bluuebunny/crossref_metadata_2025 huggingface dataset:
Schutzzielorientierte brandschutztechnische Bemessung für mehrgeschossige Gebäude
Authors: Hosser Dietmar , Zehfuß Jochen , Dehne Michael
Published: July 2004

In den meisten Ländern erfolgt die brandschutztechnische Bemessung bei mehrgeschossigen Gebäuden auf der Grundlage der Einheitstemperaturzeitkurve (ISO 834), die real zu erwartende Brände auf der sicheren Seite liegend abdecken soll. Eine Bemessung, die realistischere natürliche Brände und die Umlagerungsmöglichkeiten von Tragsystemen berücksichtigt, ist sowohl risikogerecht als auch wirtschaftlich. Ausgehend von internationalen Erfahrungen und Versuchsergebnissen sowie eigenen Forschungsarbeiten des iBMB wurden Bemessungsbrände und sog. Realbrandkurven entwickelt. Sie werden in Verbindung mit sog. allgemeinen Rechenverfahren (nach den Eurocodes) für die Simulation des Brandverhaltens von Tragsystemen genutzt. Ein probabilistisches Sicherheitskonzept gewährleistet die erforderliche Zuverlässigkeit der Brandschutzbemessung, wobei die Wahrscheinlichkeit der Brandentwicklung, die Bedingungen für den Personenschutz sowie die Unsicherheiten der Bemessungsparameter berücksichtigt werden.
Konsistente geometrische Ersatzimperfektionen für den numerisch gestützten Beulsicherheitsnachweis axial gedrückter Schalen
Authors: Schneider Werner
Published: July 2004

Eine geometrisch und materiell nichtlineare Analyse des imperfekten Schalentragwerks (GMNIA) ist die anspruchsvollste und perspektivisch wirklichkeitsnächste Methode des numerisch gestützten Beulsicherheitsnachweises stählerner Schalentragwerke. Von grundlegender Bedeutung sind bei diesem Nachweis die geometrischen Ersatzimperfektionen, die die Wirkung der verschiedenen Abweichungen von den Sollparametern auf der Widerstandsseite abdecken sollen. Die damit im Zusammenhang stehenden grundsätzlichen Probleme werden im Beitrag diskutiert. Der Eurocode gibt Hinweise für geometrische Ersatzimperfektionen und macht Angaben über anzusetzende Vorbeultiefen. Es wird dargestellt, daß mit den gegenwärtigen Regelungen noch nicht alle tragfähigkeitsrelevanten Imperfektionsparameter erfaßt sind und in manchen Geometriebereichen Inkonsistenzen zwischen den numerisch und experimentell ermittelten Beulwiderständen bestehen. Für den Basisbeulfall der axial gedrückten Schale werden Vorschläge unterbreitet, um konsistente geometrische Ersatzimperfektionen zu erhalten.
Zur Tragfähigkeit von Ankerplatten in bewehrtem Beton
Authors: Kuhlmann Ulrike , Imminger Thomas , Rybinski Markus
Published: July 2004

Zur Lasteinleitung in Betonbauteile werden häufig Ankerplatten mit angeschweißten Kopfbolzendübeln verwendet. Am Institut für Konstruktion und Entwurf wurden zwei Versuchsreihen an bewehrten Stahlbetonbauteilen durchgeführt, die zeigen, daß Bewehrung auf die Tragfähigkeit großen Einfluß hat und die tatsächlich übertragbaren Lasten rechnerisch bisher eher unterschätzt werden. Auf der Grundlage von 27 Versuchsergebnissen und ergänzenden FE‐Analysen wird ein erstes auf der Komponentenmethode basierendes mechanisches Modell vorgestellt, das die Tragfähigkeit von Ankerplatten mit angeschweißten Kopfbolzendübeln in bewehrten Stahlbetonbauteilen beschreibt.
MDMA‐evoked changes in cerebral blood flow in living porcine brain: Correlation with hyperthermia
Authors: Rosa‐Neto Pedro , Olsen Aage K. , Gjedde Albert , Watanabe Hideaki , Cumming Paul
Published: July 2004

3,4‐Methylenedioxymethamphetamine (MDMA) acutely releases intraneuronal dopamine and serotonin and evokes hyperthermia which is linked to toxicity for serotonin fibers. The acute effects of MDMA on cerebral blood flow (CBF) in living brain have not been described in an animal model of MDMA intoxication. We predicted that MDMA‐induced hyperthermia should correlate with increased CBF in the hypothalamus, a serotonin‐rich brain region subserving thermoregulation. To test this prediction, we used positron emission tomography with statistical parametric mapping for exploratory analysis of the focal changes in the magnitude of CBF in the anesthetized female Landrace pig (n = 9) at 30 and 150 min after acute challenge with MDMA‐HCl (1 mg/kg, i.v.). The MDMA treatment was followed by increased CBF in the occipital cortex and in the medial mesencephalon overlapping the dorsal raphé nucleus, and reduced CBF in the cerebellar vermis and in a cluster in the medulla encompassing the left locus coeruleus. The individual increase of body temperature correlated positively with increased CBF in the vicinity of the raphé nucleus, in the hypothalamus (regions linked to thermoregulation), and also in the medial frontal cortex, which together comprise the regions receiving the most dense serotonin innervations in pig brain. Thus, individual differences in the susceptibility to MDMA‐induced hyperthermia in this population correlated with the magnitude of focal increases in CBF within specific brain regions endowed with a dense serotonin innervation, including regions linked to thermoregulation. Synapse 53:214–221, 2004. © 2004 Wiley‐Liss, Inc.
MDMA‐evoked changes in [11C]raclopride and [11C]NMSP binding in living pig brain
Authors: Rosa‐Neto Pedro , Gjedde Albert , Olsen Aage K. , Jensen Svend B. , Munk Ole L. , Watanabe Hideaki , Cumming Paul
Published: July 2004

