Influence of limestone grain size on glass homogeneity

International audienceThe lack of homogeneity in a glass is characterized by the occurrence of layers of different chemical compositions and densities. When starting materials relevant for the synthesis of soda-lime silicate glasses are melted in a crucible, silica- and calcium-enrichments are observed at the top and at the bottom of the melt respectively. This behaviour may be due to the occurrence of several reaction pathways. In this respect, an interesting observation is that the grain size of limestone is found to be an important parameter influencing the level of glass homogeneity. The reasons for this have been studied here using systematic differential thermal analysis and thermogravimetric analysis. The experiments showed that, in presence of limestone of small grain size (< 200 micrometers), sodium carbonate disappears before the temperature at which it is observed to interact with silica in the CaO - free system. We infer that this is most probably due to production of a mixed carbonate liquid, which subsequently reacts with silica to spontaneously yield a homogeneous silicate melt. A characteristic of this probable mixed carbonate (assumed to be close to the composition CaNa2(CO3)2) is its density of 2.54g/cm3, close to that of the silicates and of silica itself. On the contrary, coarse limestone decomposes to CaO (and CO2), which is slowly incorporated in the sodium silicate liquid formed when sodium carbonate interacts with silica. The much higher density of CaO (3.35 g/cm3) and of calcium silicates could explain the tendency for CaO concentrations to be greatest towards the base of melting crucibles

Psychogeriatric Inventory of Disconcerting Symptoms and Syndromes (PGI-DSS): validity and reliability of a new brief scale compared to the Neuropsychiatric Inventory for Nursing Homes (NPI-NH)

International audienceObjectives: To validate the Psychogeriatric Inventory of Disconcerting Symptoms and Syndromes (PGI-DSS), a single scale in A4 format comprising four disconcerting syndromes (violence, refusal, words, and acts). The scale enables an immediate conversion of a qualitative assessment to a quantitative assessment. The PGI-DSS was compared with the Neuro Psychiatric Inventory for Nursing Homes (NPI-NH).Design: Cross-sectional descriptive and correlational studies.Setting: Thirty geriatric care units and nursing homes.Participants: Raters interviewed nurses and nursing assistants in charge of older adults hospitalized in geriatric care units or living in nursing homes (N = 226).Measurements: The French version of the PGI-DSS and the French version of the NPI-NH.Results: The correlation coefficient between the PGI-DSS and the NPI-NH was 0.70 (p < 0.0001). The PGI-DSS threshold score corresponding to the NPI threshold score was 17 (specificity: 87%, sensitivity: 63%). Four statistical factors, corresponding to the four clinical syndromes, explained 53.4% of the total variance. The internal consistency of the PGI-DSS (Cronbach's alpha = 0.695) was higher than that of the NPI-NH (Cronbach's alpha = 0.474). Test-retest reliability was better for the PGI-DSS than for the NPI-NH. The intraclass correlations were 0.80 [0.73; 0.86] and 0.75 [0.67; 0.83], respectively. Interrater reliability was better for the PGI-DSS than for the NPI-NH. The intraclass correlations were 0.65 [0.55-0.76] and 0.55 [0.43-0.68], respectively.Conclusion: The PGI-DSS was developed to overcome the limitations of the NPI-NH. New, brief, easy to administer in less than 4 minutes, foldable in four parts, pocket-sized, easy-to-read in the palm of the hand, PGI-DSS could have similar or better statistical properties than the NPI-NH. Whereas the 10 domains in the NPI-NH have clinical utility for clinicians, the four easily understandable syndromes in the PGI-DSS can help avoid inappropriate attitudes and can guide psychosocial interventions. It could likewise improve dialogue between caregivers and clinicians

Zr environment in aluminosilicate glasses Zr environment and nucleation role in aluminosilicate glasses

International audienceWe have investigated the role of ZrO 2 on the nucleation/crystallization properties of aluminosilicate glasses. A comparison between Zr-free and Zr-bearing glasses shows that adding ZrO 2 favors nucleation in Li-, Mg-, Ca-and Zn-bearing glasses and has no effects in Na-bearing glasses. The Zr environment has been elucidated coupling X-ray absorption spectroscopy at both Zr K-and L 2,3 -edges. The Zr environment corresponds to six-fold coordinated sites (Li and Na glasses) and seven-fold coordinated sites (Mg, Ca and Zn glasses), indicating the coordination number has little influence on the ability to crystallize. Direct Zr-Zr polyhedral linkages are observed for all glasses except the Na-bearing one. Since no correlation between the local Zr site and its ability to promote nucleation can be observed, the origin of the nucleating role of Zr has been interpreted as resulting from the Zr distribution with the aluminosilicate matrix. The poor crystallization ability for Na-bearing glasses is due to the lack of direct Zr-Zr linkages. Medium range ordering appears as a key parameter to explain properties of Zr-bearing glasses

