A Role for the Vacuolating Cytotoxin, VacA, in Colonization and Helicobacter pylori-Induced Metaplasia in the Stomach

Carriage of Helicobacter pylori strains producing more active (s1/i1) forms of VacA is strongly associated with gas-tric adenocarcinoma. To our knowledge, we are the first to determine effects of different polymorphic forms of VacA on inflammation and metaplasia in the mouse stomach. Bacteria producing the less active s2/i2 form of VacA colonized mice more efficiently than mutants null for VacA or producing more active forms of it, providing the first evidence of a positive role for the minimally active s2/i2 toxin. Strains producing more active toxin forms induced more severe and extensive metaplasia and in flammation in the mouse stomach than strains producing weakly active (s2/i2) toxin. We also examined the association in humans, controlling for cag PAI status. In human gastric biopsy specimens, the vacA i1 allele was strongly associated with precancerous intestinal metaplasia, with almost complete absence of intestinal metaplasia in subjects infected with i2-type strains, even in a vacA s1, cagA+ background

Accent and ablaut in the Vedic verb

Most scholars nowadays reconstruct a static root present with an alternation between lengthened grade in the active singular and full grade in the active plural and in the middle. I am unhappy about this traditional methodology of loosely postulating long vowels for the proto-language. What we need is a powerful theory which explains why clear instances of original lengthened grade are so very few and restrains our reconstructions accordingly. Such a theory has been available for over a hundred years now: it was put forward by Wackernagel in his Old Indic grammar (1896: 66-68). The crucial element of his theory which is relevant in the present context is that he assumed lengthening in monosyllabic word forms, such as the 2nd and 3rd sg. active forms of the sigmatic aorist injunctive

Interference and communications among active network applications

This paper focuses on active networks applications and in particular on the possible interactions among these applications. Active networking is a very promising research field which has been developed recently, and which poses several interesting challenges to network designers. A number of proposals for e±cient active network architectures are already to be found in the literature. However, how two or more active network applications may interact has not being investigated so far. In this work, we consider a number of applications that have been designed to exploit the main features of active networks and we discuss what are the main benefits that these applications may derive from them. Then, we introduce some forms of interaction including interference and communications among applications, and identify the components of an active network architecture that are needed to support these forms of interaction. We conclude by presenting a brief example of an active network application exploiting the concept of interaction

Some interacting dark energy models

In this paper we study new cosmological models involving new forms of non-gravitational interaction between cold dark matter and dark energy. The main purpose is to demonstrate the applicability of the forms of interaction to the problem in modern cosmology known as accelerated expansion of the large scale universe. It is well known, that a non-gravitational interaction can improve theoretical prediction, but a fundamental theory allowing to derive the form of the interaction is missing. Therefore, an active sought to find a correct form of the interaction from various phenomenological assumptions is still one of the active branches of research in modern cosmology. Besides cosmographic analysis, we perform $Om$ analysis

Flavour transitions of Dirac-Majorana neutrinos

From a phenomenological point of view, we study active-active and active-sterile flavour-changing (and flavour-conserving) oscillations of Dirac-Majorana neutrinos both in vacuum and in matter. The general expressions for the transition probabilities in vacuum are reported. We then investigate some interesting consequences following from particular simple forms of the neutrino mass matrices, and for the envisaged scenarios we discuss in detail neutrino propagation in matter. Special emphasis is given to the problem of occurrence of resonant enhancement of active-active and active-sterile neutrino oscillations in a medium. The peculiar novel features related to the Dirac-Majorana nature of neutrinos are particularly pointed out.Comment: latex 2e, 19 pages, 1 figure; to be published in The European Journal of Physics

Consumption in action. Mapping consumerism in international academic literature

The consumer-citizen and more generally, the emergence of active forms of citizenship mediated by consumption point to a change in the relations of production, consumption and distribution. These forms of citizenship come to encompass opposite poles of consumption such as hedonism and social responsibility. When consumption choices are associated with the social and environmental issues connected to manufacturing and distribution processes, the space claimed by the active consumer comes to represents a form of social identity recognition. This \u2018political\u2019 sphere, made up of individual and/or collective claims mediated by consumer society comes in the wake of a long period of market de-politicization. On the basis of these assumptions, this article surveys and evaluates the topics related to critical consumption that are most discussed in the social sciences. Such forms of socially oriented consumption \u2013 enacted in the form of individual or collective consumer choices \u2013 represent a new form of political participation and are understood as practices of active-citizenship promotion. The findings of this article are based on data gathered from 478 peer-reviewed articles published between 2004 and 2013. The articles were selected from Scopus on the basis of their broad connection to critical consumerism and forms of socially oriented consumerism. A software-based content analysis run through T-Lab software was used to generate an analytical model of the main research axis of the most recent international literature on these arguments. The heterogeneous body of scholarly literature on socially oriented consumption reflects the rich diversity of perspectives adopted to understand the political and ethical role of consumers in contemporary societies

Intracellular mechanochemical waves in an active poroelastic model

Many processes in living cells are controlled by biochemical substances regulating active stresses. The cytoplasm is an active material with both viscoelastic and liquid properties. We incorporate the active stress into a two-phase model of the cytoplasm which accounts for the spatiotemporal dynamics of the cytoskeleton and the cytosol. The cytoskeleton is described as a solid matrix that together with the cytosol as an interstitial fluid constitutes a poroelastic material. We find different forms of mechanochemical waves including traveling, standing, and rotating waves by employing linear stability analysis and numerical simulations in one and two spatial dimensions.Peer ReviewedPostprint (published version

The Relevance of Accommodation in Understanding Intercultural and Intracultural Relationship Quality

Research comparing intercultural and intracultural relationship quality has been inconsistent. The current study examined whether accommodation, the specific reactions to relationship problems, can shed new insight on that mixed literature. Undergraduate women (n = 207) completed an online survey containing measures of relationship quality, accommodation, and demographic characteristics. Analyses revealed that women in intercultural relationships reported greater relationship commitment and satisfaction relative to women in intracultural relationships. Active forms of accommodation, or handling problems in a direct way, were related to commitment (but not satisfaction) more strongly in the intracultural group relative to the intercultural group. Passive forms did not vary by group for commitment nor satisfaction. These findings suggest that active accommodation may be less relevant for intercultural compared to intracultural relationship commitment. Altogether, these findings highlight the importance of studying relationship processes in their distinct contexts

Bending Moments in Free-Swimming Flagella

The bending of a flagellum, such as the flagellum which forms the tail of a sea-urchin spermatozoon, is the result of active mechanochemical processes occurring within the flagellum itself, which cause it to bend actively throughout its length (Gray, 1955; Machin, 1958). To understand how flagella operate, we must understand not only the mechanisms which generate bending, but also the control mechanisms which initiate and coordinate the active bending of different parts of the flagellum in order to generate smoothly propagated bending waves which will efficiently propel a cell