Positron emission tomography (PET) studies with radiolabeled dopamine D2‐like receptor ligands reveal d‐amphetamine‐evoked increases in the competition from endogenous dopamine. However, the corresponding effects of methylenedioxymethamphetamine (MDMA, “Ecstasy”), which releases catecholamines and also serotonin, are unknown. Using PET, we measured the binding potentials (pBs) of the benzamide [11C]raclopride and the butyrophenone N‐[11C]methylspiperone ([11C]NMSP) in brain of living pigs first in a baseline condition and at 45 and 165 min after infusion of (+/‐)‐MDMA‐HCl (1 mg/kg, i.v.). Concomitant studies of cerebral blood flow did not reveal significant perfusion changes in the cerebellum reference region or in striatum, supporting the present use of reference tissue methods for the mapping of MDMA‐evoked pB changes. Relative to the baseline pB of [11C]raclopride for dopamine D2/3 receptors in striatum (pB = 1.5–2.2), MDMA‐treatment reduced pB by 35% in the first posttreatment scan and by 22% in the second posttreatment scan, comparable to changes typically evoked by d‐amphetamine at a similar dose. In most previous studies, the in vivo binding of butyrophenones has been nearly insensitive to d‐amphetamine‐evoked dopamine release. However, we found the baseline pB of [11C]NMSP for dopamine D2‐like receptors in striatum (pB = 4–5) was decreased by 30% in the first post‐MDMA scan and by 50% in the second post‐MDMA scan, irrespective of assumptions about the extent of equilibrium binding attained during the 90‐min‐long PET recordings. Distinct properties of MDMA such as simultaneous release of dopamine and serotonin in brain may account for the present finding of progressive decline in the availability of [11C]NMSP binding sites in striatum. Synapse 53:222–233, 2004. © 2004 Wiley‐Liss, Inc.
Hormonelike effects of humic substances on fish, amphibians, and invertebrates
Authors: Steinberg Christian E. W. , Höss Sebastian , Kloas Werner , Lutz Ilka , Meinelt Thomas , Pflugmacher Stephan , Wiegand Claudia
Published: July 2004

Humic substances comprise the majority of organic matter in freshwater ecosystems and were thought to be inert or refractory, except for photolytic degradation. However, evidence is increasing that humic substances interact with aquatic organisms similarly to weak anthropogenic chemicals with nonspecific and specific effects. One specific effect is a hormonelike effect, namely, modulation of the number of offspring, which was first described with the nematode Caenorhabditis elegans. Yet a hormonelike effect is not restricted to only the nematode. With the ornamental swordtail fish, Xiphophorus helleri, and the South African clawed frog, Xenopus laevis, we present phenomenological evidence that slight feminization occurred when these vertebrate species were exposed to a synthetic humic substance, a condensation product of polyphenols. The slight feminization was dose dependent. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 409–411, 2004.
Comparison of 17 biotests for detection of cyanobacterial toxicity
Authors: Maršálek Blahoslav , Bláha Luděk
Published: July 2004

The aim of the present study was to compare the sensitivity of 17 acute bioassays of cyanobacterial toxicity by assessment of crude extracts of three cyanobacterial samples (all dominated by Microcystis sp. but substantially differing in microcystin‐LR content). Toxicity of the fractions prepared by solid‐phase extraction (SPE) for microcystins was also determined. The most sensitive bioassay was the 24‐h test with crustacean Thamnocephalus platyurus, which elicited high lethality in the samples and also in fractions without microcystins. The fruit fly Drosophila melanogaster, protozoans Spirostomum ambiguum and Tetrahymena termophyla, and the crustacean Daphnia pulex formed the second group of sensitive bioassays. Good selective toxicity response to microcystins also was observed in the weakly sensitive biotests with the oligochaete Tubifex tubifex and the rotifer Brachionus calyciflorus. Preconcentration of microcystins by SPE substantially decreased variation of the results in bioassays and improved the discriminating potential of most assays employed. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 310–317, 2004.
Effect of lead and chromium on reproductive success of Japanese quail
Authors: Butkauskas D. , Sruoga A.
Published: July 2004

