The Effect of External Conditions on Coremium Production in Paecilomyces farinosus Bainier

Paecilomyces farinosus grew and produced coremia under laboratoryconditions on media containing wide ranges of carbon and nitrogensources. The fungus tolerated higher concentrations of complexcarbon and nitrogen sources than of simple ones. Sustained lowconcentrations of simple carbon and nitrogen nutrients favouredcoremium production. Once P. farinosus colonies had consumedsufficient nutriment, coremium production could take place withoutfurther access to external nutrients. Light was essential for initiation and development of coremia.The tips of the coremia were photosensitive throughout theirgrowth. After growth in darkness during the initial trophicphase of development, P. farinosus required exposure to lightfor at least 8 days before coremia were initiated. The isolate used produced non-coremial strains spontaneously.These usually also lacked the orange, alcohol soluble, pH sensitivepigment found in the coremial strains.     

Characterization of the Malaria Pigment (Hemozoin) from the Avian Malaria Parasite Plasmodium lophurae*

SYNOPSIS. Plasmodium lophurae hemozoin (malaria pigment) is a heme-containing protein which is distinctly different from hemoglobin and hematin by immunologic, spectrophotometric, fingerprint, heme-iron, gel filtration, and starch gel electrophoretic analyses. The calculated average molecular weight of P. lophurae hemozoin is ca. 40,000. Hemozoin contains at least 3 antigenic components and shows some indication of cross-reaction with hemoglobin.     

The differentiation of bunodont Listriodontinae (Mammalia,Suidae) of Africa: new data from Kalodirr and Moruorot,Kenya

The early Miocene sites of Moruorot and Kalodirr (Kenya, 17.5 Myr) have yielded a rich collection of mammals. New listriodont material from these localities, including a complete skull and a partial mandible, provide long awaited information on cranial features of early bunodont Listriodontinae. The evolution and systematics of the group are highly debated, especially regarding its first representatives. The new material described here sheds light on the differentiation of bunodont Listriodontinae in Africa and clarifies the systematics of the group. The first phylogenetic analysis of the Listriodontinae is here performed and supports close relationships between Kubanochoerus and a clade (Eurolistriodon, Listriodon). Lopholistriodon is the most basal representative of the listriodontine clade. These first results stress the role of the African continent in the biogeographical history of the Listriodontinae. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 157 , 653–678.     

Speciation in the greater galagos (Prosimii: Galaginae): review and synthesis*

A marked morphological and genetical discontinuity among the greater galagos points to the existence of two genetical species within the taxon, Galago crassicaudatus E. Geofl'roy 1812. This contribution investigates the conditions surrounding this speciation event, and places it within a phylogenetic context. Information pertaining to body size, litter size, sexual dimorphism, locomotor mode and karyotypic structure is assessed. It is hypothesized that G. crassicaudatus diverged from its more gracile sibling, G. garnettii, approximately 2 million years ago, in respotise lo the increasing aridification of Africa that accompanied the Northern Hemisphere Pleistocene glaciations.     

Juvenile Hormone: The Status of "Status Quo"

SYNOPSIS. Cuticular proteins show specificity for stage, age,and anatomical region. Analysis of the cuticular proteins ofsecond pupae created by application of juvenile hormone demonstratesthat the hormone prevents the onset of new sequences of synthesesand favors repetition of the region-specific, temporal patternof syntheses used in the previous stage. The argument made isthat juvenile hormone might exert this "status quo" action bypreventing alterations in chromatin configuration. Evidencefrom a wide variety of systems shows that polyamines might beinvolved in reprogramming chromatin. Ecdysterone induces ornithinedecarboxylase, the rate limiting enzyme in animal polyaminesynthesis. I suggest that juvenile hormone might be exertingits status quo action by inhibiting this induction. Preliminarystudies of ornithine decarboxylase induction support this specifichypothesis; experiments with an inhibitor of this enzyme, -difluoromethylornithine, however, do not show the expected juvenile hormonemimicry. Further studies are needed to define the control ofpolyamine biosynthesis in insects and to discover whether juvenilehormone plays a role in this control.     

Effects of forest fire on headwater stream macroinvertebrate communities in eastern Washington,U.S.A.

1. Recent increases in fire frequency in North America have focused interest on potential effects on adjacent ecosystems, including streams. Headwaters could be particularly affected because of their high connectivity to riparian and downstream aquatic ecosystems through aquatic invertebrate drift and emergence. 2. Headwater streams from replicated burned and control catchments were sampled in 2 years following an intense forest fire in northeastern Washington (U.S.A.). We compared differences in benthic, drift and emergent macroinvertebrate density, biomass and community composition between five burned and five unburned catchments (14–135 ha). 3. There were significantly higher macroinvertebrate densities in burned than control sites for all sample types. Macroinvertebrate biomass was greater at burned sites only from emergence samples; in benthic and drift samples there was no significant difference between burn and control sites. 4. For all sample types, diversity was lower in the burned catchments, and the macroinvertebrate community was dominated by chironomid midges. 5. Compared to the effects of fire in less disturbed ecosystems, this study illustrated that forest fire in a managed forest may have greater effects on headwater macroinvertebrate communities, influencing prey flow to adjacent terrestrial and downstream aquatic habitats for at least the first 2 years post‐fire.     

Characterisation of watermelon curly mottle virus, a geminivirus distinct from squash leaf curl virus

Purified preparations of watermelon curly mottle virus (WCMoV), a whitefly-transmitted geminivirus, contained dimeric or geminate particles of 20 times 30 nm and the virus was transmissible by mechanical means. Virus yields ranged from 100–150 μg/100 g leaf tissue. Purified preparations exhibited a typical nucleoprotein absorbance profile with a maximum absorbance at 258 nm, and A280 / A260 ratio of 0.61–0.64. Infectivity was associated with two light-scattering, virus-containing bands following sucrose density gradient centrifugation. The viral capsid protein was resolved as a doublet by SDS-PAGE. The estimated mol. wts of the two bands within the doublet were 29 100 (±1550) and 27 733 (±1550), respectively. DNA isolated from virus particles was resolved by gel electrophoresis into two circular single-stranded DNA bands of approximately 2.6 to 2.7 kb. The two bands are believed to represent the individual components of a bipartite genome, characteristic of previously described whitefly-transmitted geminiviruses.     

What's Class Got to Do with It? American Society in the Twenty-First Century

What's Class Got to Do with It? American Society in the Twenty-First Century . Michael Zweig, ed. Ithaca, NY: Cornell University Press, 2004. 211 pp.