Implications of the serpentine phase transition on the behaviour of beryllium and lithium-boron of subducted ultramafic rocks

The Totalp-Platta-Malenco ophiolites in the Eastern Central Alps offer a unique opportunity to study the behaviour of Li, Be and B in ultramafic rocks in response to serpentinization and to progressive Alpine metamorphism. These units represent the remnants of a former ocean-continent transition that was intensely serpentinized during exposure on the Jurassic seafloor of the Ligurian Tethys. From north to the south, three isograd reactions (lizardite double right arrow antigorite + brucite; lizardite + talc double right arrow antigorite; lizardite + tremolite double right arrow antigorite + diopside) have been used to quantify the evolution of the light element content of metamorphic minerals. We determined the Li, Be and B concentrations in major silicate minerals from the ultramafic bodies of Totalp, Platta and Malenco by secondary ion mass spectrometry. Mantle minerals have Be concentrations (e.g. <0.001-0.009 mu g/g in olivine) similar to the metamorphic minerals that replace them (e.g. <0.001-0.016 mu g/g in serpentine). The mantle signature of Be is thus neither erased during seafloor alteration nor by progressive metamorphism from prehnite-pumpellyite to epidote-amphibolite facies. In contrast, the Li and B inventories of metamorphic minerals are related to the lizardite-to-antigorite transition. Both elements display higher concentrations in the low-temperature serpentine polymorph lizardite (max. 156 mu/g Li, max. 318 mu g/g B) than in antigorite (max. 0.11 mu g/g Li, max. 12 mu g/g B). Calculated average B/Li ratios for lizardite (similar to 1395) and antigorite (similar to 115) indicate that Li fractionates from B during the lizardite-to-antigorite transition during prograde metamorphism in ultramafic rocks. In subduction zones, this signature is likely to be recorded in the B-rich nature of forearc fluids. Relative to oceanic mantle the Be content of mantle clinopyroxene is much higher, but similar to Be values from mantle xenoliths and subduction-related peridotite massifs. These data support previous hypothesis that the mantle rocks from the Eastern Central Alps have a subcontinental origin. We conclude that Be behaves conservatively during subduction metamorphism of ultramafic rocks, at least at low-temperature, and thus retains the fingerprint of ancient subduction-related igneous events in mantle peridotites. (C) 2010 Elsevier Ltd. All rights reserved.

Photoactive sawhorse-type diruthenium tetracarbonyl complexes

Sawhorse-type diruthenium tetracarbonyl complexes incorporating carboxyphenyl porphyrin bridges and pyridine axial ligands have been prepared, characterized and evaluated as potential photosensitizing and chemotherapeutic agents in several human cancer cells (A2780, A549, Me300, HeLa). The mono carboxyphenyl porphyrin derivatives, 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin (HOOCR1-H2) and 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin-Zn (HOOCR1-Zn), after reaction with Ru-3(CO)(12) and pyridine, give the dinuclear complexes [Ru-2(CO)(4)(OOCR1-H2)(2)(NC5H5)(2)] (1) and [Ru-2(CO)(4)-(OOCR1-Zn)(2)(NC5H5)(2)] (2), respectively. Under the same reaction conditions, the di-carboxyphenyl porphyrin derivatives, 5,10-di(4-carboxyphenyl)-15,20-diphenyl-21,23H-porphyrin (HOOCR2-H2COOH) and 5,10-di(4-carboxyphenyl)-15,20-diphenylporphyrin-Zn (HOOCR2-ZnCOOH), give rise to the tetranuclear complexes, [{Ru-2(CO)(4)(NC5H5)(2)}(2)(OOCR2-H2COO)(2)] (3) and [{Ru-2(CO)(4)(NC5H5)(2! )}(2)(OOCR2-ZnCOO)(2)] (4), in which two sawhorse diruthenium tetracarbonyl units are linked by the di-carboxyphenyl porphyrin ligands. When tested in human cancer cell lines, both Zn(II) metallo-porphyrin derivatives 2 and 4 and the tetranuclear derivative 3 show some degree of cytotoxicity in the dark, but seem to present no phototoxicity upon irradiation at 652 nm. These results demonstrate the effect of the Zn(II) ion insertion into the porphyrin core, resulting in increased cytotoxicity and decreased phototoxicity. On the other hand, complex 1, the less cytotoxic derivative with IC50 > 170 mu M in HeLa cervix and A2780 ovarian cancer cell lines, shows an excellent phototoxicity toward these cancer cell lines with LD50 comprised between 4.5 and 7.5 J/cm(2) (irradiance 30 mW/cm(2)) at 5 mu M concentration (incubation time: 24 h). Overall, an excellent ratio between photo-and cytotoxicity has been found for the metal-free porphyrin derivative [Ru-2(CO)(4)(OOCR1-H2)(2)(! NC5H5)(2)] (1).