An experimental model based on application of Japanese quail (Coturnix coturnix japonica) lines with high (H) and low (L) concentrations of plasma lactate was designed in order to investigate the effects of lead and chromium on embryonic development and reproductive success of experimental groups representing different genotypes. During the first stage of the trial, mature males from quail lines H and L (marked as generation T) were fed subchronically for 12 weeks with lead as Pb(NO3)2 and chromium as K2Cr2O7 (dosage 0.8 and 0.142 g/kg, respectively, in the feed). In addition, a binary mixture of both lead and chromium was administered to the third group of males. The control group consisted of untreated birds. After mating with untreated females (8 ♀ × 5 ♂ in each group), progeny with four genotypes were obtained. The chicks were marked as generation F1 and used in the second stage of the trial. The data obtained show that heavy metals decreased the hatchability of sexually mature quail males: chromium (14%), lead (19%), and binary lead–chromium mixture (28%). Early embryonic mortality increased as much as 2–3 times. Single lead and binary lead‐chromium additions decreased fertility after treating Japanese quail during the development of sexual maturity: lead increased the number of unfertile eggs up to 30% (twofold), binary lead and chromium, up to 50% (more than threefold) relative to untreated controls. There was no effect of chromium alone on fertility. In general, hatchability, fertility, embryonic mortality and reproductive success of Japanese quail were dependent on age, sex, genotypes, and on single or binary treatment with the inorganic salts of lead and chromium. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 412–415, 2004
Spirotox—Spirostomum ambiguum acute toxicity test—10 years of experience
Authors: Nałęcz‐Jawecki Grzegorz
Published: July 2004

Spirotox is a short‐term acute toxicity test with a large ciliated protozoan Spirostomum ambiguum. The test was created in the Department of Environmental Health Sciences, Medical University of Warsaw, Poland, during the early 1990s. It was presented for the first time during the 6th International Symposium on Toxicity Assessment, in Berlin in 1993. S. ambiguum was very resistant to a wide range of environmental conditions, especially to pH and dissolved oxygen. Over the last 10 years the sensitivity of S. ambiguum to many classes of toxicants was evaluated. Spirotox was found to be very sensitive to heavy metals, fungicides, and pharmaceuticals used to cure diseases of the human nervous system. On the other hand, it was generally less sensitive than standard bioassays to simple organics. Spirotox was also used for analysis of cyanobacterial blooms. Though it was moderately sensitive to hepatotoxins, the test seems to be a good tool for evaluation of the entire toxicity of blooms. The last but not the least of the applications of the Spirotox test was evaluation of the toxicity of extracts from medical devices. Protozoa, which are the simplest eukaryotes, seem to be good screening bioassays for monitoring the technology of medical device production. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 359–364, 2004.
Defense systems of benthic invertebrates in response to environmental stressors
Authors: Vasseur P. , Leguille C.
Published: July 2004

Environmental stress factors may be responsible for biological changes in living species that are able to overcome deleterious effects depending on their detoxifying capacities. Defense systems present in every living species are involved in elimination of reactive chemical species of endogenous or exogenous origin, neutralization of their effects, repair of initial lesions, and compensation of deficient metabolic pathways. Consequently, the performance of defense systems and their inducibility will explain adaptation to environmental disturbances, whereas their alteration will augur toxicity in the exposed species. Several field studies have illustrated the relationships between antioxidants and toxicity in benthic invertebrates in rivers. They highlighted that defense systems may be useful biomarkers in mechanistic studies of ecotoxicity and in the biomonitoring of living species in polluted environments. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 433–436, 2004
Toxicity assessment of wastewaters, river waters, and sediments in Austria using cost‐effective microbiotests
Authors: Latif Muna , Licek Elisabeth
Published: July 2004

The toxicity and chemical quality of surface water and sediment in the River Traun in Austria were studied because of recurrent fish mortality in some alpine rivers over the last few years. The analyses were carried out on samples collected during winter and summer upstream and downstream of two municipal wastewater treatment plants (WWTPs) and on effluents taken at the points of discharge of these two plants. Toxicity tests were performed on 20 samples of surface water, effluent, and sediment pore water. The test battery was composed of microbiotests with protozoans (Protoxkit F™), microalgae (Algaltoxkit F™), crustaceans (Daphtoxkit F™ magna and Thamnotoxkit F™), and a higher plant (seed germination and root elongation assay on cress). Direct contact tests were performed on whole sediment with crustaceans (Ostracodtoxkit F™). The physical‐chemical characteristics of the surface water, effluent, and sediment pore water samples analyzed were conductivity, total hardness, pH, O2, BOD5, TOC, DOC, AOX, NH4, NH3, NO2, PO4P, Cd, Pb, Cu, and Zn. The toxicity data were expressed as percentage mortality or percentage inhibition, depending on the effect criterion of the respective assay. None of the water samples collected upstream and downstream of the WWTPs showed any significant (short‐term) toxicity in either winter or in summer, but the effluents of the first municipal wastewater treatment plant were toxic to some of the test biota. All the sediment pore water samples induced serious inhibition of root growth of cress, and several pore waters were toxic to other test biota as well, particularly at the outlets of the WWTPs. The toxic character of some sediments was confirmed by direct contact tests with the ostracod crustacean. The chemical analyses did not reveal particularly high concentrations of any chemical that is very toxic. As a result no direct causal relationship could be established between the detected toxic effects and the chemical composition of the surface waters or sediment pore waters. The outcome of this preliminary study again highlights the need to complement chemical analyses with toxicity tests to determine the toxic hazard to aquatic environments that may be threatened by contamination. Furthermore, the investigations also confirmed the need to apply a battery of tests for an ecologically meaningful evaluation of the hazards of waters, sediments, and wastewaters. Finally, the results of the 360 bioassays performed show that culture‐independent microbiotests are practical and reliable tools for low‐cost toxicity monitoring of aquatic environments. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 302–309, 2004.
Physical and chemical aspects of long‐term biodeterioration of some polymers and composites
Authors: Lugauskas A. , Prosychevas I. , Levinskaitė L. , Jaskelevičius B.
Published: July 2004

