The Mexican Axolotl in Schools

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Thomas, R. M.

1976-01-01

Suggests and describes laboratory activities in which the Mexican axolotl (Ambystoma mexicanum Shaw) is used, including experiments in embryology and early development, growth and regeneration, neoteny and metamorphosis, genetics and coloration, anatomy and physiology, and behavior. Discusses care and maintenance of animals. (CS)

A Tissue-Mapped Axolotl De Novo Transcriptome Enables Identification of Limb Regeneration Factors

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Donald M. Bryant

2017-01-01

Full Text Available Mammals have extremely limited regenerative capabilities; however, axolotls are profoundly regenerative and can replace entire limbs. The mechanisms underlying limb regeneration remain poorly understood, partly because the enormous and incompletely sequenced genomes of axolotls have hindered the study of genes facilitating regeneration. We assembled and annotated a de novo transcriptome using RNA-sequencing profiles for a broad spectrum of tissues that is estimated to have near-complete sequence information for 88% of axolotl genes. We devised expression analyses that identified the axolotl orthologs of cirbp and kazald1 as highly expressed and enriched in blastemas. Using morpholino anti-sense oligonucleotides, we find evidence that cirbp plays a cytoprotective role during limb regeneration whereas manipulation of kazald1 expression disrupts regeneration. Our transcriptome and annotation resources greatly complement previous transcriptomic studies and will be a valuable resource for future research in regenerative biology.

Ambiguities in the relationship between gonadal steroids and reproduction in axolotls (Ambystoma mexicanum).

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Eisthen, Heather L; Krause, Brianne Chung

2012-05-01

Axolotls (Ambystoma mexicanum) are aquatic salamanders that are widely used in research. Axolotls have been bred in laboratories for nearly 150 years, yet little is known about the basic biology of reproduction in these animals. We investigated the effects of changing day length, time of year, and food availability on levels of circulating estradiol and androgens in adult female and male axolotls, respectively. In addition, we examined the effects of these variables on the mass of ovaries, oviducts, and eggs in females and on mass of testes in males relative to each individual's body weight, to calculate a form of gonadosomatic index (GSI). In both sexes, GSI was not correlated with levels of circulating steroids. In female axolotls, estradiol levels were influenced by food availability, changes in day length, and season, even when animals were held at a constant temperature and day length was decorrelated with calendar date. In addition, the mass of ovaries, oviducts, and eggs varied seasonally, peaking in the winter months and declining during the summer months, even though our animals were not breeding and shedding eggs. In males, levels of androgens appeared to vary independently of external conditions, but GSI varied dramatically with changes in day length. These results suggest that reproduction in axolotls may vary seasonally, as it does in many other ambystomid species, although both male and female axolotls are capable of reproducing several times each year. The physiological basis of this ability remains enigmatic, given the indications of seasonality contained in our data. Copyright © 2012 Elsevier Inc. All rights reserved.

Evolutionary genetics of metamorphic failure using wild-caught vs. laboratory axolotls (Ambystoma mexicanum).

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Voss, S R; Shaffer, H B

2000-09-01

In many organisms metamorphosis allows for an ecologically important habitat-shift from water to land. However, in some salamanders an adaptive life cycle mode has evolved that is characterized by metamorphic failure (paedomorphosis); these species remain in the aquatic habitat throughout the life cycle. Perhaps the most famous example of metamorphic failure is the Mexican axolotl (Ambystoma mexicanum), which has become a focal species for developmental biology since it was introduced into laboratory culture in the 1800s. Our previous genetic linkage mapping analysis, using an interspecific crossing design, demonstrated that a major gene effect underlies the expression of metamorphic failure in laboratory stocks of the Mexican axolotl. Here, we repeated this experiment using A. mexicanum that were sampled directly from their natural habitat at Lake Xochimilco, Mexico. We found no significant association between the major gene and metamorphic failure when wild-caught axolotls were used in the experimental design, although there is evidence of a smaller genetic effect. Thus, there appears to be genetic variation among Mexican axolotls (and possibly A. tigrinum tigrinum) at loci that contribute to metamorphic failure. This result suggests a role for more than one mutation and possibly artificial selection in the evolution of the major gene effect in the laboratory Mexican axolotl.

Highly efficient targeted mutagenesis in axolotl using Cas9 RNA-guided nuclease

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Flowers, G. Parker; Timberlake, Andrew T.; Mclean, Kaitlin C.; Monaghan, James R.; Crews, Craig M.

2014-01-01

Among tetrapods, only urodele salamanders, such as the axolotl Ambystoma mexicanum, can completely regenerate limbs as adults. The mystery of why salamanders, but not other animals, possess this ability has for generations captivated scientists seeking to induce this phenomenon in other vertebrates. Although many recent advances in molecular biology have allowed limb regeneration and tissue repair in the axolotl to be investigated in increasing detail, the molecular toolkit for the study of this process has been limited. Here, we report that the CRISPR-Cas9 RNA-guided nuclease system can efficiently create mutations at targeted sites within the axolotl genome. We identify individual animals treated with RNA-guided nucleases that have mutation frequencies close to 100% at targeted sites. We employ this technique to completely functionally ablate EGFP expression in transgenic animals and recapitulate developmental phenotypes produced by loss of the conserved gene brachyury. Thus, this advance allows a reverse genetic approach in the axolotl and will undoubtedly provide invaluable insight into the mechanisms of salamanders' unique regenerative ability. PMID:24764077

Courtship Pheromone Use in a Model Urodele, the Mexican Axolotl (Ambystoma mexicanum).

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Maex, Margo; Van Bocxlaer, Ines; Mortier, Anneleen; Proost, Paul; Bossuyt, Franky

2016-02-04

Sex pheromones have been shown to constitute a crucial aspect of salamander reproduction. Until now, courtship pheromones of Salamandridae and Plethodontidae have been intensively studied, but information on chemical communication in other urodelan families is essentially lacking. The axolotl (Ambystoma mexicanum, Ambystomatidae) has a courtship display that suggests a key role for chemical communication in the orchestration of its sexual behavior, but no sex pheromones have yet been characterized from this species. Here we combined whole transcriptome analyses of the male cloaca with proteomic analyses of water in which axolotls were allowed to court to show that male axolotls secrete multiple ca. 20 kDa glycosylated sodefrin precursor-like factor (SPF) proteins during courtship. In combination with phylogenetic analyses, our data show that the male cloaca essentially secretes a courtship-specific clade of SPF proteins that is orthologous to salamandrid courtship pheromones. In addition, we identified an SPF protein for which no orthologs have been described from other salamanders so far. Overall, our study advocates a central role for SPF proteins during the courtship display of axolotls and adds knowledge on pheromone use in a previously unexplored deep evolutionary branch of salamander evolution.

Role of Myofibril-Inducing RNA in cardiac TnT expression in developing Mexican axolotl

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Sferrazza, Gian-Franco; Zhang, Chi; Jia, Pingping; Lemanski, Sharon L.; Athauda, Gagani; Stassi, Alyssa; Halager, Kristine; Maier, Jennifer A.; Rueda-de-Leon, Elena; Gupta, Amit; Dube, Syamalima; Huang, Xupei; Prentice, Howard M.; Dube, Dipak K.; Lemanski, Larry F.

2007-01-01

The Mexican axolotl, Ambystoma mexicanum, has been a useful animal model to study heart development and cardiac myofibrillogenesis. A naturally-occurring recessive mutant, gene “c”, for cardiac non-function in the Mexican axolotl causes a failure of myofibrillogenesis due to a lack of tropomyosin expression in homozygous mutant (c/c) embryonic hearts.. Myofibril-Inducing RNA (MIR) rescues mutant hearts in vitro by promoting tropomyosin expression and myofibril formation thereafter. We have studied the effect of MIR on the expression of various isoforms of cardiac Troponin-T (cTnT), a component of the thin filament that binds with tropomyosin. Four alternatively spliced cTnT isoforms have been characterized from developing axolotl heart. The expression of various cTnT isoforms in normal, mutant, and mutant hearts corrected with MIR, is evaluated by real-time RT-PCR using isoform specific primer pairs; MIR affects the total transcription as well as the splicing of the cTnT in axolotl heart PMID:17408593

Experimentally induced metamorphosis in axolotls reduces regenerative rate and fidelity

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Stier, Adrian C.; Michonneau, François; Smith, Matthew D.; Pasch, Bret; Maden, Malcolm

2014-01-01

Abstract While most tetrapods are unable to regenerate severed body parts, amphibians display a remarkable ability to regenerate an array of structures. Frogs can regenerate appendages as larva, but they lose this ability around metamorphosis. In contrast, salamanders regenerate appendages as larva, juveniles, and adults. However, the extent to which fundamental traits (e.g., metamorphosis, body size, aging, etc.) restrict regenerative ability remains contentious. Here we utilize the ability of normally paedomorphic adult axolotls (Ambystoma mexicanum) to undergo induced metamorphosis by thyroxine exposure to test how metamorphosis and body size affects regeneration in age‐matched paedomorphic and metamorphic individuals. We show that body size does not affect regeneration in adult axolotls, but metamorphosis causes a twofold reduction in regeneration rate, and lead to carpal and digit malformations. Furthermore, we find evidence that metamorphic blastemal cells may take longer to traverse the cell cycle and display a lower proliferative rate. This study identifies the axolotl as a powerful system to study how metamorphosis restricts regeneration independently of developmental stage, body size, and age; and more broadly how metamorphosis affects tissue‐specific changes. PMID:27499857

Esterases activity in the axolotl Ambystoma mexicanum exposed to chlorpyrifos and its implication to motor activity.

