bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and Institutionalisation of Romani Representation and Administration. Part 1
Authors: Klímová-Alexander Ilona
Published: August 2004

The post-1989 rise of ethnic conflicts in the former Eastern Bloc have led to the renewed salience of minority rights and their prominence in international relations. The 1990s witnessed a proliferation of legal instruments and offices dedicated to minority rights at the intergovernmental level (mainly within the Organisation for Security and Cooperation in Europe, Council of Europe, but also the United Nations). After decades of arguing that rights of persons belonging to national, ethnic or religious minorities can be sufficiently ensured within the framework of universal human rights, attributed to individuals regardless of group membership, liberal political theorists (most notably Will Kymlicka) have started to advocate the need to supplement these traditional human rights with minority rights (meaning certain group-differentiated rights or “special status” for minority cultures) in order to ensure justice in multicultural states.
Astana's Privatised Independence: Private and National Interests in the Foreign Policy of Nursultan Nazarbayev
Authors: Bukkvoll Tor
Published: August 2004

Nursultan Nazarbayev has been President of Kazakhstan since that country became independent in 1991. Observers expect him to remain in his current position until 2013, and there are clear indications that he has started to prepare for his daughter, Dariga Nazarbayeva, to take over power after 2013. Analyses of Kazakhstan's foreign policy therefore both has had and will continue to have a close focus on the person of Nursultan Nazarbayev. In addition, this is all the more true because foreign policy in Kazakhstan to an extreme degree is a one-man affair. The present article discusses the interplay between personal and national interests as motivating factors in the foreign policy of Nazarbayev. More specifically, it investigates how these different types of motivation have influenced Nazarbayev's attempts to seek partnership with or distance from the USA and Russia.
Christianity and Nationality in Soviet and Post-Soviet Central Asia: Mutual Intrusions and Instrumentalizations
Authors: Peyrouse Sebastien
Published: August 2004

The five Central Asian Muslim republics (Kazakhstan, Kyrgyzstan, Uzbekistan, Tajikistan, Turkmenistan) count many Christian—Orthodox, Catholic, Armenian and Protestant—minorities. Unlike the religious communities in the Near and Middle East, most Christians in Central Asia consist of Slavic/European minorities (Russians, Germans, Poles, Armenians, Greeks, etc.), which came in the area during the Russian colonization in the eighteenth-nineteenth centuries. The main traditionally Christian nationalities living in Central Asia are Slavs and Germans. Today, Russians are mainly present in Kazakhstan (4.5 million), in Kyrgyzstan (600,000) and in Uzbekistan (at least half a million). There are only several tens of thousand Russians in Turkmenistan and Tajikistan. Like Russians, the number of the other Slavic nationalities has considerably decreased in Central Asia since the last three decades. There are 50,000 Ukrainians in Kyrgyzstan, 500,000 in Kazakhstan and about 100,000 in Uzbekistan. Byelorussians number 111,000 in Kazakhstan, and about 20,000 in Uzbekistan. According to the 1999 census, there are only 47,000 Poles in Kazakhstan. Today there are 353,000 Germans in Kazakhstan, 21,000 in Kyrgyzstan, and less than 8,000 in Uzbekistan, and their community is nearly nonexistent in Turkmenistan and Tajikistan. Other nationalities are also present in the Christian communities, though more modestly: among them, Koreans (about 160,000 in Uzbekistan, close to 100,000 in Kazakhstan in 1999), Greeks (10,000 in Uzbekistan), Tatars (248,000 in Kazakhstan) as well as Armenians (there remained 40,000 Armenians in Turkmenistan in 1995, with 42,000 in Uzbekistan today). Armenians have only one cult building in Samarkand. Moreover, after the fall of the USSR, more and more natives have been converted to Christianity: many—especially Protestant—missions, are now acting among Kazakhs, Kyrgyz, Uzbeks, etc.
Evacuation to a Cold Country: Child Refugees from the Greek Civil War in the German Democratic Republic, 1949–1989*
Authors: Troebst Stefan
Published: August 2004

We Greek political emigres celebrate the thirtieth historical anniversary of the GDR as our own holiday since we are vitally connected to this state from its first steps onwards. We feel better than any other foreigner the great joy and the pride of the people of the GDR since, from the foundation of its socialist state, we are marching side by side and since then we by way of our small contribution feel as co-constructors of this grand act. The thirtieth anniversary of the GDR coincides with the thirtieth anniversary of our political emigration to this hospitable country. Today we all remember the first years after our arrival and our caring reception in the GDR. (Speech of the day at the central celebration of the Greek political emigres in the GDR devoted to the thirtieth anniversary of the GDR and the thirtieth anniversary of the political emigration, Dresden, 29 September 1979).
Carcinogenic Effect of N-Nitrosodimethylamine on Diploid and Triploid Zebrafish (Danio rerio)
Authors: Mizgireuv Igor V. , Majorova Irina G. , Gorodinskaya V.M. , Khudoley Veniamin V. , Revskoy Sergei Y.
Published: August 2004