A biodeterioration study was performed on synthetic polymeric materials including homogenous film made from poly(tetrafluorine ethylene), copolymer film made from tetrafluorine ethylene and perfluoromethyl vinyl ether, vulcanized rubber containing natural caoutchouc, and vulcanized rubber, the main component of which was synthetic butadiene nitrile caoutchouc. The materials were exposed for 12 years to the open air, in mycological containers, and in a cellar in maritime climate conditions: air humidity 72%–90% and seasonal average temperature of 17°C in summer and −2.5°C in winter. The studies of optical and electron microscopy revealed that microorganisms were able to develop not only on the surface of the materials but also to penetrate inside into deeper layers. The fungi that produced the most intensive deterioration in the fluorine polymers and vulcanized rubbers belonged to the Alternaria, Aspergillus, Aureobasidium, Cladosporium, Penicillium, Oidiodendron and Trichoderma genera. The fungi Aspergillus fumigatus, A. niger, Aureobasidium pullulans, and Trichoderma viride produced the most intensive deterioration in the fluorine films, whereas Alternaria tenuissima, Cladosporium herbarum, C. sphaerospermum, and fungi of the Oidiodendron genus were widespread on vulcanized rubbers. Fungi of the Aspergillus and Penicillium genera prevailed on both fluorine films and rubbers exposed in a cellar. Infrared spectroscopy indicated that the structures of poly(tetrafluorine ethylene) and the copolymer of tetrafluorine ethylene and perfluoromethyl vinyl ether did not change after the 12‐year exposure; only insignificant changes in surface morphology were observed by optical microscopy. Vulcanized rubber made both from natural and from synthetic caoutchouc exposed for the same length of time showed rather evident changes in appearance and structure. X‐ray graphical analysis revealed that new crystallization of the caoutchouc and a possible change in chemical composition of the fillers had occurred. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 318–328, 2004.
Impact of crude oil on bacteriocenosis of the digestive tract of mollusks
Authors: Šyvokienė J. , Mickėnienė L.
Published: July 2004

In this study the effect of crude oil on intestinal bacterial populations of the mollusk Viviparus contactus was investigated. The addition of crude oil into an environment of mollusks induced no clear changes in the saprophytic, amylolytic, and total coliform bacterial counts in the digestive tract of the mollusk. After 10 days of contamination, the saprophytic, amylolytic, and total coliform bacterial numbers were of the same order of magnitude as the initial numbers. Significant numbers of indigenous hydrocarbon‐degrading bacteria were observed in the intestinal tracts of mollusks before contamination with crude oil. Introduction of crude oil into the mollusk environment resulted in an increase of 2 orders of magnitude in the number of hydrocarbon‐degrading bacteria in the digestive tract. Therefore, measuring the hydrocarbon‐degrading bacterial populations in the digestive tracts of hydrobionts can be considered an important component of contaminated‐site assessment studies. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 421–424, 2004.
Acute toxicity investigations of ester‐based lubricants by using biotests with algae and bacteria
Authors: Michel K. , Brinkmann C. , Hahn S. , Dott W. , Eisentraeger A.
Published: July 2004

Although ester‐based lubricants are ecologically acceptable due to their good biodegradability, there are still some environmental ecotoxicological impacts that have to be considered. Information on the acute ecotoxicological behavior of lubricants is obtained in this work using several single species bioassays. In previous studies it was observed that lubricating fluids containing additives for the enhancement of their technical performance were more problematic than base fluids especially with respect to algae growth inhibition. In order to clarify the influence of additives, the anti‐wear additive tri‐n‐butyl phosphate was tested. It was very toxic to algae though not to bacteria. Additionally, a mixture of this additive with a base fluid is characterized. Despite the high toxicity of the single additive, the water extract of the mixture of tri‐n‐butyl phosphate with hydraulic base fluid caused almost no toxicity. Therefore, tri‐n‐butyl phosphate cannot explain the effect observed for the toxicity of water extracts of the commercially available lubricants. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 445–448, 2004.
Were volatile organic compounds the inducing factors for subjective symptoms of employees working in newly constructed hospitals?
Authors: Takigawa Tomoko , Horike Tokushi , Ohashi Yasuhiro , Kataoka Hiroyuki , Wang Da‐Hong , Kira Shohei
Published: July 2004

This study demonstrated possible relationships between environmental, personal, and occupational factors and changes in the subjective health symptoms of 214 employees after the relocation of a hospital in a region of Japan. Eight indoor volatile organic compounds (VOCs) were detected in at least one of the 19 rooms investigated, and total VOC (TVOC) concentrations in 8 rooms exceeded the advisable value (400 μg/m3) established by the Ministry of Health, Labour and Welfare of Japan. Formaldehyde was detected in all the investigated rooms, but none of the results exceeded the guideline value (100 μg/m3). Multiple logistic regression analysis was applied to select variables significantly associated with the subjective symptoms that can be induced by sick building syndrome. The results showed that subjective symptoms of deterioration in the skin, eye, ear, throat, chest, central nervous system, autonomic system, musculoskeletal system, and digestive system among employees were associated mainly with gender difference and high TVOC concentrations (>1200 μg/m3). Long work hours (>50 h per week) in females and smoking in males were to be blamed for the deterioration of their symptoms. The present findings suggest that to protect employees from indoor environment‐related adverse health effects, it is necessary to reduce the concentration of indoor chemicals in new buildings, to decrease work hours, and to forbid smoking. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 280–290, 2004.
Toxicity of pesticides to predatory mites and insects in apple‐tree site under field conditions
Authors: Raudonis L. , Survilienė E. , Valiuškaitė A.
Published: July 2004

