Proteins represent a large portion of organic nitrogen and carbon in wastewater treatment effluents, but their detailed characteristics and their role and fate in receiving waters are virtually unknown. We used two protein fractionation techniques to characterize effluent proteins and proteolytic enzymes in three activated sludge plants, as a first step to elucidate the fate and role of proteins in receiving water environments. The quantitative data first showed that the protein concentration in primary and secondary effluents was significantly correlated with organic nitrogen and could comprise up to 60% of effluent organic nitrogen. Protein separation results showed that some proteins persisted through secondary treatment, while others were produced during biological treatment. Despite a high similarity of protein and enzyme profiles in primary effluent across three facilities, those in secondary effluent were consistently different, suggesting that effluent proteins could serve as markers of different wastewater treatment works. These profile fingerprints can be used to track effluent proteins in laboratory bioassays, or directly in receiving waters, and may permit the determination of the fate of effluent proteins, and thus a significant fraction of effluent organic nitrogen, in the environment.
Mutations in the genes for components of the dynein-dynactin complex disrupt axon path finding and synaptogenesis during metamorphosis in the Drosophila central nervous system. In order to better understand the functions of this retrograde motor in nervous system assembly, we analyzed the path finding and arborization of sensory axons during metamorphosis in wild-type and mutant backgrounds. In wild-type specimens the sensory axons first reach the CNS 6-12 h after puparium formation and elaborate their terminal arborizations over the next 48 h. In Glued1 and Cytoplasmic dynein light chain mutants, proprioceptive and tactile axons arrive at the CNS on time but exhibit defects in terminal arborizations that increase in severity up to 48 h after puparium formation. The results show that axon growth occurs on schedule in these mutants but the final process of terminal branching, synaptogenesis, and stabilization of these sensory axons requires the dynein-dynactin complex. Since this complex functions as a retrograde motor, we suggest that a retrograde signal needs to be transported to the nucleus for the proper termination of some sensory neurons.
We evaluated the egg parasitoid Trichogramma ostriniae (Pang et Chen) (Hym.: Trichogrammatidae) for control of European corn borer [Lep.:Crambidae: Ostrinia nubilalis (Hu¨bner)] in fields of commercial processing sweet corn in New York in 2002 and 2003.We made inoculative releases of 75 000 T. ostriniae/ha when corn was at midwhorl and regional O. nubilalis activity had begun. Each release field was paired with a similar non-release control. The incidence of egg mass parasitism, number of stalk tunnels, incidence of ear damage and effect on insecticide spray decisions were evaluated. Parasitism of cumulative number of O. nubilalis egg masses was 51.3 ± 7.2% and 43.5 ± 5.7% (mean ± SEM) in release fields in 2002 and 2003 respectively. The incidence of ear damage by O. nubilalis was not affected by T. ostriniae in either year of the study. There was no difference in stalk damage between release fields and control fields in either 2002 or 2003. However, individual comparisons between paired release and control fields showed reduced stalk tunnelling in 10 of 19 fields, but ear damage was reduced in only two of 19 fields. Neither the number of actual insecticide sprays nor the number of decisions to spray based on sequential sampling were affected significantly by releasing T. ostriniae. In a separate but related study, where releases were conducted in commercial fresh market sweet corn and used higher rates of release, T. ostriniae had no effect on the number of insecticidal sprays. In an additional experiment using small plots of sweet corn, ear damage was similar whether plots were treated with T. Ostriniae or with insecticide. Additional research should focus on improving the timing, frequency and rate of releases.
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