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  • 2009  (34)
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  • 2009  (34)
  • 1
    Language: English
    In: Environmental Toxicology and Chemistry, April 2009, Vol.28(4), pp.809-817
    Description: A field study was conducted at three different sites along the Lourens River (South Africa) to assess aquatic macroinvertebrate abundances and community structures in relation to seasonal changes in rainfall and particle‐associated organophosphorous (OP) insecticide contamination. Redundancy analysis indicated OP insecticide contamination (azinphos‐methyl and chlorpyrifos) as the only significant variable determining the community composition. Principal response curves indicated that the invertebrate community dynamics of the Lourens River at the most‐contaminated site, Lourens River 3 (38 ± 23.0 μg total OP/kg suspended particles), differed significantly from the less‐contaminated site, Lourens River 2 (8.0 ± 4.9 μg total OP/kg in suspended particles) during the dry season (October–December; pesticide application period), whereas no difference was found during the wet season (July–September). Ephemeroptera abundances increased significantly ( = 0.0021) at the control site, Lourens River 1, from the wet to dry season, whereas abundances significantly decreased ( = 0.0011) at Lourens River 3. Two‐by‐three factorial analysis of variance demonstrated a significant interaction of site and season for the three most abundant mayfly taxa, sp., sp., and sp., confirming a possible OP effect. Lourens River 3, however, differed significantly from the other two sites in flow, ‐phosphate, and algae growth, which may partly explain the lower abundance of sensitive species. Apart from the OP contamination, only flow velocities showed significant differences between the wet and dry season at some sites. In conclusion, the present study suggests that particle‐associated OPs affected community structure in the Lourens River at levels greater than 30 μg total OP/kg, whereas levels less then 10 μg total OP/kg yielded no significant effects.
    Keywords: Organophosphate Insecticides ; Ephemeroptera ; Leptophlebiidae ; Community Structure ; Multivariate Statistics
    ISSN: 0730-7268
    E-ISSN: 1552-8618
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  • 2
    Language: English
    In: Applied Physics Letters, 06 July 2009, Vol.95(1)
    Description: In this letter we experimentally demonstrate the sensitivity and overall performance of iterative correction for light attenuation in optoacoustic tomography as a function of number of iterations and accuracy of the tissue optical properties estimations. Experimental optoacoustic data were obtained by circularly illuminating a tissue-mimicking phantom with a high intensity pulsed near infrared laser and measuring the subsequent acoustic waves using a broadband acoustic hydrophone. We showcase an improvement in image fidelity and quantification due to the iterative inversion but find the method sensitive to the background optical properties and of a diverging behavior when increasing the number of iterations.
    Keywords: Biophysics And Bio-Inspired Systems
    ISSN: 0003-6951
    E-ISSN: 1077-3118
    Source: © 2009 American Institute of Physics (AIP)〈img src=http://exlibris-pub.s3.amazonaws.com/AIP_edited.gif style="vertical-align:middle;margin-left:7px"〉
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  • 3
    Language: English
    In: Ecotoxicology and Environmental Safety, 2009, Vol.72(4), pp.1058-1062
    Description: Pyriproxyfen a juvenile hormone analoga (JHA) was used in a two-generation test with (Diptera). The protocol is an extension of the OECD test methods to test duration from first-instar larvae in the parental (P) generation to emergence of midges in the filial (F1) generation. Test species were exposed to concentrations ranging from 0.001 to 0.1 mg/L. The results showed significant adverse effects compared to the solvent control for emergence rate ( 〈0.001), development rate ( 〈0.001), fecundity ( 〈0.05) and fertility of egg ropes but not for the sex ratio. No observed effect concentrations (NOEC), respectively, lowest observed effect concentration (LOEC) values were lower for emergence rate and development rate in the F1 (0.003 mg/L, respectively, 0.01mg/L each) than in the P generation (0.01 mg/L, respectively, 0.03 mg/L). The two-generation test provided additional information, which might be useful in the risk assessment of agrochemicals with potential endocrine effects.