Various applications of active ingredients of six fungicides and three insecticides and acaricides at normally recommended dosages were tested on two predatory mite species (Amblyseius andersoni Chant and Anthoseius bakeri Garman) from the family Phytoseiidae and on two predatory insect species (Coccinella septempunctata L. Chrysopa perla L.) dominantly present on apple trees. Small differences were found between fungicide treatments. On the trees treated with six fungicide applications the predatory mites and insects survived and increased to a high level, often 20–40 phytoseiids per 100 leaves and 4–8 predatory insects per sample unit. Only the active ingredients tolylfluanid and myclobutanil resulted in lower densities of predatory mites (10–20 phytoseiids per 100 leaves). One application of insecticides‐acaricides (active ingredients: clofentezine, phosalone) showed no toxic effect on predatory mites and insects. Two applications of phosalone and one of alpha‐cypermethrine were slightly or moderately toxic. Two applications of alpha‐cypermethrine and eight routine sprays of various insecticides‐acaricides and fungicides were very toxic and resulted in the lowest maximum number of predatory mites and insects, approximately 0–10 phytoseiids per 100 leaves and 1–4 predatory insects per sample unit. The toxicity of pesticides to predatory mites and insects is based on the toxicity of the pesticide' active ingredient and the spray frequency. The active ingredients of fungicides and only one or two applications of insecticides and acaricides were not or slightly toxic and could be used in integrated pest management. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 291–295, 2004.
Increase of crustacean sensitivity to purified hepatotoxic cyanobacterial extracts by manipulation of experimental conditions
Authors: Drobniewska Agata , Tarczyńska Małgorzata , Mankiewicz Joanna , Jurczak Tomasz , Zalewski Maciej
Published: July 2004

Toxic cyanobacterial blooms are one of the most common consequences of water eutrophication. Microbiotests with crustaceans are not expensive and are easy to prepare for screening tests. They can be applied in the determination of bioactivity and interaction between toxic substances in water, including hepatotoxins. The principal aim of this study was to modify the standard conditions in the Thamnotoxkit F™ and Artoxkit M in order to increase crustacean sensitivity to purified cyanobacterial extracts containing microcystins. The results reported show that exposure time, higher temperature, and presence of DMSO can increase the sensitivity of microbiotests to microcystins. The best sensitivity with the Artemia salina test was achieved after a 48‐h exposure at 25°C. The tests using a 24‐h exposure at 27°C were the most sensitive for Thamnocephalus platyurus. The test without preincubation with DMSO provided the best correlation of microcystin concentration and LC50 for Thamnocephalus platyurus and is recommended. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 416–420, 2004.
Use of freshwater algae and duckweeds for phytotoxicity testing
Authors: Blinova Irina
Published: July 2004

The toxicity of contaminated water of different origins and chemicals [Cr(III), Pb(II), Cu(II), Cd(II), pyrene] were tested using four test species: the alga Selenastrum capricornutum (new name Raphidocelis subcapitata), the duckweed Lemna minor, and the crustaceans Thamnocephalus platyurus and Daphnia magna. On the basis of the results obtained, the sensitivity of plant species and problems concerning the interpretation of the phytotoxicity data are discussed. The data indicated that the sensitivities of crustaceans and plant species both to individual contaminants and to mixtures are unpredictable and that there is no reason to consider plant species less sensitive than animal species. Lemna minor is more sensitive than Selenastrum capricornutum. With colored samples, duckweed is preferable for toxicity testing. To raise the predictive utility of the phytotoxicity data, it is recommended that natural water be used in the test procedure. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 425–428, 2004.
A novel approach for phytotoxicity assessment by CCD fluorescence imaging
Authors: Gavel Alan , Maršálek Blahoslav
Published: July 2004

Rapidity, cost effectiveness, ecological reliability, and the possibility of the direct interpretation of bioassay results are the main motivations for the development of new approaches in ecotoxicity testing. Color, turbidity, and nutrient content are factors of great importance in phytotoxicity testing of natural samples. Some algal bioassay end points are markedly influenced by such factors or are impossible to estimate in their presence. An algal toxicity test applicable as an early‐warning system has to be able to give a signal in the shortest time possible (hours). We used CCD fluorescence imaging to evaluate toxicity effects in algae, cyanobacteria, and vascular plants, and the data were compared with standard end points. Plant physiologists use this device mainly for photosynthesis research, but common photosynthetic parameters used to characterize chlorophyll fluorescence (Fv/Fm, F0, and Fm) or its quenching (NPQ) have only limited ecotoxicological applicability. Previously published estimations based on the geometrical complement to measured data (complementary area) in the fast kinetics (Kautsky effect) respond especially to pollutants affecting electron transport in the PSII. We recommend using a definite integral value combined with relative fluorescence decay (Rfd) to obtain a sensitive and fast toxicity response. Our approach integrates more mechanisms of toxicity (effects on membranes, proton pump, ATP synthesis, etc.) and improves the toxicity signal, which is more ecotoxicologically relevant. This method can give results after 2–6 h of exposure and is especially useful as an early‐warning system and for the toxicity assessment of environmental samples with unknown nutrient status. Results with our approach after 4–6 h are comparable with those obtained with a 96‐h standard algal assay. A similar methodical approach can be applied for toxicity evaluation of plants or lichens, or for in situ ecotoxicological studies of microphytobenthos communities. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 429–432, 2004.
Production and comprehension of graphic symbol utterances expressing complex propositions by adults who use augmentative and alternative communication systems
Authors: SUTTON ANN , MORFORD JILL P. , GALLAGHER TANYA M.
Published: July 2004