Viability of polyploid organisms in lower vertebrates including fish provides an additional tool to investigate genetic mechanisms of neoplastic transformation caused by carcinogens. Here we present data on differential sensitivity of diploid and triploid zebrafish ( Danio rerio) to N-nitrosodimethylamine (NDMA) induced hepatocarcinogenesis. The effect of the carcinogen was studied in 100 diploid and 120 triploid zebrafish. Zebrafish, age 5—6 weeks, were exposed to 50 ppm NDMA for 8 weeks and then were transferred into fresh carcinogen-free water until necropsy. At the necropsy performed 24 weeks after beginning the treatment, cholangiolar tumors (cholangiocarcinomas and cholangiomas) were essentially observed in diploid zebrafish only, while the incidence of hepatocellular tumors (hepatocellular carcinomas and adenomas) was similar in diploid and triploid zebrafish, 7.7% and 9.5%, respectively. By contrast, 36 weeks after beginning the treatment, the incidence of hepatocellular tumors was significantly lower in diploid animals as compared to triploid ones, 10.3% and 33.8%, respectively. The incidence of cholangiolar tumors in diploid and triploid zebrafish was not significantly different, 10.3% and 14.9%, respectively. Therefore, the increase of ploidy appeared to have a differential effect on the induction of these 2 types of liver tumors in zebrafish. This finding suggests a difference in genetic mechanisms of the tumor development revealed by utilization of triploid animals in this study. However, triploid zebrafish demonstrated an overall increase in latency period in the development of both types of hepatic tumors, a finding that can be interpreted as an increased resistance of triploid animals to the carcinogenic effect of NDMA.
Protective Activity of Hesperidin and Lipoic Acid Against Sodium Arsenite Acute Toxicity in Mice
Authors: Pires Das Neves Ricardo N. , Carvalho Félix , Carvalho Márcia , Fernandes Eduarda , Soares Elisa , Bastos Maria De Lourdes , Pereira Maria De Lourdes
Published: August 2004

The objective of the present work was to evaluate the toxic effects of sodium arsenite, As(III), in mice and the protective effect of 2 antioxidants, hesperidin and lipoic acid, against the observed As(III)-induced toxicity. In each study, mice were assigned to 1 of 4 groups: control, antioxidant, antioxidant + arsenite, and arsenite. Animals were first injected with the vehicle or 25 mg antioxidant/kg BW. After 30 minutes they received an injection of 10 mg arsenite/kg BW or 0.9% NaCl. Two hours after the first injection, the liver, kidney, and testis were collected for histological evaluation. Liver samples were also taken for quantification of arsenic. In mice exposed only to As(III), various histopathological effects were observed in the liver, kidneys, and testes. In mice pretreated with either hesperidin or lipoic acid, a reduction of histopathologic effects on the liver and kidneys was observed. No protective effects were observed in the testes for either of the 2 studied antioxidants. In conclusion, hesperidin and lipoic acid provided protective effects against As(III)-induced acute toxicity in the liver and kidneys of mice. These compounds may potentially play an important role in the protection of populations chronically exposed to arsenic.
Oxidative Damage Precedes Nitrative Damage in Adriamycin-Induced Cardiac Mitochondrial Injury
Authors: Chaiswing Luksana , Cole Marsha P. , St. Clair Daret K. , Ittarat Wanida , Szweda Luke I. , Oberley Terry D.
Published: August 2004

The purpose of the present study was to determine if elevated reactive oxygen (ROS)/nitrogen species (RNS) reported to be present in adriamycin (ADR)-induced cardiotoxicity actually resulted in cardiomyocyte oxidative/nitrative damage, and to quantitatively determine the time course and subcellular localization of these postulated damage products using an in vivo approach. B6C3 mice were treated with a single dose of 20 mg/kg ADR. Ultrastructural damage and levels of 4-hydroxy-2-nonenal (4HNE)-protein adducts and 3-nitrotyrosine (3NT) were analyzed. Quantitative ultrastructural damage using computerized image techniques showed cardiomyocyte injury as early as 3 hours, with mitochondria being the most extensively and progressively injured subcellular organelle. Analysis of 4HNE protein adducts by immunogold electron microscopy showed appearance of 4HNE protein adducts in mitochondria as early as 3 hours, with a peak at 6 hours and subsequent decline at 24 hours. 3NT levels were significantly increased in all subcellular compartments at 6 hours and subsequently declined at 24 hours. Our data showed ADR induced 4HNE-protein adducts in mitochondria at the same time point as when mitochondrial injury initially appeared. These results document for the first time in vivo that mitochondrial oxidative damage precedes nitrative damage. The progressive nature of mitochondrial injury suggests that mitochondria, not other subcellular organelles, are the major site of intracellular injury.
Working Memory Period: The Endurance of Mental Representations
Authors: Towse John N. , Hitch Graham J. , Hamilton Zoë , Peacock Kirsty , Hutton Una M. Z.
Published: August 2004

