Movement of leukocytes from peripheral blood into tissues, also called leukocyte extravasation, is absolutely essential for immunity in higher organisms. Over the past decade, our understanding of the molecular mechanisms involved in white blood cell extravasation during both normal immune surveillance and the generation of protective immune responses has taken a great leap forward with the discovery of the chemokine gene superfamily. Chemokines are low-molecular-weight cytokines whose major collective biological activity appears to be that of chemotaxis of both specific and (...) overlapping subsets of leukocytes. They are therefore likely to play a critical role in the directed movement of leukocytes from the bloodstream into tissue. These molecules are almost exclusively secreted and act as extracellular messengers for the immune system. However, emerging data also show that various members of the chemokine gene superfamily exert other biological effects outside the immune system. All nucleated cells and all tissues examined to date are capable of expressing at least some chemokines, and it seems likely therefore that by the time all the chemokines are identified, and all their biological functions elucidated, we will find that, as a family, these molecules perform an extracellular messenger role in all tissues and systems of the body. BioEssays 1999;21:17–28. © 1999 John Wiley & Sons, Inc. (shrink)

Cell signalling mediators derived from membrane phospholipids are frequent participants in biological processes. The family of phosphoinositide 3-kinases (PI3Ks) phosphorylate the membrane lipid phosphatidylinositol, generating second messengers that direct diverse responses. These PI3K products are fundamental for leukocyte migration or chemotaxis, a pivotal event during the immune response. This system is therefore of significant biomedical interest. This review focuses on the biochemistry and signalling pathways of PI3K, with particular emphasis on chemokine (chemotactic cytokine)-directed responses. The key objectives of chemotaxis are (...) motility and direction. The latter—direction—requires distinct events at the front and back of a cell. In light of this, the coordinated localisation of signalling factors, an event choreographed by a sharp intracellular gradient of PI3K-derived products, is a common theme. BioEssays 27:153–163, 2005. © 2005 Wiley Periodicals, Inc. (shrink)

It is well known that microbial pathogens are able to subvert the host immune system in order to increase microbial replication and propagation. Recent research indicates that another arm of the immune response, that of the chemokine system, is also subject to this sabotage, and is undermined by a range of microbial pathogens, including viruses, bacteria, and parasites. Currently, it is known that the chemokine system is being challenged by a number of mechanisms, and still more are likely to be (...) discovered with further research. Here we first review the general mechanisms by which microbial pathogens bypass mammalian chemokine defences. Broadly, these can be grouped as viral chemokine interacting proteins, microbial manipulation of host chemokine and chemokine receptor expression, microbial blockade of host chemokine receptor signalling, and the largely hypothetical mechanisms of microbial enhancement of host anti‐chemokine networks (including digestion, antagonism, and neutralisation of host chemokines and chemokine receptors). We then discuss the potential results of these interactions in terms of outcome of infection. BioEssays 25:478–488, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

Music Criticism in Vienna records a culture in which musical criticism had achieved the status of a minor art form. The period covered - October 1896 to December 1897 - was an eventful time in Vienna. Bruckner died, then Brahms; Mahler arrived; premieres of works by Czech composers coincidedwith increasing tension in the Empire between Czechs and Germans; Puccini's La Boheme reached Vienna on its sensational progress around the world; and the great programme music debate continued. These events and issues (...) were recorded and debated by some two dozen critics ranging from Eduard Hanslick,widely credited with (and blamed for) raising music criticism to an art, to Heinrich Schenker. The focus of Sandra McColl's monograph is unashamedly on the critics themselves, and her reconstruction of the climate of debate about whatever music or musicians came to their notice. She illuminates theintellectual climate in which the music was created, performed and received, and provides a foundation for the study of musical criticism in the post-Hanslick generation. (shrink)

Directed cell migration is a fundamental component of numerous biological systems and is critical to the pathology of many diseases. Although the importance of secreted chemoattractant factors in providing navigational cues to migrating cells bearing specific chemoattractant receptors is now well‐established, how the function of these factors is regulated is not so well understood and may be of key importance to the design of new therapeutics for numerous human diseases. While regulation of migration clearly takes place on a number of (...) different levels, it is becoming clear that so‐called ‘atypical’ receptors play a role in scavenging, or altering the localisation of, chemoattractant molecules such as chemokines and complement components. These receptors do this through binding and/or internalising their chemoattractant ligands without activating signal transduction cascades leading to cell migration. The atypical chemokine receptor family currently comprises the receptors D6, DARC and CCX‐CKR. In this review, we discuss the evidence from in vitro and in vivo studies that these receptors play a role in regulating cell migration, and speculate that other orphan receptors may also belong to this family. Furthermore, with the advent of gene therapy on the horizon, the therapeutic potential of these receptors in human disease is also considered. BioEssays 29: 237–247, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

In 1952, Quine showed that the problem of reducing a propositional formula to a simplest normal equivalent can be solved in two steps, viz., (i) express the given formula, Φ, equivalently as the disjunction of all its prime implicants, and (ii) find all non-redundant disjunctions of the latter that are equivalent to Φ (Quine 1952). However, it seems not generally known that an ingenious form of the same two-step process was published by Hugh McColl in 1878.

Title: Move Your ShadowPublisher: PenguinISBN: 0140093265Author: Joseph LelyveldTitle: Crossing the LinePublisher: PerseaISBN: 0892553251Author: William FinneganTitle: South Africa Without ApartheidPublisher: University of California PressISBN: 0520057708Author: Heribert Adam and Kogila Moodley.

