In their environment, plants are continuously submitted to natural stimuli such as wind, rain, temperature changes, wounding, etc. These signals induce a cascade of events which lead to metabolic and morphogenetic responses.In this paper the different steps are described and discussed starting from the reception of the signal by a plant organ to the final morphogenetic response. In our laboratory two plants are studied: Bryonia dioica for which rubbing the internode results in reduced elongation and enhanced radial expansion and Bidens (...) pilosa for which the response occurs at distance, hence pricking the cotyledon of a plantlet induces the growth inhibition of both the hypocotyl and the axillary bud of the pricked cotyledon. (shrink)

In their environment, plants are continuously submitted to natural stimuli such as wind, rain, temperature changes, wounding, etc. These signals induce a cascade of events which lead to metabolic and morphogenetic responses. In this paper the different steps are described and discussed starting from the reception of the signal by a plant organ to the final morphogenetic response. In our laboratory two plants are studied: Bryonia dioica for which rubbing the internode results in reduced elongation and enhanced radial expansion and (...) Bidens pilosa for which the response occurs at distance, hence pricking the cotyledon of a plantlet induces the growth inhibition of both the hypocotyl and the axillary bud of the pricked cotyledon. Reception of the signal and transmission of the message. In Bryonia the signal is received by epidermal cells while in Bidens they are the cells adjacent to the midrib of the cotyledon which receive the mechanical signal. In both plants the message is transmitted via a wave of electric depolarization. This latter is composed of an action potential associated with a slow wave whose transmission rates are respectively 1cm s−1 and 1 mm s−1. Recent results have shown the involvement of Ca2+ in the triggering of the slow wave and the role of the H+ pump during the slow wave. Transient and fast biochemical responses. An entry of extraceilular Ca2+ into the cells and a transient increase in IP3 occur within seconds following the mechanical stimulus. At the same time, the membrane becomes more fluid, correlated with qualitative changes in phospholipids. The rapid increase in the concentration of peroxidated lipids may be correlated with ethylene biosynthesis which is stimulated after rubbing. Other parameters such as cytoplasmic pH, relative water content, hydric potential, membrane potential and modifications of K+, Mg2+-ATPase and Ca2+-ATPase activities, play a key role in the early responses induced by the traumatisms. Irreversible-biochemical responses. The mechanical stimulus performed on a Bryonia internode induces an acceleration of: i) enzymatic activities related to the lignification, ii) esterification of phenolic acids in the cell wall. Consequently the lignification process is accelerated. Storage of the information. After being received by the target cells the information can be stored during several days before being expressed. At the level of cotyledonary bud, the first message, previously stored, can be expressed or not by a second treatment. Bidens thus behaves as if it was able to “store” and to “retrieve” morphogenetic messages, using a sort of rudimentary memory. The nuclei of the bud cells of the pricked cotyledon show that these cells, initially in G2 phase, divide and then remain in the G1 phase. In Bryonia, calli derived from young stimulated internodes, keep thigmomorphogenetic characteristics during several weeks. In the last part of this paper the particularity of our plant model which permits a study of the transmission and storage of the message, is underlined. The links between the different steps induced by the stimulus are discussed. Special attention is devoted to second messengers and to the amplification of the message. (shrink)

Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.

Although the social and economic structure of peasant households exhibited much continuity before and after the rise of capitalism, those households were not rigid or inflexible in the face of economic change. A study of peasants in a Dutch region shows that households, motivated and bound by both cultural and economic factors, made careful choices in how to react to capitalist pressures. By responding actively and deliberately, peasants were able to exert significant control over their lives and their future and (...) did not become mere victims of capitalist development. Indeed, instead they actually helped shape the local economy. (shrink)

Some patients with schizophrenia are not told their diagnosis. The moral, clinical and practical issues involved in telling or not telling the patient are discussed. In some cases a relative is told the diagnosis but not the patient. The implications for the family and clinical outcome are outlined. A case history illustrating some of these issues is presented.

