Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Induction and reversion of multixenobiotic resistance in the marine snail Monodonta turbinata (1995)
    Springer
    Marine biology 123 (1995), S. 305-312 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Many marine organisms inherently express the presence and function of a new defence mechanism, termed multixenobiotic resistance mechanism (MXRM) because of its similarity to multidrug resistance (MDR) found in tumor cell lines resistant to chemotherapeutic drugs. However, previously no information was available on a possible induction of the activity of MXRM in organisms living at polluted sites. The purpose of the present study was to demonstrate the inducibility of this defence mechanism in the marine snail Monodonta turbinata, an organism known to inhabit a wide range of environmental conditions existing along a pollution gradient. Specimens of M. turbinata used in the present study were collected from March 1993 through March 1994 near Rovinj, Croatia. The accumulation of generally labelled 3H-vincristine (3H-VCR) in the gills of snails living at an unpolluted site was 67% higher and very sensitive to verapamil, an inhibitor of P-glycoprotein activity in comparison to snails living at a polluted site. The accumulation of vincristine (VCR) in snails from a polluted site was reduced and insensitive to verapamil due to the induced state of P-glycoprotein, as was demonstrated immunochemically by the enhanced concentration of a 140 kDa protein cross-reacting with the polyclonal antibodies raised against mammalian P-glycoprotein. MXRM could be induced in snails from the unpolluted site to the level found in snails living at a polluted site either by transplantation for 3 d to a polluted site, or by exposure for 3 d to sea water polluted with Diesel-2 oil (hydrocarbon concentration equivalent to 50 ppb of Kuwait oil). Discovery of the inducibility of this new defence mechanism in aquatic organisms may have important implications in ecotoxicology, as was demonstrated by a 104% enhanced accumulation of VCR in the presence of the MXRM-inhibitor, the so-called “chemosensitizer”. Besides, a striking difference in the levels of MXRM-elements (the sensitivity of the accumulation rate of xenobiotics to verapamil, immunochemical expression of P-glycoprotein, and the sensitivity of the binding of xenobiotics on membrane vesicles to verapamil) found between specimens living at the polluted and unpolluted sites offers a new molecular biomarker for exposure to pollutants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00353622
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    High attenuation tunable microwave notch filters utilizing ferromagnetic resonance (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 6911-6913 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have constructed a series of microstrips for transmission of microwaves. These microstrips incorporate ferromagnetic and dielectric layers and therefore absorb microwave energy at the ferromagnetic resonance (FMR) frequency. The absorption notch in transmission can be tuned to various frequencies by varying an external applied magnetic field. For our devices, which incorporate Fe as the ferromagnetic material, the resultant FMR frequencies range from 10–20 GHz for applied fields up to only 1000 Oe. This frequency range is substantially higher than those found in devices utilizing a dielectric ferrimagnet such as YIG. We constructed devices using monocrystalline Fe films grown in a molecular beam epitaxy system. Our devices are of different construction than other Fe dielectric microstrips and show much improvement in terms of notch width and depth. We observed maximum attenuation on the order of 100 dB/cm, much larger than previously reported values of 4 dB/cm. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.372883
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Mesozooplankton Sampling Experiments with the 'Adriatic' Sampler: Differences of Catch Between 250 and 125 μm Mesh Netting Gauze
    Amsterdam : Elsevier
    Estuarine, Coastal and Shelf Science 38 (1994), S. 113-118 
    Details
    ISSN: 0272-7714
    Keywords: Adriatic Sea ; mesozooplankton ; sampling experiments
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Geography , Geosciences
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1006/ecss.1994.1007
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Antimutagenic activity of the novel antileukemic agents, avarone and avarol
    Amsterdam : Elsevier
    Mutation Research Letters 144 (1985), S. 63-66 
    Details
    ISSN: 0165-7992
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0165-7992(85)90002-8
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Age, growth, mortality and sex ratio of sand smelt, Atherina boyeri Risso, 1810 (Pisces: Atherinidae) in the estuary of the Mala Neretva River (middle-eastern Adriatic, Croatia) (2004)
