A compilation of literature data on the Fe-Mg composition of coexisting chlorite and chloritoid from metapelites metamorphosed at various P-T conditions shows that the logarithm of the Fe-Mg partitioning (lnK D ) varies linearly with the inverse of temperature, from about 2.4 at 300°C to about 1.3 at 600°C. In contrast, no trend was observed with pressure, and the molar volumes of Mg-and Fe-chlorite endmembers suggest that the pressure dependence of lnK D is not significant. Therefore, the chloritoid-chlorite Mg-Fe exchange reaction is a potential thermometer and has been empirically calibrated using the analyses of 112 chloritoid-chlorite pairs from 28 different localities. Temperatures estimated using the Chl-Cld thermometer were checked against independent estimates for 20 samples not involved in the calibration (Beni Mzala window, Morocco), and the results are in fair agreement with independent temperature estimates. However, the analytical uncertainties and errors are too large to obtain reliable temperature estimates for extremely Mg-rich or Fe-rich compositions. The Chl-Cld thermometer is unreliable at XMg-CLD <0.2 and XMg-CLD >0.8 at 700°C, and XMg-CLD <0.1 and XMg-CLD >0.9 at 300°C. Using the results of the empirical calibration, we calculated new thermodynamic data for daphnite. Implementing these data, it becomes possible to estimate T and P conditions of metamorphism for the invariant chlorite-chloritoid-quartz-aluminosilicate assemblage that is widespread in low-grade metapelites. These estimates appear to be relevant only in the stability field of kyanite, whereas the uncertainties on the calculated pressure conditions are very large in the stability field of kaolinite and pyrophyllite.

The destruction of Bacillus spores in oxygen-based plasmas sustained in the millitorr pressure range has been studied as functions of various biological and plasma parameters, namely Bacillus species, surface concentration of spores, treatment temperature, and gas composition. In an oxygen plasma, Bacillus stearothermophilus appears less plasma-resistant than the other spores tested. Oxygen, H2O2 and chiefly CO2 plasmas are clearly shown to be much more efficient in destroying Bacillus subtilis spores than pure argon plasma. The bacterial surface concentration on the spore carriers and the treatment temperature also lead to significant variations in the destruction efficiency of spores when using CO2 plasma.

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The development of a malaria vaccine is a priority for improved and sustained malaria control. Optimal use of a vaccine in Africa will only be achieved if it can be delivered through the Expanded Programme of Immunization (EPI). We have completed a trial of the peptide vaccine SPf66 in Tanzanian infants, given alongside the EPI vaccines. This paper describes the humoral responses to SPf66 and the EPI vaccines. A total of 1207 infants were recruited into a two-arm, double-blind, individually randomized placebo-controlled trial of SPf66. The objectives of the trial were to determine the safety, immunogenicity and efficacy of SPf66 and to assess interactions with EPI vaccines when three doses of SPf66 were delivered alongside the EPI vaccines. Cross-sectional surveys were carried out to asses seroconversion rates to the EPI vaccines and the antibody response to SPf66 (NANP)50 and Plasmodium falciparum lysates. Seroconversion rates to EPI vaccines were high and no statistically significant differences in prevalence or titres were found between SPf66 and placebo recipients. IgG antibodies against SPf66 (NANP)50 and whole P. falciparum lysate were present in high titres in mothers of recruited children at the time of birth. Vaccination with SPf66 stimulated a good anti-SPf66 IgG response which declined to preimmunization levels by 2 years of age and which was not associated with protection against clinical malaria. The vaccine induced no IgG antibodies against (NANP)50 or P. falciparum lysates. SPf66 stimulated a humoral immune response when given to very young infants and did not interfere with seroconversion to EPI vaccines. The response to SPf66 was qualitatively different from that seen in older children, in whom SPf66 has been shown to be moderately efficacious. This difference raises concerns about the difficulties of immunizing very young infants who need to be targeted by antimalarial vaccination programs.