous, that so-called mixed quotation is nothing but subsentential quotation, and that the major problem of quotation is to explain its dual reference or meaning—its ordinary meaning and its metalinguistic reference to the quoted phrase attributed to the quoted subject. Stern argues that the key to understanding quotation is the idea that quotations are pictures or have a pictorial character. As a phenomenon where linguistic competence meets a nonlinguistic symbolic ability, the pictorial, quotation is a combination of features drawn from the two different symbol systems of language and pictures, which explains the exceptional and sometimes idiosyncratic data about quotation. In light of this analysis of verbal quotation, in the last chapters Stern analyzes scare quotation as a nonliteral expressive use of the inverted commas and explores the possibility of quotation in pictures themselves. (shrink)

Hegel, the western and classical modernity. The myth and the frontier ; The hero in the epochs of mythical and the bourgeois ; The end of the individual ; The end of the subject -- Romanticism, crime and agonal modernity. The return of tragedy in modernity ; Heroes of coolness and the ironist -- Nietzsche, science fiction and hybrid modernity. Heroic individualismus and metaphysics ; Superhumans, supermen, cyborgs ; Heroes of the future.

Das Buch stellt Nietzsches und Levinas' Destruktionen des griechisch-europäauml;ischen Denkens und der in ihm eingeschlossenen Moral einander gegenüuuml;ber. Dabei werden Anlässe ihrer Kritik und ihre Ausnahmestellung im philosophischen Diskurs herausgearbeitet. Im Anschluss werden Nietzsches und Levinas' Alternativen zu den allgemeinen moralischen Werten verglichen und ihre Vereinbarkeit und Unvereinbarkeit geklärt. Beide Alternativen führen auf eine prinzipiell unbegrenzte Verantwortung des Einzelnen hinaus, die mit Textbeispielen Dostojewskijs unterlegt wird.

Name der Zeitschrift: Nietzsche-Studien Jahrgang: 43 Heft: 1 Seiten: 250-259.

The book represents a historical overview of the way the topic of gesture and sign language has been treated in the 18th century French philosophy. The texts treated are grouped into several categories based on the view they present of deafness and gesture. While some of those texts obviously view deafness and sign language in negative terms, i.e. as deficiency, others present deafness essentially as difference, i.e. as a set of competences that might provide some insights into how spoken language (...) works. One of the arguments of the book is that these two views of deafness and sign language still represent two dominant paradigms present in the current debates on the issue. The aim of the book, therefore, is not only to provide a historical overview but to trace what might be called a "history of the present". (shrink)

What Does "Academic" Mean? focuses, in two essays, on the prospects of contemporary universities. The term "academic" is traced back to Plato's Academy in a grove in Athens. The Academy is isolated, far away from the hustle and bustle of the city. Western universities founded in the Middle Ages show continuity, via Byzantium, with Plato's Academy. Not surprisingly, the Oxford Dictionary quoted by Pieper defines "academic" as "Not leading to a decision; unpractical." The preoccupation of the academic as academic is (...) seen by Pieper to be fundamentally theoretical, not practical. Pure theory is that which cannot at all be pressed into service. Clearly, many university disciplines that are richly funded by industry and business concerns tend to be favored by university administrations, which, intent on financial survival, frown on "unproductive" disciplines such as pure philosophy: metaphysics being a case in point, since it is the discipline least capable of practical application. (shrink)

Das religiose Sinnangebot einer letzten Verankerung in Gott, in einem Leben nach dem Tod, scheint heutzutage gegenuber der Faszination des Diesseits, dem Leben im Hier und Jetzt zu verblassen. Das Buch ergrundet diese geistige Atmosphare unserer Gegenwart und tritt dazu in einen Dialog mit den Denkern Yuval Noah Harari ('Homo Deus') und Hartmut Rosa ('Resonanz'), deren Utopien ein groaes Echo gefunden haben. Der Autor zeigt, wie der Glaube dabei eine neue Sprache finden kann: als Einladung an die menschliche Sehnsucht nach (...) tiefer Vitalitat, Lebensfreude und Lebenszugewandtheit, sich selbst auch in den Grenzerfahrungen von Scheitern, Krankheit und Tod zu vertrauen. (shrink)

The Christian idea of man -- The idea of man in general -- The Christian idea of man and St. Thomas Aquinas's theory of virtues -- The true concept of virtue and the hierarchy of virtues -- Prudence -- Justice -- Courage and fear of the Lord -- Discipline and moderation -- Faith, hope, and love -- The distinction between a natural and supernatural ethos.

Pieper distinguishes between Platonic stones in which Plato crystallizes mythical fragments from the mere stories which contain them, and Platonic myths, in which he purifies the proper mythical elements, freeing them of the non-mythical elements which tend to obscure them.

A model of writing in cognitive development, Understanding the Representational Mind synthesizes the burgeoning literature on the child’s theory of mind to provide an integrated account of children’s understanding of representational and mental processes, which is crucial in their acquisition of our commonsense psychology. Perner describes experimental work on children’s acquisition of a theory of mind and representation, offers a theoretical account of this acquisition, and gives examples of how the increased sophistication in children’s theory of mind improves their understanding (...) of social interaction and how, in the case of autistic children, an impairment results in social ineptitude. He analyzes the concepts of representation and metarepresentation as they appear in current discussion in the philosophy of cognitive science and explains how the unfolding of mental representation enables infants to comprehend change over time, engage in pretence, and use representational systems like pictures and language. Perner goes on to show that around age four children become able to understand the representational nature of pictures and language and to distinguish appearance from reality. Introducing basic distinctions in philosophy of mind for characterizing the mental, Perner discusses differences in how commonsense and cognitive psychology view the mind. Tracing the onset of a commonsense psychology in the social and emotional awareness of early infancy, he reveals how the child begins to take a cognitive, representational view of the mind with repercussions for children’s episodic memory, self control, and their ability to engage in deception. Perner concludes by describing the observed developmental changes as a case of theory change And contrasts his thesis with competing proposals. Josef Perner is Lecturer in Experimental Psychology at Sussex University, Brighton, England. (shrink)

Name der Zeitschrift: Nietzscheforschung Jahrgang: 23 Heft: 1 Seiten: 325-327.