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11.
In this paper the purpose is to discuss a concept of technology that can explain how the transfer of technology implies the risk of new failures, misuse, accidents and unhealthy workplaces. Production technologies are often transformed through a steady stream of incremental changes appropriate to their social context, and the technology will therefore gradually acquire some contextually dependent preconditions for use. These preconditions will most probably be revealed when a technology is transferred from one context to another. Thus, a technology transfer project may trigger a long process of re-innovations just to make the technology fully operational in its new context. In a transfer process, technological risks may arise due to incomplete transfer of mastering capacity; mismatch between transferred technology and the environment; transfer of latent conditions for failure; and the transformation of latent conditions or known risks when the technology is installed in a new environment. Longitudinal data from the Norwegian petroleum industry indicates that the first phases in a transfer process will create high technological risks. It will take many years before the transferred technologies are adapted to the new context and the risk level has been normalised. 相似文献
12.
Sources of polycyclic aromatic hydrocarbons (PAHs) in sediments of the Biobio River in south central Chile 总被引:2,自引:0,他引:2
Ricardo Barra Roberto Quiroz Katia Saez Alberto Araneda Roberto Urrutia Peter Popp 《Environmental Chemistry Letters》2009,7(2):133-139
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment; there are concerns about them due to their toxic
properties. Human activities could significantly contribute to the total PAH burden in river sediments. In this work, we document
the analysis of PAHs in sediments taken in the middle stretch of the Biobio River in south central Chile. This river is a
principal system, draining more than 24,000 km2 and subjected to a diverse variety of human-made stressors (pulp mill and urban effluents, agricultural drainage systems,
etc). During 2003, several sediment samples were taken in more than 45 sampling sites located in the river’s middle stretch.
Due to the granulometric characteristics (mainly sandy sediments), only 17 samples were analyzed, taking into consideration
the presence of a fine section within the sediment sample. Using HPLC with fluorescence detection, 15 EPA priority PAHs and
perylene were analyzed. The composition of PAHs in the sediment samples is rather similar between sites and levels averaged
104 ± 78 ng g−1 d.w. The highest levels were detected downstream from an industrial discharge. A good correlation was observed between PAH
levels and organic carbon content in the tested sediments; however, concentrations above 134 ng g−1 d.w. did not indicate correlation. The samples PAH ratios (Flu/Pyr and Chr/B(a)A) reveal a strong pyrolytic PAH pattern in
the sediments tested, supporting evidence indicating that PAHs come mainly from pyrolytic sources. This result contrasts with
previous records that have shown a natural influence in the upper basin and a petrogenic pattern near the mouth. 相似文献
13.
Brown JE Iospje M Kolstad KE Lind B Rudjord AL Strand P 《Journal of environmental radioactivity》2002,60(1-2):49-60
The objective of this study was to reassess 99Tc transit times and transfer factors, from Sellafield to northern Norway, and to determine the extent of 99Tc migration to the Barents Sea. Filtered seawater samples were collected on a monthly basis from Hilles?y, northern Norway, and in February 1999 from the Barents Sea. Results showed an increase in levels of 99Tc at Hilles?y where activity concentrations have increased from a baseline of 0.2-0.4Bq m(-3) to a maximum of 1.6 Bq m(-3). A transit time of 42 months and a transfer factor of 6Bq m(-3) per PBq a(-1) have been derived, using cross-correlation analysis. The current study predicts that future levels are unlikely to increase dramatically over the levels observed in 1998. Levels of 99Tc in the Barents Sea ranged from 0.2 Bq m(-3) to 1.1 Bq m(-3) showing the influence of new 99Tc inputs by early 1999. 相似文献
14.
Bone mineral density (mg cm(-3)) was studied in male Baltic grey seals (4-23 years of age) by noninvasive computed tomography (pQCT). The material was grouped according to year of collection. Group A: 1850-1955, a period before the main introduction of organochlorines (OCs); Group B: 1965-1985, a period with very high OC contamination; and Group C: 1986-1997, a period with decreasing concentrations of OCs. The reproducibility of the measurements was good with a Coefficient of Variation (CV) ranging from 0.1% to 2.1%. Trabecular bone mineral density of the radius was significantly higher in specimens collected 1986-1997 than in those collected 1965-1985 (p < 0.05). Cortical bone mineral density of the mandible was significantly lower in specimens collected 1986-1997 compared with those collected 1850-1955 (p < 0.05). These results indicate different responses over time in trabecular and cortical bone. During the period of very high OC contamination (1965-1985), trabecular bone density was lowest, whereas cortical bone density was lowest in specimens collected 1985-1997, representing a period of fairly low OC contamination. The mechanisms behind these effects are not known. However, it can be assumed that OCs are involved. Information about residue levels of OCs in the studied individuals is lacking and, therefore, it was not possible to evaluate the impact of OCs in this respect. 相似文献
15.
