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La mortalité et la morbidité spécifique dues à Schistosoma bovis et S. curassoni a été quantifiée chez des caprins élevés au Niger. L’étude a porté sur neuf animaux suivis pendant 380 jours après infestation expérimentale à l’aide de respectivement 1 800 et 2400 cercaires. S. bovis s’est révélé significativement plus pathogène que S. curassoni que ce soit en termes de mortalité, de perte de poids ou d’altération de l’hématocrite. L’intensité des symptômes cliniques s’est en outre révélée être significativement et positivement corrélée au niveau d’excrétion fécale des oeufs. Un différentiel de croissance par rapport aux témoins non infestés de respectivement 1600 et 880 grammes par mois doivent inciter à considérer S. bovis et S. curassoni comme des parasites d’importance économique dans les pays sahéliens.

The Centre de Recherche sur les Méningites et les Schistosomes (CERMES) is a research institute depending on the Organisation de Coordination et de Coopération pour la lutte contre les Grandes Endémies - a West African Organization for Public Health - devoted to the studies on schistosomiasis and meningitis. The staff includes 32 persons with 11 scientists and one financial officer. The activities of the CERMES involving schistosomiasis concern three research units: (a) ecology of human and animal schistosomiasis transmission; the CERMES defined the different patterns of schistosomiasis transmission in Niger (involving African dry savana); in this field, we have shown, (i) the existence of important variability in conditions of transmission of S. haematobium and, (ii) natural hybridization between parasitic species of the ruminants (S. bovis and S. curassoni) and genetic interaction between human and animal parasites; (b) definition of morbidity indicators usable for rapid assessment methods, for appraisal of the severity of the disease and for the evaluation of the efficiency of control methods; we have established the correlation between ultrasonographic data and some cheap and simple field indicators; (c) immune response and protective immunity induced by recombinant glutathion S-transferase (Sm28, Sb28 and Sh28) in homologous and heterologous animal models including goats, sheep and non human primates (Erythrocebus patas). In Niger, we participate in all control programs against schistosomiasis to define control strategies, to supervise operations and to participate in their evaluation with external experts. International collaborations constitute a frame including four laboratories in Africa and six laboratories in developed countries (Europe and USA)

A ligand-field model is used to compute the spin–lattice coupling coefficient C11 to strains of symmetry EΘ of the fundamental state 6A1 of Mn in cubic ZnS and ZnSe. It is shown that the proposed ligand-field model in which C11 is given by a second-order perturbation scheme involving the molecular spin–orbit interaction between the fundamental state 6A1 and the three orbital triplet states 4T1 at lower energy gives theoretical values which correctly account for the experimental results. A detailed study is made of the strain-induced variations of the crystal electrostatic field, the metal–ligand, and ligand–ligand group overlap integrals and the molecular spin–orbit interaction. It is shown that in ZnS the strain-induced variation of the crystal electrostatic field is almost completely compensated by the strain-induced variations of the group overlap integrals and the molecular spin–orbit interaction thus explaining the small experimental value for C11 in this compound. In ZnSe the contributions of the strain-induced variation of the group overlaps and of the molecular spin–orbit interaction are preponderant. [ABSTRACT FROM AUTHOR]

A molecular orbital model has been elaborated to determine the orbit–lattice coupling coefficients to strains of symmetry E of the orbital triplet states of d5 ions in tetrahedral symmetry. The wave functions and energies of the monoelectronic molecular orbitals have been determined for a tetrahedral molecule MnX4 in a crystal and for a slightly distorted molecule of symmetry D2d corresponding to a strain Eθ. It is shown that in D2d symmetry, the splitting of the monoelectronic molecular orbitals e and t2 is due to the variations of the group overlap integrals and the variation of the crystal electrostatic field with respect to their values in cubic symmetry. The orbit–lattice coupling coefficients which are independent of the spin–orbit interactions, are obtained by diagonalizing the Tanabe–Sugano matrices for the orbital triplet states and then using the molecular orbitals in D2d symmetry as zero-order wave functions in a first-order perturbation scheme. The proposed model for the orbit–lattice coupling coefficients of the orbital triplet states 4T1 and 4T2 at lower energy for Mn2+ in ZnS and ZnSe gives theoretical values which differ at most by 30% from the experimental values. It is shown that three fifths of the theoretical values for the orbit–lattice coupling coefficients are due to the variations of the group-overlap integrals, the remaining part of the theoretical values being due to the variations of the crystal electrostatic field describing the Coulomb’s interaction in the molecular model. [ABSTRACT FROM AUTHOR]