We explored production and comprehension of complex sentences constructed using a limited vocabulary on a graphic symbol display with voice output by 25 adults who use augmentative and alternative communication. When asked to construct subject (SS) and object (OS) relative clause sentences, only a minority of participants encoded SS and OS relative clause sentences using different word orders. When asked to interpret graphic symbol utterances, most participants chose an SS interpretation. Thus, the word order used most frequently in production appeared to have a single preferred interpretation. The relationship between the word orders produced in graphic symbol utterances and the way the same word orders are interpreted is not necessarily straightforward.
Growth and predictive relations of vocabulary and inflectional morphology in children with and without familial risk for dyslexia
Authors: LYYTINEN PAULA , LYYTINEN HEIKKI
Published: July 2004

The growth and predictive relations of early vocabulary and inflectional morphology were examined in children with (N=107) and without (N=93) familial risk for dyslexia. Children's receptive and expressive vocabulary and inflectional morphological skills were assessed longitudinally at 2, 2.5, 3.5, and 5 years by using a parent report tool (the MacArthur Communicative Development Inventory), measures from a spontaneous speech sample, and standardized tests. Children with and without familial risk for dyslexia did not differ from each other, either in expressive vocabulary or in composite scores of inflectional morphology at the age of 2 years. However, language skills indicated increasing group differences with age. Inflectional morphology showed differing predictive patterns for the at-risk group and their controls. Proficiency of inflections at 2 years significantly predicted 5-year-olds' language skills in the at-risk group. In contrast, for their age-matched controls inflections were not a significant predictor until the age of 3.5 years. Our findings suggest that children from families with dyslexia risk status and low inflectional skills at an early age are at higher risk for impairments in subsequent language development than are their age-matched controls.
Tense marking in children with autism
Authors: ROBERTS JENNY A. , RICE MABEL L. , TAGER–FLUSBERG HELEN
Published: July 2004

A recent large-scale study identified a subgroup of children with autism who had a language profile similar to that found among children with specific language impairment (SLI), including difficulties with nonsense word repetition, an ability that has been implicated as one clinical marker for SLI. A second clinical marker for English-speaking children with SLI is high rates of omission of grammatical morphemes that mark tense in obligatory contexts. This study used experimental probes designed to elicit third person and past tense morphology with a large heterogeneous sample of children with autism. The subgroup of children with autism who were language impaired showed high rates of omission of tense marking on the experimental tasks. In addition, some of the children with autism made performance errors that were specific to the autistic population, such as echolalia. These findings further refine the characteristics of language impairment found in a subgroup of children with autism.
An examination of the variables that affect express saccade
generation
Authors: SCHILLER PETER H. , HAUSHOFER JOHANNES , KENDALL GEOFFERY
Published: July 2004

The frequency with which express saccades are generated under a
variety of conditions in rhesus monkeys was examined. Increasing the
gap time between fixation spot termination and target onset increased
express saccade frequency but was progressively less effective in doing
so as the number of target positions in the sample was increased.
Express saccades were rarely produced when two targets were presented
simultaneously and the choice of either of which was rewarded; a
temporal asynchrony of only 17 ms between the targets reinstated
express saccade generation. Express saccades continued to be generated
when the vergence or pursuit systems was coactivated with the saccadic
system.
L-type calcium channels mediate transmitter release in isolated,
wide-field retinal amacrine cells
Authors: VIGH JOZSEF , LASATER ERIC M.
Published: July 2004

Transmitter release in neurons is triggered by intracellular
Ca2+ increase via the opening of voltage-gated
Ca2+ channels. Here we investigated the voltage-gated
Ca2+ channels in wide-field amacrine cells (WFACs) isolated
from the white-bass retina that are functionally coupled to transmitter
release. We monitored transmitter release through the measurement of
the membrane capacitance (Cm). We found
that 500-ms long depolarizations of WFACs from −70 mV to 0 mV
elicited about a 6% transient increase in the
Cm or membrane surface area. This
Cm jump could be eliminated either by
intracellular perfusion with 10 mM BAPTA or by extracellular
application of 4 mM cobalt. WFACs possess N-type and L-type
voltage-gated Ca2+ channels. Depolarization-evoked
Cm increases were unaffected by the
specific N-type channel blocker ω-conotoxin GVIA, but they were
markedly reduced by the L-type blocker diltiazem, suggesting a role for
the L-type channel in synaptic transmission. Further supporting this
notion, in WFACs the synaptic protein syntaxin always colocalized with
the pore-forming subunit of the retinal specific L-type channels
(CaV1.4 or α1F), but never with that of the N-type
channels (CaV2.2 or α1B).
Role of the cervico-ocular reflex in the “flying” pigeon: Interactions with the optokinetic reflex
Authors: MAURICE M. , GIOANNI H.
Published: July 2004

We studied the cervico-ocular reflex (COR) alone and in combination with the optokinetic (OKN) reflex in head-fixed pigeons. We analyzed these responses in two behavioral conditions: (1) animals were hung in a harness (“resting” condition); and (2) animals were additionally submitted to a frontal airflow that provoked a flight posture (“flying” condition). In both conditions, cervical stimulation provoked a slow phase of very low gain (around 0.05) in the opposite direction to that of the stimulation and fast phases triggered near the head–body alignment in the same direction as the stimulation. The slow phase showed a phase lag of 20 deg at 0.5 Hz. The gain of the slow phase was not modified by the velocity, amplitude, or frequency of the stimuli. This gain was not changed by the presence of a fixed visual surround.