Working memory span assesses the maximum number of items that can be remembered in the face of concurrent processing. Models of working memory differ on several dimensions, yet many rely exclusively on this span procedure for their evidence. Three experiments consider an alternative paradigm that attempts to capture the endurance limits for remembering a fixed number of items during concurrent processing. Eight-year-old children performed two versions of this working memory period measure—operation period and reading period. Period scores show healthy test–retest reliability and external validity for scholastic attainment, comparing well with span scores in these respects. In addition, period is highly correlated with span and shows similar effects of varying the order in which stimuli are presented. We conclude that the durability of representations is an important factor in both span and period.
Validation and performance of an invertebrate index of biotic integrity for Lakes Huron and Michigan fringing wetlands during a period of lake level decline
Authors: Uzarski D. G. , Burton T. M. , Genet J. A.
Published: August 2004

Development of indicators of ‘ecosystem health’ for the Great Lakes was identified as a major need at the State-of-the-Lakes Ecosystem Conference in 1998, 2000, and 2002. Our goal was to develop an invertebrate-based index of biotic integrity that was robust to water level fluctuations and applied to broad classes of lacustrine wetlands across wave-exposure gradients. Our objectives were to evaluate the performance and test the robustness of our preliminary index (e.g., Burton et al., 1999) at a range of water levels, eliminate any problems with the index of biotic integrity, remove the preliminary status, test the index on similar wetlands of Lake Michigan, and establish stressor:ecological-response relationships. Twenty-two sites, both open- and protected-fringing lacustrine marshes of Lake Huron and Michigan were selected for study. Correspondence analysis and Mann-Whitney U tests were used to test the robustness of existing metrics and search for additional metrics. Wilcoxon Signed Rank tests were used to determine if metrics were responding to inter-annual water level fluctuation. Principal components analysis and Pearson correlations were used to establish stressor:ecological response relationships. Analyses confirmed the utility of most of the metrics suggested in our preliminary index, but we recommended several improvements. With improvements, the index was able to place all sites in a comparable order of disturbance that we placed them a priori based on adjacent landuse/landcover, limnological parameters and observed disturbances. The improved index worked very well from 1998 through 2001 despite the substantial decreases in lake level over this time-period. Analyses of 2001 data collected from similar fringing wetlands along the northern shore of Lake Michigan suggested that the index could also be used for fringing wetlands of northern Lake Michigan. We are confident that our index is ready for implementation as a tool for agencies to use in assessing wetland condition for Lakes Huron and Michigan fringing wetlands.
Factors affecting the evolution of coastal wetlands of the Laurentian Great Lakes: An overview
Authors: Mayer T. , Edsall T. , Munawar M.
Published: August 2004

Coastal wetlands play a pivotal role in the Great Lakes ecosystem. As buffer zones between the land and open waters of the Great Lakes, they perform a variety of essential functions providing both direct and indirect anthropogenic benefits. Geology, morphology and climate are the dominant variables that influence Laurentian Great Lakes wetland development. However, anthropogenic factors are the major contributors to alteration of natural wetland processes. This paper provides an overview of natural and anthropogenic factors important in Great Lakes coastal wetland development and provides statistical information describing the Great Lakes Basin. A brief description of wetlands classification and research issues is also presented.
Morphometric factors in the formation of Great Lakes coastal wetlands
Authors: Herdendorf C. E.
Published: August 2004

The Great Lakes basins were carved from ancient river valleys by continental ice sheets that receded from the region less than 10,000 years ago. Not only did the glaciers create the basins now holding the lakes, but they are responsible for many of the shallow depressions in the coastal margin that have since developed as coastal wetlands of various types. For the past four thousand years, coastal processes in the lakes have further modified the shore topography to form embayments, coastal lagoons, estuaries, deltas, and solution basins where thousands of hectares of wetlands have become established. This paper will explore the origin of the various morphometric forms which these wetlands have taken and their characteristic hydrologic processes.
Great Lakes wetlands as amphibian habitats: A review
Authors: Hecnar S. J.
Published: August 2004

Amphibians are highly adapted for life in wetland habitats. They form a major component of wetland faunas, and being both prey and predator, they are important in ecosystem functioning. Wetlands provide aquatic habitats that amphibians require for breeding, development, foraging, hibernation and refuge, and they form an interface with essential adjacent upland habitat. The size and type of wetlands as well as their spatial configuration and local structural characteristics are important features of these habitats for amphibian use. Because of their dependence on water, use of both aquatic and terrestrial habitat, permeable skin, and other biological characteristics, amphibians are considered to be excellent indicators of ecosystem health. Amphibians have a tremendous diversity of natural history characteristics and species differ in their patterns of habitat and microhabitat selection. Over 30 species of amphibians occur in wetlands within the Great Lakes Basin and an increasing trend in species richness exists from north to south across the region. Since European settlement, this region has lost over 50% of its wetlands. Loss rates of coastal and inland wetlands exceed 90% in some areas. Many restoration efforts are underway across the region but losses still exceed gains. No species have been extirpated from the entire basin but numerous local extirpations have occurred. However, nearly half of the species are officially designated as being of conservation concern somewhere in the basin. A more realistic estimate suggests that at least 2/3 of species are of concern. Habitat loss is reported as the primary cause of decline for 60% of species and habitat degradation by pollution is cited for 43% of the fauna. Considering the extent of wetland loss across the basin it seems reasonable to assume a similar magnitude of amphibian population loss. The current conservation status of amphibians indicates that Great Lakes wetlands are unhealthy ecosystems.
Coordinating coastal wetlands monitoring in the North American Great Lakes
Authors: Lawson R.
Published: August 2004

