bluuebunny/crossref_metadata_2025 huggingface dataset:
The location of Islam: Inhabiting Istanbul in a Muslim way
Authors: HENKEL HEIKO
Published: February 2007

In this article, I emphasize the endeavor of religious Muslims to weave Muslim practices and institutions into the heterogeneous lifeworlds of modern society. Pairing a practice–theoretical approach with a phenomenological one, this article shows that an important aspect of “inhabiting Istanbul in a Muslim way” is the active perception of this heterogeneous lifeworld, which foregrounds certain of its elements as distinctive. Through these strategies of inhabitation and perception, I suggest, social heterogeneity can be at once recognized and transcended.
Socialist scenarios, power, and state formation in Sandinista Nicaragua
Authors: MONTOYA ROSARIO
Published: February 2007

Drawing on the concept of “scenario,” I examine the ideological construction of an agricultural cooperative in a “model” village in revolutionary Nicaragua (1979–90). I argue that the state's modernist project of development placed the burden of cooperative members' transformation into model revolutionaries on individual will rather than on national and global political–economic relations. This resulted in Tuleños' inability to live up to Sandinista expectations and authorized the production of Sandinista and academic discourses that cast these producers as failed revolutionaries. These discourses helped constitute and naturalize the vanguardist relationship established by the state's modernist project between the state and the cooperative sector.
Discursive constructions of homelessness in a small city in the Canadian prairies: Notes on destructuration, individualization, and the production of (raced and gendered) unmarked categories
Authors: KINGFISHER CATHERINE
Published: February 2007

In this article, I explore the conversations, debates, and constructions that inform and precede actual policy formation regarding homelessness in a small Canadian prairie city. On the basis of analyses of videotapes of public hearings coupled with participant‐observation and interviews with decision makers, my discussion focuses on two related phenomena: first, the interactional production, via indexicality and omission, of an unmarked categorization of the homeless person as “male Aboriginal addict”; and, second, the destructuring, individualizing influences of discourses of “diversity.” I conclude with a discussion of the policy implications of both phenomena, with particular emphasis on unintended consequences.
High‐Stakes Accountability, Minority Youth, and Ethnography: Assessing the Multiple Effects
Authors: Sloan Kris
Published: February 2007

In this article, I offer a review of the ethnographic research that reports the effects of current accountability policies on minority youth. Included in this article are qualitative investigations that have significant field‐based components, most especially direct observations at the classroom level. In this article, I demonstrate both the power and potential of ethnography to offer clearer, more detailed portraits of the varied ways that current accountability policies affect teachers of minority youth, the curriculum and pedagogy that minority youth experience, minority youth in general, and the schooling of minority youth.
The Cultural Politics of the Texas Educational Reform Agenda: Examining Who Gets What, When, and How
Authors: Salinas Cinthia S.
Published: February 2007

This critical policy examination of the economistic discourses that control Texas's accountability reforms explores how over the last three decades Texas business elite utilized the policy process, power relationships, and educational value conflicts that promote accountability as the paradigm for education reform. Attention on “who gets what, when, and how” finds the balance of educational values is distorted on behalf of the business‐power elites and undermines the democratic authority of accountability reforms.
Scientifically Debased Research on Learning, 1854–2006
Authors: Mcdermott Ray
Published: February 2007

By its emphasis on arbitrary standards and misleading systems of accountability, the No Child Left Behind Act has had deleterious effects on classroom practice, teacher education, and even educational research. The new constraints on educational research, driven by a logic of randomized field tests, are part of a larger and more invidious international managerialism that subordinates individual biographies to state‐based bureaucratic control.
"A Child Is a Child": Fostering Experiences in Northwestern Cameroon
Authors: Verhoef Heidi , Morelli Gilda
Published: February 2007

Past research comparing fostered and nonfostered children's welfare in sub‐Saharan Africa has led to inconsistent results. One reason for this disparity might be that children's experiences are shaped more by the circumstances in which they are fostered than by merely being raised away from their parents. This article examines how fostered children in one urban community in northwestern Cameroon spend time relative to their nonfostered peers and, by grouping fostered children according to fostering circumstances, how they spend time relative to one another. Analysis of children's activities suggests little variance between the experiences of fostered and nonfostered children, but significant differences among fostered children. These results are interpreted using children's views of activities, and the potential consequences of children's relative integration in foster households are discussed.
The Architecture of Cosleeping among Wage‐Earning and Subsistence Farming Cameroonian Nso Families
Authors: Yovsi Relindis D. , Keller Heidi
Published: February 2007

This article addresses early caregiving environments, specifically cosleeping patterns among wage‐earning and subsistence farming—based Cameroonian Nso families and their children during the first year of life. Forty‐three wage‐earning and 35 farming Nso mothers were interviewed at home about their formal schooling, economic activities, living conditions, children's sleeping arrangements, and night care. The findings provide ethnographic evidence that the Nso have a cosleeping culture, and that wage earning is an index of social and cultural change and exerts a substantial influence on sleeping patterns. The traditional pattern in the farming family is that mothers share the bed only with the infant, engage in no bedtime routines or schedules, and plan to wean their children later than do mothers in wage‐earning families. The wage‐earning mothers share a bed with an infant and others, predominantly the father. They also have bedtime routines and schedules and plan to wean their children approximately five months earlier than do mothers in farming families. The results are discussed with respect to the Nso culture and sociohistorical changes related to changes in economic livelihood and urbanization.
The Cultural Politics of Tourism in San Francisco's Chinatown, 1882-1917
Authors: RAST RAYMOND W.
Published: February 2007