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Robles-Mendoza, Cecilia; Zúñiga-Lagunes, Sebastian R; Ponce de León-Hill, Claudia A; Hernández-Soto, Jesús; Vanegas-Pérez, Cecilia

2011-10-01

The axolotl Ambystoma mexicanum is a neotenic salamander considered a good biological model due to its ability to regenerate limbs, tail, brain and heart cells. Nevertheless, severe reduction of A. mexicanum wild populations in the lacustrine area of Xochimilco, the natural habitat of the axolotl, could be related to several environmental pressures as the presence of organophosphate pesticides (OPPs), intensively applied in agricultural activities in Xochimilco. Thus the aim of this study was to evaluate the effect of environmentally realistic chlorpyrifos (CPF) concentrations, a OPP commonly used in this zone, on esterases activity (acetylcholinesterase and carboxylesterase) and bioconcentration of CPF and to relate them with the motor activity of A. mexicanum juveniles. Axolotls were exposed 48 h to 0.05 and 0.1mg CPF/L, and the responses were evaluated at the end of the CPF exposure. Results suggest that CPF is bioconcentrated into axolotls and that the CPF internal concentrations are related with the observed inhibition activity of AChE (>50%) and CbE (≈ 50%). CPF concentration responsible of the inhibition of the 50% of AChE activity (IC50) was estimated in 0.04 mg CPF/L; however IC50 for CbE activity was not possible to calculate since inhibition levels were lower than 50%, results that suggest a higher resistance of CbE enzymatic activity to CPF. However, motor activity was a more sensitive endpoint to CPF poisoning since time that axolotls spent active and walking, frequency and speed of swimming, frequency of prey attack were reduced >90% of control groups. The motor activity alterations in the axolotl could be related with the registered esterases inhibition. Thus important alterations on axolotls were identified even at short time and low concentrations of CPF exposure. Also, it was possible to link biochemical responses as esterases activity with higher levels of biological organization as behavior. This study provides tools for the regulation of the

Propofol (2,6-diisopropylphenol) is an applicable immersion anesthetic in the axolotl with potential uses in hemodynamic and neurophysiological experiments

DEFF Research Database (Denmark)

Thygesen, Mathias; Rasmussen, Mikkel Mylius; Madsen, Jesper Guldsmed

2017-01-01

The Mexican axolotl (Ambystoma mexicanum) is an important model species in regenerative biology. Traditionally, axolotls are anesthetized using benzocaine or MS-222, both of which act to inhibit voltage gated sodium channels thereby preventing action potential propagation. In some neurophysiologi......The Mexican axolotl (Ambystoma mexicanum) is an important model species in regenerative biology. Traditionally, axolotls are anesthetized using benzocaine or MS-222, both of which act to inhibit voltage gated sodium channels thereby preventing action potential propagation. In some...... neurophysiological experiments this is not desirable; therefore we tested propofol as an alternative anesthetic in the axolotl. We evaluated benzocaine, MS-222, and propofol's cardiovascular effects, effects on action potential propagation in the spinal cord, and gross limb regenerative effects. We found...

Evidence for balancing selection at the DAB locus in the axolotl, Ambystoma mexicanum.

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Richman, A D; Herrera, G; Reynoso, V H; Méndez, G; Zambrano, L

2007-12-01

The axolotl (Ambystoma mexicanum) has been characterized as immunodeficient, and the absence of major histocompatibility complex (MHC) class II polymorphism has been cited as a possible explanation. Here we present evidence for considerable allelic polymorphism at the MHC class II DAB locus for a sample of wild-caught axolotls. Evidence that these sequences are the product of balancing selection for disease resistance is discussed.

Injection of an antibody against a p21 c-Ha-ras protein inhibits cleavage in axolotl eggs.

OpenAIRE

Baltus, E; Hanocq-Quertier, J; Hanocq, F; Brachet, J

1988-01-01

The presence of a ras protein was demonstrated in cleaving axolotl eggs by selective immunoprecipitation with a polyclonal antibody against a peptide encoded by the c-Ha-ras oncogene, cellular homolog of the v-Ha-ras oncogene of Harvey rat sarcoma virus. Injection of this antibody into axolotl oocytes subjected to progesterone treatment does not prevent meiotic maturation. Injection of the same antibody into a blastomere of axolotl eggs at the 2- or 4-cell stage causes cleavage arrest in the ...

Neuronale Korrelate sozialer Interaktion beim Menschen und deren genetische Modulation unter besonderer Berücksichtigung des Spiegelneuronensystems

OpenAIRE

Cordes, Andrea

2013-01-01

Die in vielen Lebenssituationen über Erfolg und Misserfolg, Sympathie und Antipathie entscheidende, unterschiedlich ausgeprägte Fähigkeit zur sozialen Interaktion ist Gegenstand neurowissenschaftlicher Untersuchungen. Die Versuche einer kortikalen Lokalisierung führten zur Beschreibung des Spiegelneuronensystems (SNS) in Hirnregionen, die sowohl beim Ausführen einer Aktion Aktivität zeigten als auch beim Beobachten derselben beim Gegenüber. Die stärkste Aktivierung dieser Areale wurde bei sch...

Data on chemical activation of Wnt/β-catenin during axolotl limb regeneration

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Sabina Wischin

2017-04-01

Full Text Available Limb amputation in axolotls was performed to obtain data demonstrating that a chemical agonist of Wnt (int-related protein/β-catenin signalling can have a role in axolotl limb regeneration (Wischin et al., 2017 [1]. The data revealed that active β-catenin protein was present during limb regeneration in some Leydig cells in the epithelium; after the chemical treatment, it was observed in more Leydig cells. In addition, the chemical agonist of Wnt generated distinct limb malformation.

Gallium nitrate: effects on cartilage during limb regeneration in the axolotl, Ambystoma mexicanum.

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Tassava, Roy A; Mendenhall, Luciara; Apseloff, Glen; Gerber, Nicholas

2002-09-01

Gallium nitrate, a drug shown to have efficacy in Paget's disease of bone, hypercalcemia of malignancy, and a variety of experimental autoimmune diseases, also inhibits the growth of some types of cancer. We examined dose and timing of administration of gallium nitrate on limb regeneration in the Mexican axolotl, Ambystoma mexicanum. Administered by intraperitoneal injection, gallium nitrate inhibited limb regeneration in a dose-dependent manner. Gallium nitrate initially suppressed epithelial wound healing and subsequently distorted both anterior-posterior and proximo-distal chondrogenic patterns. Gallium nitrate given at three days after amputation severely inhibited regeneration at high doses (6.25 mg/axolotl) and altered the normal patterning of the regenerates at low doses (3.75 mg/axolotl). Administration of 6.25 mg of gallium nitrate at four or 14 days prior to amputation also inhibited regeneration. In amputated limbs of gallium-treated axolotls, the chondrocytes were lost from inside the radius/ulna. Limbs that regenerated after gallium treatment was terminated showed blastema formation preferentially over the ulna. New cartilage of the regenerate often attached to the sides of the existing radius/ulna proximally into the stump and less so to the distal cut ends. J. Exp. Zool. 293:384-394, 2002. Copyright 2002 Wiley-Liss, Inc.

Highly restricted diversity of TCR delta chains of the amphibian Mexican axolotl (Ambystoma mexicanum) in peripheral tissues.

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André, Sébastien; Kerfourn, Fabienne; Affaticati, Pierre; Guerci, Aline; Ravassard, Philippe; Fellah, Julien S

2007-06-01

Gammadelta T cells localize at mammalian epithelial surfaces to exert both protective and regulatory roles in response to infections. We have previously characterized the Mexican axolotl (Ambystoma mexicanum) T cell receptor delta (TRD) chain. In this study, TRD repertoires in spleen, liver, intestine and skin from larvae, pre-adult and adult axolotls were examined and compared to the thymic TRD repertoire. A TRDV transcript without N/D diversity, TRDV1S1-TRDJ1, dominates the TRD repertoires until sexual maturation. In adult tissues, this canonical transcript is replaced by another dominant TRDV1S1-TRDJ1 transcript. In the thymus, these two transcripts are detected early in development. Our results suggest that gammadelta T cells that express the canonical TRDV1S1-TRDJ1 transcript emerge from the thymus and colonize the peripheral tissues, where they are selectively expanded by recurrent ligands. This particular situation is probably related to the neotenic state and the slow development of the axolotl. In thymectomized axolotls, TRD repertoires appear different from those of normal axolotls, suggesting that extrathymic gammadelta T cell differentiation could occur. Gene expression analysis showed the importance of the gut in T cell development.

Efficient gene knockin in axolotl and its use to test the role of satellite cells in limb regeneration.

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Fei, Ji-Feng; Schuez, Maritta; Knapp, Dunja; Taniguchi, Yuka; Drechsel, David N; Tanaka, Elly M

2017-11-21

Salamanders exhibit extensive regenerative capacities and serve as a unique model in regeneration research. However, due to the lack of targeted gene knockin approaches, it has been difficult to label and manipulate some of the cell populations that are crucial for understanding the mechanisms underlying regeneration. Here we have established highly efficient gene knockin approaches in the axolotl ( Ambystoma mexicanum ) based on the CRISPR/Cas9 technology. Using a homology-independent method, we successfully inserted both the Cherry reporter gene and a larger membrane-tagged Cherry-ER T2 -Cre-ER T2 (∼5-kb) cassette into axolotl Sox2 and Pax7 genomic loci. Depending on the size of the DNA fragments for integration, 5-15% of the F0 transgenic axolotl are positive for the transgene. Using these techniques, we have labeled and traced the PAX7-positive satellite cells as a major source contributing to myogenesis during axolotl limb regeneration. Our work brings a key genetic tool to molecular and cellular studies of axolotl regeneration.

Transgenesis in axolotl (Ambystoma mexicanum).

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Khattak, Shahryar; Tanaka, Elly M

2015-01-01

Transgenic animals have been indispensable in elucidating and deciphering mechanisms underlying various biological phenomena. In regeneration, transgenic animals expressing fluorescent protein genes have been crucial for identifying the source cells for regeneration and the mechanism of blastema formation. Animals are usually generated by manipulating their genome using various techniques at/in one cell embryo/fertilized egg stage. Here, we describe the generation of germline transgenic axolotls (Ambystoma mexicanum) using the I-SceI meganuclease and Tol2 transposase.

Proteinaceous Pheromone Homologs Identified from the Cloacal Gland Transcriptome of a Male Axolotl, Ambystoma mexicanum.

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Kevin W Hall

Full Text Available Pheromones play an important role in modifying vertebrate behavior, especially during courtship and mating. Courtship behavior in urodele amphibians often includes female exposure to secretions from the cloacal gland, as well as other scent glands. The first vertebrate proteinaceous pheromone discovered, the decapeptide sodefrin, is a female attracting pheromone secreted by the cloacal gland of male Cynops pyrrhogaster. Other proteinaceous pheromones in salamanders have been shown to elicit responses from females towards conspecific males. The presence and levels of expression of proteinaceous pheromones have not been identified in the family Ambystomatidae, which includes several important research models. The objective of this research was therefore to identify putative proteinaceous pheromones from male axolotls, Ambystoma mexicanum, as well as their relative expression levels. The results indicate that axolotls possess two different forms of sodefrin precursor-like factor (alpha and beta, as well as a putative ortholog of plethodontid modulating factor. The beta form of sodefrin precursor-like factor was amongst the most highly expressed transcripts within the cloacal gland. The ortholog of plethodontid modulating factor was expressed at a level equivalent to the beta sodefrin precursor-like factor. The results are from a single male axolotl; therefore, we are unable to assess how representative our results may be. Nevertheless, the presence of these highly expressed proteinaceous pheromones suggests that male axolotls use multiple chemical cues to attract female conspecifics. Behavioral assays would indicate whether the putative protein pheromones elicit courtship activity from female axolotls.