    Keywords: Pyriproxyfen ; Jha ; Insect Endocrine System ; Chironomus Riparius ; Two-Generation Test ; Agrochemicals ; Ecology ; Public Health
    ISSN: 0147-6513
    E-ISSN: 1090-2414
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  • 4
    Language: English
    In: Environmental Toxicology and Chemistry, January 2009, Vol.28(1), pp.197-203
    Description: Recent evidence indicates that a variety of antibiotic residues may affect the integrity of streams located downstream from wastewater treatment plants. Aquatic communities comprising bacterial and fungal decomposers and invertebrate detritivores (shredders) play an important role in the decomposition of allochthonous leaf litter, which acts as a primary energy source for small running waters. The aim of the present study was to assess whether an antibiotic mixture consisting of sulfamethoxazole, trimethoprim, erythromycin‐HO, roxithromycin, and clarithromycin has an effect on such a decomposer–detritivore system. Leaf discs were exposed to these antibiotics (total concentration of 2 or 200 μg/L) for approximately 20 d before offering these discs and corresponding control discs to an amphipod shredder, , in a food choice experiment. preferred the leaf discs conditioned in the presence of the antibiotic mixture at 200 μg/L over the control discs (pair‐wise test; = 0.006). A similar tendency, while not significant, was observed for leaves conditioned with antibiotics at a concentration of 2 μg/L. The number of bacteria associated with leaves did not differ between treatments at either antibiotic concentration ( test; = 0.57). In contrast, fungal biomass (measured as ergosterol) was significantly higher in the 200 μg/L treatment ( test; = 0.038), suggesting that the preference of may be related to a shift in fungal communities. Overall these results indicate that mixtures of antibiotics may disrupt important ecosystem processes such as organic matter flow in stream ecosystems, although effects are likely to be weak at antibiotic concentrations typical of streams receiving wastewater treatment plant effluents.
    Keywords: Ecosystem Process ; Food Choice ; Antibiotic ; Indirect Effect ; Microbial Community
    ISSN: 0730-7268
    E-ISSN: 1552-8618
    Source: John Wiley & Sons, Inc.
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  • 5
    Language: English
    In: Journal of biomedical optics, 2009, Vol.14(6), pp.064012
    Description: We present a novel fluorescence imaging system developed for real-time interventional imaging applications. The system implements a correction scheme that improves the accuracy of epi-illumination fluorescence images for light intensity variation in tissues. The implementation is based on the use of three cameras operating in parallel, utilizing a common lens, which allows for the concurrent collection of color, fluorescence, and light attenuation images at the excitation wavelength from the same field of view. The correction is based on a ratio approach of fluorescence over light attenuation images. Color images and video is used for surgical guidance and for registration with the corrected fluorescence images. We showcase the performance metrics of this system on phantoms and animals, and discuss the advantages over conventional epi-illumination systems developed for real-time applications and the limits of validity of corrected epi-illumination fluorescence imaging.
    Keywords: Image Processing, Computer-Assisted -- Methods ; Spectrometry, Fluorescence -- Methods
    ISSN: 10833668
    E-ISSN: 1560-2281
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  • 6
    Language: English
    In: Journal of the Optical Society of America. A, Optics, image science, and vision, April 2009, Vol.26(4), pp.919-23
    Description: Hybrid imaging systems combining x-ray computed tomography (CT) and fluorescence tomography can improve fluorescence imaging performance by incorporating anatomical x-ray CT information into the optical inversion problem. While the use of image priors has been investigated in the past, little is known about the optimal use of forward photon propagation models in hybrid optical systems. In this paper, we explore the impact on reconstruction accuracy of the use of propagation models of varying complexity, specifically in the context of these hybrid imaging systems where significant structural information is known a priori. Our results demonstrate that the use of generically known parameters provides near optimal performance, even when parameter mismatch remains.
    Keywords: Optics and Photonics ; Tomography, X-Ray Computed -- Instrumentation
    ISSN: 1084-7529
    E-ISSN: 15208532
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  • 7
    Language: English
    In: Environmental Toxicology And Chemistry, 2009, Vol.28(1), pp.197-203
    Description: Recent evidence indicates that a variety of antibiotic residues may affect the integrity of streams located downstream from wastewater treatment plants. Aquatic communities comprising bacterial and fungal decomposers and invertebrate detritivores (shredders) play an important role in the decomposition...