Development and validation of the Transition to Retirement Questionnaire

The aim of this study was to present the initial validation of a new questionnaire, the Transition to Retirement Questionnaire (TRQ) and to study its relationship with resistance to change and personality dimensions. Based on Schlossberg's typology of the retired, the TRQ is designed to assess five dimensions related to personal perceptions of transition to retirement, retirement, and personal plans and activities. The sample consisted of 1,054 professionally active or retired adults from the Swiss French-speaking Canton of Vaud. Exploratory principal components and confirmatory factor analyses highlighted a five-factor solution that fit coherently with Schlossberg's typology. Moreover, TRQ dimensions were related to resistance to change tendencies and personality dimensions. The TRQ seems to be an interesting tool for use in research but also for interventions with young retirees or people preparing for retirement.

Reaction-diffusion waves of advance in the transition to agricultural economics

In a previous paper [J.Fort and V.Méndez, Phys. Rev. Lett. 82, 867 (1999)], the possible importance of higher-order terms in a human population wave of advance has been studied. However, only a few such terms were considered. Here we develop a theory including all higher-order terms. Results are in good agreement with the experimental evidence involving the expansion of agriculture in Europe

Time-Delayed Theory of the Neolithic Transition in Europe

The classical wave-of-advance model of the neolithic transition (i.e., the shift from hunter-gatherer to agricultural economies) is based on Fisher's reaction-diffusion equation. Here we present an extension of Einstein's approach to Fickian diffusion, incorporating reaction terms. On this basis we show that second-order terms in the reaction-diffusion equation, which have been neglected up to now, are not in fact negligible but can lead to important corrections. The resulting time-delayed model agrees quite well with observations

Assessing heterogeneity of effects on blood pressure in a meta-analysis of pharmacist interventions trials

Background: Recent reviews of randomized control trials have shown that pharmacist interventions improve cardiovascular diseases (CVD) risk factors in outpatients. Various interventions were evaluated in different settings, and a substantial heterogeneity was observed in the effect estimates. To better express uncertainties in the effect estimates, prediction intervals (PI) have been proposed but are, however, rarely reported. Objective: Pooling data from two systematic reviews, we estimated the effect of pharmacist interventions on systolic blood pressure (BP), computed PI, and evaluated potential causes of heterogeneity. Methods: Data were pooled from systematic reviews assessing the effect of pharmacist interventions on CVD risk factors in patients with or without diabetes, respectively. Effects were estimated using random effect models. Results: Systolic BP was the outcome in 31 trials including 12 373 patients. Pharmacist interventions included patient educational interventions, patient-reminder systems, measurement of BP, medication management and feedback to physician, or educational intervention to health care professionals. Pharmacist interventions were associated with a large reduction in systolic BP (-7.5 mmHg; 95% CI: -9.0 to -5.9). There was a substantial heterogeneity (I2: 66%). The 95% PI ranged from -13.9 to -1.0 mmHg. The effect tended to be larger if the intervention was conducted in a community pharmacy and if the pharmacist intervened at least monthly. Conclusion: On average, the effect of pharmacist interventions on BP was substantial. However, the wide PI suggests that the effect differed between interventions, with some having modest effects and others very large effects on BP. Part of the heterogeneity could be due to differences in the setting and in the frequency of the interventions.

Improving blood pressure control through pharmacist interventions: a meta-analysis of randomized controlled trials.

BACKGROUND: Control of blood pressure (BP) remains a major challenge in primary care. Innovative interventions to improve BP control are therefore needed. By updating and combining data from 2 previous systematic reviews, we assess the effect of pharmacist interventions on BP and identify potential determinants of heterogeneity. METHODS AND RESULTS: Randomized controlled trials (RCTs) assessing the effect of pharmacist interventions on BP among outpatients with or without diabetes were identified from MEDLINE, EMBASE, CINAHL, and CENTRAL databases. Weighted mean differences in BP were estimated using random effect models. Prediction intervals (PI) were computed to better express uncertainties in the effect estimates. Thirty-nine RCTs were included with 14 224 patients. Pharmacist interventions mainly included patient education, feedback to physician, and medication management. Compared with usual care, pharmacist interventions showed greater reduction in systolic BP (-7.6 mm Hg, 95% CI: -9.0 to -6.3; I(2)=67%) and diastolic BP (-3.9 mm Hg, 95% CI: -5.1 to -2.8; I(2)=83%). The 95% PI ranged from -13.9 to -1.4 mm Hg for systolic BP and from -9.9 to +2.0 mm Hg for diastolic BP. The effect tended to be larger if the intervention was led by the pharmacist and was done at least monthly. CONCLUSIONS: Pharmacist interventions - alone or in collaboration with other healthcare professionals - improved BP management. Nevertheless, pharmacist interventions had differential effects on BP, from very large to modest or no effect; and determinants of heterogeneity could not be identified. Determining the most efficient, cost-effective, and least time-consuming intervention should be addressed with further research.