Proteinaceous Pheromone Homologs Identified from the Cloacal Gland Transcriptome of a Male Axolotl, Ambystoma mexicanum.

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Hall, Kevin W; Eisthen, Heather L; Williams, Barry L

2016-01-01

Pheromones play an important role in modifying vertebrate behavior, especially during courtship and mating. Courtship behavior in urodele amphibians often includes female exposure to secretions from the cloacal gland, as well as other scent glands. The first vertebrate proteinaceous pheromone discovered, the decapeptide sodefrin, is a female attracting pheromone secreted by the cloacal gland of male Cynops pyrrhogaster. Other proteinaceous pheromones in salamanders have been shown to elicit responses from females towards conspecific males. The presence and levels of expression of proteinaceous pheromones have not been identified in the family Ambystomatidae, which includes several important research models. The objective of this research was therefore to identify putative proteinaceous pheromones from male axolotls, Ambystoma mexicanum, as well as their relative expression levels. The results indicate that axolotls possess two different forms of sodefrin precursor-like factor (alpha and beta), as well as a putative ortholog of plethodontid modulating factor. The beta form of sodefrin precursor-like factor was amongst the most highly expressed transcripts within the cloacal gland. The ortholog of plethodontid modulating factor was expressed at a level equivalent to the beta sodefrin precursor-like factor. The results are from a single male axolotl; therefore, we are unable to assess how representative our results may be. Nevertheless, the presence of these highly expressed proteinaceous pheromones suggests that male axolotls use multiple chemical cues to attract female conspecifics. Behavioral assays would indicate whether the putative protein pheromones elicit courtship activity from female axolotls.

Diffusion tensor tractography reveals muscle reconnection during axolotl limb regeneration.

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Cheng-Han Wu

Full Text Available Axolotls have amazing ability to regenerate their lost limbs. Our previous works showed that after amputation the remnant muscle ends remained at their original location whilst sending satellite cells into the regenerating parts to develop into early muscle fibers in the late differentiation stage. The parental and the newly formed muscle fibers were not connected until very late stage. The present study used non-invasive diffusion tensor imaging (DTI to monitor weekly axolotl upper arm muscles after amputation of their upper arms. DTI tractography showed that the regenerating muscle fibers became visible at 9-wpa (weeks post amputation, but a gap was observed between the regenerating and parental muscles. The gap was filled at 10-wpa, indicating reconnection of the fibers of both muscles. This was confirmed by histology. The DTI results indicate that 23% of the muscle fibers were reconnected at 10-wpa. In conclusion, DTI can be used to visualize axolotls' skeletal muscles and the results of muscle reconnection were in accordance with our previous findings. This non-invasive technique will allow researchers to identify the timeframe in which muscle fiber reconnection takes place and thus enable the study of the mechanisms underlying this reconnection.

Identification of Conserved and Novel MicroRNAs during Tail Regeneration in the Mexican Axolotl

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Micah D. Gearhart

2015-09-01

Full Text Available The Mexican axolotl salamander (Ambystoma mexicanum is one member of a select group of vertebrate animals that have retained the amazing ability to regenerate multiple body parts. In addition to being an important model system for regeneration, the axolotl has also contributed extensively to studies of basic development. While many genes known to play key roles during development have now been implicated in various forms of regeneration, much of the regulatory apparatus controlling the underlying molecular circuitry remains unknown. In recent years, microRNAs have been identified as key regulators of gene expression during development, in many diseases and also, increasingly, in regeneration. Here, we have used deep sequencing combined with qRT-PCR to undertake a comprehensive identification of microRNAs involved in regulating regeneration in the axolotl. Specifically, among the microRNAs that we have found to be expressed in axolotl tissues, we have identified 4564 microRNA families known to be widely conserved among vertebrates, as well as 59,811 reads of putative novel microRNAs. These findings support the hypothesis that microRNAs play key roles in managing the precise spatial and temporal patterns of gene expression that ensures the correct regeneration of missing tissues.

Identification of Mutant Genes and Introgressed Tiger Salamander DNA in the Laboratory Axolotl, Ambystoma mexicanum.

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Woodcock, M Ryan; Vaughn-Wolfe, Jennifer; Elias, Alexandra; Kump, D Kevin; Kendall, Katharina Denise; Timoshevskaya, Nataliya; Timoshevskiy, Vladimir; Perry, Dustin W; Smith, Jeramiah J; Spiewak, Jessica E; Parichy, David M; Voss, S Randal

2017-01-31

The molecular genetic toolkit of the Mexican axolotl, a classic model organism, has matured to the point where it is now possible to identify genes for mutant phenotypes. We used a positional cloning-candidate gene approach to identify molecular bases for two historic axolotl pigment phenotypes: white and albino. White (d/d) mutants have defects in pigment cell morphogenesis and differentiation, whereas albino (a/a) mutants lack melanin. We identified in white mutants a transcriptional defect in endothelin 3 (edn3), encoding a peptide factor that promotes pigment cell migration and differentiation in other vertebrates. Transgenic restoration of Edn3 expression rescued the homozygous white mutant phenotype. We mapped the albino locus to tyrosinase (tyr) and identified polymorphisms shared between the albino allele (tyr a ) and tyr alleles in a Minnesota population of tiger salamanders from which the albino trait was introgressed. tyr a has a 142 bp deletion and similar engineered alleles recapitulated the albino phenotype. Finally, we show that historical introgression of tyr a significantly altered genomic composition of the laboratory axolotl, yielding a distinct, hybrid strain of ambystomatid salamander. Our results demonstrate the feasibility of identifying genes for traits in the laboratory Mexican axolotl.

Evaluation of the anesthetic effects of MS222 in the adult Mexican axolotl (Ambystoma mexicanum

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Zullian C

2016-01-01

Full Text Available Chiara Zullian,1 Aurore Dodelet-Devillers,1 Stéphane Roy,2 Pascal Vachon1 1Département de Biomédecine Vétérinaire, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, 2Département de Stomatologie, Faculté de Médecine Dentaire, Montréal, Québec, Canada Abstract: The Mexican axolotl (Ambystoma mexicanum is a unique research model in several fields of medicine, where surgical and invasive procedures may be required. As yet, little is known about the efficacy of MS222 (tricaine methanesulfonate, which is the most commonly used anesthetic agent in amphibians. The main objectives of this study were to evaluate the anesthetic effects and physiological changes in adult axolotls following a 20-minute immersion bath, containing progressive MS222 concentrations starting at 0.1%. Depth of anesthesia and physiological changes were evaluated every 15 minutes post-MS222 exposure with the following parameters: righting behavior, withdrawal reflex, acetic acid test response, heart rate, and blood oxygen saturation, as well as cloacal and body surface temperatures. A 20-minute exposure in a 0.1% MS222 immersion bath (n=6 animals had no anesthetic effects on adult axolotls after 20 minutes of exposure. With a 0.2% MS222 solution, all axolotls (n=9 were deeply anesthetized at 15 minutes, and 80% were still unresponsive at 30 minutes postexposure. Blood oxygen saturation and heart rate were slightly, but significantly, increased when compared with the baseline value and remained stable up to recovery. There was no significant increase in surface and cloaca temperatures, compared with baseline. With the 0.4% MS222 solution, the duration of anesthesia lasted for 90 minutes to at least 120 minutes (n=3 animals and this concentration was deemed too high. In conclusion, a 20-minute immersion bath with 0.2% MS222 may be used for short procedures (15–30 minutes requiring anesthesia of adult axolotls. Keywords: Ambystoma mexicanum

Propofol (2,6-diisopropylphenol) is an applicable immersion anesthetic in the axolotl with potential uses in hemodynamic and neurophysiological experiments

DEFF Research Database (Denmark)

Thygesen, Mathias; Rasmussen, Mikkel Mylius; Madsen, Jesper Guldsmed

2017-01-01

The Mexican axolotl (Ambystoma mexicanum) is an important model species in regenerative biology. Traditionally, axolotls are anesthetized using benzocaine or MS-222, both of which act to inhibit voltage gated sodium channels thereby preventing action potential propagation. In some...... neurophysiological experiments this is not desirable; therefore we tested propofol as an alternative anesthetic in the axolotl. We evaluated benzocaine, MS-222, and propofol's cardiovascular effects, effects on action potential propagation in the spinal cord, and gross limb regenerative effects. We found...... that propofol is applicable as a general anesthetic in the axolotl allowing for neurophysiological experiments and yielding a stable anesthesia with significantly less cardiovascular effect than both benzocaine and MS-222. Additionally, propofol did not affect gross limb regeneration. In conclusion we suggest...

Organophosphorus pesticides effect on early stages of the axolotl Ambystoma mexicanum (Amphibia: Caudata).

Science.gov (United States)

Robles-Mendoza, C; García-Basilio, C; Cram-Heydrich, S; Hernández-Quiroz, M; Vanegas-Pérez, C

2009-02-01

Ambystoma mexicanum is an endemic salamander of Xochimilco, a wetland of the basin of Mexico valley. Nowadays, axolotl populations are decreasing due environmental stressors. Particularly, studies about organophosphorus pesticides (OPPs; i.e. chlorpyrifos and malathion) toxicity are of great importance due to their intensive use in agricultural activities in Xochimilco. Thus, the aim of this study was to evaluate under controlled conditions the toxicity of chlorpyrifos (CPF) and malathion (MLT) on embryos and larvae (stage 44 and 54) of A. mexicanum. Embryos and larvae were exposure 96h from 0.5 to 3mg CPFL(-1) and from 10 to 30mg MLTL(-1) in independent tests. Embryos at the end of this period were maintained 9d without pesticide in order to identify possible recuperation. Differences obtained in mortality, hatching success, development, morphological abnormalities, behaviour and activity, suggest that toxicity of CPF and MLT differs in embryos and larval stages. Embryos were less sensitive to OPPs acute exposure than axolotl larvae; additionally, toxicity of CPF in larval stages was greater than MLT. On the other hand, data obtained in axolotl embryos during the period of recuperation to CPF in particular as delay and inhibition of development, malformations and success of hatching, indicated that these responses turned out more sensitive than mortality. This study allowed to identify the toxicological potential of OPPs on early developmental stages of A. mexicanum and it is a valuable contribution for the future management of the axolotl wild population.

