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11.
Projected climate change might increase the deposition of nitrogen by about 10% to seminatural ecosystems in southern Norway. At Storgama, increased precipitation in the growing season increased the fluxes of total organic carbon (TOC) and total organic nitrogen (TON) in proportion to the water flux. In winter, soil temperatures near 0 degrees C, common under a snowpack, induced higher runoff of inorganic nitrogen (N) and lower runoff of TOC. By contrast, soil temperatures below freezing, caused by little snow accumulation (expected in a warmer world), reduced runoff of inorganic N, TON, and TOC. Long-term monitoring data showed that reduced snowpack can cause either decreased or increased N leaching, depending on interactions with N deposition, soil temperature regime, and winter discharge. Seasonal variation in TOC was mainly climatically controlled, whereas deposition of sulfate and nitrate (NO3) explained the long-term TOC increase. Upscaling to the river basin scale showed that the annual flux of NO3 will remain unchanged in response to climate change projections.  相似文献   
12.
Objective: The aim of this study is to develop an on-scene injury severity prediction (OSISP) algorithm for truck occupants using only accident characteristics that are feasible to assess at the scene of the accident. The purpose of developing this algorithm is to use it as a basis for a field triage tool used in traffic accidents involving trucks. In addition, the model can be valuable for recognizing important factors for improving triage protocols used in Sweden and possibly in other countries with similar traffic environments and prehospital procedures.

Methods: The scope is adult truck occupants involved in traffic accidents on Swedish public roads registered in the Swedish Traffic Accident Data Acquisition (STRADA) database for calendar years 2003 to 2013. STRADA contains information reported by the police and medical data on injured road users treated at emergency hospitals. Using data from STRADA, 2 OSISP multivariate logistic regression models for deriving the probability of severe injury (defined here as having an Injury Severity Score [ISS] > 15) were implemented for light and heavy trucks; that is, trucks with weight up to 3,500 kg and ??16,500 kg, respectively. A 10-fold cross-validation procedure was used to estimate the performance of the OSISP algorithm in terms of the area under the receiver operating characteristic curve (AUC).

Results: The rate of belt use was low, especially for heavy truck occupants. The OSISP models developed for light and heavy trucks achieved cross-validation AUC of 0.81 and 0.74, respectively. The AUC values obtained when the models were evaluated on all data without cross-validation were 0.87 for both light and heavy trucks. The difference in the AUC values with and without use of cross-validation indicates overfitting of the model, which may be a consequence of relatively small data sets. Belt use stands out as the most valuable predictor in both types of trucks; accident type and age are important predictors for light trucks.

Conclusions: The OSISP models achieve good discriminating capability for light truck occupants and a reasonable performance for heavy truck occupants. The prediction accuracy may be increased by acquiring more data. Belt use was the strongest predictor of severe injury for both light and heavy truck occupants. There is a need for behavior-based safety programs and/or other means to encourage truck occupants to always wear a seat belt.  相似文献   
13.
This article discusses the strengths and weaknesses of various kinds of standardization, when applied to the field of safety management. Recently, there are signs that organizations operating in high risk environments take further steps towards standardization. On the positive side, standardization has the potential to enhance the predictability of normal operations as well as facilitating the transfer of lessons learnt across organizational contexts. On the negative side, standardization is by definition a strategy for dealing with known hazards and accident scenarios. We discuss how too strong an emphasis on standardization can involve unintended negative consequences for organizations’ crisis-handling capabilities.  相似文献   
14.
Objective: Driver fatigue is considered to be a major contributor to road traffic crashes. Cardiac monitoring and heart rate variability (HRV) analysis is a candidate method for early and accurate detection of driver sleepiness. This study has 2 objectives: to evaluate the (1) suitability of different preprocessing strategies for detecting and removing outlier heartbeats and spectral transformation of HRV signals and their impact of driver sleepiness assessment and (2) relation between common HRV indices and subjective sleepiness reported by a large number of drivers in real driving situations, for the first time.

Methods: The study analyzed >3,500 5-min driving epochs from 76 drivers on a public motorway in Sweden. The electrocardiograph (ECG) data were recorded in 3 studies designed to evaluate the physiological differences between awake and sleepy drivers. The drivers reported their perceived level of sleepiness according to the Karolinska Sleepiness Scale (KSS) every 5?min. Two standard methods were used for identifying outlier heartbeats: (1) percentage change (PC), where outliers were defined as interbeat intervals deviating >30% from the mean of the four previous intervals and (2) standard deviation (SD), where outliers were defined as interbeat interval deviating >4 SD from the mean interval duration in the current epoch. Three standard methods were used for spectral transformation, which is needed for deriving HRV indices in the frequency domain: (1) Fourier transform; (2) autoregressive model; and (3) Lomb-Scargle periodogram. Different preprocessing strategies were compared regarding their impact on derivation of common HRV indices and their relation to KSS data distribution, using box plots and statistical tests such as analysis of variance (ANOVA) and Student’s t test.