Great Lakes coastal wetlands have critically important ecological values and functions. However, coordinated monitoring of coastal wetland quantity and quality is lacking. The Great Lakes Coastal Wetlands Consortium was formed in 2000 to address this critical need for North American Great Lakes. This paper presents the background, framework, objectives, and current and future work of the Consortium. The Consortium consists of wetlands researchers and managers from the United States and Canada. Several Consortium members present papers on specific topics in this journal issue. The Consortium's goal is to design a plan for implementing a long-term monitoring program focused on a concise set of environmental indicators. A year of development work and a year of field work have been completed to date. The Consortium is currently working toward final development and implementation of the monitoring program.
Linkages between groundwater and coastal wetlands of the Laurentian Great Lakes
Authors: Crowe A. S. , Shikaze S. G.
Published: August 2004

Groundwater flow regimes adjacent to coastal wetlands of the Great Lakes are highly transient and vary among different types of coastal wetlands. Groundwater flow is controlled by (1) the physiography of the land adjacent to the wetland, (2) the relative elevations of the wetland and the lake, as they fluctuate over time, and (3) the amount of infiltration and evapotranspiration that occurs at the land and wetland. Groundwater from the mainland adjacent to a wetland will flow towards and discharge into the wetland throughout the year. In a spit that partially protects a wetland from a lake, the source of groundwater is precipitation and snowmelt; not water from the lake or wetland. Here, groundwater continually flows from either side of a central groundwater divide towards the lake or wetland, with the elevation of the lake only affecting the rate of groundwater drainage. Because barrier bars completely separate a lake from a wetland, the elevation of the lake and wetland are different. When the barrier bar is narrow, the resultant hydraulic gradient across the barrier bar causes groundwater flow to oscillate between flowing towards the lake during the fall and winter and towards the wetland during the spring and summer. But as the width of the barrier bar increases, the impact of the lake and wetland diminish relative to the amount of precipitation and snowmelt infiltrating into the barrier bar. Thus, the groundwater flow regime is characterized by a central groundwater divide with groundwater on either side continuously flowing towards the lake and wetland throughout the year. Intradunal wetlands are actually several small wetlands within a series of relic beach ridges and parabolic dunes. Groundwater flow regimes here are highly variable and transient with flow adjacent to different wetlands, and at different times of the year, exhibiting continuous flow to a wetland, oscillating direction of flow, and lateral migration of the groundwater divide. However, these groundwater flow patterns are caused by precipitation and evapotranspiration within the wetland complex and not by fluctuating lake levels.
Implications of hydrologic variability on the succession of plants in Great Lakes wetlands
Authors: Wilcox D. A.
Published: August 2004

Primary succession of plant communities directed toward a climax is not a typical occurrence in wetlands because these ecological systems are inherently dependent on hydrology, and temporal hydrologic variability often causes reversals or setbacks in succession. Wetlands of the Great Lakes provide good examples for demonstrating the implications of hydrology in driving successional processes and for illustrating potential misinterpretations of apparent successional sequences. Most Great Lakes coastal wetlands follow cyclic patterns in which emergent communities are reduced in area or eliminated by high lake levels and then regenerated from the seed bank during low lake levels. Thus, succession never proceeds for long. Wetlands also develop in ridge and swale terrains in many large embayments of the Great Lakes. These formations contain sequences of wetlands of similar origin but different age that can be several thousand years old, with older wetlands always further from the lake. Analyses of plant communities across a sequence of wetlands at the south end of Lake Michigan showed an apparent successional pattern from submersed to floating to emergent plants as water depth decreased with wetland age. However, paleoecological analyses showed that the observed vegetation changes were driven largely by disturbances associated with increased human settlement in the area. Climate-induced hydrologic changes were also shown to have greater effects on plant-community change than autogenic processes. Other terms, such as zonation, maturation, fluctuations, continuum concept, functional guilds, centrifugal organization, pulse stability, and hump-back models provide additional means of describing organization and changes in vegetation; some of them overlap with succession in describing vegetation processes in Great Lakes wetlands, but each must be used in the proper context with regard to short- and long-term hydrologic variability.
Plants as regional indicators of Great Lakes coastal wetland health
Authors: Albert D. A. , Minc L. D.
Published: August 2004

In this paper we explore the potential for developing plant-based indicators for key dimensions of wetland stress, including 1) hydrologic flow modification (through water-level regulation and diking), 2) water quality degradation (through nutrient loading and sedimentation), and 3) ecological structural breakdown or physical degradation. Based on a review of the literature, we identify species or species groups that potentially function as indicators of individual dimensions of anthropogenic stress and propose floristic metrics for monitoring wetland health. We then examine the utility of these metrics for evaluating wetland disturbance at both regional and local scales, utilizing a database of wetland sites spanning the entire U.S. Great Lakes shoreline. We conclude that multiple dimensions of wetland disturbance can be measured based on coverage values of key aquatic plants.
Invertebrate habitat use in relation to fetch and plant zonation in northern Lake Huron coastal wetlands
Authors: Burton T. M. , Uzarski D. G. , Genet J. A.
Published: August 2004

