Alterations in hepatic metallothionein content in perch, Perca fluviatilis, environmentally exposed to cadmium     

Per-Erik Olsson  Carl Haux 《Marine environmental research》1985,17(2-4)

During recent years laboratory studies have demonstrated the presence of metallothionein in several species of teleosts.^1–3 The role of metallothionein (MT) in protection against cadmium toxicity has been investigated by exposing fish to high levels of cadmium in the water.^4–6 So far, however, few field studies have focused on the existence of MT and its role in subcellular distribution of cadmium.⁷ In the present study the synthesis of MT as a possible mechanism by which perch adapt to cadmium contamination was investigated in a wild population of perch. An increased MT content of perch liver was found to correlate to an increase in cadmium present in the liver.  相似文献   

A climatology of mesoscale model simulated low-level wind jets over Cook Inlet and Shelikof Strait, Alaska     

Haibo Liu  Peter Q. Olsson  Karl P. Volz  Han Yi 《Estuarine, Coastal and Shelf Science》2006,70(4):551

Weather in the North Gulf of Alaska is characterized by a high frequency of deep synoptic-scale low-pressure systems, especially during the cold season. The strong pressure gradients of these storms interact with the extremely rugged terrain of the coastal mountains to produce a variety of channeled flows. These surface wind regimes are not well documented in the scientific community, due to the paucity of observations. Modeling of these phenomena in regions of complex terrain is of great interest to those working with hydrodynamic, wave, and pollutant transport models in coastal and shelf areas. Such models, when coupled with ocean and coastal-ecology counterparts, give a broad view of the role surface winds play in shaping local coastal marine ecosystem in this region. This paper presents a climatology of simulated low-level wind jets over the domain of Cook Inlet and Shelikof Strait along Alaska's south-central coast. Daily simulations using the RAMS model were conducted in a 36-h forecast mode for the cold-season period 10/1/03 to 3/31/04. Systematic analysis of the resulting simulated low-level wind field makes it possible to characterize these jets and gap flows in spatial and temporal detail. The comparison between the RAMS winds and the Synthetic Aperture Radar (SAR)-derived winds when available verifies the existence of these wind jets and the capability of the model to simulate these cases. Clearly, the results of a study in this region depend on the fidelity of the model at these scales (O[5 km]). The SAR comparisons attempt to help establish this. From the 6 months of simulations over Cook Inlet and Shelikof Strait, the low-level wind jets are classified into 10 different regimes by location and orientation. These regimes are categorized into four more general groups: cross-channel westerly, easterly, and up and down Inlet flows. The nature of a particular regime is largely a function of pressure gradient orientation and local topography. Jets in the same group have a similar occurrence distribution with time. Some form of jet occurred in the study region almost daily each month of the period, with December 2003 having the highest frequency of wind jets.  相似文献   

Partial isolation and purification of cadmium-binding proteins from rainbow trout liver     

Carl Haux  Per Erik Olsson  Inger Thorsen  Lars Frlin  ke Larsson 《Marine environmental research》1984,14(1-4)

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Palaeoclimatic studies in South Shetland Islands,Antarctica, based on numerous stratigraphic variables in lake sediments     

Svante Björck  Hannelore Håkansson  Siv Olsson  Lena Barnekow  Jan Janssens 《Journal of Paleolimnology》1993,8(3):233-272