Expression of Msx genes in regenerating and developing limbs of axolotl.

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Koshiba, K; Kuroiwa, A; Yamamoto, H; Tamura, K; Ide, H

1998-12-15

Msx genes, homeobox-containing genes, have been isolated as homologues of the Drosophila msh gene and are thought to play important roles in the development of chick or mouse limb buds. We isolated two Msx genes, Msx1 and Msx2, from regenerating blastemas of axolotl limbs and examined their expression patterns using Northern blot and whole mount in situ hybridization during regeneration and development. Northern blot analysis revealed that the expression level of both Msx genes increased during limb regeneration. The Msx2 expression level increased in the blastema at the early bud stage, and Msx1 expression level increased at the late bud stage. Whole mount in situ hybridization revealed that Msx2 was expressed in the distal mesenchyme and Msx1 in the entire mesenchyme of the blastema at the late bud stage. In the developing limb bud, Msx1 was expressed in the entire mesenchyme, while Msx2 was expressed in the distal and peripheral mesenchyme. The expression patterns of Msx genes in the blastemas and limb buds of the axolotl were different from those reported for chick or mouse limb buds. These expression patterns of axolotl Msx genes are discussed in relation to the blastema or limb bud morphology and their possible roles in limb patterning.

Molecular and immunohistochemical analyses of cardiac troponin T during cardiac development in the Mexican axolotl, Ambystoma mexicanum.

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Zhang, C; Pietras, K M; Sferrazza, G F; Jia, P; Athauda, G; Rueda-de-Leon, E; Rveda-de-Leon, E; Maier, J A; Dube, D K; Lemanski, S L; Lemanski, L F

2007-01-01

The Mexican axolotl, Ambystoma mexicanum, is an excellent animal model for studying heart development because it carries a naturally occurring recessive genetic mutation, designated gene c, for cardiac nonfunction. The double recessive mutants (c/c) fail to form organized myofibrils in the cardiac myoblasts resulting in hearts that fail to beat. Tropomyosin expression patterns have been studied in detail and show dramatically decreased expression in the hearts of homozygous mutant embryos. Because of the direct interaction between tropomyosin and troponin T (TnT), and the crucial functions of TnT in the regulation of striated muscle contraction, we have expanded our studies on this animal model to characterize the expression of the TnT gene in cardiac muscle throughout normal axolotl development as well as in mutant axolotls. In addition, we have succeeded in cloning the full-length cardiac troponin T (cTnT) cDNA from axolotl hearts. Confocal microscopy has shown a substantial, but reduced, expression of TnT protein in the mutant hearts when compared to normal during embryonic development. 2006 Wiley-Liss, Inc.

Myofibril-Inducing RNA (MIR is essential for tropomyosin expression and myofibrillogenesis in axolotl hearts

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Lemanski Sharon L

2009-09-01

Full Text Available Abstract The Mexican axolotl, Ambystoma mexicanum, carries the naturally-occurring recessive mutant gene 'c' that results in a failure of homozygous (c/c embryos to form hearts that beat because of an absence of organized myofibrils. Our previous studies have shown that a noncoding RNA, Myofibril-Inducing RNA (MIR, is capable of promoting myofibrillogenesis and heart beating in the mutant (c/c axolotls. The present study demonstrates that the MIR gene is essential for tropomyosin (TM expression in axolotl hearts during development. Gene expression studies show that mRNA expression of various tropomyosin isoforms in untreated mutant hearts and in normal hearts knocked down with double-stranded MIR (dsMIR are similar to untreated normal. However, at the protein level, selected tropomyosin isoforms are significantly reduced in mutant and dsMIR treated normal hearts. These results suggest that MIR is involved in controlling the translation or post-translation of various TM isoforms and subsequently of regulating cardiac contractility.

Rheumatische Erkrankungen beim älteren Patienten

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Köller M

2008-01-01

Full Text Available Muskuloskeletale Erkrankungen stellen beim älteren Menschen die häufigste Ursache für Aktivitätseinschränkungen dar. Die Prävalenz der Osteoarthrose (OA steigt mit dem Lebensalter sprunghaft an. Nach den Allgemeinmaßnahmen ist bei der medikamentösen Therapie der OA Paracetamol der Vorzug zu geben. Die rheumatoide Arthritis (RA als häufigste entzündliche Gelenkerkrankung des Erwachsenenalters zeigt im Alter oft atypische Verlaufsformen und ist unter Umständen von der Polymyalgia rheumatica schwer abzugrenzen. Jedenfalls erscheint die RA beim älteren Patienten oft nicht adäquat behandelt. Auch hier sind konventionelle Therapien wie Methotrexat Mittel der Wahl und Biologika erscheinen ebenso sicher bei älteren Patienten. Das Infektrisiko wird vorwiegend durch die begleitende Kortikosteroid-Dosis bestimmt. Die Polymyalgia rheumatica betrifft in 90 % der Fälle Patienten älter als 60 Jahre. Kortikosteroide sind hier nach wie vor die wichtigste Therapie, welche meist über ein bis zwei Jahre erforderlich ist. Eine Riesenzellarteriitis muss bei Patienten mit PMR immer ausgeschlossen werden. Bei Vorliegen dieser Vaskulitis muss im Falle einer Mitbeteiligung der Augengefäße möglichst rasch eine hoch dosierte Steroidgabe erfolgen. Die Biopsie der Schläfenarterie kann auch einige Zeit nach Therapiebeginn erfolgen, ohne dass die diagnostische Aussagekraft darunter leidet.

Regulation of antibody synthesis in the X-irradiated Mexican axolotl

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Charlemagne, J.

1981-01-01

The effects of X-irradiation were studied on the Mexican axolotl antibody synthesis. To reduce the anti-horse red blood cell (HRBC) antibody titers, 150 rd and smaller doses are ineffective, 200-450 rd are increasingly effective, and 700 rd are maximally effective (and lethal). A significant enhancement of the anti-HRBC titers was observed in low doses (50-150 rd X-irradiated animals). This enhancement was also observed when a low X-ray dose was applied only on the thymic areas. In whole body, but thymus area-shielded, 100 rd X-irradiated animals, the anti-HRBC titers were similar to those of the nonirradiated, HRBC-immunized control group. To explain these phenomena, it is suggested that a radiosensitive, adult thymectomy-sensitive and hydrocortisone-sensitive suppressor T cell subpopulation regulates the antibody synthesis in the axolotl. (orig.) [de

Regulation of antibody synthesis in the X-irradiated Mexican axolotl

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Charlemagne, J.

1981-09-01

The effects of X-irradiation were studied on the Mexican axolotl antibody synthesis. To reduce the anti-horse red blood cell (HRBC) antibody titers, 150 rd and smaller doses are ineffective, 200-450 rd are increasingly effective, and 700 rd are maximally effective (and lethal). A significant enhancement of the anti-HRBC titers was observed in low doses (50-150 rd X-irradiated animals). This enhancement was also observed when a low X-ray dose was applied only on the thymic areas. In whole body, but thymus area-shielded, 100 rd X-irradiated animals, the anti-HRBC titers were similar to those of the nonirradiated, HRBC-immunized control group. To explain these phenomena, it is suggested that a radiosensitive, adult thymectomy-sensitive and hydrocortisone-sensitive suppressor T cell subpopulation regulates the antibody synthesis in the axolotl.

Terminal-Nerve-Derived Neuropeptide Y Modulates Physiological Responses in the Olfactory Epithelium of Hungry Axolotls (Ambystoma mexicanum)

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Mousley, Angela; Polese, Gianluca; Marks, Nikki J.; Eisthen, Heather L.

2007-01-01

The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the olfactory epithelium, displays anatomical and neurochemical characteristics that suggest that it modulates activity in the olfactory epithelium. Using immunocytochemical techniques, we demonstrate that neuropeptide Y (NPY) is abundantly present in the terminal nerve in the axolotl (Ambystoma mexicanum), an aquatic salamander. Because NPY plays an important role in regulating appetite and hunger in many vertebrates, we investigated the possibility that NPY modulates activity in the olfactory epithelium in relation to the animal's hunger level. We therefore characterized the full length NPY gene from axolotls to enable synthesis of authentic axolotl NPY for use in electrophysiological experiments. We find that axolotl NPY modulates olfactory epithelial responses evoked by L-glutamic acid, a food-related odorant, but only in hungry animals. Similarly, whole-cell patch-clamp recordings demonstrate that bath application of axolotl NPY enhances the magnitude of a tetrodotoxin-sensitive inward current, but only in hungry animals. These results suggest that expression or activity of NPY receptors in the olfactory epithelium may change with hunger level, and that terminal nerve-derived peptides modulate activity in the olfactory epithelium in response to an animal's changing behavioral and physiological circumstances. PMID:16855098

Terminal nerve-derived neuropeptide y modulates physiological responses in the olfactory epithelium of hungry axolotls (Ambystoma mexicanum).

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Mousley, Angela; Polese, Gianluca; Marks, Nikki J; Eisthen, Heather L

2006-07-19

The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the olfactory epithelium, displays anatomical and neurochemical characteristics that suggest that it modulates activity in the olfactory epithelium. Using immunocytochemical techniques, we demonstrate that neuropeptide Y (NPY) is abundantly present in the terminal nerve in the axolotl (Ambystoma mexicanum), an aquatic salamander. Because NPY plays an important role in regulating appetite and hunger in many vertebrates, we investigated the possibility that NPY modulates activity in the olfactory epithelium in relation to the animal's hunger level. We therefore characterized the full-length NPY gene from axolotls to enable synthesis of authentic axolotl NPY for use in electrophysiological experiments. We find that axolotl NPY modulates olfactory epithelial responses evoked by l-glutamic acid, a food-related odorant, but only in hungry animals. Similarly, whole-cell patch-clamp recordings demonstrate that bath application of axolotl NPY enhances the magnitude of a tetrodotoxin-sensitive inward current, but only in hungry animals. These results suggest that expression or activity of NPY receptors in the olfactory epithelium may change with hunger level, and that terminal nerve-derived peptides modulate activity in the olfactory epithelium in response to an animal's changing behavioral and physiological circumstances.

