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71.
72.
蒲洼生态系统的规划与分析徐明(北京市气象局农气中心,100081)ProgrammingandAnalysisandAnalysisofPuwaEcosysten.¥XuMing(BeijingMeteorologicalBureau,100081)...  相似文献   
73.
Microtubers of 13 cultivars, largely grown in Italy and other European countries, were induced. They were stored in the dark at 3°C for different periods (28, 56, 84 and 105 days), prior to being transferred to 20°C for between 4 and 17 weeks. Following removal to room temperature, sprouting was recorded and dormancy duration quantified. Dormancy decreased from 28.1 to 19.9, 11.1 and 7.8 days with reduced time of storage. Cvs Arsy, Nicola and Jaerla took consistently more time for dormancy release. The dormancy duration was linearly and inversely correlated with the length of storage. After sprouting, tubers were held at 20°C for various intervals and a range of physiological ages (0, 368, 720 and 1008 degree days) were accumulated. The field comparison of microtubers evidenced a plant growth response and tuber yield/plant affected by the cultivar and physiological age. In early cultivars (Jaerla), a better performance was shown by younger tubers; the opposite trend was noted in Alpha (a later cultivar) with an increase in stems/plant, tubers/plant and tuber yield/plant for tubers with greater physiological age. Like conventional seed tubers, microtubers showed differences in optimum physiological age associated with cultivar earliness. This study has provided some indications on how to enhance emergence and haulm development of plants from microtubers.  相似文献   
74.
中欧生命科学领域国际合作的途径与步骤   总被引:1,自引:1,他引:0  
欧盟框架计划是欧盟科技发展的行动纲领,所设置的项目具有世界一流水平。从1983年开始实施科技框架计划以来,共制定实施了6个框架计划。目前正在实施的是第六框架计划(2002~2006),是第一个对中国全面开放的框架计划。第六框架计划七个优先主题领域中的第一个优先主题领域即“与健康相关的生命科学、基因组学和生物技术”。中方科研机构参加第六框架国际科技合作可采取“物色项目负责人、准备项目申请、通知科技部”三步走的快捷方案 。  相似文献   
75.
In food establishments, cleaning and disinfection programmes contribute to provide the environmental conditions that are necessary for the production of safe and healthy food. Compliance with validated programmes is evaluated through verification activities, in order to establish, through objective evidence, if they are implemented as they were written and if they are effective, achieving continuous improvement of the sanitation programmes. In accordance with the specific guidelines of each country, food companies set up their technical specifications and develop their own cleaning and disinfection programmes. Depending on the analytical method used, one of the main challenges was to establish a reasonable limit of acceptability according to the impact that each surface has on the safety and hygiene of the food that is prepared. This review was focused on the procedures implemented to verify the cleaning and disinfection programmes in food establishments. In particular, this study examines the methodologies used (audits and analytical methods), sites for the collection of samples, acceptance criteria and main findings. The results of the analysed studies constitute a scientific basis for designing or improving sanitation procedures and their verification in food companies, and also provide relevant information for food safety authorities.  相似文献   
76.
BackgroundThis is the first evaluation study to assess the demographic characteristics of the colorectal cancer (CRC) cases detected in the prevalent round of the population-based Colorectal Cancer Screening Programme (CRCSP) in Hong Kong and to explore the effectiveness of the programme on the stage distribution of CRC.MethodsThis study covered the period between 28 September 2016 and 31 December 2018. Information on CRC diagnosis, age and stage at diagnosis were retrieved and reviewed by the Hong Kong Cancer Registry (HKCaR). The CRC detection rate among CRCSP-screened participants and incidence rate among the Hong Kong general population were calculated respectively. The odds ratio (OR) was calculated to measure the strength of association and quantify the effect of CRCSP on stage shift between CRCSP-detected CRC cases and an age-matched cohort of CRC cases diagnosed outside the programme.ResultsThe CRC detection rate among participants of the CRCSP during the study period was 736.0/100,000, whereas the overall CRC incidence rate among general population of similar age groups was 393.7/100,000. For all ages and both sexes, the OR of stage I CRCSP-detected CRC compared to the CRC from the age-matched cohort was 3.91 (95%CI=3.41–4.48) and the OR dropped to 0.54 (95%CI=0.41–0.70) at stage IV. Meanwhile, the overall OR of CRCSP-detected CRC compared to CRC from the age-matched cohort dropped from 2.24 (95%CI=1.97–2.56) to 1.62 (95%CI=1.40–1.87) with increasing age.ConclusionThe present study has demonstrated the initial impact of the CRCSP on shifting the stage at diagnosis towards earlier stage. The benefit of stage-shift was similar for all ages from 60 to 77 in both sexes and seems to increase with younger age. Given the stage-dependent survival outcomes, this stage-shift could lead to a reduction in CRC-associated mortality in Hong Kong in future.  相似文献   
77.
