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131.
Summary The linked gas chromatographical/electroan-tennogram (GC/EAG) technique revealed that the parasitic reindeer nose bot fly is able to specifically sense components produced by the interdigital pheromone gland of reindeer. The head-space extraction technique, with Porapak Q as the collecting polymer, was used to trap pheromone gland and urine components used to assess fly responses. One component from reindeer urine also was a potent stimulus for the sensory neurons of the fly. These components can be important chemical signals to the flies for long distance orientation towards host animals. This is the first report on EAG in Oestridae.  相似文献   
132.
We studied the abundance, length-frequency distribution and body composition (lipid accumulation) of the ctenophore Mertensia ovum in Kongsfjorden, Svalbard (79°N) between May 2001 and April 2002. The highest abundances were found during summer in the outer and middle areas of the fjord, possibly caused by the concentration of advected zooplankton. Polymodal length-frequencies indicated a life span of 2 years, with 0, 1 and 2-groups being present in summer. Total lipid for a standardized animal decreased from May to August, and increased to the highest level in September. Relative lipid content was always highest in the 0-group, probably reflecting reduction of lipid levels due to increased energy costs during reproduction for the older age groups. Lipids probably are used to fuel prolonged reproduction from May to August until spawning ends by September. The overwintering age groups (0 and 1) subsequently build up lipid reserves for the next years’ spawning.  相似文献   
133.
Sixty healthy non-smoking white collar employees, aged 30–50, from a large corporation in Sweden participated in the study. There were four groups: 15 male and 15 female middle managers, 15 male and 15 female clerical workers. Each participant was examined individually with regard to cardiovascular and neuroendocrine functions and self-reports for 12 consecutive hours under each of two conditions: (1) a normal day at work (9 a.m.–5 p.m.) and after work (6–9 p.m.), and (2) for the same time period during work-free conditions at home. In addition, everyone was given a videotaped type A-interview and a general health check-up including blood-lipid determination. Attitudes towards work, total workload (including responsibilities outside the paid work) and sex role identity were examined by questionnaires. As expected, all groups showed a moderate increase in cardiovascular and neuroendocrine activity during the day at work. After work, however, interesting group differences emerged, suggesting slower unwinding in female managers. Differences related to occupational level and/ or sex were found for autonomy and social support at work, competitiveness, sex role and reported conflict between demands from paid work and other responsibilities. The stress profile of the female managers was considered in terms of possible long-term health risks.  相似文献   
134.
在地磁场中直接测量海水电导变化而产生的势能可以用来估算海洋通量.为了评估监测波罗的海气候的可行性,按照上述原理在瑞典沿岸建立了若干临时观测系统.本文给出了此类观测的一些结果,并且对在该领域开展进一步的工作做了展望.  相似文献   
135.
使用一种新方法-多余度分析(RDA),检查了是否挪威西部奈于斯特流域酸化的化学复原在大型底栖动物群落结构中产生了可测的复原.RDA结果与基于使用高度专门化和区域化界定的生物酸度指数测得的变化的复原测量值作了比较.我们发现,在1989~1998年期间,奈于斯特流域生物复原即开始出现.复原是在奈于斯特河上游及其各支流发生的.多变量方法已证明是酸度指数方法的一种补充,将两者结合使用能够得到大量的生物信息.RDA方法是一种保守的方法,即不会过高地估计生物复原,而且不像酸度指数,从地理上来说不会受到约束.我们还发现,一些季节性气候因素强烈地影响着底栖生物群落,可能引起对生物复原过程检测的混淆.  相似文献   
136.
Norovirus causes large outbreaks involving all age groups and are considered the most common cause of infectious foodborne diseases worldwide. The aim of this study was to describe a norovirus outbreak connected to insufficient heat treatment during preparation of a shellfish soup in serving portions, during a company Christmas celebration in Norway, December 2013. A questionnaire sent to the employees, showed that 67 % (n = 43) of the celebration participants, reported gastrointestinal symptoms including stomach pain, vomiting, diarrhoea and light fever in the period between 24 and 48 h post celebration. Several dishes were served, including shellfish soup made with carpet shell clams (Tapes rhomboides) in porcelain cups. Consuming this soup, was the only significant risk factor for infection. Norovirus GI and GII were detected in the remaining raw shellfish. To mimic the time and temperature obtained during bivalve soup preparation, raw chopped shellfish tissue and raw cepa onion were added in porcelain cups tempered to 20 °C. To each of these cups, boiling soup base was added. The temperature in the shellfish tissue was continuously recorded, and showed a maximum of 49 °C in the period between 3 and 7 min after adding the boiling soup base. After 1 h the temperature was 30 °C. This time and temperature combination was obviously not sufficient for inactivation of norovirus present in the shellfish tissue. In conclusion, the heat-absorbing capacity of cold ingredients, utensils and table wear porcelain should not be underestimated during food production. Consumers who want to avoid eating raw shellfish, should not assume that the shellfish tissue in preparation as described in our study is adequately heat treated.  相似文献   
137.
