开放性——互联网的DNA

开放性是互联网最根本的特性，互联网的开放性不仅仅是技术层面上的，它还有更深的内涵。在过去的15年，随着覆盖面越来越大，互联网的增长速度不断加快，互联网意义越来越重大。互联网的开放标准使得“互连”更加便宜和便捷，消融了学术之间、企业之间以及消费者网络之间的界限。正如国家之间的自由贸易协定增加了市场规模、扩大了收益，互联网...     

Failure to establish congenital bluetongue virus infection by infecting cows in early pregnancy.

Two groups of 10 pregnant cows were inoculated with bluetongue virus type 11 at either 40 or 60 days of gestation. All the cows became infected as judged by the detection of viraemia and seroconversion but they showed no clinical signs. Seventeen of the cows produced live calves none of which showed any evidence of prenatal infection. After challenge with the same virus all the calves became viraemic and seroconverted. The response to challenge of the two groups did not differ from that of a control group challenged at the same time. It was concluded that the infection of pregnant cows in early gestation with this virus did not result in the transplacental infection of the fetuses and did not produce immunotolerant, latently infected calves.     

Use of an animal model in situations of limited subclass numbers and high degrees of relationships

Breeding value estimation procedures for two traits with moderate and high heritability were evaluated by using a single-trait animal model and computer-simulated data designs. Of interest were the effects of differing numbers of animals and degrees of relationships among animals within and across contemporary groups (tests). Test effects were assumed fixed and animal effects were assumed random. Family size, number of families per contemporary group, and degree of genetic relationships within and across contemporary groups were varied to determine interrelationships among the factors. Results were compared on the basis of accuracy by using both the correlation of true and estimated breeding values and the prediction error variance obtained from the inverse of the coefficient matrix of the mixed-model equations. Small contemporary groups in conjunction with evaluation of closely related families caused average accuracy to decrease relative to that obtained with the same number of unrelated animals because genetically related animals were less accurately evaluated relative to one another. Connecting contemporary groups with a genetic relationship matrix formed a large set of interdependent equations and improved the average accuracy of predicted breeding values. The slight decrease in accuracy for genetically related animals was more than offset by the increase in accuracy of evaluation for their unrelated test mates because the proportion of fixed effects to random effects was smaller. Care must be exercised in designing evaluation schemes involving small populations, and the decision of which fixed effects to include in the model is critical.     

Intravenous administration of 9-aminocamptothecin to dogs with lymphoma

A colloidal dispersion formulation of 9‐aminocamptothecin (9‐AC) was administered intravenously to 10 dogs with previously untreated, spontaneously occurring, multicentric lymphoma. The dogs received a 72‐h infusion of 9‐AC at a rate of 46.5–51.25 µg m^?2 h^?1 (total dose range 3.35–3.69 mg m^?2). This dose range was associated with myelosuppression, consisting principally of neutropenia with a nadir at 7 days following the start of infusion. Neutropenia and thrombocytopenia were the most common toxicoses and are most likely to be dose‐limiting toxicities; low‐grade gastrointestinal signs were rarely seen. Concentrations of 9‐AC lactone, as well as clinical toxicities, compare favourably with those found in humans. Tumour responses were seen in all treated dogs. Response to other chemotherapy, following cessation of 9‐AC treatment, was not obviously compromised even in dogs clinically resistant to 9‐AC. 9‐AC is a novel treatment drug for canine lymphoma, which appears to show great promise.     

Production and characterization of monoclonal antibodies specific for bovine gamma-interferon

Nine stable hybridoma cell lines were established which secreted specific monoclonal antibodies (MAbs) to bovine gamma-interferon (BoIFN-gamma). Specific binding of each of the MAbs to recombinant BoIFN-gamma (rBoIFN-gamma) was demonstrated in an indirect ELISA, whilst none of the MAbs bound to rBoIFN-alpha or rBoIFN-beta. In a Western blot the MAbs reacted with the 16 kDa and 32 kDa polypeptides present in rBoIFN-gamma preparations. Competitive ELISA's showed that four MAbs bound to one epitope on rBoIFN-gamma, and the other five MAbs bound to a separate epitope. Two MAbs, each recognising different epitopes, were shown to neutralise the anti-viral activity of natural BoIFN-gamma.     

The effect of environment on level of resistance to Phomopsis leptostromiformis in lupins and implications for resistance breeding to this disease

Summary Four varieties of lupins were sown at three planting dates and the level of Phomopsis leptostromiformis measured on the mature stems. When averaged over planting dates the varieties did not differ in resistance to this disease, however there were highly significant interactions between varieties and planting dates for level of disease. The implications of this result for resistance breeding to Phomopsis leptostromiformis are discussed.     

Determination of aflatoxin concentrations in peanut butter by enzyme-linked immunosorbent assay (ELISA): study of three commercial ELISA kits

Sixteen United Kingdom analytical laboratories participated in an evaluation of 3 commercially available enzyme-linked immunosorbent assay (ELISA) kits for analysis of aflatoxin in peanut butter. Each laboratory was sent 3 sets of 10 randomly numbered samples of peanut butter. Each set consisted of 5 pairs of undisclosed duplicates. Four of the sets of duplicates were naturally contaminated butters with "target" aflatoxin values (estimated by liquid chromatography) between 8 and 81 micrograms/kg. The fifth pair was a blank peanut butter containing approximately 3 micrograms/kg of total aflatoxins. A statistical treatment of the results of the study is presented, together with discussion of the relative merits of the different kits.     

The Potted-Plant Microcosm Substantially Reduces Indoor Air VOC Pollution: I. Office Field-Study

Volatile organic compounds (VOCs) are major contaminants of indoor air, with concentrations often several times higher than outdoors. They are recognized as causative agents of “building-related illness” or “sick-building syndrome”. Our previous laboratory test-chamber studies have shown that the potted-plant/root-zone microorganism microcosm can eliminate high concentrations of air-borne VOCs within 24 hours, once the removal response has been induced by an initial dose. However, the effectiveness of the potted-plant microcosm in ‘real-world’ indoor spaces has never previously been tested experimentally. This paper reports the results of a field-study on the effects of potted-plant presence on total VOC (TVOC) levels, measured in 60 offices (12 per treatment), over two 5–9 week periods, using three planting regimes, with two ‘international indoor-plant’ species. Fourteen VOCs were identified in the office air. When TVOC loads in reference offices rose above 100 ppb, large reductions, of from 50 to 75% (to <100 ppb), were found in planted offices, under all planting regimes The results indicate that air-borne TVOC levels above a threshold of about 100 ppb stimulate the graded induction of an efficient metabolic VOC-removal mechanism in the microcosm. Follow-up laboratory dose-response experiments, reported in the following paper, confirm the graded induction response, over a wide range of VOC concentrations. The findings together demonstrate that potted-plants can provide an efficient, self-regulating, low-cost, sustainable, bioremediation system for indoor air pollution, which can effectively complement engineering measures to reduce indoor air pollution, and hence improve human wellbeing and productivity.