ABSTRACT Scholarship in the area of social movements points to the importance of inter-group collaboration and alliance building. In the case of Indigenous-led movements and the issue of solidarity with non-Indigenous movement participants, scholarship at the intersection of Native studies and social movements suggests that such alliances can be built and sustained but that unlearning colonial attitudes and behaviors is central to this process. Through in-depth interviews with non-Native solidarity participants, this article considers how engagement with Indigenous thought and action (...) re-shapes particpants’ conceptions of environment and place. Findings suggest that such involvement calls attention to histories of violence as well as ongoing practices of dispossession causing activists to grapple not only with their personal and family histories but also with their evolving relationship with environmentalism. (shrink)

In his concept of an anthropological physiology, F.J.J. Buytendijk has tried to lay down the theoretical and scientific foundations for an anthropologically-oriented medicine. The aim of anthropological physiology is to demonstrate, empirically, what being specifically human is in the most elementary physiological functions. This article contains a sketch of Buytendijk''s life and work, an overview of his philosophical-anthropological presuppositions, an outline of his idea of an anthropological physiology and medicine, and a discussion of some episternological and methodological problems. It is (...) demonstrated that Buytendijk''s design of an anthropological physiology is fragmentary and programmatic and that his methodology offers few points of contact for specific anthropological experimental research.Notwithstanding, it is argued that Buytendijk''s description of the subjective, animated body forms a pre-eminent point of reference for all research in physiology and psychology in which the specific human aspect is not ignored beforehand. (shrink)

Four years after completing his Ph.D. on “The Psychology of Kant,” one of Peirce’s most famous students, John Dewey, published a compendium of Leibniz’s main theses, his 1888 Leibniz’s New Essays.1 Such a move from critical to pre-critical rationalism seems to echo Peirce’s judgment that to fully understand Kant, a thorough familiarity with Leibniz’s philosophy is an indispensable preliminary (N 2:186, 1899); for Kant himself “was reposing in a firm belief in the metaphysics of Leibnitz as theologized by Wolff when (...) he first read the book of Hume.” (W 1:104, 1863) Peirce himself started his reflection with the study of Kant’s thought. The purpose of the present paper is to demonstrate that his actual implicit.. (shrink)

The Plasmodium falciparum genome‐sequencing project has provided malariologists with vast amounts of new information pertinent to a multitude of cellular processes that previously were only guessed about. In exploring this morass of predicted genes and proteins, there is now a danger of simply re‐inventing the cell. Fortunately, new global transcriptional analyses reassure malariologists that they are not dealing with just “any old cell.” The informative papers on the plasmodial transcriptome by Le Roch et al. (2003)1 and Bozdech et al. (2003)2 (...) discussed below forge a bridge between the genomics and proteomics of P. falciparum. They are likely to act as a fulcrum upon which much future research will turn: for example, the study of regulation and feed‐back loops. BioEssays 26:339–342, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

Forcing with [κ] κ over a model of set theory with a strong partition cardinal, M. Spector produced a generic ultrafilter G on κ such that κ κ /G is not well-founded. Theorem. Let G be Spector-generic over a model M of $ZF + DC + \kappa \rightarrow (\kappa)^\kappa_\alpha, \kappa > \omega$ , for all $\alpha . 1) Every cardinal (well-ordered or not) of M is a cardinal of M[ G]. 2) If A ∈ M[ G] is a well-ordered subset (...) of M, then A ∈ M. Let Φ = κ κ /G. 3) There is an ultrafilter U on Φ such that every member of U has a subset of type Φ, and the intersection of any well-ordered subset of U is in U. 4) Φ satisfies Φ → (Φ) α β for all $\alpha and all ordinals β. 5) There is a linear order Φ' with property 3) above which is not "weakly compact", i.e., $\Phi' \nrightarrow (\Phi')^2$. (shrink)