Basis set superposition error-counterpoise corrected potential energy surfaces : application to hydrogen peroxide ... X (X=F-, Cl-, Br-, Li+, Na+) complexes

Møller-Plesset (MP2) and Becke-3-Lee-Yang-Parr (B3LYP) calculations have been used to compare the geometrical parameters, hydrogen-bonding properties, vibrational frequencies and relative energies for several X- and X+ hydrogen peroxide complexes. The geometries and interaction energies were corrected for the basis set superposition error (BSSE) in all the complexes (1-5), using the full counterpoise method, yielding small BSSE values for the 6-311 + G(3df,2p) basis set used. The interaction energies calculated ranged from medium to strong hydrogen-bonding systems (1-3) and strong electrostatic interactions (4 and 5). The molecular interactions have been characterized using the atoms in molecules theory (AIM), and by the analysis of the vibrational frequencies. The minima on the BSSE-counterpoise corrected potential-energy surface (PES) have been determined as described by S. Simón, M. Duran, and J. J. Dannenberg, and the results were compared with the uncorrected PES

Effect of basis set superposition error on the electron density of molecular complexes

The effect of basis set superposition error (BSSE) on molecular complexes is analyzed. The BSSE causes artificial delocalizations which modify the first order electron density. The mechanism of this effect is assessed for the hydrogen fluoride dimer with several basis sets. The BSSE-corrected first-order electron density is obtained using the chemical Hamiltonian approach versions of the Roothaan and Kohn-Sham equations. The corrected densities are compared to uncorrected densities based on the charge density critical points. Contour difference maps between BSSE-corrected and uncorrected densities on the molecular plane are also plotted to gain insight into the effects of BSSE correction on the electron density

C-H···O H-bonded complexes: how does basis set superposition error change their potential-energy surfaces?

Geometries, vibrational frequencies, and interaction energies of the CNH⋯O3 and HCCH⋯O3 complexes are calculated in a counterpoise-corrected (CP-corrected) potential-energy surface (PES) that corrects for the basis set superposition error (BSSE). Ab initio calculations are performed at the Hartree-Fock (HF) and second-order Møller-Plesset (MP2) levels, using the 6-31G(d,p) and D95++(d,p) basis sets. Interaction energies are presented including corrections for zero-point vibrational energy (ZPVE) and thermal correction to enthalpy at 298 K. The CP-corrected and conventional PES are compared; the unconnected PES obtained using the larger basis set including diffuse functions exhibits a double well shape, whereas use of the 6-31G(d,p) basis set leads to a flat single-well profile. The CP-corrected PES has always a multiple-well shape. In particular, it is shown that the CP-corrected PES using the smaller basis set is qualitatively analogous to that obtained with the larger basis sets, so the CP method becomes useful to correctly describe large systems, where the use of small basis sets may be necessary

Antigen-secretory IgA immune complexes are retro-transported into mouse Peyer's patches: immunotargeting to dendritic cells

