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Notes: The distribution of product in a turbulent reacting coflow jet was investigated in which dilute HCl issued into a coflowing stream of dilute NH3. Mass concentrations of the product, NH4Cl aerosol, were inferred from Mie scattering measurements. Probability density functions (PDFs) of the product exhibited a preferred concentration, or mode, that remained constant across the jet while the flow was in an early stage of reaction, indicating that production occurred in large scale structures that extended across the jet. In contrast, in regions where the reaction had progressed to a significant degree, the mode marched to lower concentrations with radial distance from the centerline, such that the PDF resembled that of a passive scalar. In these regions, radial distributions of the mean and rms fluctuations of product concentration were similar to those of mixture fraction, measured using laser induced fluorescence of acetone. In regions where reaction was still in the early stages, product distributions differed markedly from mixture fraction distributions. The PDFs suggested that product was formed at the edges of large structures of rather uniform reactant concentration. A two-dimensional image of Mie-scattered laser light from the aerosol product supports this interpretation by revealing long, narrow regions of product. © 2000 American Institute of Physics.

Notes: Work on some unusual techniques employing inhalation agents, some of which are now rarely used, is described, collated and assessed.

Notes: Abstract DMFT scores were determined in series of 1) urban Black adolescents (132 boys, 143 girls) aged 16–18 yr, and 2) rural Black mothers (480) aged 20–35 yr. Each series was divided into upper and lower thirds, with respect to DMFT. No relationship was apparent between segments with good versus inferior teeth, and blood groups.

Notes: The ontogeny of haematopoiesis in the perciform fish, spot Leiostomus xanthurus, differed from that reported as the norm for fishes, as exemplified by the cypriniform zebrafish Danio rerio, and observed in the batrachoidiform oyster toadfish Opsanus tau. Erythropoiesis in spot was first evident in the head kidney of yolk-sac larvae 3 days after hatching (DAH). No embryonic intermediate cell mass (ICM) of primitive stem cells or blood islands on the yolk were apparent within embryos. Erythrocytes were first evident in circulation near the completion of yolk absorption, c. 5 DAH, when larvae were c. 2·0 mm notochord length (LN). Erythrocyte abundance increased rapidly with larval development for c. 14 to 16 DAH, then became highly variable following changes in cardiac chamber morphology and volume. Erythrocytic haemoglobin (Hb) was not detected within whole larvae until they were 12 DAH or c. 3·1 mm LN, well after yolk and oil-globule absorption. The Hb was not quantified until larvae were 〉47 DAH or 〉7 mm standard length. The delayed appearance of erythrocytes and Hb in spot was similar to that reported for other marine fishes with small embryos and larvae. In oyster toadfish, a marine teleost that exhibits large embryos and larvae, the ICM and Hb were first evident in two bilateral slips of erythropoietic tissue in the embryos, c. 5 days after fertilization. Soon thereafter, erythrocytes were evident in the heart, and peripheral and vitelline circulation. Initial haematopoiesis in oyster toadfish conformed with that described for zebrafish. While the genes that code for the development of haematopoiesis are conserved among vertebrates, gene expression lacks phylogenetic pattern among fishes and appears to conform more closely with phenotypic expression related to physiological and ecological influences of overall body size and environmental oxygen availability. 


Notes: BOOK REVIEWS

Notes: Background  Lipoid proteinosis (LiP) is a rare autosomal recessive disorder characterized by a hoarse voice, warty skin infiltration and scarring. Mutations within the extracellular matrix protein 1 (ECM1) gene cause LiP. Since the early 1970s it has been recognized that South Africa has one of the largest groups of LiP patients worldwide, suggesting a probable founder effect. As LiP patients present with considerable clinical variability, this group of patients offers a unique opportunity for genotype–phenotype correlation.Objectives  To assess the clinical features and the molecular basis of LiP in patients from the Namaqualand area of the Northern Cape province of South Africa and to examine molecular evidence for a founder effect.Subjects and methods  The LiP patient cohort consisted of 29 Coloured patients from Namaqualand and a further seven Caucasoid patients from other areas of South Africa. The control group included 100 healthy geographically and ethnically matched individuals from Namaqualand. Samples were collected after informed consent and with ethics committee approval from the University of the Witwatersrand. LiP patients were examined clinically and a structured recording sheet was completed. A brief neurological evaluation was also performed. The LiP founder effect was investigated at the molecular level by ECM1 mutation detection and haplotype analysis.Results  The most consistent clinical signs for a diagnosis of LiP in this group were a hoarse voice and thickened sublingual frenulum leading to restricted tongue movement. Homozygosity for a nonsense mutation in exon 7 of the ECM1 gene, Q276X, was identified in all patients (Coloured and Caucasoid). Despite this genetic homogeneity, considerable clinical variability in skin presentation and psychiatric involvement was observed. Haplotype analysis using markers from a 9·98-Mb region around the ECM1 locus confirmed the founder effect with a founder core haplotype, 19-Q276X-12 (ND1-ECM1-D1S2343), in all but four LiP-associated alleles (n = 58). A LiP carrier rate of 1 in 9 was observed among the 100 Namaqualand controls, predicting a LiP incidence of 1 in 324 in this community.Conclusions  Although several consistent clinical features in LiP patients homozygous for the Q276X mutation in the ECM1 gene were observed, there remains considerable clinical variability. This suggests the action of genetic and environmental modifiers of disease severity. Strong molecular evidence supports a single founder effect for the high prevalence of LiP in South Africans, both Coloured and Caucasoid.

Notes: The return of Gladstone as prime minister, after the Liberals had secured a decisive majority at the polls in April 1880, has for long been established in the mythology of the Liberal party. In retrospect, the series of events which had drawn Gladstone back into active politics after his retirement in 1875 – his opposition to Beaconsfield's Eastern policy, the oratorical campaigns in Midlothian, and the rout of ‘Jingoism’ at the general election – came to be seen as a natural, linear development, whereby his special sense of affinity with the ‘;people’ was re-established and the great election victory assured. His subsequent resumption of the premiership accordingly became surrounded by an air of inevitability: the hesitant leadership of the whigs giving way to that of the man who had inspired the struggle against Beaconsfield's ‘system of government’ and who alone could command the allegiance of all sections of the great Liberal majority.