During the 1880s San Francisco bohemians began to portray Chinatown as a place in which the forces of marginalization allowed a premodern authenticity to fl ourish. Their depictions of Chinatown resonated with a growing number of tourists. Historians have examined these developments, but few have considered the ways in which touristic interest in "authentic Chinatown" created new opportunities for entrepreneurial activity and social action. As this article argues, white and Chinese San Franciscans seized these opportunities. By the 1890s white tour guides had begun to stage scenes of depravity and present them as "authentic." Some Chinese San Franciscans performed within these scenes; others responded to tourists with practiced indifference, contempt, or hostility. A loose coalition of Chinatown merchants pursued a third strategy. They sought to rechannel touristic interest by locating Chinatown's authenticity within its exotic architecture, theatrical performances, curios, and cuisine. In doing so, they affi rmed perceptions of Chinese American "otherness."
Exhibiting World War II in Japan and the United States since 1995
Authors: HEIN LAURA , TAKENAKA AKIKO
Published: February 2007

Museum professionals, like most people, dislike being the focus of criticism, yet many have recently found themselves in this predicament over exhibits focusing on the histories of major social confl icts. An especially tense issue for both Japanese and American museums has been treatment of World War II, particularly how to portray the motives, policies, and conduct of their own governments during the war. Curators have not always been prepared for the intense criticism and for the charge that differences of opinion are caused by a clash of irreconcilable ideologies, only one of which is valid. Japanese and American museums have deployed similar strategies-some effective, some self-defeating-for meeting those challenges. Neither has found ideal solutions, although some approaches, such as presenting multiple points of view and providing opportunities for interaction, seem to hold greater promise than others.
The Church Historians Who made the First Amendment What it is Today
Authors: Drakeman Donald L.
Published: February 2007

Thomas Jefferson and James Madison are frequently identified as the framers of the religion clauses in the First Amendment, thus making their efforts to establish religious freedom in colonial Virginia relevant to the Constitution's meaning. This interpretive approach first appeared in a Supreme Court opinion in 1878 when Chief Justice Morrison Waite applied the religion clauses to the case of a Mormon official prosecuted under a federal antipolygamy law. For historical background, Justice Waite studied books by church historians Robert Reid Howison and Robert Baylor Semple. There, he encountered narratives of the political activism of the Baptists and Presbyterians who, in conjunction with the efforts of Madison and Jefferson, were responsible for Virginia's statutory commitment to religious freedom. The Chief Justice then grafted Madison's Memorial and Remonstrance against Religious Assessments and Jefferson's now-famous “wall of separation” letter onto the Constitution's bare text, an emendation that has endured for well over a century. Church historians Semple and Howison, and the pivotal role they played in the foundation of First Amendment jurisprudence, have been essentially lost from the historiographical record of church-state relations in America, a situation this article seeks to remedy.
“Beautiful Women Dig Graves”: Richard Baker-roshi, Imported Buddhism, and the Transmission of Ethics at the San Francisco Zen Center
Authors: Bivins Jason C.
Published: February 2007

There is little reckoning with the development of religions in the United States without confronting the related processes of importation and appropriation. This article explores these processes specifically as reflected in the story of the San Francisco Zen Center. Partaking of an interpretative ethos established by the nineteenth-century Transcendentalists and refined during the 1950s “Zen boom,” the architects of the SFZC's communalism shaped this complicated tradition specifically for disaffected young practitioners seeking an experiential path beyond their middleclass, Judeo-Christian backgrounds. It was during the 1983 scandals surrounding SFZC leader, Richard Baker-roshi, that many of the interpretive lacunae—specifically, a relative inattention to ethical languages—became readily apparent. This article accounts for these scandals historically (by situating them in the history of American appropriations of Buddhism and of the religious disaffection of the post-World War II period) and theoretically (by reading the SFZC's patterns of transmission and interpretation through the category “interpretative double movement). This double movement among practitioners captures the ways in which those in search of an alternative to their religious culture impose their own idiosyncratic values onto another religious tradition, all the while remaining paradoxically within the interpretive confines of the culture they hope to escape. Reading this complicated history—including both its “scandals” and their aftermaths—through such categories sheds light on the ways in which American religious exchanges are enacted and identities constructed.
Trauma and Visuality: Art Spiegelman's Maus and In the Shadow of No Towers
Authors: Orbán Katalin
Published: February 2007

In Art Spiegelman's comic books, ambivalence about visuality in representing the historical and private traumas of the Holocaust and 9/11 manifests itself as blindness: seeing inwardly and seeing through touch. The emphasis on materiality and proximity links the haptic visuality of In the Shadow of No Towers to other visual practices memorializing 9/11 that withdraw to the local landscape of the neighborhood and demonstrates the challenge posed by the images of 9/11 to historical interpretation.
"On Seeing Me Write": Inscription Devices in the South Seas
Authors: Schaffer Simon
Published: February 2007

Recent historical and sociological work has used the notion of the inscription device to account for European sciences' long-range powers. Such devices are supposed to generate traces of encounters and observations, which can then be mobilized and combined elsewhere along complex networks of travel and information transfer. Europeans' voyages in the South Seas have often been used to illuminate this process. This paper examines an episode of 1792 when a British astronomer was invited to tattoo a Marquesan chief by the chief himself. The episode suggests intriguingly symmetrical relations between acts of inscribing, writing, and tattooing and analyzes the ways inscriptions worked in such encounters. Assumptions about European authority and indigenous difference can thus be reexamined.
Early Childhood Gender Differences in Anterior and Posterior Cerebral Blood Flow Velocity and Autoregulation
Authors: Tontisirin Nuj , Muangman Saipin L. , Suz Pilar , Pihoker Catherine , Fisk Dana , Moore Anne , Lam Arthur M. , Vavilala Monica S.
Published: February 2007

OBJECTIVE. We aimed to describe gender differences in blood flow velocity and autoregulation of the anterior and posterior cerebral circulations in prepubertal children.