    Keywords: Other Biological Topics ; Annan Biologi
    ISSN: 0730-7268
    E-ISSN: 15528618
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  • 8
    Language: German
    In: Zeitschrift für Gerontologie und Geriatrie, 2009, Vol.42(2), pp.131-136
    Description: Byline: Susanne Hengstermann (1), Anja Hanemann (1), Rolf Nieczaj (1), Nadia Abdollahnia (1), Antje Schweter (1), Elisabeth Steinhagen-Thiessen (1), Andreas Lun (2), Gernot Lammler (1), Ralf-Joachim Schulz (1) Keywords: Homocystein; Folsaure; kognitive Defizite; multimorbide Senioren; homocysteine; folate; cognitive dysfunction; multimorbidity; elderly Abstract (German): Hintergrund Der Zusammenhang zwischen Homocystein (Hcys)- bzw. Folsaurespiegeln im Blut und kognitiven Defiziten wurde bisher bei gesunden, nicht aber bei multimorbiden Senioren beschrieben. Die aktuelle Fragestellung ist daher, ob sich dieser Zusammenhang bei multimorbiden geriatrischen Patienten bestatigt. Methodik Der kognitive Status wurde von 189 (131 f/58 m) multimorbiden geriatrischen Patienten im Alter von 78,6 +- 7,3 Jahren mittels Syndrom-Kurztest (SKT) in einer Querschnittserhebung untersucht. Neben biochemischen Parametern (Plasma-Hcys, Serum-Folsaure, Vitamin B.sub.12, Blutbild), Ernahrungsstatus (BMI, Mini Nutritional Assessment) wurde die Selbststandigkeit der Patienten erfasst. Die Bestimmung der Vitaminzufuhr erfolgte anhand des 3-Tage- Ernahrungsprotokolls. Ergebnisse Nach SKT zeigten 25,4% keine kognitive Leistungsstorungen, bei 21,2% lag ein Verdacht auf leichte kognitive Defizite vor, 12,7% hatten leichte, 9,0% massige und 31,7% schwere kognitive Defizite. Plasma Hcys-Spiegel waren unabhangig von kognitiven Defiziten um 20% erhoht. Folsaure und Vitamin B.sub.12 im Serum lagen im Normbereich, obwohl die Folsaurezufuhr um 75% vermindert war. Unterschiede zwischen SKT-Gruppen waren weder hinsichtlich Ernahrungsstatus, Selbstandigkeit, Anzahl der Diagnosen oder Medikation noch hinsichtlich biochemischer Parameter signifikant. Schlussfolgerungen Es wurden erhohte Hcys-Spiegel bei multimorbiden geriatrischen Patienten mit kognitiven Defiziten und normalen Folsaure- und Vitamin B.sub.12- Konzentrationen analysiert. Hcys im Plasma erscheint als kein geeigneter biologischer Risikofaktor fur kognitive Defizite bei multimorbiden geriatrischen Patienten. Abstract: Background Total blood homocysteine (Hcys) and folate have been investigated in association with cognitive dysfunction (CD) in healthy but not in multimorbid elderly patients. We hypothesized that total Hcys and folate are adequate markers to identify multimorbid elderly patients with CD. Methods According to the Short Performance Cognitive Test (SKT) CD was determined in a cross-sectional study with 189 (131 f/58 m) multimorbid elderly patients with a mean age of 78.6 +- 7.3 yrs. Besides the analyses of biochemical parameters (Hcys, folate, vitamin B.sub.12, hemogram) nutritional status (BMI, Mini Nutritional Assessment) as well as activities of daily living were assessed. Daily nutritional intake was measured with a 3-day nutrition diary. For analysis, we used the nutritional software program DGE-PC professional. Results According to SKT 25.4% showed no cerebral cognitive dysfunction, 21.2% had a suspicion about incipient cognitive dysfunction, 12.7% showed mild, 9.0% moderate, 31.7% of patients severe cognitive deficits. Median plasma Hcys was about 20% elevated in multimorbid elderly patients independent of CD. Serum folate and vitamin B.sub.12 levels were within range, though dietary folate intake (97 [80--128] Aug/d) was reduced about 75% (recommendation 400 Aug/d). Significant correlations between vitamin intake and plasma/serum levels of Hcys, folate and vitamin B.sub.12 were not present. We did not find significant differences between SKT groups of nutritional status, activities of daily living, index of diseases, medications, or selected biochemical parameters. Conclusion We analysed elevated serum Hcys levels in multimorbid elderly patients with normal plasma folate and vitamin B.sub.12 concentration and CD. Plasma Hcys or serum folate did not appear as an important biological risk factor on CD in multimorbid elderly patients. Author Affiliation: (1) Charite -- Universitatsmedizin Berlin, Campus Virchow-Klinikum, Forschungsgruppe Geriatrie am aEvangelischen Geriatriezentrum Berlin", Reinickendorfer Strasse 61, 13347, Berlin, Germany (2) Charite -- Universitatsmedizin Berlin, Campus Virchow-Klinikum, Zentralinstitut fur Laboratoriumsmedizin und Pathobiochemie, Berlin, Germany Article History: Registration Date: 01/01/2008 Received Date: 20/11/2007 Accepted Date: 06/05/2008 Online Date: 13/06/2008
    Keywords: homocysteine ; folate ; cognitive dysfunction ; multimorbidity ; elderly
    ISSN: 0948-6704
    E-ISSN: 1435-1269
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  • 9
    Language: English