When cervical stimuli (0.05–0.5 Hz) were added to an optokinetic stimulation (30 deg/s) in the “resting” condition, the slow phase velocity (SPV) of the optokinetic reflex was modulated with a time course close to that produced by the cervico-ocular reflex alone. The SPV was alternately increased and decreased round the SPV level corresponding to the steady-state OKN. In the “flying” condition, optokinetic-cervical stimulation provoked an eye beating field and a strong SPV modulation synchronized with the position of the cervical stimulation. The number of nystagmic beats (OKN) and the amplitude and velocity of the fast phases were modulated in correlation with the SPV. Consequently, the optokinetic response was increased or decreased according to whether the cervical stimuli were in the reverse direction or in the same direction as the optokinetic stimulation, respectively.

These data are interpreted as an improvement of gaze stabilization by the COR. This mechanism is context dependent, since it is strongly reinforced during the flight.
AII amacrine cells in the rabbit retina possess AMPA-, NMDA-, GABA-, and glycine-activated currents
Authors: ZHOU CHENGWEN , DACHEUX RAMON F.
Published: July 2004

Physiological properties of ligand-activated currents were characterized for morphologically identified AII amacrine cells in the rabbit retina by using whole-cell recordings in a superfused retina slice preparation. The AII amacrine cells were identified based on their distinct narrow-field, bistratified morphology. In the present study, the whole-cell recordings from AII amacrine cells synaptically isolated from presynaptic influences demonstrated the presence of glutamate AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid) receptors, but no kainate receptors. The presence of only AMPA receptors on rabbit AII amacrine cells is in contrast to an earlier study on rabbit AII amacrine cells by Bloomfield and Xin (2000), but consistent with previous studies on rat AII amacrine cells. In addition, NMDA (N-methyl-D-aspartate) -activated currents blocked by the NMDA antagonist D-AP7 (D-2-amino-7-phosphonoheptanoic acid) were found on the AII amacrine cells. These most likely extrasynaptic NMDA-activated currents were attenuated by the presence of Co2+interacting with Mg2+and Ca2+as they competed for divalent cation-binding sites within the NMDA channel. AII amacrine cells also possessed GABA (γ-aminobutyric acid) -activated currents that were unaffected by the GABACreceptor antagonist TPMPA (1,2,5,6-tetrahydropyridine-4-yl methylphosphinic), but were completely blocked by the GABAAantagonist bicuculline. This indicates that the major inhibitory inputs were mediated by only GABAAreceptors located directly on the AII amacrine cells. Furthermore, although the AII amacrine cells were glycinergic amacrine cells, they also possessed glycine-activated currents that may be mediated by autoreceptors.
Visual processing of the zebrafish optic tectum before and after optic nerve damage
Authors: McDOWELL ANGELA L. , DIXON LEE J. , HOUCHINS JENNIFER D. , BILOTTA JOSEPH
Published: July 2004

Although the zebrafish has become an important model in visual neuroscience, little has been done to examine the processing of its higher visual centers. The purpose of this work was twofold. The first purpose was to examine the physiology of the zebrafish retinotectal system and its relationship to retinal physiology. Spectral sensitivity functions were derived from visually evoked tectal responses and these functions were compared to the functions of electroretinogram (ERG) responses obtained using the same stimulus conditions. The second purpose was to examine the recovery of visual functioning of the tectum following optic nerve damage. The optic nerves of adult zebrafish were damaged (crushed), and tectal visual processing was assessed following damage. The results showed that the spectral sensitivity functions based on the On-responses of the tectum and ERG were qualitatively similar. The functions based on each response type received similar cone contributions including both nonopponent and opponent contributions. However, the spectral sensitivity functions based on the Off-responses of the tectum and ERG differed. The results also showed that the zebrafish visual system is capable of neural regeneration. By 90 days following an optic nerve crush, the spectral sensitivity function based on the tectal On-response was similar to functions obtained from normal zebrafish. Although the tectal Off-response did recover, the spectral sensitivity based on the Off-response was not the same as the function of normal zebrafish. These results support the notion that different levels of the visual system process information differently and that the zebrafish visual system, like those of other lower vertebrates, is capable of functional regeneration.
Identification of retinal neurons in a regressive rodent eye (the naked mole-rat)
Authors: MILLS STEPHEN L. , CATANIA KENNETH C.
Published: July 2004

