Aging-related changes in the sensitivity of the system of respiratory control and the intensity of free-radical processes in humans

Results of a comparative study of the sensitivity of the system of respiratory control to increases in the CO₂ concentration and the intensity of free-radical processes in young and elderly subjects are described. It is shown that normal (natural) aging is accompanied by a decrease in the sensitivity of the respiratory system to hypercapnic stimulation and a parallel significant decrease in the activity of catalase in the blood of examined subjects. Mechanisms responsible for the modifications of the sensitivity of the system of respiratory control to hypercapnia are discussed; these shifts can be at least partly related to changes in the intensity of production of free radicals observed in elderly subjects. Neirofiziologiya/Neurophysiology, Vol. 40, No. 1, pp. 53–57, January–February, 2008.     

Differential response to hepatic differentiation stimuli of amniotic epithelial cells isolated from four regions of the amniotic membrane

Human Amniotic Epithelial Cells (hAEC) isolated from term placenta are a promising source for regenerative medicine. However, it has long been debated whether the hAEC population consists of heterogeneous or homogeneous cells. In a previous study, we investigated the characteristics of hAEC isolated from four different regions of the amniotic membrane finding significant heterogeneity. The aim of this study was to evaluate the hepatic differentiation capability of hAEC isolated from these four regions. Human term placentae were collected after caesarean section and hAEC were isolated from four regions of the amniotic membrane (R1-R4, according to their relative distance from the umbilical cord) and treated in hepatic differentiation conditions for 14 days. hAEC-derived hepatocyte-like cells showed marked differences in the expression of hepatic markers: R4 showed higher levels of Albumin and Hepatocyte Nuclear Factor (HNF) 4α whereas R1 expressed higher Cytochrome P450 enzymes, both at the gene and protein level. These preliminary results suggest that hAEC isolated from R1 and R4 of the amniotic membrane are more prone to hepatic differentiation. Therefore, the use of hAEC from a specific region of the amniotic membrane should be taken into consideration as it could have an impact on the outcome of therapeutic applications.     

Upstream Regulators and Downstream Effectors of NADPH Oxidases as Novel Therapeutic Targets for Diabetic Kidney Disease

Oxidative stress has been linked to the pathogenesis of diabetic nephropathy, the complication of diabetes in the kidney. NADPH oxidases of the Nox family, and in particular the homologue Nox4, are a major source of reactive oxygen species in the diabetic kidney and are critical mediators of redox signaling in glomerular and tubulointerstitial cells exposed to the diabetic milieu. Here, we present an overview of the current knowledge related to the understanding of the role of Nox enzymes in the processes that control mesangial cell, podocyte and tubulointerstitial cell injury induced by hyperglycemia and other predominant factors enhanced in the diabetic milieu, including the renin-angiotensin system and transforming growth factor-β. The nature of the upstream modulators of Nox enzymes as well as the downstream targets of the Nox NADPH oxidases implicated in the propagation of the redox processes that alter renal biology in diabetes will be highlighted.     

Epilogue — Demography and anthropology

As a conclusion, this paper reviews briefly the content of the volume. The wealth of demographic data has not been adequately exploited in anthropology; this is why this publication is valuable in showing attempts to apply demographic data in a variety of anthropological problems. This symposium has explored many interesting points which we recall here. Yet it has also opened up a whole range of further questions on the material presented as well as in this broad field. Several directions of research could be developed, for instance, testing among human populations, over long periods, the ecological thoughts of ecosystems evolving as a cascade of instabilities, rather than a succession of equilibrium states. Let us also recall the pervasive nature of demographic facts in topics such as the energy cycle or the genetic structure and evolution of human populations.     

Ants resort to majority concession to reach democratic consensus in the presence of a persistent minority

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Competitive and facilitative relationships among three shrub species,and the role of browsing intensity and rooting depth in the Succulent Karoo,South Africa

Abstract. The nearest‐neighbour technique is used to infer competition and facilitation between the three most abundant species in a semi‐arid region of western South Africa. Relationships among the shrubs Leipoldtia schultzei and Ruschia robusta, which are leaf‐succulent members of the Mesembryanthemaceae (‘mesembs’) and Hirpicium alienatum a non‐succulent Asteraceae, were compared on two adjacent sites with different histories of browsing intensity. Competition was more prevalent and more important than facilitation. The only evidence for facilitation was found at the heavily‐browsed site where the palatable Hirpicium was larger under the unpalatable Leipoldtia. Generally the prevalence and importance of competition was reduced at the heavily‐browsed site. Strong evidence was obtained for intraspecific competition in each of the three species; also, competition was evident between the two mesembs, where Leipoldtia was competitively dominant over Ruschia, although neither species inhibited Hirpicium. Minimal competition between the mesembs and the asteraceous shrub was interpreted in terms of differentiation in rooting depth, and competition within the mesembs, in terms of overlap in rooting depth. The mesembs had the bulk of their roots in the top 5 cm of soil, while the asteraceous shrub had the bulk of its roots, and all its fine roots, at greater depths. The shallow‐rooted morphology of the mesembs is well adapted to utilize small rainfall events, which occur frequently in the Succulent Karoo, and do not penetrate the soil deeply. Modifications of existing methods are applied for analysing nearest‐neighbour interactions.     

Paired pleural disks in Dicaulograptus cumdiscus n. sp.

A diplograptid graptolite with strongly introverted thecae and unusual thecal processes was isolated from limestones of the Ordovician Pratt Ferry Formation of Alabama and is described as a new species Dicaulograptus cumdiscus. The thecal processes are referred to as pleural disks. They occur in pairs above every thecal aperture and are inferred to have functioned as suspension processes receiving uplift from small-scale turbulent water motion. Such a function is compatible with a passively buoyant mode of life and is difficult to reconcile with an automobile mode of life.     

Cartography and Clandestinité in Leïla Sebbar’s Shérazade: 17 ans, brune, frisée, les yeux verts

In this paper, I read Leïla Sebbar’s staging in her novel Shérazade: 17 ans, brune, frisée, les yeux verts of the resistance by children of North African and other immigrants in the early 1980s to the French state’s cartographic modes and documents of control. The paper will consider the many uses to which the map was put by the French state in its colonization of North Africa and particularly Algeria, and later in its attempts to control the banlieues its policies of citizenship and cartographic control yielded on the margins of Paris. In this context, I will explore the ways in which the novel’s characters, living clandestinely in a squatt, simultaneously resist, put to use, and even supercede state documents of control as they disrupt everyday life and conduct heists across the city of Paris. The paper will explore unofficial cartographies of Paris, from those afforded by the radios libres and alternative publications such as Libération and Sans Frontièrez, to oral and almost proverbial networks of knowledge criss-crossing the city of Paris, while also tracing the uses to which supplemental cartographic sketches and counterfeit identity cards are put in the pages of the novel. The paper will be in dialogue with theoretical and critical formulations of space, cartography, and state control put forward by Michel de Certeau, Henri Lefebvre, Michel Foucault, and Tom Conley. The paper will conclude with a consideration of the means and limits of resistance by the novel’s characters in the context of this body of theory and criticism.