A theoretical determination of the Jahn–Teller coupling constants of d5 ions in tetrahedral clusters is performed in the framework of the angular overlap model and the quasimolecular approximation. It is shown that the angular model correctly predicts the trend of the preponderant coupling of the 4T1(G) and 4T2(G) levels of Mn2+ in MnS4 and MnSe4 to the E-vibrational effective mode. Finally, the limitations of this model are discussed. In particular, it is shown that more elaborated covalent models are needed to interpret the Jahn–Teller coupling coefficients of the 4E and 4A1 levels of d5 configurations and to determine the influence of the crystal on the clusters. [ABSTRACT FROM AUTHOR]

In the framework of the MOZAIC-IAGOS program, ozone and carbon monoxide vertical profiles are available since 1994 and 2002, respectively. This study investigates the variability and trends of both species at several tropospheric layers above the Frankfurt and Munich airports where about 21 600 flights have been performed over the 1994-2012 period, which represents the densest dataset in the world (about 75 flights per month on average). Over that period, most mean ozone trends are positive but insignificant at a 95% confidence level, except in winter where significant upward trends (around +0.38 ± 0.24 ppb yr-1) are found. Conversely, a significant increase of annual background ozone is highlighted, mostly during winter and autumn. Mean annual ozone trends increase with altitude, the largest increase being found in summer due to a noticeable decrease of highest ozone concentrations observed in the lower troposphere during the second half period. Over the 2002-2012 period, most mean CO trends are significantly negative, the decrease being higher in the lower troposphere compared to the mid- and upper troposphere with again, major differences in summer. Trends in the ozone seasonal cycle are also investigated, with a focus on the phase. Ozone maxima occur earlier and earlier with a shift around -10.6 ± 2.9 days decade-1 in the lower troposphere, in agreement with previous studies. The analysis of other ozone datasets in Europe (including surface stations and ozone soundings) confirms this trend, but highlights strong heterogeneities in the phase change. Interestingly, this shift is shown to decrease with altitude, with trends of -4.3 ± 2.4 and -2.0 ± 1.7 days decade-1 in the mid- and upper troposphere, respectively. The geographic origin of the air masses sampled by aircraft is analysed with FLEXPART backward simulations and suggests, together with trends and phase changes results, that an increase of the Asian contribution to ozone in the upper troposphere may compensate during summer the decrease of European and North American contributions associated to emission control over these two regions. [ABSTRACT FROM AUTHOR]

In-situ observational data on the relative humidity (RH) in the upper troposphere and lowermost stratosphere (UT/LS), or tropopause region, respectively, collected aboard civil passenger aircraft in the MOZAIC (Measurements of OZone, water vapour, carbon monoxide and nitrogen oxides by in-service AIrbus airCraft) programme were reanalysed for the period 2000 to 2009. Previous analyses of probability distribution functions (PDF) of upper troposphere humidity (UTH) data from MOZAIC observations from year 2000 and later indicated a bias of UTH data towards higher RH values compared to data of the period 1994 to 1999. As a result, PDF of UTH data show a substantial fraction of observations above 100% relative humidity with respect to liquid water (RHliquid), which is not possible from thermodynamical principles. An in-depth reanalysis of the data set recovered a calibration artefact from year 2000 on, while data of the previous period from 1994 to 1999 were found to be correct. The full data set for 2000-2009 was reanalysed applying the adjusted calibration procedure. Applied correction schemes and a revised error analysis are presented along with the reanalysed PDF of RHliquid and RHice. [ABSTRACT FROM AUTHOR]

In order to evaluate the observed high rural ozone levels in the eastern Mediterranean area during summertime, vertical profiles of ozone measured in the period 1994-2008 in the framework of the MOZAIC project (Measurement of Ozone and Water Vapor by Airbus in Service Aircraft) over the eastern Mediterranean basin (Cairo, Tel Aviv, Heraklion, Rhodes, Antalya) were analyzed, focusing in the lower troposphere (1.5-5 km). At first, vertical profiles collected during extreme days with very high or very low tropospheric ozone mixing ratios have been examined together with the corresponding back-trajectories. Also, the average profiles of ozone, relative humidity, carbon monoxide, temperature gradient and wind speed corresponding to the 7% highest and the 7% lowest ozone mixing ratios for the 1500-5000m height layer for Cairo and Tel Aviv have been examined and the corresponding composite maps of geopotential heights at 850 hPa have been plotted. Based on the above analysis, it turns out that the lower-tropospheric ozone variability over the eastern Mediterranean area is controlled mainly by the synoptic meteorological conditions, combined with local topographical and meteorological features. In particular, the highest ozone concentrations in the lower troposphere and subsequently in the boundary layer are associated with largescale subsidence of ozone-rich air masses from the upper troposphere under anticyclonic conditions while the lowest ozone concentrations are associated with low pressure conditions inducing uplifting of boundary-layer air, poor in ozone and rich in relative humidity, to the lower troposphere. [ABSTRACT FROM AUTHOR]