The retina consists of many parallel circuits designed to maximize the gathering of important information from the environment. Each of these circuits is comprised of a number of different cell types combined in modules that tile the retina. To a subterranean animal, vision is of relatively less importance. Knowledge of how circuits and their elements are altered in response to the subterranean environment is useful both in understanding processes of regressive evolution and in retinal processing itself. We examined common cell types in the retina of the naked mole-rat,Heterocephalus glaberwith immunocytochemical markers and retrograde staining of ganglion cells from optic nerve injections. The stains used show that the naked mole-rat eye has retained multiple ganglion cell types, 1–2 types of horizontal cell, rod bipolar and multiple types of cone bipolar cells, and several types of common amacrine cells. However, no labeling was found with antibodies to the dopamine-synthesizing enzyme, tyrosine hydroxylase. Although most of the well-characterized mammalian cell types are present in the regressive mole-rat eye, their structural organization is considerably less regular than in more sighted mammals. We found less precision of depth of stratification in the inner plexiform layer and also less precision in their lateral coverage of the retina. The results suggest that image formation is not very important in these animals, but that circuits beyond those required for circadian entrainment remain in place.
Mongolian Tenggerism and Modern Globalism
Authors: Bira Sh.
Published: July 2004

A study of historical, political and religious thought of the early Mongols undertaken during the last few years has provided a thesis that, during the period of their world domination in the thirteenth and fourteenth centuries, they initiated an original universal concept with the purpose of substantiating and justifying the world's largest land empire. Furthermore, this concept was so developed that it constituted a cohesive theory that can be called Tenggerism or Heavenism.
Foreword
Authors: Ansari Sarah
Published: July 2004

The Royal Asiatic Society was founded in March 1823. The practice of holding meetings at which papers were given and discussed commenced the following month in April of that year. Throughout the first decade of the Society's existence, these orally delivered papers were later printed and distributed in substantial quarto volumes entitled ‘Transactions’.
The Picnic, The Buddha, and St Matthew
Authors: Derrett J. Duncan M.
Published: July 2004

Once upon a time twenty nine upper middle-class friends and their wives entered a thicket where the Buddha happened to be and began to play. Another friend had no wife, so a prostitute was brought for him. While they were “disporting themselves” she took his things and ran away. The remainder joined in a search for her. Roaming in that thicket they found the Buddha seated at the root of a tree. They asked, “Lord, has the Blessed One seen a certain woman (ekam itthim)?” “What have you, young men, to do with the woman?”, he exclaimed. They explained. “Now what do you, young men, think?”, he asked, “Which is better for you, to search for a woman or to search for yourselves?” “That, Lord, would be preferable – to search for ourselves.” So he preached and gave them ordination. The story is contrived as a setting for the rhetorical question (like Mark 12:13–17).
‘Do ut des’: Patterns of Exchange in Zoroastrianism
Authors: Hintze Almut
Published: July 2004

Exchange and reciprocity are central concepts in all forms of human society. Based on a system of mutual obligation, they denote any activity in which valuables are circulated between individuals or groups of people. In the religious sphere they include the transfer of both material and immaterial goods between human and spiritual beings. As outlined by Marcel Mauss in his Essai sur le don, the classic work on the total system of reciprocity, such exchange is governed by the principle of the gift entailing the counter-gift.
Mikrogenetische Studien zum physikalischen Wissenserwerb von Kindern:
Authors: Krist Horst , Bach Sylvia , Öndül Selin , Huber Susanne
Published: July 2004

Zusammenfassung. In zwei mikrogenetischen Studien mit 7-jährigen Kindern wurde am Beispiel der Balkenwaagen-Aufgabe und mit Hilfe der Rule-Assessment-Methode untersucht, inwieweit intuitives physikalisches Vorwissen den Erwerb neuen physikalischen Regelwissens beeinflusst. In einem Vortest wurden jeweils solche Versuchsteilnehmer ausgewählt, welche bei Vorhersagen des Verhaltens der Balkenwaage ausschließlich die Gewichtsdimension beachteten (Regel I). In einer Trainingssitzung beobachteten sie dann entweder reguläre (mögliche) oder hierzu inverse (unmögliche) Ereignisse, in denen sich die Waage bei augenscheinlich gleichem Gewicht nach der Seite mit dem größeren bzw. kleineren Hebelarm neigte. In Experiment 1, bei dem in der Trainingsphase acht solcher Trials dargeboten wurden, lernten annähernd ebenso viele Kinder die inverse Berücksichtigung des Hebelarms (bei inversem Training) wie dessen reguläre Berücksichtigung (bei regulärem Training). Während der Lernphase machten die regulär trainierten Kinder jedoch häufiger korrekte Vorhersagen als die invers trainierten. In Experiment 2 wurde deshalb die Zahl der kritischen Trainingstrials auf zwei reduziert. Es ergab sich ein deutlicher, statistisch bedeutsamer Effekt zugunsten der regulären Trainingsbedingung. Unsere Ergebnisse bestätigen insgesamt die Annahme einer differentiellen Lernbereitschaft und liefern Evidenz für hypothesengeleitetes Lernen bei 7-jährigen Kindern.
A Triadic Approach to the Construct Validity of the Assessment Center
Authors: Kolk Nanja J. , Born Marise Ph. , van der Flier Henk
Published: July 2004

Abstract: This study examined the influence on construct validity of implementing the triad Feeling, Thinking, and Power as a taxonomy for behavioral dimensions in assessment center (AC) exercises. A sample of 1567 job applicants participated in an AC specifically developed according to this taxonomy. Each exercise tapped three dimensions, one dimension from each cluster of the taxonomy. Confirmatory Factor Analysis of the multitrait-multimethod matrix showed evidence for construct validity. Thus, the ratings matched the a priori triadic grouping to a good extent. Practical implications are discussed.