METHODS. A prospective observational cohort study was performed at Harborview Medical Center's Cerebrovascular Laboratory after institutional review board approval, consent, and assent procedures. Children underwent measurement of middle cerebral and basilar artery flow velocities and cerebral autoregulation testing of the middle cerebral and basilar arteries. Cerebral autoregulation was quantified using the autoregulatory index, and estimated cerebrovascular resistance was calculated. Autoregulatory index <0.4 reflects impaired cerebral autoregulation. Data are presented as mean ± SD. Patients were healthy 4- to 8-year-old children.

RESULTS. Forty-eight children (24 boys and 24 girls) 4 to 8 years of age (mean: 6 ± 2 years) were enrolled. Middle cerebral artery flow velocity was higher than basilar artery flow velocity (96 ± 13 vs 65 ± 11 cm/s). Girls had higher middle cerebral artery flow velocity (99 ± 11 vs 91 ± 13 cm/s) and basilar artery flow velocity (70 ± 10 vs 61 ± 9 cm/s) than boys. Cerebral autoregulation was intact in all children. There was no gender difference in autoregulation between the middle cerebral artery (boys: 0.97 ± 0.07; girls: 0.94 ± 0.11) or basilar artery (boys: 0.94 ± 0.13; girls: 0.94 ± 0.11).

CONCLUSIONS. Similar to older children and adults, girls between 4 and 8 years of age had higher middle cerebral and basilar artery flow velocity than age-matched boys. This difference may reflect inherent differences in cerebral metabolic rate and/or estimated cerebrovascular resistance between the genders.
Allogeneic Intrabone Marrow-Bone Marrow Transplantation plus Donor Lymphocyte Infusion Suppresses Growth of Colon Cancer Cells Implanted in Skin and Liver of Rats
Authors: Koike Yasushi , Adachi Yasushi , Suzuki Yasuhiro , Iwasaki Masayoshi , Koike-Kiriyama Naoko , Minamino Keizo , Nakano Keiji , Mukaide Hiromi , Shigematsu Akio , Kiyozuka Yasuhiko , Tubura Airo , Kamiyama Yasuo , Ikehara Susumu
Published: February 2007

We have recently found that allogeneic intrabone marrow-bone marrow transplantation (IBM-BMT) + donor lymphocyte infusion (DLI) using CD4+ cell-depleted spleen cells (CD4− cells) can prevent graft-versus-host disease (GvHD) but suppress tumor growth (Meth A: fibrosarcoma) in mice. In the present study, we show that allogeneic IBM-BMT + DLI using CD4− cells also has suppressive effects on the growth of colon cancer cells implanted not only in the skin but also in the liver of rats. First, we examined the effects of allogeneic IBM-BMT + DLI on the subcutaneously inoculated ACL-15 (rat colon cancer cell line). Lethally irradiated Fischer rats (F344 rats) were transplanted with T-cell-depleted bone marrow cells (BMCs) from Brown Norway (BN) rats. Simultaneously, DLI was performed using whole spleen cells (whole cells), CD4+ cell-depleted spleen cells (CD4− cells) or CD8+ cell-depleted spleen cells (CD8− cells) of BN rats. Although allogeneic IBM-BMT + DLI suppressed tumor growth, a considerable number of rats treated with allogeneic IBM-BMT + DLI using whole cells or CD8− cells died due to GvHD. In contrast, allogeneic IBM-BMT + DLI using CD4− cells also suppressed tumor growth, but there was no GvHD. Based on these findings, we next examined the effects of allogeneic IBM-BMT + DLI using CD4− cells on the cancer cells implanted in the liver. Allogeneic IBM-BMT + DLI using CD4− cells via the portal vein significantly prolonged the survival. These results suggest that allogeneic IBM-BMT + DLI using CD4− cells could become a new strategy for the treatment of solid tumors.
Qualification of Embryonal Carcinoma 2102Ep As a Reference for Human Embryonic Stem Cell Research
Authors: Josephson Richard , Ording Carol J. , Liu Ying , Shin Soojung , Lakshmipathy Uma , Toumadje Araz , Love Bradley , Chesnut Jonathan D. , Andrews Peter W. , Rao Mahendra S. , Auerbach Jonathan M.
Published: February 2007

As the number of human embryonic stem cell (hESC) lines increases, so does the need for systematic evaluation of each line's characteristics and potential. Comparisons between lines are complicated by variations in culture conditions, feeders, spontaneous differentiation, and the absence of standardized assays. These difficulties, combined with the inability of most labs to maintain more than a few lines simultaneously, compel the development of reference standards to which hESC lines can be compared. The use of a stable cell line as a reference standard offers many advantages. A line with a relatively unchanging hESC-like gene and protein expression pattern could be a positive control for developing assays. It can be used as a reference for genomics or proteomics studies, especially for normalizing results obtained in separate laboratories. Such a cell line should be widely available without intellectual property restraints, easily cultured without feeders, and resistant to spontaneous changes in phenotype. We propose that the embryonal carcinoma (EC) line 2102Ep meets these requirements. We compared the protein, gene, and microRNA expression of this cell line with those of hESC lines and alternative reference lines such as the EC line NTERA-2 and the karyotypically abnormal hESC line BG01V. The overall expression profiles of all these lines were similar, with exceptions reflecting the germ cell origins of EC. On the basis of global gene and microRNA expression, 2102Ep is somewhat less similar to hESC than the alternatives; however, 2102Ep expresses more hESC-associated microRNAs than NTERA-2 does, and fewer markers of differentiated fates.
Patients without Borders: The Emergence of Medical Tourism
Authors: de Arellano Annette B. Ramírez
Published: February 2007