    Berlin, Germany : Blackwell Verlag GmbH
    Journal of applied ichthyology 20 (2004), S. 0 
    Details
    ISSN: 1439-0426
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The present study investigated the age, growth, mortality and morphometry of the sand smelt, Atherina boyeri, in the Mala Neretva River estuary (mid-eastern Adriatic Sea). The study of scale annuli showed that the population is up to 4 years of age. However, most sand smelt are in their first and second year; the numbers of older individuals are very low because they migrate upstream and are heavily fished. The von Bertalanffy parameters for the total sample of sand smelt were found to be L∞ = 13.5 cm, K = 0.37 year−1 and t0 = −0.97. Overall total mortality was estimated at 1.81 year−1, natural mortality was 0.90 year−1 and fishing mortality was 0.91 year−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1439-0426.2004.00560.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Preliminary results on growth and feeding of wild-caught young goldblotch grouper, Epinephelus costae, in captivity (2003)
    Berlin, Germany : Blackwell Verlag GmbH
    Journal of applied ichthyology 19 (2003), S. 0 
    Details
    ISSN: 1439-0426
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Growth, food intake, feed conversion, survival, and behaviour of wild-caught goldblotch grouper, Epinephelus costae Steindachner, (initial weight=103.04 ± 8.27g) were evaluated when reared in captivity. Average weight gains ranged between 0.106 and 0.278 g day−1, while corresponding gains in length ranged between 0.005 and 0.018 cm day−1. Average daily growth rate was between 0.075 and 0.232% body weight day−1 (overall 0.141 ± 0.08% bw/day). Daily rate of feeding was estimated to be between 0.299 and 0.418% bw day−1 (overall 0.365 ± 0.09% bw day−1). Food conversion ratio (FCR) ranged between 0.21 and 0.77 (overall FCR=0.423). Food intake was dependent on water temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1439-0426.2003.00446.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    A Technique for Estimating Polar Ozone Loss: Results for the Northern 1991/92 Winter Using EASOE Data (1999)
    Springer
    Journal of atmospheric chemistry 34 (1999), S. 365-383 
    Details
    ISSN: 1573-0662
    Keywords: stratospheric ozone ; Arctic ; chemical loss
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract In this paper we describe a technique for estimating chemical ozone loss in the Arctic vortex. Observed ozone and temperature profiles are combined with the model potential vorticity field to produce time series of vortex averaged ozone mixing ratios on chosen isentropic surfaces. Model-derived radiative heating rates and observed vertical gradients of ozone are then used to estimate the change in ozone that would occur due to diabatic descent. Discrepancies with the observed ozone are interpreted as being of chemical origin, assuming that there is negligible horizontal transport or mixing of air into the vortex. The technique is illustrated using ozone sonde measurements collected during the 1991/92 European Arctic Stratospheric Ozone Experiment (EASOE), meteorological analyses from the European Centre for Medium-range Weather Forecasts (ECMWF) and radiative heating rates extracted from the Global Atmospheric Modelling Programme (UGAMP) 3D General Circulation Model. Our results show that there was photochemical ozone destruction inside the Arctic vortex in early 1992 with a loss between 475 K and 550 K (around 20 km) of 0.32±0.15 ppmv in the first 20 days of January, equivalent to a rate of 0.51±0.24%/day (at the 95% confidence level).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006273211790
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Towards a control model for the Murray Mouth (1996)
    Springer
    Environmental modeling and assessment 1 (1996), S. 37-44 
    Details
    ISSN: 1573-2967
    Keywords: Murray Mouth ; river flow ; recursive estimation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The River Murray in Australia drains an area of one million square kilometres, but in 1981 the mouth closed for some weeks. It is important that this be prevented, as the environmental consequences of permanent closure are severe. The size of the mouth is influenced by wind and wave activity at the mouth, and by the river flow, which is controlled by a system of weirs and barrages. We have been able to demonstrate using recursive estimation techniques that river flow is the most important explanatory variable for mouth size, so that the proper management of flow alone has the potential to prevent future closures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01874845
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...