Novel axolotl cardiac function analysis method using magnetic resonance imaging

NARCIS (Netherlands)

Sanches, Pedro Gomes; Op 't Veld, Roel C.; de Graaf, Wolter; Strijkers, Gustav J.; Grüll, Holger

2017-01-01

The salamander axolotl is capable of complete regeneration of amputated heart tissue. However, non-invasive imaging tools for assessing its cardiac function were so far not employed. In this study, cardiac magnetic resonance imaging is introduced as a non-invasive technique to image heart function

Novel axolotl cardiac function analysis method using magnetic resonance imaging

NARCIS (Netherlands)

Sanches, P.G.; Op ‘t Veld, R.C.; de Graaf, W.; Strijkers, G.J.; Grüll, H.

2017-01-01

The salamander axolotl is capable of complete regeneration of amputated heart tissue. However, non-invasive imaging tools for assessing its cardiac function were so far not employed. In this study, cardiac magnetic resonance imaging is introduced as a noninvasive technique to image heart function of

Comparative RNA-seq analysis in the unsequenced axolotl: the oncogene burst highlights early gene expression in the blastema.

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Ron Stewart

Full Text Available The salamander has the remarkable ability to regenerate its limb after amputation. Cells at the site of amputation form a blastema and then proliferate and differentiate to regrow the limb. To better understand this process, we performed deep RNA sequencing of the blastema over a time course in the axolotl, a species whose genome has not been sequenced. Using a novel comparative approach to analyzing RNA-seq data, we characterized the transcriptional dynamics of the regenerating axolotl limb with respect to the human gene set. This approach involved de novo assembly of axolotl transcripts, RNA-seq transcript quantification without a reference genome, and transformation of abundances from axolotl contigs to human genes. We found a prominent burst in oncogene expression during the first day and blastemal/limb bud genes peaking at 7 to 14 days. In addition, we found that limb patterning genes, SALL genes, and genes involved in angiogenesis, wound healing, defense/immunity, and bone development are enriched during blastema formation and development. Finally, we identified a category of genes with no prior literature support for limb regeneration that are candidates for further evaluation based on their expression pattern during the regenerative process.

Neuregulin-1 signaling is essential for nerve-dependent axolotl limb regeneration.

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Farkas, Johanna E; Freitas, Polina D; Bryant, Donald M; Whited, Jessica L; Monaghan, James R

2016-08-01

The Mexican axolotl (Ambystoma mexicanum) is capable of fully regenerating amputated limbs, but denervation of the limb inhibits the formation of the post-injury proliferative mass called the blastema. The molecular basis behind this phenomenon remains poorly understood, but previous studies have suggested that nerves support regeneration via the secretion of essential growth-promoting factors. An essential nerve-derived factor must be found in the blastema, capable of rescuing regeneration in denervated limbs, and its inhibition must prevent regeneration. Here, we show that the neuronally secreted protein Neuregulin-1 (NRG1) fulfills all these criteria in the axolotl. Immunohistochemistry and in situ hybridization of NRG1 and its active receptor ErbB2 revealed that they are expressed in regenerating blastemas but lost upon denervation. NRG1 was localized to the wound epithelium prior to blastema formation and was later strongly expressed in proliferating blastemal cells. Supplementation by implantation of NRG1-soaked beads rescued regeneration to digits in denervated limbs, and pharmacological inhibition of NRG1 signaling reduced cell proliferation, blocked blastema formation and induced aberrant collagen deposition in fully innervated limbs. Taken together, our results show that nerve-dependent NRG1/ErbB2 signaling promotes blastemal proliferation in the regenerating limb and may play an essential role in blastema formation, thus providing insight into the longstanding question of why nerves are required for axolotl limb regeneration. © 2016. Published by The Company of Biologists Ltd.

Ultrastructure of the renal juxtaglomerular complex and peripolar cells in the axolotl (Ambystoma mexicanum) and toad (Bufo marinus).

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Hanner, R H; Ryan, G B

1980-01-01

Renal juxtaglomerular regions were examined in the axolotl (Ambystoma mexicanum and toad (Bufo marinus). Prominent granulated peripolar epithelial cells were found surrounding the origin of the glomerular tuft in the axolotl. These cells resembled the peripolar cells recently discovered in mammalian species. They contained multiple electron-dense cytoplasmic granules, some of which showed a paracrystalline substructure and signs of exocytoxic activity. Such cells were difficult to find and smaller in the toad. In contrast, granulated juxtaglomerular arteriolar myoephithelial cells were much more readily found and larger in the toad than in the axolotl. No consistent differences were noted in juxtaglomerular cells or their granules in response to changes in environmental chloride concentration. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:7410189

Qualität beim E-Learning: Der Lernende als Grundkategorie bei der Qualitätssicherung

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Ulf Ehlers

2002-03-01

Full Text Available Qualität wird über die zukünftigen Erfolgschancen des E-Learning entscheiden. Das ist das Ergebnis vieler Analysen und Entwicklungen der letzten Zeit. So stellte etwa die KPMG-Studie heraus, dass es beim E-Learning nicht nur auf gute Technologie ankommt, sondern die betriebliche Lernkultur und der Lerner wesentlich mehr als bisher einzubeziehen sind. Dieser Beitrag beschäftigt sich damit, was Qualität beim E-Learning eigentlich ist und welche Konzepte zur Beschreibung und Sicherung von Qualität bestehen.

Regeneration of limb joints in the axolotl (Ambystoma mexicanum).

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Lee, Jangwoo; Gardiner, David M

2012-01-01

In spite of numerous investigations of regenerating salamander limbs, little attention has been paid to the details of how joints are reformed. An understanding of the process and mechanisms of joint regeneration in this model system for tetrapod limb regeneration would provide insights into developing novel therapies for inducing joint regeneration in humans. To this end, we have used the axolotl (Mexican Salamander) model of limb regeneration to describe the morphology and the expression patterns of marker genes during joint regeneration in response to limb amputation. These data are consistent with the hypothesis that the mechanisms of joint formation whether it be development or regeneration are conserved. We also have determined that defects in the epiphyseal region of both forelimbs and hind limbs in the axolotl are regenerated only when the defect is small. As is the case with defects in the diaphysis, there is a critical size above which the endogenous regenerative response is not sufficient to regenerate the joint. This non-regenerative response in an animal that has the ability to regenerate perfectly provides the opportunity to screen for the signaling pathways to induce regeneration of articular cartilage and joints.

Regeneration of limb joints in the axolotl (Ambystoma mexicanum.

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Jangwoo Lee

Full Text Available In spite of numerous investigations of regenerating salamander limbs, little attention has been paid to the details of how joints are reformed. An understanding of the process and mechanisms of joint regeneration in this model system for tetrapod limb regeneration would provide insights into developing novel therapies for inducing joint regeneration in humans. To this end, we have used the axolotl (Mexican Salamander model of limb regeneration to describe the morphology and the expression patterns of marker genes during joint regeneration in response to limb amputation. These data are consistent with the hypothesis that the mechanisms of joint formation whether it be development or regeneration are conserved. We also have determined that defects in the epiphyseal region of both forelimbs and hind limbs in the axolotl are regenerated only when the defect is small. As is the case with defects in the diaphysis, there is a critical size above which the endogenous regenerative response is not sufficient to regenerate the joint. This non-regenerative response in an animal that has the ability to regenerate perfectly provides the opportunity to screen for the signaling pathways to induce regeneration of articular cartilage and joints.

Microarray Analysis of microRNA Expression during Axolotl Limb Regeneration

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Holman, Edna C.; Campbell, Leah J.; Hines, John; Crews, Craig M.

2012-01-01

Among vertebrates, salamanders stand out for their remarkable capacity to quickly regrow a myriad of tissues and organs after injury or amputation. The limb regeneration process in axolotls (Ambystoma mexicanum) has been well studied for decades at the cell-tissue level. While several developmental genes are known to be reactivated during this epimorphic process, less is known about the role of microRNAs in urodele amphibian limb regeneration. Given the compelling evidence that many microRNAs tightly regulate cell fate and morphogenetic processes through development and adulthood by modulating the expression (or re-expression) of developmental genes, we investigated the possibility that microRNA levels change during limb regeneration. Using two different microarray platforms to compare the axolotl microRNA expression between mid-bud limb regenerating blastemas and non-regenerating stump tissues, we found that miR-21 was overexpressed in mid-bud blastemas compared to stump tissue. Mature A. mexicanum (“Amex”) miR-21 was detected in axolotl RNA by Northern blot and differential expression of Amex-miR-21 in blastema versus stump was confirmed by quantitative RT-PCR. We identified the Amex Jagged1 as a putative target gene for miR-21 during salamander limb regeneration. We cloned the full length 3′UTR of Amex-Jag1, and our in vitro assays demonstrated that its single miR-21 target recognition site is functional and essential for the response of the Jagged1 gene to miR-21 levels. Our findings pave the road for advanced in vivo functional assays aimed to clarify how microRNAs such as miR-21, often linked to pathogenic cell growth, might be modulating the redeployment of developmental genes such as Jagged1 during regenerative processes. PMID:23028429

Microarray analysis of microRNA expression during axolotl limb regeneration.

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Edna C Holman

Full Text Available Among vertebrates, salamanders stand out for their remarkable capacity to quickly regrow a myriad of tissues and organs after injury or amputation. The limb regeneration process in axolotls (Ambystoma mexicanum has been well studied for decades at the cell-tissue level. While several developmental genes are known to be reactivated during this epimorphic process, less is known about the role of microRNAs in urodele amphibian limb regeneration. Given the compelling evidence that many microRNAs tightly regulate cell fate and morphogenetic processes through development and adulthood by modulating the expression (or re-expression of developmental genes, we investigated the possibility that microRNA levels change during limb regeneration. Using two different microarray platforms to compare the axolotl microRNA expression between mid-bud limb regenerating blastemas and non-regenerating stump tissues, we found that miR-21 was overexpressed in mid-bud blastemas compared to stump tissue. Mature A. mexicanum ("Amex" miR-21 was detected in axolotl RNA by Northern blot and differential expression of Amex-miR-21 in blastema versus stump was confirmed by quantitative RT-PCR. We identified the Amex Jagged1 as a putative target gene for miR-21 during salamander limb regeneration. We cloned the full length 3'UTR of Amex-Jag1, and our in vitro assays demonstrated that its single miR-21 target recognition site is functional and essential for the response of the Jagged1 gene to miR-21 levels. Our findings pave the road for advanced in vivo functional assays aimed to clarify how microRNAs such as miR-21, often linked to pathogenic cell growth, might be modulating the redeployment of developmental genes such as Jagged1 during regenerative processes.