William T. Vollmann, le roman historique en question

Cet ouvrage servira d'introduction à l'écrivain américain William T. Vollmann à travers l'étude d'un roman en particulier. The Rifles déconstruit le roman historique : à la suite de l'explorateur anglais du XIXe siècle John Franklin, le héros américain Subzero s'aventure sur ses traces dans l'Arctique, à la recherche d'un dépassement de soi. Il erre sur le permafrost de sa mémoire, à contre-courant de son histoire hégémonique, dont il brouille à dessein les pistes. Déployant une poétique de l'anachronisme, ce récit révèle le rêve de déculpabilisation de l'homme occidental, dans une récriture post-moderne du gothique. Entre l'esquive et l'engagement, entre la projection amoureuse et la réticence solitaire de l'explorateur aveugle, les voix de Vollmann cherchent l'Autre à travers les reflets fragmentaires d'un soi sans image, tel un nouveau cachalot blanc, après celui de Melville

Sur le vif. Photographie et anthropologie

L’histoire de l’anthropologie et celle de la photographie sont étroitement liées depuis leur apparition quasi simultanée au XIXe siècle. Mais force est de constater la relative absence de travaux portant sur les pratiques, les usages et plus généralement l’histoire des « images » de l’anthropologie dans l’entre-deux-guerres, période pendant laquelle l’institutionnalisation de la discipline va de pair avec l’essor d’une modernité photographique. Or, les archives d’ethnologues montrent aujourd’hui l’importance de la pratique photographique sur le terrain, l’apparition d’appareils légers comme le Leica et celle du genre du photoreportage, les ayant influencés et séduits. Leurs carnets de l’époque contiennent souvent de nombreuses photos, des collections muséales se constituent et des réseaux de diffusion visuels variés débordent le cadre strictement scientifique. Par ailleurs, la réutilisation de la photographie de « types » physiques, encore très courante, illustre la tension entre la permanence de schèmes visuels hérités de l’anthropologie physique du XIXe siècle et la volonté d’une science moderne de remettre en question l’existence des races. Ce numéro interroge aussi les enjeux techniques et financiers de conservation, de classement et d’archivage ainsi que le traitement éditorial des images parfois révélateur de tensions entre les logiques scientifique, économique et esthétique. Il fait le point sur les enjeux que présente la photographie en anthropologie dans l’entre-deux-guerres, en abordant différentes traditions nationales et aires géographiques et propose de questionner le geste photographique en tant que geste scientifique, car les images font partie intégrante de l’histoire de la discipline, à l’instar des grands textes classiques

Characteristics of pro-T ALL subgroups: Comparison with late T-ALL

A group of 30 acute lymphoblastic leukemias (ALL) with the early pro-T phenotype CD7+ /cCD3+ /CD1- /CD3- /CD4- /CDS- were identified among 103 newly diagnosed ALL with T-lineage markers (T-ALL). Pro T-ALL was more often observed in adults, and showed a lower incidence of hyperleukocytosis than more mature T-ALL. Mediastinal masses and polar acid phosphate se positivity in blast cells were however observed with the same frequency in pro T-ALL and late T-ALL, and rearrangements of both T-cell receptor (TCR) beta and gamma genes were observed in half the pro T-ALL cases tested. The expression of CD34, DR, and myeloid (My) markers was significantly more frequent in pro T-ALL than in late T-ALL, and these three features were strongly linked. TCR gene rearrangements were two to three times more frequent in CD34- and My-pro T-ALL. However, both CD34+ and My+ pro T-ALL showed an incidence of mediastinal masses and polar acid phosphatase positivity similar to this observed in CD34- and My- cases. This supports the assumption that both types of ALL indeed are engaged in the T-lineage, and confirms intracytoplasmic cCD3 as the earliest marker for this lineage. Moreover, CD34 appears to persist up to an early stage of T-cell maturation, where the cells retain myeloid potentiality. Loss of CD34 correlates with TCR-beta gene rearrangement and definitive commitment to the T lineage. Event-free survival analysis suggested a poorer outcome for pro T-ALL in adult patients.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Rational targeted therapies to overcome microenvironment-dependent expansion of mantle cell lymphoma

International audienceKey Points • CD40L plus cytokines induces cell-cycle progression and loss of mitochondrial priming, leading to drug resistance in MCL. • CD40L plus cytokines mimics in situ molecular profiles and allows the development of new approaches by integrating the role of the microenvironment. Mantle cell lymphoma (MCL) accumulates in lymphoid organs, but disseminates early on in extranodal tissues. Although proliferation remains located in lymphoid organs only, suggesting a major role of the tumor ecosystem, few studies have assessed MCL microenvironment. We therefore cocultured primary circulating MCL cells from 21 patients several weeks ex vivo with stromal or lymphoid-like (CD40L) cells to determine which interactions could support their proliferation. We showed that coculture with lymphoid-like cells, but not stromal cells, induced cell-cycle progression, which was amplified by MCL-specific cytokines (insulin Q : 5-like growth factor-1, B-cell activating factor, interleukin-6, interleukin-10). Of interest, we showed that our model recapitulated the MCL in situ molecular signatures (ie, proliferation, NF-kB, and survival signatures). We further demonstrated that proliferating MCL harbored an imbalance in Bcl-2 family expression, leading to a consequent loss of mitochondrial priming. Of interesting, this loss of priming was overcome by the type II anti-CD20 antibody obinutuzumab, which counteracted Bcl-x L induction through NF-kB inhibition. Finally, we showed that the mitochondrial priming directly correlated with the sensitivity toward venetoclax and alkylating drugs. By identifying the microenvironment as the major support for proliferation and drug resistance in MCL, our results highlight a selective approach to target the lymphoma niche. (Blood. 2016;00(00):1-11