Results: The ability of HRV indices to discriminate between alert and sleepy drivers does not differ significantly depending on which outlier detection and spectral transformation methods are used. As expected, with increasing sleepiness, the heart rate decreased, whereas heart rate variability overall increased. Furthermore, HRV parameters representing the parasympathetic branch of the autonomous nervous system increased. An unexpected finding was that parameters representing the sympathetic branch of the autonomous nervous system also increased with increasing KSS level. We hypothesize that this increment was due to stress induced by trying to avoid an incident, because the drivers were in real driving situations.

Conclusions: The association of HRV indices to KSS did not depend on the preprocessing strategy. No preprocessing method showed superiority for HRV association to driver sleepiness. This was also true for combinations of methods for frequency domain HRV indices. The results prove clear relationships between HRV indices and perceived sleepiness. Thus, HRV analysis shows promise for driver sleepiness detection.  相似文献   
15.
Mate sampling behaviour of black grouse females (Tetrao tetrix)   总被引:2,自引:0,他引:2  
We studied female mate sampling behaviour in lekking black grouse (Tetrao tetrix). Females mainly visited males occupying territories in the centre of the lek with relatively large territories. They were also more likely to visit males that had high attendance. The same factors were also correlated with male mating success. A multiple regression model including these factors explained more of the variance in female visits per male (53%) than in mating success (33%). The pattern of female sampling conformed with a pool comparison (best-of-n) tactic. Such a tactic is expected if the costs of sampling are low. Females of high body mass visited more males than lighter females, however, which indicates that females may vary in their search tactics and suggests that there may be search costs. The existence of costs is further suggested by the fact that if the mate from a previous year was still present, females always mated with the same male in the following year. Though search costs were not measured directly, our findings suggest that some costs are negligible (e.g. energetic exhaustion or predation) whereas others (timing of mating) may be more important.  相似文献   
16.
17.
High concentrations of Cu of up to 200 mg/kg, and Cd of up to 4.0 mg/kg, were found in sediments from the aquatic environment around Sisimiut, Greenland. These concentrations are four times higher than the limiting concentration where toxicological effects are expected. The pollution could be linked to human activities in Sisimiut, a link that have not been investigated previously in Greenland. Except from the most polluted samples there was good correlation between heavy metal concentration and organic matter. Also some relationship between fine fraction and heavy metal concentration was observed.  相似文献   
18.
Summary Using the linked gas chromatographical/electroantennogram (GC/EAG) technique it was revealed that the reindeer warble fly (H. tarandi) was specifically able to sense the same components from reindeer interdigital pheromone gland as the reindeer nose bot fly (C. trompe) another reindeer endoparasite. These two species belong to the same family (Oestridae), but different subfamilies, and the evolution towards an endoparasitic life cycle is thought to have been independent. The development of olfactory abilities to find reindeer from long distances is hypothesized to have taken place through convergent evolution or exists because of their common ancestry.  相似文献   
19.
The outer layer of the eggshell in birds is in many cases covered by pigments that are assumed to be genetically determined traits with a negligible environmental component. To test the hypothesis that spring environmental conditions (i.e., temperature and rainfall) may affect bird egg pigmentation, we measured by spectrophotometry and photography egg coloration and spottiness on reed warbler (Acrocephalus scirpaceus L.) clutches parasitized by the common cuckoo (Cuculus canorus L.) collected over a period of 24 years and preserved in the Zoological Museum, Copenhagen, Denmark. In addition, we investigated whether spring environmental conditions may influence the coevolutionary relationship between the cuckoo and its host via changes in cuckoo–host egg matching. Generalized mixed models revealed that reed warbler eggs were more brilliant in those springs with a higher rainfall and tended to be bluer and greener in springs with a lower relative temperature. On the other hand, cuckoo eggs were bluer and greener in springs with a higher rainfall. Cuckoo–host egg matching in blue-greenness and spottiness was better in springs with a higher rainfall. These results provide support for the existence of an environmental component on bird egg coloration and suggest that environmental factors may potentially affect the outcome of important features of the arms race between cuckoos and reed warblers.  相似文献   
20.
Despite political efforts, diffuse pollution from agriculture continues to be the single largest source of nitrogen (N) emissions into the aquatic environment in many countries and regions. This fact, and the recent enactment of a new Swedish environmental code, led to the design of a study targeted at the evaluation of new N pollution abatement strategies. An actor game was chosen as the key component of the study, with a focus on four major goals: to test the implementability of legally binding environmental quality standards for nitrate concentration in groundwater and N transport to the sea, to find sets of agriculturally feasible and cost-effective measures to decrease N loads, to investigate the possibilities for collective action through negotiated and institutionalized actor cooperation, and to investigate the role of mathematical modeling in environmental N management. Characteristics from the agriculturally dominated catchment of Genevads?n (224 km2) on the southwest coast of Sweden served as the playing field for the actor game. The most noteworthy result from the study was that it appeared to be possible to meet ambitious environmental N standards with less economically drastic measures than anticipated by most of the participants. The actor game was shown to be a good method for learning about the new Swedish environmental code and its application and for gaining deeper insight into the issues of N management. In addition, the actor game functioned as an arena for gaining a more thorough understanding of the views of different stakeholders.  相似文献   
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