A growing number of patients from the United States and other developed countries are traveling abroad with the express purpose of obtaining health care, including elective surgery and long-term care. This trend is not innocuous. It can lead developing countries to emphasize technology-intensive tertiary care for foreigners at the expense of basic health care for their citizens. Moreover, it can exacerbate the brain drain from the public to the private sector. The examples of Thailand and India suggest the distorting effects of this trend and raise questions of social equity in the distribution of scarce resources.
Effects of Reflection Prompts When Learning with Hypermedia
Authors: Bannert Maria
Published: February 2007

In this study the assumption was tested experimentally, whether prompting for reflection will enhance hypermedia learning and transfer. Students of the experimental group were prompted at each navigation step in a hypermedia system to say the reasons why they chose this specific information node out loud whereas the students of the control group learned without reflection prompting. University students ( N = 46) participated and were counterbalanced according to their prior knowledge, metacognitive knowledge, and verbal intelligence. The students' task was to learn the concepts of operant conditioning within 35 minutes. Students were completely free in navigation and students' individual learning sessions were videotaped. Immediately afterwards learning outcome was obtained. As expected, students learning with reflection prompts showed better transfer performance compared to the control group, especially if their navigation was based on strategic decisions. Even though prompting for reflection was successful, ways of further optimizing this kind of metacognitive intervention are discussed.
Methods for Recruiting White, Black, and Hispanic Working-Class Women and Men to a Study of Physical and Social Hazards at Work: The United for Health Study
Authors: Barbeau Elizabeth M. , Hartman Cathy , Quinn Margaret M. , Stoddard Anne M. , Krieger Nancy
Published: February 2007

Despite research on work and health having a long-standing concern about unjust exposures and inequitable burdens of disease, there are few studies that document the joint distribution and health effects of physical and psychosocial hazards (e.g., noise, dusts, fumes, and job strain) and social hazards (e.g., racial discrimination and gender harassment) encountered at work. Also, there is a paucity of data on how these exposures, singly and combined, are distributed in relation to sociodemographic characteristics including race/ethnicity, gender, socioeconomic position, and nativity. This article presents a conceptual model for redressing these knowledge gaps and describes recruitment strategies and the characteristics of study participants in the United for Health study. Working with labor unions, the authors recruited 14 (67%) of 21 worksites from manufacturing, meat processing, retail, and transportation, and 1,282 workers (72% response rate), of whom 62 percent were men, 36 percent were women, 39 percent were black, 23 percent were Hispanic, 25 percent were white, 31% earned less than a living wage, 40 percent were below the poverty level, and 23 percent had less than a high school education.
Variation of Socioeconomic Gradients in Children's Developmental Health across Advanced Capitalist Societies: Analysis of 22 Oecd Nations
Authors: Siddiqi Arjumand , Kawachi Ichiro , Berkman Lisa , Subramanian S. V. , Hertzman Clyde
Published: February 2007

Within societies, there is a well-established relation between socioeconomic position and a wide range of outcomes related to well-being, and this relation is known to vary in magnitude across countries. Using a large sample of nations, the authors explored whether differences in social policies explain differences in socioeconomic gradients across nations. Analyses were conducted on reading literacy in 15-year-olds, as an outcome related to cognitive development and to a host of factors that contribute to future well-being, including educational attainment and health. The results show a systematic variation in socioeconomic gradients and average scores across countries. Scores were favorable in countries with a long history of welfare state regimes, but countries where institutional change unfolded more recently and rapidly, or where welfare states are less well developed, clustered at the bottom of the rankings. Strong support was found for the “flattening up” hypothesis, which suggests that nations with higher average scores have less socioeconomic inequality in scores (or flatter gradients). Potential explanations for the observed patterns include differences between nations in the extent and distribution of income and social goods important for children's development.
Remapping Worker Citizenship in Contemporary Occupational Health and Safety Regimes
Authors: Tucker Eric
Published: February 2007

The article draws on the rapidly growing field of citizenship studies to map and explore the dynamics of contemporary occupational health and safety (OHS) regulation. Using two key dimensions of OHS regulation (protection and participation), the author constructs four ideal types of worker citizenship (market, public, private industrial, and public industrial citizens). Historically, workers have been written into OHS regulatory regimes in each of these ways. Most recently lawmakers have created a new species of OHS regimes, best described as mandated partial self-regulation. Its distinguishing characteristic is its flexibility, such that worker citizenship can take on any of the forms previously described, often without changing the statutory framework. Using Ontario as an example, the study finds that in the late 20th century, workers made significant strides toward public industrial citizenship and, surprisingly, even under a neoconservative government, workers successfully defended their participatory rights and saw their right to protection modestly strengthened through increased enforcement. The conditions under which this regime operates, however, constantly threaten to undermine the efficacy of worker participation rights and to weaken the enforcement effort. Some suggestions are made about using a citizenship discourse to revitalize the worker OHS movement and strengthen OHS rights.
The Dispossession of African Wealth at the Cost of Africa's Health
Authors: Bond Patrick
Published: February 2007

