Studies of lipopolysaccharides from Yersinia pseudotuberculosis subtypes VA and VB

Lipopolysaccharides (LPS) from various strains of Yersinia pseudotuberculosis type V have been isolated and characterised. Differences in sugar composition and serological activity of LPS from various strains within the same subtype of Y. pseudotuberculosis have been revealed.     

Genetic control and expression of the major ejaculatory bulb protein (PEB-me) inDrosophila melanogaster

PEB-me is a predominant protein of matureDrosophila melanogaster ejaculatory bulbs. It is resolved into four or five closely spaced subfractions (apparent molecular weight 35–39 kD) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Four electrophoretic variants of PEB-me differing in apparent molecular weight by 200–800 daltons were found. These appear to be controlled by four alleles of a gene (peb) located by recombination and deletion mapping to the 60F1-2 region of chromosome 2. A minor ejaculatory bulb protein of ca. 80 kD (hPEB) was found to be immunochemically related to PEB and possibly encoded bypeb. PEB is not detected by immunoblotting techniques in virgin females, in male tissues other than the ejaculatory bulb, or during developmental stages preceding the formation of this organ. The results of transplantations of genital imaginal discs and of immature ejaculatory bulbs between two strains having different PEB alleles suggest that the ejaculatory bulb is the site of PEB synthesis. In flies mutant fortra, tra-2, dsx, orix, tissue specificity of PEB localization is retained and the protein is found whenever the ejaculatory bulb is formed, regardless of the chromosomal sex of the fly. The protein is transferred into the female genital duct during mating, where it can be detected for up to 12 hr. Possible functions of PEB inDrosophila reproduction are discussed.     

Dynamics of viscoelastic spherical membranes—the balloon model of the alveolus

Double-valued pressure-volume relationships in dynamic conditions for spherical membranes, modelling the lung alveoli, were obtained at small deformations. This hysteretic behavior was considered to be produced by at least three independent mechanisms: (1) the lung parenchyma exhibits viscoelastic properties; (2) the lung surface film, independent of the tissue, exhibits viscoelastic properties and (3) the pressure acting on the inner membrane surface depends on the rate of the alveolus volume change, due to the air viscous resistance in the bronchial tree. In each case, the maximum volume change, the hysteresis loop area, the tilt angle of the hysteresis loop and the relaxation time of the system were calculated. The results show pronounced hysteresis at normal breathing due to the air viscous resistance and smaller one due to the tissue and surface viscoelastic properties. In quasistatic conditions the values of the surface viscoelasticity and the tissue viscoelasticity effects are comparable or different, depending on the concrete external conditions. Comparison with the available experimental data is discussed in detail.     

Trainmasters or Easyjet pilots? Historical production,labor organizing,and the Spanish engine drivers’ union

This article presents an analysis of the relationship between historical memory and the emergence and reproduction of a specific model of unionism. I argue that in order to understand the militant particularism of the Spanish engine drivers, we need to look at the historical representations that it is embedded in. Recourse to a generational framework makes possible the sustained presentation of the union as a case of successful workers’ organizing, in spite of evidence to the contrary. The historical ethnographic analysis of SEMAF, the Spanish engine drivers’ union, contributes to the analysis of historical memory within the contemporary anthropology of class. The article contributes to theoretical debates in the anthropology of class by reclaiming Michel Trouillot’s conceptualization of the historical process. Two aspects of Trouillot’s work are singled out: his dynamic understanding of the process of historical production and the corollary formulation of the overlapping capacities in which people participate in it (as agents, actors, and subjects) and his emphasis on the importance of expanding scholarly views of the field of historical production.     

Critical threshold meal size and molt initiation in Rhodnius prolixus

The molting process and body growth in Rhodnius prolixus (Hemiptera: Reduviidae) (Ståhl, 1859) are significantly influenced by the availability and quality of food. Based on the body weight of each stage, the present study provides estimates of a potential critical weight threshold required for molt initiation in R. prolixus. In addition, a new measure given by the area under the weight curve is proposed, which encapsulates both body weight and time. It is shown that this measure is consistent with the data, and allows the estimation of a pre‐refractory period (i.e. the time interval between the moment at which the critical weight threshold is reached and the moment when no further meals are accepted). The present analysis estimates the critical weight threshold as 1.6, 5.3, 12.9, 42.0 and 97.0 mg for stages 1–5, respectively, whereas the values of the area under the curve threshold as 5, 16, 31.2, 159.7 and 329.9 mg days for stages 1–5, respectively. The results of the present study confirm the existence of a weight‐dependent mechanism for the initiation of molting in R. prolixus.     

Autonomy,productiveness, and community: the rise of inequality in an Amazonian society

In Amazonian societies, autonomy is said to be a core value motivating egalitarian politics. This article shows how the quest for autonomy and productiveness presently sets in motion processes that encroach upon these very values. Among the Shuar of Amazonian Ecuador, the realization of autonomy and productiveness increasingly depends on the capture of state resources. Shuar interact with the local state as members of relatively recent sedentary communities and through the mediation of elected leaders. In these processes, ‘community’ itself is transformed: being a channel to regenerate domestic livelihoods, it also becomes an end in itself, giving rise to new economistic attitudes while legitimizing inequalities between commoners and leaders. The article suggests that the pursuit of autonomy and productiveness within a process of village formation is central to the transformation of egalitarianism that occurs when small-scale Amazonian polities engage with nation-state politics.