Environmental tobacco smoke in commercial aircraft

Environmental tobacco smoke and other pollutants present in both smoking and nonsmoking cabin sections during commercial passenger flights on DC-10 aircraft were determined on four, 5-h smoking flights. The average concentrations of nicotine, 3-ethenylpyridine, CO₂, CO, NO_x, NO₂, O₃, PM2.5 and environmental tobacco smoke particles during a flight were determined with a briefcase sampling system. Concentrations of nicotine, 3-ethenylpyridine and CO as well as temperature, humidity and pressure were determined as a function of time during the flight. A model to predict penetration of environmental tobacco smoke from the smoking to the nonsmoking section of the passenger cabin under a variety of flight conditions is derived from the data.     

炼油厂污水处理负荷的削减措施

总结和分析了某厂削减污水处理负荷的主要措施及效益，预测该厂在达到16000kt/a以上加工规模时的污水处理负荷。     

'Molecular farming' of antibodies in plants

'Molecular farming' is the production of valuable recombinant proteins in transgenic organisms on an agricultural scale. While plants have long been used as a source of medicinal compounds, molecular farming represents a novel source of molecular medicines, such as plasma proteins, enzymes, growth factors, vaccines and recombinant antibodies, whose medical benefits are understood at a molecular level. Until recently, the broad use of molecular medicines was limited because of the difficulty in producing these proteins outside animals or animal cell culture. The application of molecular biology and plant biotechnology in the 1990s showed that many molecular medicines or vaccines could be synthesised in plants and this technology is termed 'molecular farming'. It results in pharmaceuticals that are safer, easier to produce and less expensive than those produced in animals or microbial culture. An advantage of molecular farming lies in the ability to perform protein production on a massive scale using hectares of cultivated plants. These plants can then be harvested and transported using the agricultural infrastructure. Thus, molecular farming allows rapid progress from genetic engineering to crop production, and new cash crops producing recombinant proteins are already being commercially exploited. We speculate that as functional genomics teaches us more about the nature of disease, molecular farming will produce many of the protein therapeutics that can remedy it.     

Reduced Chitinase Activities in Ant Plants of the Genus Macaranga

Many plant species have evolved mutualistic associations with ants, protecting their host against detrimental influences such as herbivorous insects. Letourneau (1998) reported in the case of Piper that ants defend their plants principally against stem-boring insects and also reduce fungal infections on inflorescences. Macaranga plants that were experimentally deprived of their symbiotic Crematogaster ants suffered heavily from shoot borers and pathogenic fungi (Heil 1998). Here we report that ants seem to reduce fungal infections actively in the obligate myrmecophyte Macaranga triloba (Euphorbiaceae), while ant-free plants can be easily infected. We also found extremely low chitinase activity in Macaranga plants. The plants' own biochemical defense seems to be reduced, and low chitinase activity perhaps may represent a predisposition for the evolution of myrmecophytism. These plants are therefore highly dependent on their ants, which obviously function not only as an antiherbivore defense but also as an effective agent against fungal pathogens. Received: 5 August 1998 / Accepted in revised form: 18 November 1998     

Reduced light avoidance in spiders from populations in light-polluted urban environments

Increased urbanisation is leading to a rise in light pollution. Light pollution can disrupt the behaviour and physiology of animals resulting in increased mortality. However, animals may also benefit from artificial light sources, as these may aggregate prey or signal suitable environments. For example, spiders are commonly seen congregating around artificial light sources. Changes in selective pressures engendered by urban environments are driving changes in urban organisms, driving better adaptation to these environments. Here, we ask whether urban populations of the synanthropic spider Steatoda triangulosa show different responses to light compared to rural populations. Egg-sacs from urban and rural populations were collected and incubated in a common garden setting, and the emerging spiderlings tested for light preference. While rural spiderlings avoided light (37% built webs in the light), urban spiderlings were indifferent to it (49% built webs in the light). Reduced light avoidance may benefit spiders through increased prey capture, increased movement into suitable habitats, or due to a release from selection pressure from visually hunting predators which do not enter buildings.