Calculated and Measured Ultrasonic Response of an Elastic Cylinder Embedded in an Elastic Medium

itanium metal matrix composite (TMC) materials are fabricated by consolidating alternate layers of suitable titanium foils and silicon carbide fibers. The foils are generally 0.005-0.010 in thick and the fibers have diameters ranging from 0.004 in. to 0.0055 in. Furthermore, the fibers have a core of one material and an outer annular ring of silicon carbide (Fig. 1). The fibers used in the work described here, designated SCS6 fibers, have an outer diameter of 0.0055 in. and an inner carbon core with a diameter of 0.0013 in. During consolidation, the matrix material is heated under pressure so that it flows around the fibers, forming a strong interfacial bond with the fiber and a strong diffusion bond where the adjacent foils come in contact. Several types of defects can occur during the consolidation process. There can be lack of bonding or incomplete bonding between the adjacent foils or between the matrix and the fibers. It is also possible that an undesirable reaction can occur between the fiber and the matrix, producing a brittle zone that will degrade the strength of the material.</p

Anopheles darlingi polytene chromosomes: revised maps including newly described inversions and evidence for population structure in Manaus

Salivary gland polytene chromosomes of 4th instar Anopheles darlingi Root were examined from multiple locations in the Brazilian Amazon. Minor modifications were made to existing polytene photomaps. These included changes to the breakpoint positions of several previously described paracentric inversions and descriptions of four new paracentric inversions, two on the right arm of chromosome 3 and two on the left arm of chromosome 3 that were found in multiple locations. A total of 18 inversions on the X (n = 1) chromosome, chromosome 2 (n = 7) and 3 (n = 11) were scored for 83 individuals from Manaus, Macapá and Porto Velho municipalities. The frequency of 2Ra inversion karyotypes in Manaus shows significant deficiency of heterozygotes (p < 0.0009). No significant linkage disequilibrium was found between inversions on chromosome 2 and 3. We hypothesize that at least two sympatric subpopulations exist within the An. darlingi population at Manaus based on inversion frequencies

Molecular evidence for a single taxon, Anopheles nuneztovari s.l., from two endemic malaria regions in Colombia

To elucidate the Anopheles nuneztovari s.l. taxonomic status at a microgeographic level in four malaria endemic localities from Antioquia and Córdoba, Colombia, fragments of the cytochrome oxidase subunit I (COI) and the white gene were used. The COI analysis showed low genetic differentiation with fixation index (F ST) levels between -0.02-0.137 and Nm values between 3-∞, indicating the presence of high gene flow among An. nuneztovari s.l. populations from the four localities. The COI network showed a single most common haplotype, type 1 (n = 55), present in all localities, as the likely ancestral haplotype. Analysis of the white gene showed that An. nuneztovari s.l. populations from both departments grouped with haplotypes 19 and 20, which are part of lineage 3 reported previously. The results of the present study suggest that An. nuneztovari s.l. is a single taxon in the area of the present study