Thermodynamic study of heavy metals behavior during municipal waste incineration

The incineration of municipal solid waste (MSW) contributes significantly to the presence of heavy metals in urban area aerosols. It is thus important to ascertain the quantities and chemical forms of the heavy metals (HM) that are emitted from the incineration plant stacks. The behaviour of HM, which depends strongly on the thermal and chemical environments, was investigated herein with a modelling approach, consisting of several parts. First, a refuse bed combustion model was developed for simulating on-grate MSW incineration. It describes most of the physico-chemical and thermal phenomena occurring during waste combustion. Second, results from the bed model were taken as boundary conditions to perform 3D simulations of the post-combustion zone and of the boiler. The case studied was of the Strasbourg incineration plant. Finally, the local thermal conditions and the local elementary compositions of gas and solid phases obtained from these simulations were used to carry out thermodynamic calculations of the speciation of HM at each point in the incinerator. The results for four metals (Cd, Zn, Pb, Cr) are presented, discussed and compared to available data. Predicted species are in agreement with observations for volatile metals, except lead, whose volatilization seems overestimated

Integrin/Fak/Src-mediated regulation of cell survival and anoikis in human intestinal epithelial crypt cells: selective engagement and roles of PI3-K isoform complexes

In human intestinal epithelial crypt (HIEC) cells, the PI3-K/Akt-1 pathway is crucial for the promotion of cell survival and suppression of anoikis. Class I PI3-K consists of a complex formed by a catalytic (C) and regulatory (R) subunit. Three R (p85α, β, and p55γ) and four C (p110α, β, γ and δ) isoforms are known. Herein, we analyzed the expression of PI3-K isoforms in HIEC cells and determined their roles in cell survival, as well as in the β1 integrin/Fak/Src-mediated suppression of anoikis. We report that: (1) the predominant PI3-K complexes expressed by HIEC cells are p110α/p85β and p110α/p55γ; (2) the inhibition and/or siRNA-mediated expression silencing of p110α, but not that of p110β, γ or δ, results in Akt-1 down-activation and consequent apoptosis; (3) the expression silencing of p85β or p55γ, but not that of p85α, likewise induces Akt-1 down-activation and apoptosis; however, the impact of a loss of p55γ on both Akt-1 activation and cell survival is significantly greater than that from the loss of p85β; and (4) both the p110α/p85β and p110α/p55γ complexes are engaged by β1 integrin/Fak/Src signaling; however, the engagement of p110α/p85β is primarily Src-dependent, whereas that of p110α/p55γ is primarily Fak-dependent (but Src-independent). Hence, HIEC cells selectively express PI3-K isoform complexes, translating into distinct roles in Akt-1 activation and cell survival, as well as in a selective engagement by Fak and/or Src within the context of β1 integrin/Fak/Src-mediated suppression of anoikis

Construction of Transgenic Plasmodium berghei as a Model for Evaluation of Blood-Stage Vaccine Candidate of Plasmodium falciparum Chimeric Protein 2.9

BACKGROUND:The function of the 19 kDa C-terminal region of the merozoite surface protein 1 (MSP1-19) expressed by Plasmodium has been demonstrated to be conserved across distantly related Plasmodium species. The green fluorescent protein (GFP) is a reporter protein that has been widely used because it can be easily detected in living organisms by fluorescence microscopy and flow cytometry. METHODOLOGY AND RESULTS:In this study, we used gene targeting to generate transgenic P. berghei (Pb) parasites (designated as PfMSP1-19Pb) that express the MSP1-19 of P. falciparum (Pf) and the GFP reporter protein simultaneously. The replacement of the PbMSP1-19 locus by PfMSP1-19 was verified by PCR and Southern analysis. The expression of the chimeric PbfMSP-1 and the GFP was verified by Western blot and fluorescence microscopy, respectively. Moreover, GFP-expressing transgenic parasites in blood stages can be readily differentiated from other blood cells using flow cytometry. A comparison of growth rates between wild-type and the PfMSP1-19Pb transgenic parasite indicated that the replacement of the MSP1-19 region and the expression of the GFP protein were not deleterious to the transgenic parasites. We used this transgenic mouse parasite as a murine model to evaluate the protective efficacy in vivo of specific IgG elicited by a PfCP-2.9 malaria vaccine that contains the PfMSP1-19. The BALB/c mice passively transferred with purified rabbit IgG to the PfCP-2.9 survived a lethal challenge of the PfMSP1-19Pb transgenic murine parasites, but not the wild-type P. berghei whereas the control mice passively transferred with purified IgG obtained from adjuvant only-immunized rabbits were vulnerable to both transgenic and wild-type infections. CONCLUSIONS:We generated a transgenic P. berghei line that expresses PfMSP1-19 and the GFP reporter gene simultaneously. The availability of this parasite line provides a murine model to evaluate the protective efficacy in vivo of anti-MSP1-19 antibodies, including, potentially, those elicited by the PfCP-2.9 malaria vaccine in human volunteers

Lakeside View: Sociocultural Responses to Changing Water Levels of Lake Turkana, Kenya

Throughout the Holocene, Lake Turkana has been subject to drastic changes in lake levels and the subsistence strategies people employ to survive in this hot and arid region. In this paper, we reconstruct the position of the lake during the Holocene within a paleoclimatic context. Atmospheric forcing mechanisms are discussed in order to contextualize the broader landscape changes occurring in eastern Africa over the last 12,000 years. The Holocene is divided into five primary phases according to changes in the strand-plain evolution, paleoclimate, and human subsistence strategies practiced within the basin. Early Holocene fishing settlements occurred adjacent to high and relatively stable lake levels. A period of high-magnitude oscillations in lake levels ensued after 9,000 years BP and human settlements appear to have been located close to the margins of the lake. Aridification and a final regression in lake levels ensued after 5,000 years BP and human communities were generalized pastoralists-fishers-foragers. During the Late Holocene, lake levels may have dropped below their present position and subsistence strategies appear to have been flexible and occasionally specialized on animal pastoralism. Modern missionary and government outposts have encouraged the construction of permanent settlements in the region, which are heavily dependent on outside resources for their survival. Changes in the physical and cultural environments of the Lake Turkana region have been closely correlated, and understanding the relationship between the two variables remains a vital component of archaeological research

Le voyage en Asie d'Odoric de Pordenone, traduit par Jean le Long OSB, 'Iteneraire de la Peregrinacion et du voyaige' (1351), Edition critique [responsabilità degli edd. a p. CLXXXI n. 327]

Odoric de Pordenone est un des rares voyageurs occidentaux du Moyen Age qui ait narré son périple en Asie. Un quart de siècle après Marco Polo il a vu en Inde les rites étranges du culte hindou. Ayant fait escale à Ceylan et dans plusieurs îles d'Indonésie (Sumatra, Java, peut-être Bornéo), il en présente des évocations colorées. De sa traversée de la Chine, de Canton à Pékin, il donne une vivante description. Dans la capitale de l'empire il assiste à maintes fêtes et cérémonies officielles. Son récit complète ce que disait Marco Polo. La traduction de Jean le Long diffuse tout cet ensemble de singularités et de merveilles auprès du grand public cultivé. Elle fait entrer dans notre langue bien des termes venus de l'Orient. Au milieu du XIVe siècle cette translation constitue une étape importante dans le renouvellement du vocabulaire français. Par ses curiosités Odoric, revu et divulgué par Jean le Long en 1351, s'avère un nouveau Marco Polo. Comme son illustre devancier, il fait revivre intensément les curiosités et les mystères de l'Asi