Northern Lake Huron marshes are among the most pristine wetlands in the Great Lakes. Almost 200 invertebrate taxa were collected from eight of these marshes from 1997 through 2001. Our objective was to explore relationships between wave exposure (fetch), plant community zones and invertebrate community composition using exploratory data analysis of invertebrate relative abundance. Effective fetch, an exposure measure which integrates fetch along three directions, ranged from 0.4 to 35.3 km. Invertebrates were collected with dip nets from wet meadow, Typha, and inner and outer Scirpus zones from 3 very protected (fetch <1 km), 3 protected (fetch 1–10 km) and 2 exposed (>10 km) marshes. Correspondence analyses of invertebrate relative abundance did not plot invertebrate communities of wet meadows along fetch gradients even though 7 of 30 common taxa were significantly (p < 0.05) correlated with fetch. After removing wet meadow data, correspondence analyses of data from remaining plant zones plotted marshes according to fetch with very protected and exposed sites at opposite ends of U-shaped gradients. Most taxa were generalists, occurred in marshes in all exposure categories, and plotted in the middle of correspondence analyses plots. Characteristic taxa plotting at the very protected end of the gradient included Gammarus, Crangonyx, Caecidotea, Chironomini, Tanytarsini, most Gastropoda and Sphaeriidae. Characteristic taxa plotting at the most exposed end included Sigara, Trichocorixa, Naididae (Stylaria), Tubificidae, and Bezzia. We present a conceptual model of potential changes in invertebrate community composition along gradients of wave exposure. In very protected marshes, organic sediments, detritus, and plant density are higher and dissolved oxygen is lower than in exposed marshes. Conditions are too harsh for some taxa found in very protected marshes.
Strategies for the stewardship and conservation of Great Lakes coastal wetlands
Authors: Loftus K. K. , Smardon R. C. , Potter B. A.
Published: August 2004

This is a review of Great Lakes coastal wetland protection measures for both the United States and Canada, including regulatory mechanisms, tax incentives, securement stewardship initiatives and special programs/partnerships. International, federal, provincial, state, and local government and nongovernment programs are reviewed with commentary on effectiveness of such programs. Programs vary in scope and comprehensiveness at all levels. Major recent initiatives focus on water quality improvement from federal/state government and waterfowl habitat restoration from government/nongovernment partnerships.
Appropriate use of chemical information in a best professional judgment triad weight-of-evidence evaluation of sediment quality
Authors: Lee G. F. , Jones-Lee A.
Published: August 2004

There is increasing support for the use of a best professional judgment, non-numeric, triad weight of evidence approach for evaluating aquatic sediment quality. This approach is based on an integrated use of sediment toxicity/source of bioaccumulatable chemicals, organism assemblages and chemical information to determine the potential for constituents in sediments to be adverse to the beneficial uses of the waterbody in which the sediments are located. This triad approach is a far more reliable approach for evaluating whether a chemical constituent(s) associated with a sediment is adverse to sediment/water quality than a chemical-specific numeric sediment quality guideline. Significant problems occur, however, with the use of this approach by some in incorporating chemical information into the triad. The use of total concentrations of constituents and/or the exceedance of a co-occurrence-based so-called ‘sediment quality guideline’ is technically invalid. Such an approach can distort the triad sediment quality evaluation because it incorporates information into the triad that is not related to the impact of the chemicals on aquatic-life-related beneficial uses. The chemical information that should be used in a triad evaluation includes the chemical forms and concentrations of the constituents of concern in the sediments that can be toxic to aquatic life or that can lead to bioaccumulation in higher-trophic-level organisms that are a threat to these organisms or those who use aquatic life as food. Sediment TIE information and information about the cause of toxicity or the amount of a bioaccumulatable chemical in a bioavailable form in the sediments should be used as a chemical component of a triad.
Solid phase microextraction fibers for estimating the toxicity of nitroaromatic compounds
Authors: Conder J. M. , Lotufo G. R. , Bowen A. T. , Turner P. K. , La Point T. W. , Steevens J. A.
Published: August 2004

