Age determination of Baltic herring from whole otoliths and from neutral red stained otolith cross sections   总被引：2，自引：1，他引：2  

Peltonen  Heikki; Raitaniemi  Jari; Parmanne  Raimo; Eklund  Jan; Nyberg  Kari; Halling  Folke 《ICES Journal of Marine Science》2002,59(2):323-332

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Crowdsourcing The National Map     

Elizabeth A. McCartney  Kari J. Craun  Erin Korris  David A. Brostuen  Laurence R. Moore 《制图学和地理信息科学》2015,42(4):54-57

Using crowdsourcing techniques, the US Geological Survey’s (USGS) Volunteered Geographic Information (VGI) project known as “The National Map Corps (TNMCorps)” encourages citizen scientists to collect and edit data about man-made structures in an effort to provide accurate and authoritative map data for the USGS National Geospatial Program’s web-based The National Map. VGI is not new to the USGS, but past efforts have been hampered by available technologies. Building on lessons learned, TNMCorps volunteers are successfully editing 10 different structure types in all 50 states as well as Puerto Rico and the US Virgin Islands.  相似文献   

Biomarker responses in flounder (Platichthys flesus) and mussel (Mytilus edulis) in the Klaipeda-Būtinge area (Baltic Sea)     

Barsiene J  Lehtonen KK  Koehler A  Broeg K  Vuorinen PJ  Lang T  Pempkowiak J  Syvokiene J  Dedonyte V  Rybakovas A  Repecka R  Vuontisjärvi H  Kopecka J 《Marine pollution bulletin》2006,53(8-9):422-436

During the EU project BEEP a battery of biomarkers was applied in flounder (Platichthys flesus) and the blue mussel (Mytilus edulis) collected at three locations off the Lithuanian coast (Baltic Sea) in June and September 2001 and 2002. The elevated biomarker responses in specimens sampled in September 2001 were apparently related to the extensive dredging activities in the Klaipeda port area and subsequent dumping of contaminated sediments. High concentrations of organic pollutants (organochlorines and PBDEs) were also measured in the tissues of both indicator species. In addition, response levels of genotoxicity, cytotoxicity, immunotoxicity as well as concentrations of PAH metabolites in the bile of flounder showed elevations in 2002 after an oil spill in the Būtinge oil terminal in November 2001. In flounder, biomarker measurements 10 months after the spill indicated recovery processes but in mussels a high level of genotoxicity could still be observed 22 months later. The present study illustrates the usefulness of the multi-biomarker approach in the detection of biological effects of pollution in this region of the Baltic Sea.  相似文献   

The BEEP project in the Baltic Sea: overview of results and outline for a regional biological effects monitoring strategy   总被引：1，自引：0，他引：1  

Lehtonen KK  Schiedek D  Köhler A  Lang T  Vuorinen PJ  Förlin L  Barsiene J  Pempkowiak J  Gercken J 《Marine pollution bulletin》2006,53(8-9):523-537

Field studies in the framework of the EU funded BEEP project (Biological Effects of Environmental Pollution in Marine Coastal Ecosystems, 2001-2004) aimed at validating and intercalibrating a battery of biomarkers of contaminant exposure and effects in selected indicator species in the Mediterranean, the North Atlantic and the Baltic Seas. Major strategic goals of the BEEP project were the development of a sensitive and cost-efficient biological effects monitoring approach, delivery of information and advice to end-user groups, and the implementation of a network of biomarker researchers around Europe. Based on the main results obtained in the Baltic Sea component of the BEEP the present paper summarises and assesses the applicability of biomarkers for different regions and species in this sea area. Moreover, a general strategy and some practical considerations for the monitoring of biological effects in the Baltic Sea are outlined.  相似文献   

Intranight polarization variability in radio-loud and radio-quiet AGN     

Carolin Villforth  Kari Nilsson  Roy Østensen  Jochen Heidt  Sami-Matias Niemi  Janine Pforr 《Monthly notices of the Royal Astronomical Society》2009,397(4):1893-1908

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Managing organizational change in an international scientific network: A study of ICES reform processes     