RÉSUMÉ Les plaques de Peyer (PP) représentent le site d'entrée majeur des pathogènes au niveau des muqueuses intestinales. Après avoir traversé la cellule M, l'antigène est pris en charge par les cellules dendritiques (DC) de la région sub-épithéliale du dôme des PP. Ces dernières activent une réponse immunitaire qui conduit à la production de l'IgA de sécrétion (SIgA), l'anticorps majeur au niveau muqueux. Des études précédentes dans notre laboratoire ont démontré qu'après administration de SIgA dans des anses intestinales de souris, les SIgA se lient spécifiquement aux cellules M, entrent dans les PP, et sont éventuellement internalisées par les DC. Le but de ce travail est de comprendre la relevance biologique de l'entrée des SIgA dans les PP et leur relevance physiologique dans l'homéostasie mucosale. Dans un premier temps, nous avons montré en utilisant une méthode de purification optimisée basée sur une isolation magnétique, que, en plus des DC myéloïdes (CD11c+/CD11b+) et des DC lymphoïdes (CD11c+/CD8+), les PP de souris contiennent un nouveau sous-type de DC exprimant les marqueurs CD11c et CD19. L'utilisation de la microscopie confocale nous a permis de démontrer que les DC myéloïdes internalisent des SIgA, contrairement aux DC lymphoïdes qui n'interagissent pas avec les SIgA, alors que le nouveau sous-type de DC exprimant CD19 lie les SIgA. En plus, nous avons démontré qu'aucune des DC de rate, de ganglion bronchique ou de ganglion inguinal interagit avec les SIgA. Dans le but d'explorer si les SIgA peuvent délivrer des antigènes aux DC des PP in vivo, nous avons administré des complexes immunitaires formés de Shigella flexneri complexées à des SIgA, dans des anses intestinales de souris. Nous avons observé une entrée dans les PP, suivie d'une migration vers les ganglions mésentériques drainants, contrairement aux Shigella flexneri seules, qui n'infectent pas la souris par la voie intestinale. Shigella flexneri délivrée par SIgA n'induit pas de destruction tissulaire au niveau de l'intestin. En plus de l'exclusion immunitaire, ces résultats suggèrent un nouveau rôle des SIgA, qui consiste à transporter des antigènes à l'intérieur des PP dans un contexte non-inflammatoire. RÉSUMÉ DESTINÉ À UN LARGE PUBLIC L'intestin a pour rôle principal d'absorber les nutriments digérés tout au long du tube digestif, et de les faire passer dans le compartiment intérieur sanguin. Du fait de son exposition chronique avec un monde extérieur constitué d'aliments et de bactéries, l'intestin est un endroit susceptible aux infections et a donc besoin d'empêcher l'entrée de microbes. Pour cela, l'intestin est tapissé de "casernes" appelées les plaques de Peyer, qui appartiennent à un système de défense appelé système immunitaire muqueux. Les plaques de Peyer sont composées de différents types de cellules, ayant pour rôle de contrôler l'entrée de microbes et de développer une réaction immunitaire lors d'infection. Cette réaction immunitaire contre les microbes (antigènes) débute par la prise en charge de l'antigène par des sentinelles, les cellules dendritiques. L'antigène est préparé de façon à être reconnu par d'autres cellules appelées lymphocytes T capables d'activer d'autres cellules, les lymphocytes B. La réaction immunitaire résulte dans la production par les lymphocytes B d'un anticorps spécifique appelé IgA de sécrétion (SIgA) au niveau de la lumière intestinale. De manière classique, le rôle de SIgA au niveau de la lumière intestinale consiste à enrober les microbes et donc exclure leur entrée dans le compartiment intérieur. Dans ce travail, nous avons découvert une nouvelle fonction des SIgA qui consiste à introduire des antigènes dans les plaques de Peyer, et de les diriger vers les cellules dendritiques. Sachant que les SIgA sont des anticorps qui ne déclenchent pas de réactions de défense violentes dites inflammatoires, l'entrée des antigènes via SIgA serait en faveur d'une défense intestinale maîtrisée sans qu'il y ait d'inflammation délétère. Ces résultats nous laissent supposer que l'entrée d'antigènes via SIgA pourrait conduire le système immunitaire muqueux à reconnaître ces antigènes de manière appropriée. Ce mécanisme pourrait expliquer les désordres immunitaires de types allergiques et maladies auto-immunitaires que l'on rencontre chez certaines personnes déficientes en IgA, chez qui cette lecture d'antigènes de manière correcte serait inadéquate. ABSTRACT Peyer's patches (PP) represent the primary site for uptake and presentation of ingested antigens in the intestine. Antigens are sampled by M cells, which pass them to underlying antigen-presenting cells including dendritic cells (DC). This leads to the induction of mucosal T cell response that is important for the production of secretory IgA (SIgA), the chief antibody at mucosal surfaces. Previous studies in the laboratory have shown that exogenous SIgA administrated into mouse intestinal loop binds specifically to M cells, enter into PP, and is eventually internalized by DC. The aim of this work is to understand the biological significance of the SIgA uptake by PP DC and its physiological relevance for mucosal homeostasis. As a first step, we have shown by using an optimized MACS method that, in addition to the CD11c+/CD11b+ (myeloid DC) and CD11c+/CD8+ (lymphoid DC) subtypes, mouse PP contain a novel DC subtype exhibiting both CD11c and CD19 markers. By using a combination of MACS isolation and confocal microscopy, we have demonstrated that in contrast to the lymphoid DC which do not interact with SIgA, the myeloid DC internalize SIgA, while the CD19+ subtype binds SIgA on its surface. Neither spleen DC, nor bronchial-lymph node DC, nor inguinal lymph node DC exhibit such a binding specificity. To test whether SIgA could deliver antigens to PP DC in vivo, we administered SIgA-Shigella flexneri immune complexes into mouse intestinal loop containing a PP. We found that (i) SIgA-Shigella flexneri immune complexes enter the PP and are internalized by sub-epithelial dome PP DC, in contrast to Shigella flexneri alone that does not penetrate the intestinal epithelia in mice, (ii) immune complexes migrate to the draining mesenteric lymph node, (iii) Shigella flexneri carried via SIgA do not induce intestinal tissue destruction. Our results suggest that in addition to immune exclusion, SIgA transports antigens back to the PP under non-inflammatory conditions.