At-sea observer programmes can provide spatio-temporal data on the sizes and quantities of fish being either discarded or retained, including for species and size categories that may not be sampled effectively during scientific surveys. Such data were analysed for English and Welsh fisheries operating on the continental shelf of the North Sea ecoregion (ICES Divisions 4a–c and 7d) and Celtic Seas ecoregion (ICES Divisions 6a, 7a–c, e–k) for the period (2002–2016). These data were collated for four main gear types: beamtrawl, nephrops and otter trawls, and nets (including gillnets, tangle nets and trammel nets). Beamtrawlers caught proportionally more smaller individuals than otter trawlers, whilst nets were the most size-selective gear for larger sharks. Size-related discarding was observed, with smaller spurdog Squalus acanthias and starry smooth-hound Mustelus asterias (< 60 cm total length, LT) usually being discarded. Such size-based selection was not evident for lesser-spotted dogfish Scyliorhinus canicula, which was generally landed as bait. Temporal changes in the discard–retention patterns were evident for S. acanthias and porbeagle Lamna nasus, with increased regulatory discarding as management measures became restrictive. A corresponding increase in the proportion of the non-quota M. asterias retained was also observed over the study period. Knowledge of the size-based discard–retention patterns by métier can also help inform on where future studies on discard survival could usefully be undertaken.  相似文献   
78.
Species identification tasks are generally accepted as fundamental aspects of biodiversity education. Our educational training unit, therefore, focused on identification skills by introducing stuffed specimens in combination with identification books and preparation booklets.We limited the number of bird species to six. 492 secondary school pupils (163 from 8th grade [high stratification level] and 329 from 9th grade [medium stratification level]) participated in the study. Instruction-1 pupils received a hands-on lesson about the natural history of six bird species, while Instruction-2 pupils were taught in a conventional teacher-centred manner. Pupils from the hands-on classes achieved significantly better grades in two follow-up tests. The measure of well-being was significantly enhanced by the teaching technique, while interest, anxiety and boredom were not affected. Additionally, pupils appreciated the opportunity of self-regulation. In general, a shift from the unspecific to the specific was observed: for instance, from duck and gull to mallard and black-headed gull. A reduction in the number of species presented to pupils within a lesson seems to enhance learning and retention effects.  相似文献   
79.
How predictive is a cervical smear suggesting invasive squamous cell carcinoma? Features have been described in severely dyskaryotic cervical smears that suggest frankly invasive or microinvasive squamous cell carcinoma. These are reported in three separate categories in our department. The aim of the current study was to assess the positive predictive value of these categories for invasive disease on histology. All smears reported in these categories over a five year period were correlated with the histology results. 527 smears were assessed. The positive predictive value of a smear suggesting frank invasion was 55.7% for all invasive squamous carcinomas and 40% for stage IB or above. Smears suspicious of invasion or microinvasion predicted invasive disease in 22.3% and 17.2%, respectively, most carcinomas being stage IA. Invasive squamous cell carcinoma may be predicted to a limited degree by cervical cytology especially when the smear suggests frank invasion.  相似文献   
80.
Recent evaluations of both temporal and spatial precision in bird migration have called for external cues in addition to the inherited programme defining the migratory journey in terms of direction, distance and fuelling behaviour along the route. We used juvenile European robins (Erithacus rubecula) to study whether geomagnetic cues affect fuel deposition in a medium-distance migrant by simulating a migratory journey from southeast Sweden to the wintering area in southern Spain. In the late phase of the onset of autumn migration, robins exposed to the magnetic treatment attained a lower fuel load than control birds exposed to the ambient magnetic field of southeast Sweden. In contrast, robins captured in the early phase of the onset of autumn migration all showed low fuel deposition irrespective of experimental treatment. These results are, as expected, the inverse of what we have found in similar studies in a long-distance migrant, the thrush nightingale (Luscinia luscinia), indicating that the reaction in terms of fuelling behaviour to a simulated southward migration varies depending on the relevance for the species. Furthermore, we suggest that information from the geomagnetic field act as an important external cue overriding the seasonal effect on fuelling behaviour in migratory birds.  相似文献   
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