The role of effluent monitoring in environmental control

Using effluent data from a British Columbia pulp mill, the authors demonstrate certain critical deficiencies associated with currently emplaced monitoring systems. The principal ingredient in effective environmental control is information, and current monitoring regimes entail an unacceptable level of information loss. Composite sampling systems fail to provide the two key types of information required for effective environmental control: (i) a high representational accuracy of the effluent profile; and (ii) the detection of most or all pollutant releases with potentially serious environmental consequences. In light of these conclusions, the authors make several recommendations concerning current and alternative sampling regimes.     

Comparative biological and biochemical studies in hybrid chicks. 3. Vaccination with inactivated newcastle disease vaccine and its effect on serum protein concentrations

The potency of an inactivated Newcastle disease vaccine containing a number of strains of virus (vaccine 1) was greater in 28‐day old‐chicks of a hybrid strain (hybrid A) than in Rhode Island Red X Light Sussex chicks. Vaccination with one PD50 of vaccine 1 or vaccine 2 (a single strain vaccine) produced only minor changes in the electro‐phoretically determined serum protein composition in two hybrid strains (A and B) at a time when maximum immunity had developed.     

Expression of the chicken lysozyme gene in potato enhances resistance to infection byErwinia carotovora subsp.atroseptica

Infection of potato plants and tubers with the bacteriumErwinia carotovora subsp.atroseptica produces blackleg and soft rot diseases, which cause significant losses to crops and stored potatoes. In order to obtain resistance against this bacterium, the genechly encoding the enzyme lysozyme from chicken was introduced into potato plants (cv. Desirée) viaAgrobacterium- mediated transformation. Sixty-three and 69 transgenic potato clones were evaluated in the greenhouse for resistance to blackleg and soft rot diseases, respectively. Results reported in this paper indicate that 21%-29% of the potato clones showed increased resistance to infection by the bacteriumE. c. subsp.atroseptica T7, as revealed by a reduced severity of blackleg or soft rot symptoms. Nine clones showing different levels of resistance were selected for further molecular analysis. The number of copies of the transgene integrated in the plant genome of these clones was estimated by Southern blot analysis. The level of transgene expression, detected by Northern blot analysis, correlated with the level of resistance detected in these clones.     

Early forebrain wiring: genetic dissection using conditional Celsr3 mutant mice

Development of axonal tracts requires interactions between growth cones and the environment. Tracts such as the anterior commissure and internal capsule are defective in mice with null mutation of Celsr3. We generated a conditional Celsr3 allele, allowing regional inactivation. Inactivation in telencephalon, ventral forebrain, or cortex demonstrated essential roles for Celsr3 in neurons that project axons to the anterior commissure and subcerebral targets, as well as in cells that guide axons through the internal capsule. When Celsr3 was inactivated in cortex, subcerebral projections failed to grow, yet corticothalamic axons developed normally, indicating that besides guidepost cells, additional Celsr3-independent cues can assist their progression. These observations provide in vivo evidence that Celsr3-mediated interactions between axons and guidepost cells govern axonal tract formation in mammals.