The hitherto longest found lake sediment sequence on Byers Peninsula, Livingston Island, South Shetland Islands, was analysed with respect to lithology, chronology, diatoms, Pediastrum, pollen and spores, mosses, mineralogy, and sediment chemistry. During the ca. 5000 year long development the sediments were influenced by frequent tephra fall-outs. This volcanic impact played a major role in the lake's history during two periods, 4700–4600 and 2800–2500 BP, but was of importance during the lake's entire history with considerable influence on many of the palaeoenvironmentally significant indicators. The large and complex data set was analysed and zonated with different types of multivariate analysis. This resulted in a subdivision of the sequence into 8 time periods and 21 variables. Redundancy analysis (RDA) of this data set, both without and with the tephra periods, and with 4–6 of the variables as explanatory environmental variables, reveal that climatic/environmental signals are detectable. The palaeoclimatic picture that emerged out of the tephra noise suggests that the first 100 years were characterized by mild, humid conditions. This was followed by a less mild and humid climate until ca. 4000 BP when a gradual warming seems to have started, coupled with increased humidity. These mild and humid conditions seem to have reached an optimum slightly after 3000 BP. At ca. 2500 BP a distinct climatic deterioration occurred with colder and drier conditions and long seasons with ice cover. This arid, cold phase probably reached its optimum conditions at ca. 1500 BP, when slightly warmer conditions might have prevailed for a while. Except for the modern sample with rather mild climate, the last 1400 years seem to have been fairly arid and cold, and the effects of the frequent volcanic activity during this period is only vaguely seen in the records.  相似文献   

Towards New Swedish Recommendations for Cautious Perimeter Blasting     

F. Ouchterlony  M. Olsson  I. Bergqvist 《Fragblast: International Journal for Blasting and Fragmentation》2002,6(2):235-261

A Swedish table of blast damage depths has, in one form or other, been in use since the late-1970s. Its history and the underlying theory are described. New experimental and theoretical findings that point out a number of shortcomings in the table and the underlying theory are presented and discussed. A revised version of the blast damage table was recently introduced in conjunction with new but incomplete recommendations for cautious perimeter blasting. The new table leaves the difficult task of taking into account factory like decoupling, water in the borehole, the rock properties, type of initiation, charge length and the actual bit diameter to the user. This paper discusses different ways of doing this, based on the experimental findings and a recent formula for the prediction of the lengths of radial cracks behind the half-casts. The material presented in this paper is meant to supplement and extend the new Swedish recommendations for cautious perimeter blasting of tunnels, shafts, pits and road cuts.  相似文献   

The Swedish Geotechnical Society’s methodology for risk management: a tool for engineers in their everyday work     

Johan Spross  Lars Olsson  Håkan Stille 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2018,12(3):183-189

The Swedish Geotechnical Society has adopted a general methodology for risk management in geotechnical engineering projects to reduce the costs related to negative outcomes of geotechnical risks. This technical note highlights the main features of the methodology and strives to inspire the international geotechnical community to apply sensible risk management methods. In the authors’ opinion, a successful geotechnical risk management needs to be structured, be tailored to the project, and permeate the engineers’ everyday work. Then, sufficient quality can be achieved in the project with larger probability.  相似文献   

Desertification in Africa — A critique and an alternative approach     

Lennart Olsson 《GeoJournal》1993,31(1):23-31

This article critically reviews the international debate on desertification, its status and rate as well as causes and consequences. The article rejects the commonly used concept of a degrading environment, but tries to explain the environmental problems as symptoms of a wider economic and political crisis. An alternative approach applying systems analysis of the entire socio-economic-system to the study of desertification and land degradation is discussed, with examples from the Western Sudan.  相似文献   

Cretaceous to Eocene sea-level fluctuations on the New Jersey margin     

Richard K. Olsson 《Sedimentary Geology》1991,70(2-4):195-208

The New Jersey margin contains an extensive record of Cretaceous to Eocene sea-level fluctuations. These events have been documented on the basis of sedimentology, benthic foraminiferal paleobathymetry (paleoslope), biostratigraphic recognition of unconformities and their associated hiatuses, and on seismic reflection records. The record of sea-level change for the New Jersey margin shows a long-term (second-order) rise beginning in the upper Albian that is punctuated by numerous third-order cycles of change in the Upper Cretaceous, Paleocene, and Eocene. The sequences deposited during these cycles that are most readily recognizable, are separated by type 1 unconformities. Sequences bracketed by one or two type 2 unconformities are more difficult to resolve, although many have been identified. Sequences shown on the cycle chart of Haq et al. (1987) of less than 1 Ma duration are the most difficult to recognize and many have not been identified in the New Jersey section.

