25 research outputs found
Vector meson production and nucleon resonance analysis in a coupled-channel approach for energies m_N < sqrt(s) < 2 GeV II: photon-induced results
We present a nucleon resonance analysis by simultaneously considering all
pion- and photon-induced experimental data on the final states gamma N, pi N, 2
pi N, eta N, K Lambda, K Sigma, and omega N for energies from the nucleon mass
up to sqrt(s) = 2 GeV. In this analysis we find strong evidence for the
resonances P_{31}(1750), P_{13}(1900), P_{33}(1920), and D_{13}(1950). The
omega N production mechanism is dominated by large P_{11}(1710) and
P_{13}(1900) contributions. In this second part we present the results on the
photoproduction reactions and the electromagnetic properties of the resonances.
The inclusion of all important final states up to sqrt(s) = 2 GeV allows for
estimates on the importance of the individual states for the GDH sum rule.Comment: 41 pages, 26 figures, discussion extended, typos corrected,
references updated, to appear in Phys. Rev.
Dirofilaria immitis: A cause of human intra-ocular infection
A nematode worm 8.3 mm long removed from the anterior chamber of an Australian patient's eye was identified as a female Dirofilaria immitis. A review of another worm previously removed from the eye of another patient showed that this was also a female D. immitis. Both worms were subnormal in size; this is believed to be due to their development in an unnatural host. These eye infections probably result from the normal migrations of the developing worms in the subcutaneous tissues which occur prior to their entry into the venous circulation, but the exact route of entry into the eye cannot be suggested
The survival of the eggs of Austrosimulium pestilens Mack. & Mack. (Diptera, Simuliidae)
Eggs of Austrosimulium pestilens Mack. & Mack, were separated from sandy loam deposits in river beds in Queensland by washing the deposit through a 64·5 mesh/cm plankton sieve; the eggs were then picked off the surface of the sieve. Viable eggs were recovered only from permanently wet deposits; deposits above the water table contained only empty egg shells or dead eggs. Since eggs are laid directly into the water, their distribution in the river bed is related to its topography and the degree of scour and fill. Eggs stored in the laboratory in wet river deposits were still viable after 2½ years of storage, but died rapidly when exposed to relative humidities of 96% or less. Only a few eggs hatched from samples of riverbed deposits in water following up to four days' agitation with compressed air
SPECIES OF CHRYSOMYA AS PRIMARY FLIES IN CARRION
Chrysomya rufifacies (Macquart), Chrysomya saffranea (Bigot) and Chrysomya varipes (Macquart) have been shown to be capable of acting as primary flies, i.e. initiating infestation, in carrion in southern Queensland. This appears to be common during the warmer months of the year and must be taken into consideration, in forensic entomology, when estimating the period elapsed since death. Copyrigh
Factors affecting the development of Dipylidium caninum in Ctenocephalides felis felis (Bouché, 1835)
Ctenocephalides felis felis larvae were infected with Dipylidium caninum at a range of temperatures from 20°-35°C at 3 mm Hg saturation deficit (SD) and 30°C at 8 mm Hg SD. Hosts were subsequently dissected at 6, 9 and 12 days after infection. Four replicate, experiments were performed and results of development, and host reactions analysed by the Genstat computer programme. These were found to depend on the temperature and saturation deficit of the environment. Unlike previous findings, parasite development and host reaction were found to be independent of host development. Host reaction was more marked and prolonged at 20°-25°C than at higher temperatures. No perceptible growth of the parasite occurred at 20°C. The development patterns of growth at the higher temperatures were similar but shifted in time so that faster growth occurred at higher temperatures. Rate of growth was fastest at 35°C, despite the fact that this temperature was unfavourable to the hosts, all of which died at the time of pupation
Sexual mosaics and mermithid parasitism in Austrosimulium bancrofti (Tayl.) (Diptera, Simuliidae)
One gynandromorph and six intersexes of Austrosimulium bancrofti (Tayl.) are described from specimens caught in Queensland. All of the intersexes, as well as some normal flies, were infected with mermithid larvae. The infected flies rest preferentially on trees near the river's edge which would facilitate deposition of mermithids in the river. Except for a few with mature eggs, infected females had little internal abdominal structure, and most lacked ovaries