Kari Stange  Per Olsson  Henrik Österblom 《Marine Policy》2012,36(3):681-688

Organizations involved in the governance of natural resources are challenged to adjust to the call for more holistic management approaches. This often necessitates organizational change. Here change processes in the International Council for the Exploration of the Sea (ICES) during the years 1998–2009 are investigated using semi-structured interviews combined with observations and review of documents. Several organizational reforms were implemented during the time period studied. The major drivers were the need to improve efficiency and a striving for better integration between different components within the organization. The reform processes were driven forward by individuals who navigated between opportunities and constrains embedded in the network structure of ICES. This required good leadership and communication skills. Broad consultations were important to ensure support within the ICES community. By increasing the understanding of the dynamics of change in organizations, which operate at the science–policy interface developments in desired directions can be facilitated.  相似文献   

Satellite image based vegetation classification of a large area using limited ground reference data: a case study in the Usa Basin, north-east European Russia     

Tarmo Virtanen  Kari Mikkola  Ari Nikula 《Polar research》2004,23(1):51-66

Predicted global changes can be studied effectively by combining spatially explicit data sets on vegetation and other landscape properties with process models. However, detailed knowledge of the vegetation distribution of remote Arctic areas is relatively scarce. This paper shows how a mesoscale vegetation and land cover classification of a large, remote Arctic area can be conducted at a fine spatial resolution (30 m cell size) using a limited ground reference data set. The study area is the catchment of the River Usa (93 500 km²) in north-eastern European Russia. Vegetation zones in the Usa Basin range from taiga in the south to forest-tundra and tundra in the north, and to alpine in the Ural mountains in the east. Classification was done using a mosaic of spectrally adjusted Landsat TM5 images from five different dates and a semi-supervised method. Ground reference data were collected during the summers of 1998, 1999 and 2000. Accuracy of the 21-class vegetation type/land cover classification produced was tested against test points interpreted from oblique aerial photographs taken from a helicopter (logistic limitations prohibited the collection of representative ground reference data). The main vegetation types (forests, willow dominated stands and meadows, peatlands, tundra heaths, mainly unvegetated areas, and water bodies) were distinguished with relatively high accuracy: 84% of the test points were classified correctly. Spatially detailed land cover data sets like the one described here allow detailed landscape-level analysis and process modelling on many different subjects.  相似文献   

Deformed graptolites, finite strain and volume loss during cleavage formation in rocks of the taconic slate belt, New York and Vermont, U.S.A.     

Arthur Goldstein  Jonathan Knight  Kari Kimball 《Journal of Structural Geology》1998,20(12):1769-1782

An analysis of graptolites in the Taconic slate belt of eastern New York and western Vermont (U.S.A.) shows that they are nearly ideal strain markers. For the three species used in this study, Orthograptus whitfieldii, Orthograptus calcaratus and Climacograptus bicornis, the spacing of thecae is constant except for the first five or so thecae in the proximal part of the fossil rhabdosome. Further, the thecal apertures are perpendicular to the long axis of the stipe. Observations of the thecal spacing in deformed rocks leads to a determination of extension (e=(l_f−l₀)/l₀) and a measure of the angle between thecal aperture and stipe axis yields a direct determination of angular shear strain. In practice, we find it is most straightforward to use length changes to determine the magnitude of principal strains. In Taconic slates, e₁ ranges from 1.0 to 0.24, e₂ ranges from 0.23 to −0.43 and e₃ ranges from −0.56 to −0.74. Thus, we find that the absolute finite strain in these slates is constrictional at three sites, plane strain at another and a true flattening at only one site. An examination of volume changes based on strain results in determinations of between 81% volume loss and 7% volume gain, with volume losses between 28% and 81% in 9 out of 10 calculations. These conclusions are in accord with previous determinations of volume loss based on reduction spot analyses and are consistent with the observation that pressure dissolution was a common grain scale deformation process in cleavage formation but that these slates lack abundant veins, fibrous overgrowths or other identifiable sites of reprecipitation.  相似文献   