Network based transcription factor analysis of regenerating axolotl limbs

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Cameron Jo Ann

2011-03-01

Full Text Available Abstract Background Studies on amphibian limb regeneration began in the early 1700's but we still do not completely understand the cellular and molecular events of this unique process. Understanding a complex biological process such as limb regeneration is more complicated than the knowledge of the individual genes or proteins involved. Here we followed a systems biology approach in an effort to construct the networks and pathways of protein interactions involved in formation of the accumulation blastema in regenerating axolotl limbs. Results We used the human orthologs of proteins previously identified by our research team as bait to identify the transcription factor (TF pathways and networks that regulate blastema formation in amputated axolotl limbs. The five most connected factors, c-Myc, SP1, HNF4A, ESR1 and p53 regulate ~50% of the proteins in our data. Among these, c-Myc and SP1 regulate 36.2% of the proteins. c-Myc was the most highly connected TF (71 targets. Network analysis showed that TGF-β1 and fibronectin (FN lead to the activation of these TFs. We found that other TFs known to be involved in epigenetic reprogramming, such as Klf4, Oct4, and Lin28 are also connected to c-Myc and SP1. Conclusions Our study provides a systems biology approach to how different molecular entities inter-connect with each other during the formation of an accumulation blastema in regenerating axolotl limbs. This approach provides an in silico methodology to identify proteins that are not detected by experimental methods such as proteomics but are potentially important to blastema formation. We found that the TFs, c-Myc and SP1 and their target genes could potentially play a central role in limb regeneration. Systems biology has the potential to map out numerous other pathways that are crucial to blastema formation in regeneration-competent limbs, to compare these to the pathways that characterize regeneration-deficient limbs and finally, to identify stem

Neural crest does not contribute to the neck and shoulder in the axolotl (Ambystoma mexicanum).

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Epperlein, Hans-Henning; Khattak, Shahryar; Knapp, Dunja; Tanaka, Elly M; Malashichev, Yegor B

2012-01-01

A major step during the evolution of tetrapods was their transition from water to land. This process involved the reduction or complete loss of the dermal bones that made up connections to the skull and a concomitant enlargement of the endochondral shoulder girdle. In the mouse the latter is derived from three separate embryonic sources: lateral plate mesoderm, somites, and neural crest. The neural crest was suggested to sustain the muscle attachments. How this complex composition of the endochondral shoulder girdle arose during evolution and whether it is shared by all tetrapods is unknown. Salamanders that lack dermal bone within their shoulder girdle were of special interest for a possible contribution of the neural crest to the endochondral elements and muscle attachment sites, and we therefore studied them in this context. We grafted neural crest from GFP+ fluorescent transgenic axolotl (Ambystoma mexicanum) donor embryos into white (d/d) axolotl hosts and followed the presence of neural crest cells within the cartilage of the shoulder girdle and the connective tissue of muscle attachment sites of the neck-shoulder region. Strikingly, neural crest cells did not contribute to any part of the endochondral shoulder girdle or to the connective tissue at muscle attachment sites in axolotl. Our results in axolotl suggest that neural crest does not serve a general function in vertebrate shoulder muscle attachment sites as predicted by the "muscle scaffold theory," and that it is not necessary to maintain connectivity of the endochondral shoulder girdle to the skull. Our data support the possibility that the contribution of the neural crest to the endochondral shoulder girdle, which is observed in the mouse, arose de novo in mammals as a developmental basis for their skeletal synapomorphies. This further supports the hypothesis of an increased neural crest diversification during vertebrate evolution.

Neural crest does not contribute to the neck and shoulder in the axolotl (Ambystoma mexicanum.

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Hans-Henning Epperlein

Full Text Available BACKGROUND: A major step during the evolution of tetrapods was their transition from water to land. This process involved the reduction or complete loss of the dermal bones that made up connections to the skull and a concomitant enlargement of the endochondral shoulder girdle. In the mouse the latter is derived from three separate embryonic sources: lateral plate mesoderm, somites, and neural crest. The neural crest was suggested to sustain the muscle attachments. How this complex composition of the endochondral shoulder girdle arose during evolution and whether it is shared by all tetrapods is unknown. Salamanders that lack dermal bone within their shoulder girdle were of special interest for a possible contribution of the neural crest to the endochondral elements and muscle attachment sites, and we therefore studied them in this context. RESULTS: We grafted neural crest from GFP+ fluorescent transgenic axolotl (Ambystoma mexicanum donor embryos into white (d/d axolotl hosts and followed the presence of neural crest cells within the cartilage of the shoulder girdle and the connective tissue of muscle attachment sites of the neck-shoulder region. Strikingly, neural crest cells did not contribute to any part of the endochondral shoulder girdle or to the connective tissue at muscle attachment sites in axolotl. CONCLUSIONS: Our results in axolotl suggest that neural crest does not serve a general function in vertebrate shoulder muscle attachment sites as predicted by the "muscle scaffold theory," and that it is not necessary to maintain connectivity of the endochondral shoulder girdle to the skull. Our data support the possibility that the contribution of the neural crest to the endochondral shoulder girdle, which is observed in the mouse, arose de novo in mammals as a developmental basis for their skeletal synapomorphies. This further supports the hypothesis of an increased neural crest diversification during vertebrate evolution.

Expression of Msx-2 during development, regeneration, and wound healing in axolotl limbs.

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Carlson, M R; Bryant, S V; Gardiner, D M

1998-12-15

Msx genes are transcription factors that are expressed during embryogenesis of developing appendages in regions of epithelial-mesenchymal interactions. Various lines of evidence indicate that these genes function to maintain embryonic tissues in an undifferentiated, proliferative state. We have identified the axolotl homolog of Msx-2, and investigated its expression during limb development, limb regeneration, and wound healing. As in limb buds of higher vertebrates, axolotl Msx-2 is expressed in the apical epidermis and mesenchyme; however, its expression domain is more extensive, reflecting the broader region of the apical epidermal cap in amphibians. Msx-2 expression is downregulated at late stages of limb development, but is reexpressed within one hour after limb amputation. Msx-2 is also reexpressed during wound healing, and may be essential in the early stages of initiation of the limb regeneration cascade.

Analysis of embryonic development in the unsequenced axolotl: waves of transcriptomic upheaval and stability

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Jiang, Peng; Nelson, Jeffrey D.; Leng, Ning; Collins, Michael; Swanson, Scott; Dewey, Colin N.; Thomson, James A.; Stewart, Ron

2016-01-01

The axolotl (Ambystoma mexicanum) has long been the subject of biological research, primarily owing to its outstanding regenerative capabilities. However, the gene expression programs governing its embryonic development are particularly underexplored, especially when compared to other amphibian model species. Therefore, we performed whole transcriptome polyA+ RNA sequencing experiments on 17 stages of embryonic development. As the axolotl genome is unsequenced and its gene annotation is incomplete, we built de novo transcriptome assemblies for each stage and garnered functional annotation by comparing expressed contigs with known genes in other organisms. In evaluating the number of differentially expressed genes over time, we identify three waves of substantial transcriptome upheaval each followed by a period of relative transcriptome stability. The first wave of upheaval is between the one and two cell stage. We show that the number of differentially expressed genes per unit time is higher between the one and two cell stage than it is across the mid-blastula transition (MBT), the period of zygotic genome activation. We use total RNA sequencing to demonstrate that the vast majority of genes with increasing polyA+ signal between the one and two cell stage result from polyadenylation rather than de novo transcription. The first stable phase begins after the two cell stage and continues until the mid-blastula transition, corresponding with the pre-MBT phase of transcriptional quiescence in amphibian development. Following this is a peak of differential gene expression corresponding with the activation of the zygotic genome and a phase of transcriptomic stability from stages 9 to 11. We observe a third wave of transcriptomic change between stages 11 and 14, followed by a final stable period. The last two stable phases have not been documented in amphibians previously and correspond to times of major morphogenic change in the axolotl embryo: gastrulation and

Ellbogen- und Handgelenksendoprothetik beim Rheumatiker - Richtlinien und Rehabilitation

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Chochole M

2008-01-01

Full Text Available Die Endoprothetik an Ellbogen und Handgelenk ist seit etwa drei Jahrzehnten etabliert. An beiden Gelenken haben sich einzelne Implantate oder Designs durchgesetzt. Operationstechniken und Nachuntersuchungsergebnisse sind publiziert. Wenig ist jedoch zum Thema Nachbehandlung und Nachsorge veröffentlicht. Diese Arbeit beschäftigt sich detailliert mit der ärztlichen und therapeutischen Betreuung nach Implantation einer Ellbogen- oder Handgelenksendoprothese beim Patienten mit rheumatischer Arthritis unter Aufgliederung in Krankenhausaufenthalt, ambulanter Nachsorge sowie stationärer Rehabilitation. Dabei werden Zeitrahmen, Therapieziele und Behandlungen gesondert angeführt.

Linking vertebral number to performance of aquatic escape responses in the axolotl (Ambystoma mexicanum).

Science.gov (United States)

Ackerly, Kerri L; Ward, Andrea B

2015-12-01

Environmental conditions during early development in ectothermic vertebrates can lead to variation in vertebral number among individuals of the same species. It is often seen that individuals of a species raised at cooler temperatures have more vertebrae than individuals raised at warmer temperatures, although the functional consequences of this variation in vertebral number on swimming performance are relatively unclear. To investigate this relationship, we tested how vertebral number in axolotls (Ambystoma mexicanum) affected performance of aquatic escape responses (C-starts). Axolotls were reared at four temperatures (12-24°C) encompassing their natural thermal range and then transitioned to a mean temperature (18°C) three months before C-starts were recorded. Our results showed variation in vertebral number, but that variation was not significantly affected by developmental temperature. C-start performance among axolotls was significantly correlated with caudal vertebral number, and individuals with more caudal vertebrae were able to achieve greater curvature more quickly during their responses than individuals with fewer vertebrae. However, our results show that these individuals did not achieve greater displacements or velocities, and that developmental temperature did not have any effect on C-start performance. We highlight that the most important aspects of escape swim performance (i.e., how far individuals get from a threat and how quickly they move the most important parts of the body away from that threat) are consistent across individuals regardless of developmental temperature and morphological variation. Copyright © 2015 Elsevier GmbH. All rights reserved.

Axolotl cells and tissues enhances cutaneous wound healing in mice

OpenAIRE

DEMIRCAN, Turan; KESKIN, Ilknur; GUNAL, Yalcin; ILHAN, Ayse Elif; KOLBASI, Bircan; OZTURK, Gurkan

2017-01-01

Adult mammalian skin wound repair is defective due to loss of the regulation in balancing the complete epithelial regeneration and excessive connective tissue production, and this repair process commonly results in scar tissue formation. However, unlike mammals, adult salamanders repair the wounds by regeneration compared to scarring. To elucidate the healing capability of a salamander, Axolotl, in a different species, here we addressed this question by treating the wounds in mice with Axolot...

