Antibody Detection of Marihuana

A reliable chemical means of assaying small quantities of marihuana or tetrahydrocannabinol (THC) isomers in body fluids and cell preparations has long been sought. A possible immunological approach was suggested by work with oestrogen haptens. It was established earlier that diazobenzoic acid under appropriate conditions enters the A ring by virtue of the phenolic function of C-3, yielding oestrogen azobenzoic acid derivatives^{1, 2}. These compounds are coupled readily through the benzoyl carboxyl to proteins and solid matrices containing accessible NH₂ groups, retaining the important antigenic specificities contributed by the reactive ?OH and = O groups as well as those associated with the ringed backbone^{1, 3}. Other biologically important molecules which lend themselves to similar manipulation are the principal psychotomimetics. In our search for useful haptens and active antibodies to be used in a reliable model assay system, we have chosen to report the investigation of THC. Similar results have been achieved with the phenanthrene alkaloids (S. J. G., unpublished) preserving all the determinant functional groups ^* unlike the reagent for morphine assay recently reported⁴.     

Science into policy: the role of research in the development of a recovery plan for farmland birds in England

The results of scientific research have played a central role in convincing decision-makers of the plight of farmland birds and in the development of land management measures and policies designed to reverse the population declines. Several types of study have contributed to what is now a considerable knowledge base on the ecological requirements of key species, the reasons for their declines and the remedial measures necessary to bring about population recovery. They include: monitoring; analyses of large-scale datasets; detailed studies of particular species, land-uses or land management practices; and the development and testing of solutions. As a consequence, there is now an excellent qualitative understanding of farmland bird ecology, which is well reflected in the suite of land management schemes and other policy initiatives that currently operate in England. Future research efforts should focus on the further development and testing of solutions and gaining a better understanding of the quantitative relationship between the provision of resources (especially nesting and foraging habitats) and the population response of target bird species. Such work should ensure that land management measures are deployed at the required scale, in appropriate locations and are of sufficient quality to influence the national populations of the declining species.     

The identity of the oomycete causing 'Kikuyu Yellows', with a reclassification of the downy mildews

Cultures of the causal fungus of Kikuyu Yellows disease of Pennisetum clandestinum isolated from Australia have been examined. The fungus is described. The oospore has three noteworthy features: it is plerotic even into the oogonial neck; the ooplast appears to develop a condensed core; the relative thicknesses of the oospore wall layers appear to differ from those of other Oomycetes. Oogonial characters and parasitism indicate an affinity with the graminicolous downy mildews. However, asexual sporulation is not immediately reconcilable with that of these mildews. A major re-appraisal of the classification of the peronosporalean fungi has been necessary to accommodate this fungus. Attention has been drawn to mycelial morphology. Three new orders and two new families are recognized. The division between the peronosporalean fungi and saprolegnialean fungi is recognized at the sub-class level.     

Saprophytic survival of Gaeumannomyces graminis and Phialophora spp. at various temperature-moisture regimes

The saprophytic survival of the pathogen, Gaeumannomyces graminis var. tritici and two isolates each of three avirulent fungi, G. graminis var. graminis, Phialophora graminicola and a lobed-hyphopodiate Phialophora sp. was studied in two soil types under controlled temperature and moisture conditions in the laboratory. In general, the fungi survived longest in the cool, dry soil (15°C, < -10 MPa) followed by the warm dry soil (30°C, < -10 MPa). All the fungi were virtually eliminated from the warm, moist soil (30°C, -0.3 MPa) after 3 months. Survival was intermediate under cool, moist conditions (15°C, -0.3 MPa). Under cool, moist conditions, G. graminis var. graminis survived better than the other three fungi in the first 3 months in both soil types and continued to do so for a further 3 months in one soil. Both isolates of the lobed-hyphopodiate Phialophora sp. survived poorly in the two soil types being almost eliminated after 3 months. There were considerable differences between the survival of the two isolates each of G. graminis var. graminis and P. graminicola, especially under cool, moist conditions. Of the six avirulent isolates studied, one isolate of G. graminis var. graminis (DAR24167) survived best under the three temperature-moisture regimes which showed differences. It also survived better than the take-all fungus under moist, cool conditions and at a comparable rate under dry conditions. Therefore, this variation in survival should be considered when selecting antagonists for the biological control of take-all.     

Effect of inoculum density, stage of plant growth and dew period on the incidence of black point caused by Alternaria alternata in durum wheat

Glasshouse studies showed that the incidence of black point caused by Alternaria alternata in durum wheat was positively correlated with both the density of the inoculum and the growth stage of the wheat plants at the time of inoculation. A curvilinear relationship of the form Y=a + log X was found between inoculum density and disease incidence. The incidence of black point was linearly related to the stage of plant growth, between anthesis and the late milk stages of development, at the time of inoculation. A better relationship between growth stage and disease incidence was found when plant growth was expressed as days after anthesis than when the Romig scale was used (R²= 0.30 and 0.24 respectively). A threshold dew period of 3–6 h was required for black point symptoms to develop. The incidence of black point increased with increasing duration of the dew period until maximum disease incidence occurred after exposure to a dew period of 48 h.