Five-color photometry of Saturn and its rings     

Kari Lumme  H.J. Reitsema 《Icarus》1978,33(2):288-300

Analysis of 206 high-quality plates from three recent apparitions taken in five colors has yielded several photometric parameters for Saturn and its A and B rings. Phase curves and geometric albedos are derived for two regions of Saturn and for each ring. The phase coefficients of the rings are found to be independent of the ring-plane inclination angle. A comparison of the phase curves shows that the particles of ring A exhibit a larger phase coefficient than do those of ring B. When examined with a multiple-scattering model using Henyey-Greenstein phase functions, the observations of the ring tilt effect indicate that the particles of ring A may also have lower single-scattering and geometric albedos. The color dependence of the geometric albedo of the particles in ring B is shown to be very similar to that of Europa (J II). We find for ring A an optical thickness of 0.50 (0.45 ≤ τ_A ≤ 0.57) and for the Cassini division, 0.018 ± 0.004.  相似文献   

Upper lithospheric seismic velocity structure across the Pripyat Trough and the Ukrainian Shield along the EUROBRIDGE'97 profile   总被引：1，自引：0，他引：1  

H. Thybo  T. Janik  V. D. Omelchenko  M. Grad  R. G. Garetsky  A. A. Belinsky  G. I. Karatayev  G. Zlotski  M. E. Knudsen  R. Sand  J. Yliniemi  T. Tiira  U. Luosto  K. Komminaho  R. Giese  A. Guterch  C. -E. Lund  O. M. Kharitonov  T. Ilchenko  D. V. Lysynchuk  V. M. Skobelev  J. J. Doody 《Tectonophysics》2003,371(1-4):41-79

We present new results on the structure resulting from Palaeoproterozoic terrane accretion and later formation of one of the aulacogens in the East European Platform. Seismic data has been acquired along the 530-km-long, N–S-striking EUROBRIDGE'97 traverse across Sarmatia, a major crustal segment of the East European Craton. The profile extends across the Ukrainian Shield from the Devonian Pripyat Trough, across the Palaeoproterozoic Volyn Block and the Korosten Pluton, into the Archaean Podolian Block. Seismic waves from chemical explosions at 18 shot points at approximately 30-km intervals were recorded in two deployments by 120 mobile three-component seismographs at 3–4 km nominal station spacing. The data has been interpreted by use of two-dimensional tomographic travel time inversion and ray trace modelling. The high data quality allows modelling of the P- and S-wave velocity structure along the profile. There are pronounced differences in seismic velocity structure of the crust and uppermost mantle between the three main tectonic provinces traversed by the profile: (i) the Pripyat Trough is a ca. 4-km-deep sedimentary basin, fully located in the Osnitsk–Mikashevichi Igneous Belt in the northern part of the profile. The velocity structure is typical for a Precambrian craton, but is underlain by a ca. 5-km-thick lowest crustal layer of high velocity. The development of the Pripyat Trough appears to have only affected the upper crust without noticeable thinning of the whole crust; this may be explained by a rheologically strong lithosphere at the time of formation of the trough. (ii) Very high seismic velocity and Vp/Vs ratio characterise the Volyn Block and Korosten Pluton to a depth of 15 km and probably also the lowest crust. The values are consistent with an intrusive body of mafic composition in the upper crust that formed from bimodal melts derived from the mantle and the lower crust. (iii) The Podolian Block is close to a typical cratonic velocity structure, although it is characterised by relatively low seismic velocity and Vp/Vs ratio. A pronounced SW-dipping mantle reflector from Moho to at least 70 km depth may represent the Proterozoic suture between Sarmatia and Volgo–Uralia, the structure from terrane accretion, or a later shear zone in the upper mantle. The sub-Moho P-wave seismic velocity is high everywhere along the profile, with the exception of the area above the dipping reflector. This velocity change further supports a plate tectonic origin of the dipping mantle reflector. The profile demonstrates that structure from Palaeoproterozoic plate tectonic processes are still identifiable in the lithosphere, even where younger metamorphic equilibration of the crust has taken place.  相似文献