Chemokines (chemotactic cytokines) drive and direct leukocyte traffic. New evidence suggests that the unusual CCR6/CCL20 chemokine receptor/ligand axis provides key homing signals for recently identified cells of the adaptive immune system, recruiting both pro‐inflammatory and suppressive T cell subsets. Thus CCR6 and CCL20 have been recently implicated in various human pathologies, particularly in autoimmune disease. These studies have revealed that targeting CCR6/CCL20 can enhance or inhibit autoimmune disease depending on the cellular basis of pathogenesis and the cell subtype most affected (...) through different CCR6/CCL20 manipulations. Here, we discuss the significance of this chemokine receptor/ligand axis in immune and inflammatory functions, consider the potential for targeting CCR6/CCL20 in human autoimmunity and propose that the shared evolutionary origins of pro‐inflammatory and regulatory T cells may contribute to the reason why both immune activation and regulation might be controlled through the same chemokine pathway. (shrink)

The Problem of Perception offers two arguments against direct realism--one concerning illusion, and one concerning hallucination--that no current theory of ...

In this paper I examine Grace A. de Laguna’s theory of universals in its historical context and in relation to contemporary debates in analytic metaphysics. I explain the central features of her theory, arguing that her theory should be classified as a form of immanent realism and as a powers ontology. I then show in what ways her theory affords a theory of modality in terms of potentialities and discuss some of its consequences along the way.

A. H. Louie's More Than Life Itself is an exploratory journey in relational biology, a study of life in terms of the organization of entailment relations in living systems. This book represents a synergy of the mathematical theories of categories, lattices, and modelling, and the result is a synthetic biology that provides a characterization of life. Biology extends physics. Life is not a specialization of mechanism, but an expansive generalization of it. Organisms and machines share some common features, but organisms (...) are not machines. Life is defined by a relational closure that places it beyond the reach of physicochemical and mechanistic dogma, outside the reductionistic universe, and into the realm of impredicativity. Function dictates structure. Complexity brings forth living beings. (shrink)

This book argues for the use of nonideal theory in social ontology. The central claim is that a paradigm shift is underway in contemporary social ontology, from ideal to nonideal, and that this shift should be fully followed through. To develop and defend this central claim, the first step is to show that the key questions and central dividing lines within contemporary social ontology can be fruitfully reconstructed as a clash between two worlds, referred to as ideal and nonideal social (...) ontology. Ideal social ontology is characterized by consensus and cooperation, while nonideal social ontology is characterized by conflict and contestation. The second step is to show that, when taken together, objections to the standard model of ideal social ontology (the dominant version of ideal social ontology) imply that this model needs to be given up in favor of nonideal social ontology. In other words, we should look to nonideal rather than ideal social ontology for core concepts. The third step is to offer a positive account, called the power view, of nonideal social ontology. This account places the concept of social power at the core of a general theory of the social world and replaces the flat and narrow conception of power in ideal social ontology with a richer and more extensive conception. In addition, it rectifies a shortcoming in nonideal social ontology by attending to class, which has been notably and oddly overlooked in the literature. (shrink)

This companion is a cutting-edge primer to critical forms of the posthumanities and the feminist posthumanities, aimed at students and researchers who want to catch up with the recent theoretical developments in various fields in the humanities, such as new media studies, gender studies, cultural studies, science and technology studies, human animal studies, postcolonial critique, philosophy and environmental humanities. It contains a collection of nineteen new and original short chapters introducing influential concepts, ideas and approaches that have shaped and developed (...) new materialism, inhuman theory, critical posthumanism, feminist materialism, and posthuman philosophy. A resource for students and teachers, this comprehensive volume brings together established international scholars and emerging theorists, for timely and astute definitions of a moving target – posthuman humanities and feminist posthumanities. (shrink)

I. Ókor -- II. A középkor és a reneszánsz -- III. Az újkor.

On fundamentals of Vedanta and science; a study.

La admirable riqueza cultural y artística del Renacimiento esconde una desoladora miseria y aquella "edad de la abundancia" contrasta con una inmensa pobreza. Lejos de ser una broma o una pesadilla, la celebrada Utopía de Tomás Moro fue antes que nada un desafío insoslayable, pues proponía que ninguna sociedad merece tal nombre si tolera la miseria de un solo pobre. Rico y pobre explora la cuestión en ese libro de 1516 y en otros del escritor londinense para concluir con un (...) esbozo de su vida a la luz de la pobreza como virtud indispensable y libertadora. He aquí un hombre afortunado que no fue indiferente ante el infortunio de tantos y que vio en la humanitas la virtud por excelencia que lleva a una constante atención y cuidado del prójimo. Inspirado por un cambio de actitud en su época, así como por su fe cristiana y la mejor tradición estoica, mostró una robusta preocupación sobre el tema subrayando el valor social que debe tener toda riqueza, tanto a nivel estatal como individual, destacando la grave obligación cívica de los ricos y la necesidad que tienen todos, ricos y pobres, de empeñarse en la práctica de cierto desprendimiento y generosidad si no quieren mermar su propia humanidad y fallecer en su avaricia. La percepción de la miseria había cambiado de tal manera que su remedio ya no podía estar en una u otra limosna en plazas e iglesias, sino en la acción bien pensada y perentoria de todo gobierno que se tenga por justo. Sir Tomás Moro, privilegiado desde la cuna y seguro en su trabajo profesional, vio la pobreza de tantos como un desastre social, pero uno que, al mismo tiempo, debería llevar a todo ser humano a ver en el desprendimiento y generosidad una excelencia o virtud que alumbra la "otra" libertad, y tan íntima y valiosa que en su caso brilló aun en la prisión y ante el horror de una muerte injusta y atroz." -- Page 4 of cover. (shrink)

Articles on the life and works of Āraja Ālī Mātubbara, 1901-1986, Muslim philosopher and author from Bangladesh.