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51.
A National Swedish Environmental Monitoring Programme, the PMK, has been designed for regular and permanent recording of environmental conditions and long-term changes in background regions, and for keeping track of the flux of pollutants in and between various media. Many of the projects involved deal with integrated monitoring of terrestrial and limnic ecosystems. This work is carried out in or near some 20 small watersheds, usually selected in national parks or nature reserves. The environmental factors monitored in these areas include concentrations of chemical substances in precipitation, soil, groundwater, surface water, and organisms, as well as biological parameters—such as the population size and reproductive capacity of certain species—that may indicate effects of environmental disturbances. The data from this programme can be used as a reference to environmental data acquired near pollution sources, and as a basis for measures against e.g. acid rain, heavy-metal pollution, and use of pesticides. The biological parameters may also reveal effects of yet unknown pollutants or other disturbances.  相似文献   
52.
Here we present the pooled analysis of 2 case-control studies on the association of brain tumours with mobile phone use. Use of analogue cellular phones increased the risk for acoustic neuroma by 5%, 95% confidence interval (CI) = 2-9% per 100 hrs of use. The risk increased for astrocytoma grade III-IV with latency period with highest estimates using >10-year time period from first use of these phone types. The risk increased per one year of use of analogue phones by 10%, 95% CI = 6-14%, digital phones by 11%, 95% CI = 6-16%, and cordless phones by 8%, 95% CI = 5-12%. For all studied phone types OR for brain tumours, mainly acoustic neuroma and malignant brain tumours, increased with latency period, especially for astrocytoma grade III-IV.  相似文献   
53.
In birds, there is ample evidence that the mother can manipulate the sex of the young and produce more of the sex, which gives the highest fitness return. This has previously been documented in gulls, Laridae. Gulls are sexually size dimorphic with males larger than females, and there is good evidence that parents in poor body condition switch their investment to the smallest sex. In the present study, we examined the primary sex ratio and the survival of male and female chicks of lesser black-backed gull (Larus fuscus fuscus) in relation to their blood levels of organochlorines (OCs), perfluorinated compounds (PFCs) and polybrominated diphenyl ethers (BDE-47). We show that females with high levels of OCs (but not PFCs and BDE-47) are likely to skew their sex ratio at hatching towards female offspring. Few females had very high levels of OCs, and the many females with low levels of OCs overproduced sons resulting in a male skew at hatching (59%). The survival of female offspring was lower than the survival of male offspring, causing an even stronger male skew in sex ratio (71%). There is evidence to conclude that circulating levels of OCs in the blood of females may have detrimental effect on the sex allocation strategy and could be of serious threat to the population. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
54.
This investigation provides an examination of the validity of the Job Diagnostic Survey (JDS) and the Job Characteristics Inventory (JCI). The verbal content of the two measure is examined, as are the contrasts between the verbal content of these scales and the verbal content of three popular measures of job satisfaction. The Minnesota Contextual Content Analysis program is used to examine the ideas emphasized by these research scales. Both measures of job characteristics were found to discriminate from certain measures of job satisfaction, to emphasize an instrumental and not an affective context, and to possess some internal dimensionality problems.  相似文献   
55.
The great black-backed gull Larus marinus is a top predator in subarctic and temperate marine ecosystems, and the aim of this study was to investigate if organochlorines (OCs) were related to reproductive performance in this species at the subarctic parts of the Norwegian Coast. We measured blood levels of various OCs in 53 breeding birds. The OC levels were relatively low compared to levels found in nearby arctic areas. In females, however, there was a significant positive relationship between blood concentrations of OCs, especially hexachlorobenzene (HCB) and, p,p'-dichlorodiphenyldichloroethylene (DDE), and egg laying date, and a positive relationship between the probability of nest predation and blood concentration of beta-hexachlorocyclohexane (beta-HCH), oxychlordane, and DDE. In females with high levels of OCs, especially persistent polychlorinated biphenyls (PCBs), there was also a decline in egg volume as egg laying progressed; i.e. the second and third laid egg were relatively smaller, compared to females with low OC levels. No relationships between reproductive parameters and OC levels were found in males.  相似文献   
56.
The landscape-level and multiscale biodiversity monitoring program National Inventory of Landscapes in Sweden (NILS) was launched in 2003. NILS is conducted as a sample-based stratified inventory that acquires data across several spatial scales, which is accomplished by combining aerial photo interpretation with field inventory. A total of 631 sample units are distributed across the land base of Sweden, of which 20% are surveyed each year. By 2007 NILS completed the first 5-year inventory phase. As the reinventory in the second 5-year phase (2008?C2012) proceeds, experiences and insights accumulate and reflections are made on the setup and accomplishment of the monitoring scheme. In this article, the emphasis is placed on background, scope, objectives, design, and experiences of the NILS program. The main objective to collect data for and perform analyses of natural landscape changes, degree of anthropogenic impact, prerequisites for natural biological diversity and ecological processes at landscape scale. Different environmental conditions that can have direct or indirect effects on biological diversity are monitored. The program provides data for national and international policy and offers an infrastructure for other monitoring program and research projects. NILS has attracted significant national and international interest during its relatively short time of existence; the number of stakeholders and cooperation partners steadily increases. This is constructive and strengthens the incentive for the multiscale monitoring approach.  相似文献   
57.
We studied the effects of heavy metal exposure on host plant choice and performance of the grass miner Chromatomyia milii (Diptera, Agromyzidae). Cadmium decreased plant growth in a dose-dependent way. C. milii preferred the control to the cadmium-exposed plants for feeding and oviposition. Moreover, preference for the control plants increased with increasing cadmium exposure of the alternative choice. Adult and offspring performance decreased with increasing plant cadmium exposure. This suggests that, at least under our laboratory conditions, host choice of C. milii is adaptive under pollution stress. Foliar cadmium concentration increased and the soluble sugar concentration decreased with increasing cadmium exposure. Regression analysis showed that both latter components might be responsible for the decrease in performance of C. milii on cadmium-exposed plants. The protein and amino acid concentration of the leaves, the amount of structural defenses, and water concentration were not affected by the cadmium treatment.  相似文献   
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