Benthic foraminiferal paleoslope studies indicate that relative sea-level rise on the New Jersey margin varied on the order of 10–120 m above present sea level. Much of the preserved record in the coastal plain consists of sediments deposited during rising sea level. This has led to a stacked record of sea-level rise events separated by unconformities.  相似文献   

Rock bursting phenomena in a superficial rock mass in southern central Sweden   总被引：1，自引：0，他引：1  

Anders Carlsson  Tommy Olsson 《Rock Mechanics and Rock Engineering》1982,15(2):99-110

SummaryRock Bursting Phenomena in a Superficial Rock Mass in Southern Central Sweden Rock bursting phenomena have been observed in connection with excavation of two shallow sited rock tunnels in the Forsmark area in southern, central Sweden. The tunnels are excavated in gneiss granite and the rock cover varies between 5–15 m. The stress release occurred locally in the tunnels which indicates significant variations in rock stresses.In situ measurements of the triaxial stress situation carried out in the area show values of the principal stresses in the horizontal plane of a magnitude in excess of 20 MPa in the superficial rock mass. The rock stress measurements indicate a clear correspondence of the directions of the highest compressive stress and the rock foliation. There is also a clear correspondence between the directions of a vertical and a horizontal joint set and the highest compressive stress. The three-dimensional stress tensor indicates that the horizontal fractures are exposed to the smallest closure pressure, i. e. the vertical stress, which set should therefore be most open. The horizontal joint set in the superficial rock mass has a significantly higher value of aperture than the vertical sets which may be a consequence of the stress situation in the rock mass. The rock bursting is not attributed to a breakage of the rock matrix, but merely to a propagation of already existing small fractures and potential fractures. The stress situation in the Forsmark area may be regarded as an uniaxial stress field in the horizontal plane.With 12 Figures  相似文献   

Effects of thermal discharges on the microstructural growth ofMercenaria mercenaria     

Michael J. Kennish  Richard K. Olsson 《Environmental Geology》1975,1(1):41-64

The effects of thermal discharges from the Oyster Creek Nuclear Generating Station at Barnegat Bay, New Jersey, are recorded in the microstructural growth ofMercenaria mercenaria, a common coastal marine pelecypod. The analysis of the shell microstructure shows that this bivalve acts as an effective monitor of the environmental conditions existing in the marine waters adjacent to the power station. Many physiological and environmental events such as spawning, winter (freeze) shocks, summer (heat) shocks, thermal shocks, tidal cycles, and major storms are clearly recorded in the shell microstructure. The exact time of occurrence of these events can be determined by counting daily growth increments backwards from the outer shell margins of freshly killed individuals. Microstructural growth patterns reflected in Barnegat Bay specimens indicate that these pelecypods were affected mainly by temperature extremes, temperature variations, tides, type of substratum, and age. Growth patterns in specimens from areas surrounding Oyster Creek (affected by thermal effluent) are significantly different from those from other bay localities (unaffected by thermal effluent).Mercenaria mercenaria within approximately a 1.6km radius of Oyster Creek show a lower summer growth rate (10 percent to 25 percent lower) and a greater number of growth breaks (2 to 6 more per clam) than those away from the creek. The lower summer growth rates occur in bivalves subjected to the effluent because the added heat during the summer months causes water temperatures to exceed a critical threshold for optimum growth in the species. The greater number of growth breaks takes place, in turn, because many of the breaks (thermal shock breaks) are generated by rapidly fluctuating temperatures associated with abrupt shutdowns, massive load reductions and rapid renewal of operations following shutdowns or load reduction periods at the nuclear power station. In addition, the effluent may be upsetting natural spawning events in the clams when abrupt changes in power station operations overlap with spawning periods. In this respect, spawning may be precluded by sharp temperature changes which result in physiological shocks to the animal.  相似文献