Solid phase microextraction fibers are useful for investigating bioavailable organic contaminants in complex environmental matrixes such as aquatic sediments. Solid phase microextraction fibers are polymer-coated silica fibers that sorb dissolved organic compounds from water and sediment. We investigated their concentrations as measures of exposure for 2,4,6-trinitrotoluene and its degradation products in acute sediment and water-only toxicity tests with Tubifex tubifex, Chironomus tentans, and Ceriodaphnia dubia. Results from these exposures allowed us to compare solid phase microextraction fibers concentrations to two conventional measures of toxicant dose: external matrix (water, sediment) and internal (organism) concentrations. Because trinitrotoluene degrades within sediment and organisms, doses based on sediment, water, and organism concentrations were calculated using the molar sum of trinitrotoluene and its nitroaromatic degradation products. Among species and matrixes, median lethal doses based on solid phase microextraction fiber and organism concentrations ranged from 12.6 to 55.3 (μmol nitroaromatic per ml polyacrylate and 83.4 to 172.3 nmol nitroaromatic per gram tissue, wet weight, respectively. In contrast to matrix concentrations, which are specific to sediment or water, both organism and solid phase microextraction fiber concentrations appeared to provide measures of dose independent of exposure scenario (sediment or water). Median lethal doses based on fiber concentrations in whole-sediment and water-only Tubifex tubifex toxicity tests were within a factor of 1.1 (18.7 and 21.3 (μmol nitroaromatic per ml polyacrylate, respectively). Median lethal doses based on organism concentrations were within a factor 1.4 for Chironomus tentans exposed in water-only or whole-sediment scenarios (118.0 and 83.4 nmol nitroaromatic per gram tissue, wet weight, respectively). Solid phase microextraction fibers may provide a powerful chemical estimate of exposure with which to understand bioavailability and toxicity of organic compounds to benthic organisms.
Paracelsus' dictum for sediment quality (and other) assessments
Authors: Chapman P. M.
Published: August 2004

Paracelsus' Dictum, addressing human toxicology, forms the basis for both modern medicine and ecotoxicology. The Dictum can be paraphrased as ‘The right dose makes the poison.’ What this means in terms of ecotoxicology, is that for toxicity to occur, an organism must be exposed to a contaminant and at the correct concentration. Effectively, this Dictum also separates pollutants (toxicity occurs) from contaminants (toxicity does not occur). However, as presently constituted, the Dictum neither includes nor considers two critical modifying factors, for example in the sedimentary environment: bioavailability and realistic exposure scenarios. Too many scientists, regulators and stakeholders are, explicitly or implicitly, applying the Dictum directly, without modification. Such literal interpretations have resulted in incorrect assessment of, for instance, the risk of polyaromatic hydrocarbon phototoxicity; the relative importance of pore water, overlying water and dietary exposure routes; biological tolerance mechanisms (avoidance, acclimation, non-genetic adaptation, genetic adaptation, metabolism); and secondary (indirect) toxicity. To ensure that the emphasis is on pollutants, not contaminants, the Dictum needs to be rephrased as follows and adhered to: ‘All substances are poisons; there is none which is not a poison. The right dose of a bioavailable substance, administered under realistic exposure conditions, differentiates a poison.’
Systematic approach to weight of evidence in sediment quality assessment: Challenges and opportunities
Authors: Forbes V. E. , Calow P.
Published: August 2004

Sediments are complex systems, and contaminants interact with them in a multitude of ways that influence exposure and effects on sediment-dwelling biota. Likewise a variety of non-chemical agents may act on benthic communities; these may dominate, contribute to or mask any effects from chemical contaminants. The first problem is to recognize that adverse effects have occurred. Once effects have been convincingly identified it is then necessary to assess likely causal agents retrospectively. Here we present a series of questions, elaborated from human health epidemiology, that can help to structure retrospective sediment assessments. We propose a method that aims to guide interpretation of various combinations of answers to the questions so that conclusions about the likelihood that identified agents have caused the observed effects in sediment systems can be consistently drawn. We demonstrate the approach by applying it to two published case studies. The first deals with estuarine communities in the northern Gulf of Mexico exposed to a wide variety of contaminants originating from a range of sources. The second involves a freshwater stream community impacted by road runoff. Although simpler than other weight of evidence approaches, we believe that the method provides a systematic, explicitly documented and consistent approach that may be particularly effective for defining priorities in situations where the evidence is limited and/or at least partly qualitative.
The potential of screening for agents of toxicity using gene expression fingerprinting in Chironomus tentans
Authors: Perkins E. J. , Furey J. , Davis E.
Published: August 2004

Stress responses of sediment dwelling organisms offer novel opportunities to study the toxicity of compounds within that environment. Current analytical methods are limited and do not assess exposure or bioavailability. Restriction fragment differential display-polymerase chain reaction is a gene expression profiling technique that allows comparison of the effects of different chemicals on an organism. We used the restriction reaction to assess the potential of using stress responses of invertebrates to discriminate between different contaminants. Larvae of an infaunal invertebrate, Chironomus tentans, were exposed to polyaromatics (fluoranthrene, phenanthrene, and DDT), and metals (copper, zinc and lead) in 16 hr aqueous exposures. Distinctly different restriction reaction gene expression patterns were observed in response to these exposures. These results suggest that gene expression fingerprinting could complement current procedures for detecting contaminants or classes of contaminants. Application of this approach could result in significant cost savings to sediment dredging and remediation operations.
Evaluation of a real-time Taqman® PCR method for assessment of pathogenic coliform contamination in sediment: A risk-based approach
Authors: Indest K. J. , Betts K. , Furey J. S. , Fredrickson H. L. , Hinton V. R.
Published: August 2004