Katia Vangelova Michel Israel Desimira Velkova Michaela Ivanova 《The Environmentalist》2007,27(4):551-555
The aim of this paper is to study the effect of electromagnetic radiation (EMR) on the excretion rates of stress hormones
of medical staff in physiotherapy. The excretion rates of stress hormones cortisol, adrenaline and noradrenaline were followed
during morning shift in 15 female physiotherapists using RIA kits and a spectrofluorimetric method. The mean number of treatments
with EMR emitting devices per month and the emission of each device was assessed. A control group of nurses, matched by age,
sex and work task was used. The psychosocial factors were evaluated and no differences between the two groups was found. Calculations
of the individual EMR exposure show levels above the ICNIRP guidelines. Significantly higher excretion rates of cortisol,
adrenaline and noradrenaline among the studied physiotherapists in comparison with the control group of nurses were found.
In conclusion, our data showed that EMR influenced the excretion rates of stress hormones of medical staff in physiotherapy. 相似文献
16.
17.
The anti-predator behaviour of Baltic crustacean planktivores was studied in feeding experiments under predation pressure of herring. The experiments were conducted with pelagic mysids: Mysis mixta and Mysis relicta, and with Cercopagis pengoi, a non-indigenous cladoceran, which invaded the Baltic Sea in 1992. Zooplankton was offered as prey. Two kinds of experiments were performed in the absence and presence of chemical predator cues: (1) two-prey experiments with prey, which have poor or good escape responses and all three planktivores and (2) natural prey experiments with mysids in natural zooplankton assemblages. The results showed that all three species reacted to the chemical cue of herring by decreasing their feeding rate and altering prey selection. C. pengoi selected easily captured prey (rotifers) in two-prey experiments under predation risk while selection for any prey was evident in mysids in natural prey experiments only in the absence of predator cues. This indicates that planktivores have different anti-predator strategies, which are modified by their own prey capture abilities. C. pengoi was a very efficient predator on small prey with size-specific prey consumption rate 5 to 18 times the rate of mysids. Results show that the studied planktivores are capable of adjusting their feeding behaviour to decrease their conspicuousness in order to increase survival under predation risk. Further, results support the view that C. pengoi has adapted well to the Baltic ecosystem, sharing food niche with pelagic mysids and most probably having a strong influence on the whole pelagic food web. 相似文献
18.
Duarte-Restrepo Edisson Noguera-Oviedo Katia Butryn Deena Wallace Joshua S. Aga Diana S. Jaramillo-Colorado Beatriz E. 《Environmental science and pollution research international》2021,28(12):14632-14653
Environmental Science and Pollution Research - Cartagena Bay is an estuarine system located in the Caribbean Sea (Colombia, South America), that receives fresh water from Canal del Dique, which is... 相似文献
19.
To detect threats and reduce predation risk prey animals need to be alert. Early predator detection and rapid anti-predatory action increase the likelihood of survival. We investigated how foraging affects predator detection and time to take-off in blue tits (Parus caeruleus) by subjecting them to a simulated raptor attack. To investigate the impact of body posture we compared birds feeding head-down with birds feeding head-up, but could not find any effect of posture on either time to detection or time to take-off. To investigate the impact of orientation we compared birds having their side towards the attacking predator with birds having their back towards it. Predator detection, but not time to take-off, was delayed when the back was oriented towards the predator. We also investigated the impact of foraging task by comparing birds that were either not foraging, foraging on chopped mealworms, or foraging on whole ones. Foraging on chopped mealworms did not delay detection compared to nonforaging showing that foraging does not always restrict vigilance. However, detection was delayed more than 150% when the birds were foraging on whole, live mealworms, which apparently demanded much attention and handling skill. Time to take-off was affected by foraging task in the same way as detection was. We show that when studying foraging and vigilance one must include the difficulty of the foraging task and prey orientation.Communicated by P.A. Bednekoff 相似文献
20.
Lymphomyeloid (haemopoietic) tissues produce or store blood cells — among these leucocytes rich in lysosomal enzymes. The thymus, unlike the other lymphomyeloid tissues found in fish, produces exclusively lymphocytes. The carbohydrate-hydrolysing enzymes lysozyme (EC 3.2.1.17), chitinase (EC 3.2.1.14) and exo-N-acetyl--D-glucosaminidase (NAGase; EC 3.2.1.30) were assayed in various lymphomyeloid tissues of the cartilaginous fish Chimaera monstrosa, Squalus acanthias, Etmopterus spinax and Raja radiata, and in the thymus of the marine teleost Lophius piscatorius. Lysozyme activity was high in the cranial lymphomyeloid tissue of C. monstrosa; in Leydig's organ (oesophageal lymphomyeloid tissue) and the spleen from E. spinax; and in Leydig's organ, the epigonal organ and the spleen from R. radiata. Little or no lysozyme activity was found in Leydig's organ and the epigonal organ of S. acanthias, or in the thymus of C. monstrosa, R. radiata and L. piscatorius. The pH optima for lysozyme activities lay between 4.8 and 5.4 when assayed photometrically. Chitinase was most active at pH 1 in Leydig's organ from R. radiata, and at pH 2.7 in the epigonal organ from S. acanthias. The chitinolytic activity in Leydig's organ of E. spinax may be due to lysozyme. The optimum for NAGase activity in Leydig's organ from R. radiata lay at pH 4.0, that from S. acanthias and E. spinax at pH 4.5. The role of the enzymes in the defense against microorganisms and parasites is discussed. 相似文献