Bovine subclinical mastitis can be defined as a moderated inflammatory disease characterized by a persistent accumulation of neutrophils in milk. As GMCSF-mediated delay of neutrophil apoptosis contributes to the accumulation of inflammatory cells at the site of inflammation in many human diseases, we sought to determine whether subclinical mastitis in cows is also associated with a GMCSF-dependent increase in milk-neutrophil survival. We first addressed the hypothesis that GMCSF delays bovine neutrophil apoptosis by activation of the signal transducer and activator of transcription (STAT) family members STAT3 and STAT5, which are critical regulators of the expression of various Bcl-2 family proteins. Granulocyte-macrophage colony-stimulating factor significantly delayed apoptosis of blood neutrophils obtained from healthy cows. In these cells, GMCSF activated STAT5, but not STAT3, and induced an increase in the mRNA of the antiapoptotic Bcl-2 member, Bcl-xL. Granulocyte-macrophage colony-stimulating factor-dependent STAT5 activation and up-regulation of Bcl-xL mRNA were blocked by the Jak inhibitor, AG-490. This inhibition was associated with abrogation of the prosurvival effect of GMCSF, demonstrating a key role for STAT5 in delayed neutrophil apoptosis. We further found that GMCSF expression was increased in milk cells from cows affected with subclinical mastitis. Neutrophils from these cows demonstrated a significant delay of apoptosis as compared with neutrophils obtained from healthy cows and were unresponsive to GMCSF. Active STAT5 complexes were detected in these neutrophils. Finally, in the presence of AG-490, apoptosis was induced and a time-dependent down-regulation of Bcl-xL mRNA was observed in milk neutrophils from mastitis-affected cows. These results indicate that neutrophil survival is enhanced in milk of subclinical mastitis-affected cows and suggest a role for a GMCSF-activated STAT5 signaling pathway in this... [ABSTRACT FROM AUTHOR]

The electronic fine structure of the orbital triplet levels 4T2(G) of d5 ions in tetrahedral II–VI compounds is determined from an extended molecular model involving the first- and second-order molecular spin–orbit (MSO) interaction. For the levels 4T2(G) of Mn2+ in cubic ZnS, it is shown that the first-order MSO interaction is almost identical to that predicted by the crystal-field (CF) model. For the levels 4T2(G) of Mn2+ in cubic ZnSe, the splittings of the fine structure lines due to the first-order MSO interaction is much larger than the splitting predicted by the CF-model. Concerning the second-order (MSO) interaction, it is shown that the splitting of the levels Γ8(5/2) and Γ6 at lower energy drastically depends on the spin–orbit coupling constants of the electrons p of the ligands. Finally, an analysis is made of the coupling to ϵ-vibrational modes from Ham''s model, and the selective intensity transfer observed on the fine structure lines of the level 4T2(G) of Mn2+ in ZnS and ZnSe is analyzed in detail. [Copyright &y& Elsevier]

The electronic and vibronic structures of Mn2+ in near cubic fluorescent centers in ZnS due to stacking faults are compared to the structure of the cubic centers. First, for one of the near cubic center, a phenomenological vibronic model of the fluorescent level is elaborated from the analysis of the uniaxial stress effect and of the relative dipole strengths of the four well defined fundamental vibronic lines (FVL). Second, it is shown that the electronic structure of the near cubic center due to the spin–orbit and spin–spin interactions is almost identical to that of the cubic centers. Third, it is shown that a previous model for the very unexpected electronic structure of the cubic centers is clearly confirmed from an analysis of the vibronic structure in near cubic centers. [Copyright &y& Elsevier]

Studies increased nuclear factor κB activity in milk cells of mastitis-affected cows. Method of the study; Results and discussion; Conclusion.