    In: Environmental Science and Pollution Research, 2009, Vol.16(4), pp.410-413
    Description: Byline: Andreas Schaeffer (1), Henner Hollert (1), Hans Toni Ratte (1), Martina Ross-Nickoll (1), Juliane Filser (2), Michael Matthies (3), Joerg Oehlmann (4), Martin Scheringer (5), Ralf Schulz (6), Alfred Seitz (7) Keywords: Chemicals-related environmental sciences; Environmental research and teaching; Environmental risk assessment of pollutants Abstract: Background Modern societies depend on environmental sustainability and on new generations of individuals well-trained by environmental research and teaching institutions. In the past, significant contributions to the identification, assessment, and management of chemical stressors with legal consequences have been made. Main Features Within this article, we intend to elucidate the merits and the emerging challenges of chemicals-related environmental sciences. The manuscript is supported by more than 70 professors and university academics of leading institutions in Germany, Switzerland, Austria, and other countries in Europe, but addresses topics of global concern. Results and Discussion Many environmental problems of pollutants remain to be addresses, since new chemical compounds or classes of new compounds are continuously developed and brought to the market and sooner or later "emerge" in the environment. Further issues are the inclusion of transformation products and chemical mixtures in environmental risk assessment, the long-term presence of xenobiotics bound to soils and sediments, as well as an understanding of the ecological relevance of ecotoxicological end points. Conclusion and Perspectives We point out the need for a strong academic research and education system in chemicals-related environmental sciences to ministries, politicians, and research funding institutions and we propose to create specific units in the national funding bodies that address basic and interdisciplinary research in this field. Author Affiliation: (1) Institute for Environmental Research (Biology V), RWTH Aachen University, 52074, Aachen, Germany (2) UFT, Department of General and Theoretical Ecology, University of Bremen, Leobener Str., 28359, Bremen, Germany (3) Institute for Environmental System Research, University of Osnabruck, 49069, Osnabruck, Germany (4) Department Aquatic Ecotoxicology, Institute for Ecology, Evolution and Diversity, Goethe University Frankfurt am Main, Siesmayerstrasse 70, 60054, Frankfurt am Main, Germany (5) Safety and Environmental Technology Group, ETH Zurich, HCI G 127, Wolfgang-Pauli-Str. 10, 8093, Zurich, Switzerland (6) Institute for Environmental Science, University of Koblenz--Landau, 76829, Landau, Germany (7) Department of Ecology, Zoological Institute, Johannes Gutenberg University, 55099, Mainz, Germany Article History: Registration Date: 30/04/2009 Received Date: 26/04/2009 Accepted Date: 30/04/2009 Online Date: 26/05/2009 Article note: Electronic supplementary material The online version of this article (doi: 10.1007/s11356-009-0157-x) contains supplementary material, which is available to authorized users.
    Keywords: Chemicals-related environmental sciences ; Environmental research and teaching ; Environmental risk assessment of pollutants
    ISSN: 0944-1344
    E-ISSN: 1614-7499
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  • 10
    Language: English
    In: Gerontology, May 2009, Vol.55(3), pp.288-295
    Description: Background: Geriatric patients frequently have impaired renal function. Multimorbidity leads to polypharmacy with high risk of adverse drug reactions. Objective: The aim was to evaluate the prevalence of renal impairment and risk of overdosing renally excreted drugs in hospitalized geriatric patients. Methods: In 221 patients aged ≥65 years, GFR was estimated by the MDRD, Cockcroft-Gault (CG) and lean body mass (LBM)-adjusted CG equations. Results: A reduced renal function (〈60 ml/min/1.73 m2) was found in 43% by MDRD, 61% by CG, and 71.9% by LBM-CG. The prevalence of severe impairment (〈30 ml/min/1.73 m2) was 3.3% based on MDRD, 5.4% on CG, and 13.6% on LBM-CG. At mean 10 medications were applied simultaneously. In patients with reduced eGFR, 52% of medications required dosage adjustment. Unfractionated heparins, ACE inhibitors, antibiotics, diuretics, and potassium were frequently used. Conclusions: For all limitations of formulaic GFR estimation in the elderly, routine assessment of renal function by reporting of eGFR helps to identify patients with chronic kidney disease and supports drug dosing. Implementation of routine reporting of eGFR is mandatory in standardized geriatric assessment.
    Keywords: Clinical Section ; Chronic Kidney Disease ; Elderly ; Estimation of Renal Function ; Drug Therapy ; Medicine ; Social Welfare & Social Work ; Anatomy & Physiology
    ISSN: 0304-324X
    E-ISSN: 1423-0003
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