This article synthesizes new data about the outflow of Africa's wealth, to reveal structural factors behind the continent's ongoing underdevelopment. The flow of wealth out of sub-Saharan Africa to the North occurs primarily through exploitative debt and finance, phantom aid, capital flight, unfair trade, and distorted investment. Although the resource drain from Africa dates back many centuries—beginning with unfair terms of trade, amplified through slavery, colonialism, and neocolonialism—today, neoliberal (free market) policies are the most direct causes of inequality and poverty. They tend to amplify preexisting class, race, gender, and regional disparities and to exacerbate ecological degradation. Reversing this outflow is just one challenge in the struggle for policy measures to establish a stronger funding base for the health sector.
Magnetic‐Core/Porous‐Shell CoFe2O4/SiO2 Composite Nanoparticles as Immobilized Affinity Supports for Clinical Immunoassays
Authors: Tang D. , Yuan R. , Chai Y. , An H.
Published: February 2007

This study demonstrates a novel approach towards the development of advanced protein assay systems based on physically functionalized, magnetic‐core/porous‐shell CoFe2O4/SiO2 composite nanoparticles. The preparation, characterization, and measurement of the relevant properties of the protein assay system is discussed, and the system is used for the detection of cancer antigen 15‐3 (CA 15‐3, used as a model here) in clinical immunoassays. The protein assay system, based on nanometer‐sized magnetic cores and silica shells, shows good adsorption properties for the selective attachment of CA 15‐3 antibodies specific to CA 15‐3. The core/shell nanostructures exhibit good magnetic properties, which enables their integration into a quartz crystal microbalance (QCM) detection cell with the help of a permanent magnet. Under optimal conditions, the resulting immunoassay system presents a good QCM response for the detection of CA 15‐3, and allows the detection of CA 15‐3 at concentrations as low as 1.5 U mL–1 (U: units). Importantly, the proposed protein assay system can be extended to the detection of other antigens and biological compounds.
Methods for Counting Water Bacteria – Comparison and Significance
Authors: Straškrabová V.
Published: February 2007

A comparison is made between the results of bacteriological investigations into the total of 501 samples from 4 brooks, 2 rivers, 5 reservoirs and 2 wastewater treatment facilities by means of the following methods: Cultures on plates with various media, direct counting and counting of microcolonies. Linear regressions exist between the logarithms of the numbers of germs or bacteria of cultures on plates or direct counts, the ratio of the number of bacteria to the number of germs decreasing with an increasing number of bacteria. In case of equal numbers of bacteria, stagnant waters contain fewer germs than flowing waters.
Methoden der chemischen Analyse des Klärschlammes
Authors: Malý J. , Fadrus H.
Published: February 2007

Für eine Klassifikation von Schlämmen aus der mechanischen und biologischen Abwasserbehandlung erweisen sich die in der Bodenkunde verwendeten Verfahren des Aufschlusses mit 20%iger Salzsäure sowie der Totalaufschluß in alkalischer Schmelze als durchaus geeignet. In vergleichenden Untersuchungen ist der Aufschluß mit Salzsäure nach Naßoxydation ein brauchbares Verfahren, besser ist jedoch die Gesamtanalyse aus zwei Proben: Bestimmung der Alkalien nach Oxydation mit Perchlorsäure und der übrigen Bestandteile nach alkalischer Schmelze. Die Befunde werden tabellarisch dargestellt und vergleichend diskutiert.
Disiloxanvernetzte Polymere als Phenoladsorber
Authors: Runge F. , Ackermann J.
Published: February 2007

Mit einem neuen „Disiloxan”︁‐Vernetzer (1,3‐Divinyl‐tetra‐n‐butoxydisiloxan) synthetisierte Copolymere wurden hinsichtlich ihrer Eignung als Adsorber für phenolische Verbindungen geprüft.
Oberflächengewässer als biochemische Reaktoren
Authors: Gnauck A. H.
Published: February 2007

Die Formulierung „ein Gewässer ist ein biochemischer Reaktor”︁ hat in der letzten Zeit zu neuen Überlegungen bei der Beschreibung des Stoffhaushaltes von Oberflächengewässern angeregt. Dabei wurden jedoch nur verbale Einschätzungen des Reaktors „Gewässer”︁ gegeben, ohne den bereits erprobten mathematischen Apparat, der in der technischen Reaktions‐führung mit Erfolg angewendet wird, zu nutzen. So wurden in der Vergangenheit lediglich für Fließgewässer Massenbilanzgleichungen zur Bilanzierung des Sauerstoffhaushaltes verwendet. Für gestaute Gewässer erfolgte eine solche Bilanz zur Erfassung der Biomasse. Oberflächengewässer werden gemäß ihrem Charakter mit technischen Reaktoren verglichen, wobei die Besonderheiten solcher Ökosystemreaktoren diskutiert werden.
Algal Bioassays of two tropical Rhodesian Reservoirs
Authors: Robarts R. D. , Southall G. C.
Published: February 2007

Possible nitrogen and phosphorus limitation of algal growth in two tropical impoundments was investigated using pure culture bioassays. The test organism was Selenastrum capricornutum. Phosphorus was indicated as a primary growth limiting nutrient in Mazoe Dam while in Lake McIlwaine nitrogen was generally indicated as limiting. These differences were probably related to the different major sources of nutrients in these two reservoirs.
Vorhersage des Sauerstoffgehaltes im Tiefenwasser einer neuerrichteten Talsperre für die ersten Jahre des Anstaues
Authors: Küchler L. , Kozerski H.‐P.
Published: February 2007