Hyperbaric oxygen therapy in a true regenerative environment, the regenerating limb of the axolotl

DEFF Research Database (Denmark)

Hansen, Kasper; Lauridsen, Henrik; Pedersen, Michael

2012-01-01

vertebrates such as the urodele amphibians (salamanders and newts), are excellent animal models for regenerative studies. The iconic Mexican axolotl (Ambystoma mexicanum) is capable of regenerating whole limbs, tail, jaw, and many inner organs, by dedifferentiation of cells to form a blastema (collection...

Experimental investigations of tyre-road interactions during braking; Experimentelle Untersuchungen zur Interaktion zwischen Pkw-Reifen und Fahrbahn beim Bremsen

Energy Technology Data Exchange (ETDEWEB)

Chunyang Xie

2002-07-01

Tyre-road interactions during braking were investigated experimentally. The measurements were found to be highly accurate. In the first stage, the braking force is enhanced by elastic deformation of the profile elements at the onset of tyre contact. In case of high slip or a high sliding velocity, frictional vibration of the tyre section in contact with the road may occur, which is enhanced by the reduction of braking pressure in case of automatic brake control. The eigenfreequency of the frictional vibration also depends on the road texture and friction coefficient. The measured movements of the profile elements provide a good explanation of the causes of tyre noise. [German] In der Dissertation wurde die Interaktion Reifen/Fahrbahn beim Bremsen experimentell untersucht. Die Messungen zeigen, dass die mit dem neuen Reifensensor erfassten Profilelementverformungen den Reibungszustand zwischen Reifen und Fahrbahn gut widerspiegeln. Die Bremskraft wird zunaechst durch die elastischen Verformungen der Profilelemente am Anfang des Reifenlatsches wesentlich aufgebaut. Beim hohen Bremsschlupf bzw. der hohen Gleitgeschwindigkeit kann die Reibungsschwingung des Laufstreifens des Reifens auftreten. Der Bremsdruckabbau der ABS-Regelung beguenstigt die Entstehung dieser Reibungsschwingung. Die Eigenfrequenz der Reibungsschwingung ist auch abhaengig von der Fahrbahntextur und dem Reibwert. Die aus den Signalen des Profilrillensensors berechneten Beschleunigungen der Profilelemente zeigen deutlich den Aufschlag beim Einlauf des Reifens und das Ausschnappen beim Auslauf. Durch die gemessenen Bewegungen der Profilelemente laesst sich die Entstehung des Reifengeraeusches in einigen Frequenzbereichen gut erklaeren. (orig.)

Molecular cloning, sequence analysis and phylogeny of first caudata g-type lysozyme in axolotl (Ambystoma mexicanum).

Science.gov (United States)

Yu, Haining; Gao, Jiuxiang; Lu, Yiling; Guang, Huijuan; Cai, Shasha; Zhang, Songyan; Wang, Yipeng

2013-11-01

Lysozymes are key proteins that play important roles in innate immune defense in many animal phyla by breaking down the bacterial cell-walls. In this study, we report the molecular cloning, sequence analysis and phylogeny of the first caudate amphibian g-lysozyme: a full-length spleen cDNA library from axolotl (Ambystoma mexicanum). A goose-type (g-lysozyme) EST was identified and the full-length cDNA was obtained using RACE-PCR. The axolotl g-lysozyme sequence represents an open reading frame for a putative signal peptide and the mature protein composed of 184 amino acids. The calculated molecular mass and the theoretical isoelectric point (pl) of this mature protein are 21523.0 Da and 4.37, respectively. Expression of g-lysozyme mRNA is predominantly found in skin, with lower levels in spleen, liver, muscle, and lung. Phylogenetic analysis revealed that caudate amphibian g-lysozyme had distinct evolution pattern for being juxtaposed with not only anura amphibian, but also with the fish, bird and mammal. Although the first complete cDNA sequence for caudate amphibian g-lysozyme is reported in the present study, clones encoding axolotl's other functional immune molecules in the full-length cDNA library will have to be further sequenced to gain insight into the fundamental aspects of antibacterial mechanisms in caudate.

BMP-2 functions independently of SHH signaling and triggers cell condensation and apoptosis in regenerating axolotl limbs

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Finnson Kenneth

2010-02-01

Full Text Available Abstract Background Axolotls have the unique ability, among vertebrates, to perfectly regenerate complex body parts, such as limbs, after amputation. In addition, axolotls pattern developing and regenerating autopods from the anterior to posterior axis instead of posterior to anterior like all tetrapods studied to date. Sonic hedgehog is important in establishing this anterior-posterior axis of limbs in all tetrapods including axolotls. Interestingly, its expression is conserved (to the posterior side of limb buds and blastemas in axolotl limbs as in other tetrapods. It has been suggested that BMP-2 may be the secondary mediator of sonic hedgehog, although there is mounting evidence to the contrary in mice. Since BMP-2 expression is on the anterior portion of developing and regenerating limbs prior to digit patterning, opposite to the expression of sonic hedgehog, we examined whether BMP-2 expression was dependent on sonic hedgehog signaling and whether it affects patterning of the autopod during regeneration. Results The expression of BMP-2 and SOX-9 in developing and regenerating axolotl limbs corresponded to the first digits forming in the anterior portion of the autopods. The inhibition of sonic hedgehog signaling with cyclopamine caused hypomorphic limbs (during development and regeneration but did not affect the expression of BMP-2 and SOX-9. Overexpression of BMP-2 in regenerating limbs caused a loss of digits. Overexpression of Noggin (BMP inhibitor in regenerating limbs also resulted in a loss of digits. Histological analysis indicated that the loss due to BMP-2 overexpression was the result of increased cell condensation and apoptosis while the loss caused by Noggin was due to a decrease in cell division. Conclusion The expression of BMP-2 and its target SOX-9 was independent of sonic hedgehog signaling in developing and regenerating limbs. Their expression correlated with chondrogenesis and the appearance of skeletal elements has

Endovascular interventions for multiple trauma; Endovaskulaere Interventionen beim Polytrauma

Energy Technology Data Exchange (ETDEWEB)

Kinstner, C.; Funovics, M. [Klinik fuer Radiologie und Nuklearmedizin, Medizinische Universitaet Wien, Klinische Abteilung fuer Kardiovaskulaere und Interventionelle Radiologie, Wien (Austria)

2014-09-15

oder mittels Stent zu schienen. Speziell beim Polytrauma wird die Planung dieser Eingriffe wann immer moeglich nach einem praeinterventionellen Multidetektor-CT durchgefuehrt. Der Einsatz der endovaskulaeren Intervention ermoeglicht neben einer Verringerung des operativen Traumas auch eine wesentliche Verkuerzung der Behandlungszeit. Beim vaskulaeren Trauma am Stamm oder an den Extremitaeten, wo ein operativer Zugang nur unter erhoehtem Risiko durchfuehrbar erscheint, aber auch beim pelvinen Trauma und bei arteriellen Verletzungen parenchymatoeser Organe, die nicht gaenzlich geopfert werden sollen, sowie in anderen schwer zugaenglichen Regionen wie der oberen Thoraxapertur, ist die interventionelle Versorgung mittlerweile Standardmethode geworden. Heute kann die interventionelle Radiologie in praktisch allen vaskulaeren Territorien in einem interdisziplinaeren Zugang neben der offenen chirurgischen Versorgung dazu beitragen, eine schnellere Stabilisierung der Situation herbeizufuehren. (orig.)

Randzonenveränderung beim Bohren und ihre Auswirkung auf Folgebearbeitungsverfahren

OpenAIRE

Schmier, Marcus

2004-01-01

In der Praxis kommt es bei der spanenden Bearbeitung immer wieder zu großen Standwegunterschieden identischer Werkzeuge bei vordergründig identischen Bearbeitungsrandbedingungen. Insbesondere bei Fertigungsschritten, die das Bohren als Vorbearbeitung erfordern, kommt es gelegentlich zu atypischen Verschleißerscheinungen, die auf das Entstehen einer Neuhärtezone an der Werkstückoberfläche beim Bohren zurückgeführt werden. Grundsätzlich sind Randzonenveränderungen eine Folge der mechanischen un...

Multiple regeneration from axolotl limb stumps bearing cross-transplanted minced muscle regenerates : brief note

NARCIS (Netherlands)

Carlson, Bruce M.

Flexor and extensor muscles in the upper arms of axolotls were minced and cross-transplanted. The limbs were amputated 5 and 30 days after mincing. In each experiment a high percentage of the regenerates consisted of multiple limbs. This demonstrates that the morphogenetic information which produces

Comparative Analysis of Cartilage Marker Gene Expression Patterns during Axolotl and Xenopus Limb Regeneration.

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Kazumasa Mitogawa

Full Text Available Axolotls (Ambystoma mexicanum can completely regenerate lost limbs, whereas Xenopus laevis frogs cannot. During limb regeneration, a blastema is first formed at the amputation plane. It is thought that this regeneration blastema forms a limb by mechanisms similar to those of a developing embryonic limb bud. Furthermore, Xenopus laevis frogs can form a blastema after amputation; however, the blastema results in a terminal cone-shaped cartilaginous structure called a "spike." The causes of this patterning defect in Xenopus frog limb regeneration were explored. We hypothesized that differences in chondrogenesis may underlie the patterning defect. Thus, we focused on chondrogenesis. Chondrogenesis marker genes, type I and type II collagen, were compared in regenerative and nonregenerative environments. There were marked differences between axolotls and Xenopus in the expression pattern of these chondrogenesis-associated genes. The relative deficit in the chondrogenic capacity of Xenopus blastema cells may account for the absence of total limb regenerative capacity.

Comparison of tissue processing methods for microvascular visualization in axolotls.