Management of contaminated sediments has focused predominately on chemical agents, overshadowing risks posed by pathogenic microorganisms. Current accepted bacterial indicator methods do not provide defensible data with respect to the occurrence and types of pathogens in sediments. In an effort to adapt new defensible methods for assessing the risk posed by pathogens in sediments, we evaluated the sensitivity of a commercially available real-time polymerase chain reaction TaqMan® Escherichia coli 0157:H7detection kit. The lower limit of linear quantitation of this assay was experimentally determined in sediment and sediment extract samples spiked with known amounts of E. coli 0157:H7 DNA. Parallel control experiments were conducted in pure water samples spiked with known amounts of Escherichia coli 0157:H7 DNA. The lower limit of quantification of the TaqMan® assay was 1000 colony forming units when interrogating 100 mg sediment samples. In contrast, the assay was 20-fold more sensitive with a lower limit of quantification of 50 colony forming units in pure water and sediment extract samples. These results suggest that the sensitivity of the TaqMan® Escherichia coli 0157:H7detection kit is more dependent on recovery of the desired target from the sediment matrix than efficiency of polymerase chain reaction amplification. The potential human health risk associated with the lower limit of quantification of the TaqMan® assay in the spiked sediment samples was estimated using a Beta-Poisson dose-response model. Using this approach, lower limit values corresponded to exposure levels of Escherichia coli 0157:H7 that meet United States Environmental Protection Agency accepted illness rates for recreational swimming.
The effect of two mechanical beach grooming strategies on Escherichia coli density in beach sand at a southwestern Lake Michigan beach
Authors: Kinzelman J. L. , Pond K. R. , Longmaid K. D. , Bagley R. C.
Published: August 2004

The influence of indicator bacteria associated with beach sands on recreational water quality has become increasingly recognized. Constant wave action may serve as a transport mechanism for delivering bacterial organisms to surface waters resulting in an increased frequency of dry weather advisories. The ability to reduce the concentration of these organisms may serve to improve recreational water quality. To date, few researchers have explored anthropogenic factors affecting the content of Escherichia coli in beach sands. This study explored the influence of mechanical beach grooming on in situ populations of Escherichia coli at a southwestern Lake Michigan beach to determine if an alteration in current beach management practices would serve to reduce the number of dry weather advisories in this community. Preliminary studies conducted during 2001 demonstrated that professional grooming significantly increased Escherichia coli content in beach sands relative to non-groomed or hand raked plots (p < 0.001). This data also suggested that deeper grooming might reduce differences between groomed and non-groomed areas. Subsequently, two mechanical grooming techniques were compared at Racine, WI in 2002: groomed to a depth of 5 to 7 cm with leveling of beach sands and groomed to a depth of 7 to 10 cm without leveling. Escherichia coli content between treatments were significantly correlated (p < 0.009). The density of the bacterium in deeper groomed/unleveled sands was significantly lower in visibly moist or wet but not dry sands (p = 0.038). In 2003, the manner in which beach sands were maintained using the mechanical beach groomer was altered and a follow-up study conducted. A 30 percent reduction in the number of poor water quality advisories due to dry weather events was achieved as a result of these measures. These results demonstrate that mechanical beach grooming may affect Escherichia coli content in beach sands, a potential source of non-point pollution to recreational waters.
Development of a cell-based screening assay for invertebrate molting disruption
Authors: Inouye L. S. , Ang C.-Y. , McFarland V. A.
Published: August 2004

The use of transgenic cell lines for relatively rapid, sensitive and reproducible assays for the detection and semi-quantitative measurement of contaminants in environmental media has increased in recent years. For example, many accepted assays rely on the arylhydrocarbon receptor interaction to screen for dioxins and related compounds in environmental samples. However, these systems are poorly developed or absent in lower organisms, and since arylhydrocarbon receptor interaction is a necessary early step in the development of dioxin toxicity, dioxins are relatively non-toxic to invertebrates. As a result, assays based on this interaction have no relevance for assessing the risk of environmental contamination to these organisms at the base of all food chains. Alternatively, arthropods possess highly developed ecdysone receptor systems that can be used similarly to the arylhydrocarbon receptor system as the basis of an assay with high relevance for these important classes of invertebrates. A new transgenic cell line was developed in order to create a rapid assay for ecdysone interactions to detect and measure the activity of environmental contaminants that are chronically toxic to lower organisms, specifically the invertebrate phylum Arthropoda. The cell line is based on Invitrogen's® Ecdysone-Inducible Mammalian Expression System, which consists of two plasmids, one of which expresses the heterodimeric ecdysteroid receptor while the other contains the receptor-ligand response element E/GRE. When ecdysone or another ligand having ecdysteroid activity is present, the binding of the receptor-ligand complex to the response element results in transcription of the reporter gene (β-galactosidase), the activity of which can be monitored colorimetrically. The plasmids were stably transfected into HepG2 human liver cells. Preliminary results show that Aroclor 1242, which is known to inhibit molting in invertebrates, also inhibited molting in juvenile crawfish (Procambarus clarkii) at 100 μg l−1 and normal ecdysteroid response in this new transgenic cell line, HepG2-EcR, at similar concentrations indicating that this new assay shows promise for future use as a screening tool.
Application of a sediment Toxicity Identification Evaluation in support of Total Maximum Daily Load development for the Calcasieu Estuary
Authors: Tracey G. A. , Poucher S. , Kelley B. , Crocker P.
Published: August 2004