Der folgende Beitrag informiert über die Prognose des Sauerstoffgehaltes im Hypolimnion einer geplanten Talsperre mit Hilfe eines mathematischen Modells. Nach einigen Angaben über die angewandten Methoden und notwendige Einschränkungen, zeigen die vorgestellten Rechenergebnisse die prinzipielle Eignung des beschriebenen Prognoseverfahrens. Das Einstauregime hat nach den Ergebnissen eine besonders große Bedeutung für die Sauerstoffverhältnisse in der Anstauphase. Abschließend wird auf eventuelle Fehlerquellen und Verbesserungsmöglichkeiten hingewiesen.
Der Einfluß der landwirtschaftlichen Nutzung von Talsperreneinzugsgebieten auf den Nährstoffeintrag in Trinkwassertalsperren
Authors: Wegener U. , Dörter K. , Beuschold E.
Published: February 2007

Im Einzugsgebiet der Rappbode‐Talsperre, Harz, wurde an Hand von Parzellen‐ und Großflächenversuchen die Größenordnung des Nährstoffabtrages unter verschiedenen natürlichen und unterschiedlichen Bewirtschaftungsbedingungen untersucht. Der Nährstoffabtrag naturnaher Einzugsgebiete schwankte für Phosphor von 0,21… 0,70 kg P/ha. a und für Stickstoff von 2,9… 11,8 kg N/ha. a. Dagegen wurden aus einem intensiv genutzten Gebiet Nährstoffabträge von 1,10 kg P/ha. a und 26,0 kg N/ha. a gemessen. Zur Verminderung des Nährstoffabtrages werden Maßnahmen des Erosionsschutzes und der landwirtschaftlichen Düngung vorgeschlagen.

Weiterhin wird nachgewiesen, daß der Einfluß der Landwirtschaft im vorwiegend bewaldeten Einzugsgebiet der Rappbode‐Talsperre geringer ist als in anderen Einzugsgebieten. Je landwirtschaftlich genutzter Flächeneinheit ist der Nährstoffabtrag jedoch relativ hoch, wobei besonders bei Stickstoff eine steigende Tendenz zu erwarten ist.

Auf wasserwirtschaftliche Maßnahmen zur Verminderung des Nährstoffeintrages in die Talsperre, so zum Beispiel durch den Bau von zusätzlichen Vorsperren, wird verwiesen.
Atomabsorptionsspektroskopische Bestimmung von Eisen, Kupfer, Zink, Cadmium, Mangan und Kobalt in Natur‐ und Brauchwässern mit der “Injektionsmethode” nach vorhergehender extraktiver Anreicherung
Authors: Gläser E.
Published: February 2007

In der Industrie, der Wasserwirtschaft und im Umweltschutz sind zunehmend in Wässern Schwermetallgehalte von wenigen μg/l zu bestimmen (MARGULOVAet al.;WELZ). Kolorimetrische Verfahren sind in diesem Konzentrationsbereich sehr arbeitsaufwendig und stellen hohe Anforderungen an die manuellen Fertigkeiten des Laboratoriumspersonals. Die Atomabsorptionsspektroskopie bietet eine zeit‐ und kostengünstige Alternative. Allerdings muß hier eine extraktive Anreicherung vorgeschaltet werden. Besonders günstig ist, gleichzeitig mehrere Metalle zu extrahieren und diese im gleichen Extrakt nacheinander zu bestimmen. Um trotz hoher Anreicherungsfaktoren nicht unhandlich große Wassermengen ausschütteln zu müssen, wird zur atomabsorptionsspektroskopischen Endbestimmung die sog. “Injektionsmethode” (SEBASTIANI, OHLS undRIEMER) angewendet, für die Probemengen von 0,1 ml je Bestimmung ausreichend sind.
Beitrag zur Aufbereitung arsenhaltiger Schachtwässer zu Trinkwasser. Teil 2: Ergebnisse kleintechnischer Versuche
Authors: Röske I. , Kermer K.
Published: February 2007

Die Aufbereitung schwach arsenhaltiger Schachtwässer zu Trinkwasser mit Eisensalzen durch Flockungsfiltration wird beschrieben. Die Arseneliminierungsrate ist vor allem vom Konzentrationsverhältnis Eisen(III)/Arsen, dem pH‐Wert des Rohwassers und der Enteisenungswirkung der Kiesfilteranlage abhängig.

Bei einem Arsengehalt des Schachtwassers von 0,30… 0,35 mg/l waren im Durchschnitt 1,8 mg/l Eisen(III) und ein Chlorüberschuß von ca. 0,5 mg/l ausreichend, um im Reinwasser den Grenzwert, As <0,05 mg/l, zu garantieren.