Coevolution is defined as specialized relationships between species that lead to a reciprocal evolutionary change. A particularly suitable model system for studying coevolution is the interactions between obligate avian brood parasites and their hosts. The common cuckoo (Cuculus canorus, hereafter cuckoo) is a well-known brood parasite, which utilizes a range of smaller passerines as hosts. However, warblers of the genus Hippolais have rarely been reported as being victims of cuckoos, and furthermore, few data exist on the occurrence of antiparasite defenses in these hosts. In this study, we examined possible host–parasite coevolution between cuckoos and eastern olivaceous warblers (Hippolais pallida elaeica, hereafter olivaceous warblers) in three closely situated areas in northwestern Bulgaria. The olivaceous warbler has never been reported to be a regular cuckoo host. However, the present study, carried out in 2001–2003 shows that the olivaceous warbler is regularly and heavily parasitized by the cuckoo in this area. Parasitism rate was high (26.6%, 34/128) and consistent among years, with some variation between areas. The cuckoo egg mimicry was moderately good, and olivaceous warbler rejection rate of such eggs was 50%. Cuckoo eggs laid in olivaceous warbler nests had a whitish to whitish-green ground color, and the majority appeared to be distinctly different from cuckoo eggs found in other host species in the area. The olivaceous warbler proved to be a rather good host for cuckoos as 20.6% (7/34) of cuckoo eggs laid produced fledglings, a breeding success comparable to other suitable hosts in Europe. This is the first in-depth study of brood parasitism in a warbler of the genus Hippolais, and cuckoos parasitizing olivaceous warblers probably represent a previously unknown gens.  相似文献   
138.
Depending on gender and activity, overcrowding and safety concerns may detract from urban green space use. Differences in use displacement intentions from a recreational trail in a forest in Vienna were investigated for male and female walkers as well as male and female dog-walkers (N = 425) using an image-based stated preference model. The trail scenarios were depicted as digitally calibrated images that systematically displayed combinations of levels of crowding with different mixes of user types and visitor behaviour. Visitors were asked whether the presented recreation scenario was so unacceptable that they would shift their use away from the presented trail. Hours and days of stated non-use of the recreation trail by various user groups are estimated by integrating the results of the behavioural model with annual visitation data. Use displacement intentions differed by gender and activity. High use levels were a greater concern for all respondents than very low use levels, particularly for female dog-walkers. However, only a small proportion of the recorded hours were heavily used. Safety concerns about very low use levels reduced the potential times of forest use for female walkers without a dog.  相似文献   
139.
Ice, George G., George W. Brown, John A. Gravelle, C. Rhett Jackson, Jeffrey T. Light, Timothy E. Link, Douglas J. Martin, Dale J. McGreer, and Arne E. Skaugset, 2010. Discussion –“Stream Temperature Relationships to Forest Harvest in Western Washington” by Michael M. Pollock, Timothy J. Beechie, Martin Liermann, and Richard E. Bigley. Journal of the American Water Resources Association (JAWRA) 46(4): 838-842. DOI: 10.1111/j.1752-1688.2010.00441.x  相似文献   
140.
Accident investigation manuals are influential documents on various levels in a safety management system, and it is therefore important to appraise them in the light of what we currently know – or assume – about the nature of accidents. Investigation manuals necessarily embody or represent an accident model, i.e., a set of assumptions about how accidents happen and what the important factors are. In this paper we examine three aspects of accident investigation as described in a number of investigation manuals. Firstly, we focus on accident models and in particular the assumptions about how different factors interact to cause – or prevent – accidents, i.e., the accident “mechanisms”. Secondly, we focus on the scope in the sense of the factors (or factor domains) that are considered in the models – for instance (hu)man, technology, and organization (MTO). Thirdly, we focus on the system of investigation or the activities that together constitute an accident investigation project/process. We found that the manuals all used complex linear models. The factors considered were in general (hu)man, technology, organization, and information. The causes found during an investigation reflect the assumptions of the accident model, following the ‘What-You-Look-For-Is-What-You-Find’ or WYLFIWYF principle. The identified causes typically became specific problems to be fixed during an implementation of solutions. This follows what can be called ‘What-You-Find-Is-What-You-Fix’ or WYFIWYF principle.  相似文献   
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