A Toxicity Identification Evaluation of sediments from various reaches of the Calcasieu Estuary in Louisiana was performed to improve the technical basis for Total Maximum Daily Loads under development for this water body. The Toxicity Identification Evaluation methodology involved manipulations of the physical/chemical properties of sediment pore water samples in order to sequentially remove or bind each of the major classes of contaminant compounds and confounding factors. Toxicity tests were performed in conjunction with these manipulations to directly correlate reduction in toxicity with the specifically targeted contaminant classes. Toxicity of sediment porewaters from seven locations was evaluated using the amphipod, Ampelisca abdita and the mysid, Americamysis bahia. Toxicity Identification Evaluation results demonstrated improved survival after filtration, indicating that suspended particulates and associated contaminants were a significant source of toxicity. Subsequent treatments with column extraction and ethylene diamine tetra amino acid reduced toxicity, indicating both organics and metal constituents of pore waters as contributors to toxicity. The analysis of the filters used in the Toxicity Identification Evaluation revealed that particulate copper in the porewater was above criteria values, indicating that adverse exposure potential existed from the particulate phases, and that shifts in partitioning equilibrium could mediate dissolved-phase exposures. The identification of specific contaminant classes as well as particulate effects as sources of acute toxicity from Toxicity Identification Evaluation results indicate that in place sediment contamination as well as pore water flux and resuspension are likely contributors to habitat impairment that should be considered in Total Maximum Daily Load development.
The contribution of cobalt and manganese to the acute and chronic toxicity of sediments from Lake Molnbyggen and adjacent lakes around Leksand, Sweden
Authors: Dave G. , Nilsson E.
Published: August 2004

A number of studies of pollutants and their effects on the fish fauna of Lake Molnbyggen outside Leksand, Sweden have been focused on leachate from the municipal landfill (Lindbodarna), which is located above the lake. The aim of the present study was to test the toxicity of sediment from Molnbyggen and some adjacent lakes, in order to see if this could explain the causes of the effects on the fish. The sampling sites were selected in co-operation with the project group at the Swedish Environmental Protection Agency to make the results more easily comparable with those from other studies on the fish fauna in the area. Both acute and chronic tests were made with the crustacean Ceriodaphnia dubia, and the sediment samples were equilibrated with standard reference water prior to exposure. The exposures were made under standard conditions in the laboratory to make them more readily comparable between the sampling locations and with previous studies. The effects on survival and reproduction were monitored during 8 days. After that a series of Toxicity Identification Evaluation manipulations of the tested waters were made in order to identify the cause(s) of the toxicity. The results from the Toxicity Identification Evaluation tests pointed towards heavy metals as the cause of toxicity, and the analytical results of heavy metals in the water phase showed that the concentrations of six metals (Cd, Co, Mn, Ni, Pb and Zn) were significantly correlated with toxicity. The concentrations of these metals were also correlated with each other making it hard to separate cause and effect among the metals. However, the concentrations of Cd, Ni, Pb and Zn were below the expected effect concentrations, but the measured concentrations of Co and Mn were high enough to be probable causes of the observed experimental toxicity. There was no indication that lipophilic compounds should have caused these effects. Therefore, the result of this study was rather surprising, showing that heavy metals like cobalt and/or manganese which are not generally considered as environmentally problematic may be of environmental concern. Potential effects of cobalt and manganese could be mediated through the olfactory system, because both these metals have been observed to affect this system in fish. However, the link between such effects and those observed on reproduction in Lake Molnbyggen is vague.
Switch from αvβ5 to αvβ6 integrin expression protects squamous cell carcinomas from anoikis
Authors: Janes Sam M. , Watt Fiona M.
Published: August 2004

Stratified squamous epithelia express the αvβ5 integrin, but in squamous cell carcinomas (SCCs) there is down-regulation of αvβ5 and up-regulation of αvβ6. To investigate the significance of this finding, we transduced an αv-negative human SCC line with retroviral vectors encoding αv integrins. αvβ5-expressing cells underwent suspension-induced apoptosis (anoikis), whereas αv-negative cells and cells expressing αvβ6 did not. Resistance to anoikis correlated with PKB/Akt activation in suspension, but not with changes in PTEN or p110α PI3 kinase levels. Anoikis was induced in parental and αvβ6-expressing cells by inhibiting PI3 kinase. Conversely, activation of Akt or inhibition of caspases in αvβ5-expressing cells suppressed anoikis. Caspase inhibition resulted in increased phosphoAkt, placing caspase activation upstream of decreased Akt activation. Anoikis required the cytoplasmic domain of β5 and was independent of the death receptor pathway. These results suggest that down-regulation of αvβ5 through up-regulation of αvβ6 may protect SCCs from anoikis by activating an Akt survival signal.