Ergänzend werden erste Betriebserfahrungen bei der Aufbereitung arsenhaltiger Wässer diskutiert.
The Uptake of 226Ra by Planktonic Algae under Conditions of Continuous Cultivation
Authors: Havlík B. , Hanušová J.
Published: February 2007

The radium cumulation in Coelastrum cambricum, Scenedesmus obliquus and Microcystis pulverea was studied under conditions of continuous cultivation at constant level of radium in the cultivation medium. The algae were exposed to the concentrations of 30, 300 and 3000 Bq/l 226Ra in the medium for a period of 14 days. It was found that radium started to cumulate immediately after its addition to the culture just as in the stationary type of cultivation, in the continuous cultivation, however, its content decreased with the length of exposure. This is due to the decreasing part of radium adsorbed on the cell surface. While in green algae the portion of radium incorporated into cells increased with the length of exposure, in blue‐green algae up to 90% of radium was bound to the surface or gelatinous capsules of the cells through out the experiment. With the three phytoplankton species used, the highest cumulation of radium (nonwashable part) was recorded in Coelastrum cambricum. A dependence of the radium cumulation on its content in the medium was observed in the species Scenedesmus obliquus.
Acute Toxicity of Mercury, Copper and Zinc to a Freshwater Pulmonate Snail, Lymnaea luteola (LAMARCK)
Authors: Mathur S. , Khangarot B. S. , Durve V. R.
Published: February 2007

The short‐term toxicity of mercury, copper and zinc was studied using a freshwater pulmonate snail, Lymnaea luteola (LAMARCK). The median period of survival increases with decreasing the toxicant concentration. The 96 h LC50 values and their confidence limits were 0.135 (0.112 … 0.186) ppm of Hg2+; 0.172 (0.118 … 0.355) ppm of Cu2+; and 6.13 (5.73 to 7.19) ppm of Zn2+. The relative potency ratio indicates that the Hg2+ ions were most toxic, followed by Cu2+ and Zn2+ ions.
Beurteilung der Hydrolyseaktivität von Belebtschlamm mittels spezifischer chromogener Substrate
Authors: Vaňková S. , Kasafírek E. , Kupec J. , Mládek M.
Published: February 2007

Zur Bestimmung der hydrolytischen Aktivität einer heterogenen Kultur (Belebtschlamm) wurde die Eignung einer Reihe chromogener Substrate untersucht. Auf Grund der durchgeführten Untersuchungen wurden einige Gruppen von Enzymen bestimmt, die in dieser bakteriellen Population vorkommen. Synthetische chromogene Substrate erwiesen sich als geeignetes Mittel zur raschen und unter Laboratoriumsbedingungen einfachen Beurteilung der Kapazität eines Belebtschlammes, hochmolekulare Substrate zu zersetzen.
Chromium(III) and Chromium(VI) Circulation in Aquatic Biocenoses
Authors: Starý J. , Havlík B. , Zeman A. , Kratzer K. , Prášilová J. , Hanušová J.
Published: February 2007

The cumulation of chromium(III) and (VI) has been studied in batch cultures of planktonic algae Microcystis incerta, Scedenesmus obliquus, Chlorella kessleri and Chlamydomonas geitleri at different chromium and algal cells concentrations. It has been found that chromium(VI) is practically not cumulated in algae, whereas chromium(III) is very rapidly cumulated in all types of algae investigated. The cumulation factor increases with the decrease of the radius of algae cells and it reaches the value of 106 for Microcystis incerta even after a few hours of contact. The kinetics, the cumulation factors and the capacity of algae to cumulate chromium(III) is practically the same for living as well as for dead cells and therefore it can be concluded that the cumulation of chromium(III) is due predominantly to the chemical sorption on the surface of algal cells.
Nachweis toxischer Hemmungen des biochemischen Abbaus in Flußwasser
Authors: Spott D.
Published: February 2007

The proposed analytical technique is another possibility for determining the inhibition of the biochemical decomposition of organic substances in surface waters by toxicants. The advantages and disadvantages of respective techniques having been published so far in literature and of the new method proposed are discussed. This method is based on the BOD analysis according to Vihl and peptone is used as the check substrate. Save exceptional cases with special statements of problems, the undiluted river water is tested. Examples of results on the degree of the occurrence of toxic inhibition in river waters are presented in tables.
Zum Sauerstoffhaushalt der Gewässer der Feldberger Seenplatte an Hand ausgewählter sommerlicher Tiefenprofile sei 1924 bzw. 1962. Teil 2: Zansen, Wootzen, Carwitzer See, Dreetz und Krüselin
Authors: Richter W. M.
Published: February 2007

For the four lakes of the lower Feldberg lake district as well as for the Krüselin. situated on the periphery of the lake district, summer depth profiles of the oxygen concentration together with the metalimnion, transparency, water temperature and the depth limit of the occurrence of hydrogen sulphide are represented for the period from 1924 or 1962 to 1980. The profiles very clearly demonstrate the progressive eutrophication of these lakes, but also the beginning improvement of the quality of their water. Important data of hydrography as well as the possibilities of restoration are discussed.
Bewertung subletaler Schadstoffwirkungen mit Hilfe der Sigmafunktion
Authors: Hering G.
Published: February 2007

Biostatistical measures of variability as the mean‐squared deviation are not only used for characterizing a measurement series, but they are an immediate expression of the biological variability. Physiological and ecological data are often variance‐inhomogeneous: the standard deviation is a (frequently linear) function of the mean value which is described as the sigma function. On this basis, the salt tolerance of fish fry and of marble carp hybrids (Aristichthys nobilis × Hypophthalmichthys molitrix) with or without a preceding adaptation is investigated in the range of 0 … 14% salinity. The change in mortality leads also to differences in weight due to both, reduced growth and higher mortality of the weaker, smaller individuals. The empirical sigma functions of these experiments prove a true adaptation of fish up to a salt concentration of 8% salinity at least for a retention of 14 days.
Bestimmung der Aktivität von Belebtschlamm über die Geschwindigkeit der Biosynthese von Aminopeptidasen
Authors: Vaňková S. , Veselá A. , Kupec J. , Kasafírek E. , Mládek M.
Published: February 2007

The authors describe a possibility of a fast determination of the metabolic activity of various activated sludge samples. There is not used the sludge property of digestion, but the biosynthesis of aminopeptidases. Egg albumin has been found to be the optimum standard indicator. The activity of the investigated activated sludge is derived from the rate of the biosynthesis of aminopeptidases. The technique proposed can be used also for determining the toxic effects of different substances on activated sludge.
Cumulation of Zinc, Cadmium and Mercury on the Alga Scenedesmus obliquus
Authors: Starý J. , Havlík B. , Kratzer K. , Prášilová J. , Hanušová J.
Published: February 2007

In batch experiments with the metals labelled with their radionuclides the cumulation of zinc, cadmium and mercury on Scenedesmus obliquus in dependence on the pH‐value is measured, because the original pH‐value of the solution is changed by the algae due to their absorption of hydrogen‐ions. For the uptake of zinc and cadmium the logarithm of the cumulation factor in the range of 2 … 5 is a linear function of the pH‐value in the range of 5 … 9, cumulation increasing with rising pH‐value. In contrast, the mercury cumulation is pH‐independent. If the changed pH‐value is taken into account, the cumulation factors are independent of the metal concentration in the range = 10−4 mol/l. The degree of cumulation is not changed by the presence of other metals. The cumulation factor is reduced by substances forming negatively charged complexes with the metals.
Die Auswirkung von Tensiden und das Verhalten von Bakterien gegen‐über grenzflächenaktiven Verbindungen
Authors: Walther H.‐J.
Published: February 2007

An investigation was made into the effects of seven anion‐active tensides and one non‐ionic tenside on the growth and respiration of 19 strains of the bacteria genera Proteus, Pseudomonas, Aerobacter and Sarcina. A nutrient broth with phosphate buffer and partly glucose addition was used as the culture medium. Tenside was added either at the beginning of tests in the lag‐phase of cultures or during the logarithmic growth phase. In addition, the development of resistance or adaptation were tested by establishing subcultures. The inhibitory effect of tensides depends on the combination of tenside/species of bacteria, gram‐positive bacteria being more sensitive and the inhibitory effect being lower in their logarithmic growth phase. The time course of the inhibition of respiration after the addition of tenside to the medium shows different types of inhibition and adaptation, considerably extended lag‐phases occurring frequently.
A Contribution to the Mechanism of Elimination of Dimethylformamide and Dimethylamine by a Heterogenous Culture of Microorganisms
Authors: Houser J. , Hoffmann J. , Daťková H. , Konečný J. , Kupec J. , Mládek M.
Published: February 2007

In a batch experiment with activated sludge from a large‐scale plant the hydrolytical and biochemical degradation of dimethylformamide (DMF) and its reaction product dimethylamine (DMA) and the conversion connected with this under aerobic and anaerobic conditions is investigated. Parallel to the hydrolysis of DMF the biochemical degradation of DMA occurs. The extensive conversion of these substrates is followed by the nitrification of the ammoniumions formed, and under subsequent anaerobic conditions with methanol as the carbon source also denitrification can be achieved. If the oxygen supply of the activated sludge is insufficient, however, also DMA can be used as a carbon source for denitrification, ammonium‐ions being released from DMA in addition. In the batch experiment the elimination rates referred to nitrogen were 7 … 14 mg/g · h for DMF, 0.8 … 1.7 mg/g · h for DMA, 0.3 … 0.6 mg/g · h for NH and 0.4 to 1.3 mg/g · h for nitrate in the presence of methanol. DMF and DMA are obviously not suitable as the only carbon source for denitrification.
Oxidation and Accumulation of Benzo(a)pyrene in the Presence of the Baltic Algae
Authors: Irha N. , Kirso U. , Urbas E. , Kukk H.
Published: February 2007

In batch experiments with 0.5 nM benzo(a)pyrene in artificial sea water there are investigated the distribution and degradation of benzopyrene in the presence of various plants: Cladophora glomerata, Enteromorpha intestinalis, Fucus vesiculosus and Chara aspera (in each case 10 … 20 g/l dry weight). The conversion of benzopyrene in the presence of the plants is considerably promoted compared with the pure autoxidation, except in the presence of Fucus. Obviously, there prevails initially the accumulation of benzopyrene in the biomass. Whereas for Fucus even after 10 d still 89% of benzopyrene can be detected in the biomass, in the other species a degradation of benzopyrene in the biomass takes place, the respective oxidation products as diols, quinones and phenols being detected in the biomass in proportionately higher concentrations. With the exception of Fucus, the degradation of benzopyrene comes up to 40 … 60% within a period of 5 … 6d with the other species tested.
Zur Toxizität und Spurenanalyse von Tensiden in Wasser
Authors: Hanschmann G. , Sohr H.
Published: February 2007

For judging the behaviour of tensides in water there are required not only the results or the conventional methods of determining their biochemical degradability and toxicity, but also their distribution in the sediment as well as in animal and vegetable products. Very important are properties as adsorbability, persistence, sequence of stations in the nutrient chain (bioaccumulation), relations of structure and actions and dose‐effect relations. In these investigations also changed effects of combinations of substances with tensides have to be taken into account; a power plant water and Baltic Sea sediment being used as examples. From the variety of tested possibilities of analysing very small amounts of tensides mainly the infrared spectroscopy and the thin‐layer chromatography have proved to be successful. By means of special procedures, the detection and the quantitative determinability can be shifted into the nano‐ and picogram‐ranges.