Science.gov (United States)

Montoro, Rodrigo; Dickie, Renee

2017-01-01

The vascular system, the pipeline for oxygen and nutrient delivery to tissues, is essential for vertebrate development, growth, injury repair, and regeneration. With their capacity to regenerate entire appendages throughout their lifespan, axolotls are an unparalleled model for vertebrate regeneration, but they lack many of the molecular tools that facilitate vascular imaging in other animal models. The determination of vascular metrics requires high quality image data for the discrimination of vessels from background tissue. Quantification of the vasculature using perfused, cleared specimens is well-established in mammalian systems, but has not been widely employed in amphibians. The objective of this study was to optimize tissue preparation methods for the visualization of the microvascular network in axolotls, providing a basis for the quantification of regenerative angiogenesis. To accomplish this aim, we performed intracardiac perfusion of pigment-based contrast agents and evaluated aqueous and non-aqueous clearing techniques. The methods were verified by comparing the quality of the vascular images and the observable vascular density across treatment groups. Simple and inexpensive, these tissue processing techniques will be of use in studies assessing vascular growth and remodeling within the context of regeneration. Advantages of this method include: •Higher contrast of the vasculature within the 3D context of the surrounding tissue •Enhanced detection of microvasculature facilitating vascular quantification •Compatibility with other labeling techniques.

Using Ambystoma mexicanum (Mexican axolotl) embryos, chemical genetics, and microarray analysis to identify signaling pathways associated with tissue regeneration.

Science.gov (United States)

Ponomareva, Larissa V; Athippozhy, Antony; Thorson, Jon S; Voss, S Randal

2015-12-01

Amphibian vertebrates are important models in regenerative biology because they present exceptional regenerative capabilities throughout life. However, it takes considerable effort to rear amphibians to juvenile and adult stages for regeneration studies, and the relatively large sizes that frogs and salamanders achieve during development make them difficult to use in chemical screens. Here, we introduce a new tail regeneration model using late stage Mexican axolotl embryos. We show that axolotl embryos completely regenerate amputated tails in 7days before they exhaust their yolk supply and begin to feed. Further, we show that axolotl embryos can be efficiently reared in microtiter plates to achieve moderate throughput screening of soluble chemicals to investigate toxicity and identify molecules that alter regenerative outcome. As proof of principle, we identified integration 1 / wingless (Wnt), transforming growth factor beta (Tgf-β), and fibroblast growth factor (Fgf) pathway antagonists that completely block tail regeneration and additional chemicals that significantly affected tail outgrowth. Furthermore, we used microarray analysis to show that inhibition of Wnt signaling broadly affects transcription of genes associated with Wnt, Fgf, Tgf-β, epidermal growth factor (Egf), Notch, nerve growth factor (Ngf), homeotic gene (Hox), rat sarcoma/mitogen-activated protein kinase (Ras/Mapk), myelocytomatosis viral oncogene (Myc), tumor protein 53 (p53), and retinoic acid (RA) pathways. Punctuated changes in the expression of genes known to regulate vertebrate development were observed; this suggests the tail regeneration transcriptional program is hierarchically structured and temporally ordered. Our study establishes the axolotl as a chemical screening model to investigate signaling pathways associated with tissue regeneration. Copyright © 2015 Elsevier Inc. All rights reserved.

Abdominal Distension Associated with Luminal Fungi in the Intestines of Axolotl Larvae

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Chiara Zullian

2015-01-01

Full Text Available Axolotls show a remarkable regeneration capacity compared with higher vertebrates, regenerating missing appendages such as limbs and tail as well as other body parts (i.e., apex of the heart, forebrain, and jaw after amputations which makes this animal a very interesting research model for tissue regeneration mechanisms. Larvae are individually housed in a 20% Holtfreter’s solution within clear plastic containers. The photoperiod light : darkness cycle is 12 : 12 h. Larvae with a total body length of less than 5 cm are fed once a day with large brine shrimp and blood worm. Albino larvae appeared to have a tendency to exhibit abdominal distention. No clinical signs of illness seemed to be associated with the condition; however, these animals exhibit a relatively slower growth rate. To better characterize this condition, we performed histological sectioning for cross sectional slide preparation on wild type and albino axolotl larvae following euthanasia. The only lesion seen in the albino larvae was a thickened gut wall and the presence of fungi within the intestines. We hypothesize that this may be due to a lower efficacy of the albino larvae’s immune system.

Germline Transgenic Methods for Tracking Cells and Testing Gene Function during Regeneration in the Axolotl

Science.gov (United States)

Khattak, Shahryar; Schuez, Maritta; Richter, Tobias; Knapp, Dunja; Haigo, Saori L.; Sandoval-Guzmán, Tatiana; Hradlikova, Kristyna; Duemmler, Annett; Kerney, Ryan; Tanaka, Elly M.

2013-01-01

The salamander is the only tetrapod that regenerates complex body structures throughout life. Deciphering the underlying molecular processes of regeneration is fundamental for regenerative medicine and developmental biology, but the model organism had limited tools for molecular analysis. We describe a comprehensive set of germline transgenic strains in the laboratory-bred salamander Ambystoma mexicanum (axolotl) that open up the cellular and molecular genetic dissection of regeneration. We demonstrate tissue-dependent control of gene expression in nerve, Schwann cells, oligodendrocytes, muscle, epidermis, and cartilage. Furthermore, we demonstrate the use of tamoxifen-induced Cre/loxP-mediated recombination to indelibly mark different cell types. Finally, we inducibly overexpress the cell-cycle inhibitor p16INK4a, which negatively regulates spinal cord regeneration. These tissue-specific germline axolotl lines and tightly inducible Cre drivers and LoxP reporter lines render this classical regeneration model molecularly accessible. PMID:24052945

Zu einigen entwicklungstendenzen beim ausdruck der gewissheits modalität

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Stojan Bračič

1981-12-01

Full Text Available Das verfolgte Ziel in diesem Artikel - einem für den Druck bear­ beiteten Kapitel aus der Magisterarbeit des Verfassers - ist es, möglichst viele Ausdrucksmittel zum Ausdruck der Gewissheits­ modälitat (im weiteren GMO zu finden und sie sys.tematisch zu behandeln. Ausserdem soll durch statistische Bearbeitung der im Korpus gefundenen Belege festgestellt werden, ob man in der Zeit­ spanne derletzten siebzig Jahre beim Ausdruck der GMO in der deutschen Sprache mit Entwicklungstendenzen /ET/ rechnen kann.

Live Imaging of Axolotl Digit Regeneration Reveals Spatiotemporal Choreography of Diverse Connective Tissue Progenitor Pools.

Science.gov (United States)

Currie, Joshua D; Kawaguchi, Akane; Traspas, Ricardo Moreno; Schuez, Maritta; Chara, Osvaldo; Tanaka, Elly M

2016-11-21

Connective tissues-skeleton, dermis, pericytes, fascia-are a key cell source for regenerating the patterned skeleton during axolotl appendage regeneration. This complexity has made it difficult to identify the cells that regenerate skeletal tissue. Inability to identify these cells has impeded a mechanistic understanding of blastema formation. By tracing cells during digit tip regeneration using brainbow transgenic axolotls, we show that cells from each connective tissue compartment have distinct spatial and temporal profiles of proliferation, migration, and differentiation. Chondrocytes proliferate but do not migrate into the regenerate. In contrast, pericytes proliferate, then migrate into the blastema and give rise solely to pericytes. Periskeletal cells and fibroblasts contribute the bulk of digit blastema cells and acquire diverse fates according to successive waves of migration that choreograph their proximal-distal and tissue contributions. We further show that platelet-derived growth factor signaling is a potent inducer of fibroblast migration, which is required to form the blastema. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Molecular cloning, sequence analysis and homology modeling of the first caudata amphibian antifreeze-like protein in axolotl (Ambystoma mexicanum).

Science.gov (United States)

Zhang, Songyan; Gao, Jiuxiang; Lu, Yiling; Cai, Shasha; Qiao, Xue; Wang, Yipeng; Yu, Haining

2013-08-01

Antifreeze proteins (AFPs) refer to a class of polypeptides that are produced by certain vertebrates, plants, fungi, and bacteria and which permit their survival in subzero environments. In this study, we report the molecular cloning, sequence analysis and three-dimensional structure of the axolotl antifreeze-like protein (AFLP) by homology modeling of the first caudate amphibian AFLP. We constructed a full-length spleen cDNA library of axolotl (Ambystoma mexicanum). An EST having highest similarity (∼42%) with freeze-responsive liver protein Li16 from Rana sylvatica was identified, and the full-length cDNA was subsequently obtained by RACE-PCR. The axolotl antifreeze-like protein sequence represents an open reading frame for a putative signal peptide and the mature protein composed of 93 amino acids. The calculated molecular mass and the theoretical isoelectric point (pl) of this mature protein were 10128.6 Da and 8.97, respectively. The molecular characterization of this gene and its deduced protein were further performed by detailed bioinformatics analysis. The three-dimensional structure of current AFLP was predicted by homology modeling, and the conserved residues required for functionality were identified. The homology model constructed could be of use for effective drug design. This is the first report of an antifreeze-like protein identified from a caudate amphibian.

On the participation of irradiated tissues in the formation of limb regenerate in axolotls

International Nuclear Information System (INIS)

Tuchkova, S.Ya.

1976-01-01

The aim of the study was to obtain further information on the participation of irradiated tissue cells in formation of regenerated limbs after X-irradiation of axolotls and experimental restoration of the regenerational ability. Cells of irradiated tissues were labeled with H 3 -thymidine; the presence of the label in regenerated tissues would be indicative of participation of irradiated cells in the regeneration process. Irradiation dose was 700 R. 30 axolotls with irradiated limbs were intramuscularly injected with rat muscle homogenate into the right limb once a day beginning from the day of treatment. 15 similarly irradiated animals which did not receive homogenate served as a control. The authors concluded that the presence of highly labeled cells in regenerated tissues was likely to indicate the participation of irradiated tissue cells in regeneration of the limb. However, the quantitative contribution of such cells was impossible to determine since remaining irradiated tissues of the organ contained mostly unlabeled cells. It was also impossible to rule out the possibility of cell migration from non-irradiated tissues [ru

Evidence for an RNA polymerization activity in axolotl and Xenopus egg extracts.

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Hélène Pelczar

2010-12-01

Full Text Available We have previously reported a post-transcriptional RNA amplification observed in vivo following injection of in vitro synthesized transcripts into axolotl oocytes, unfertilized (UFE or fertilized eggs. To further characterize this phenomenon, low speed extracts (LSE from axolotl and Xenopus UFE were prepared and tested in an RNA polymerization assay. The major conclusions are: i the amphibian extracts catalyze the incorporation of radioactive ribonucleotide in RNase but not DNase sensitive products showing that these products correspond to RNA; ii the phenomenon is resistant to α-amanitin, an inhibitor of RNA polymerases II and III and to cordycepin (3'dAMP, but sensitive to cordycepin 5'-triphosphate, an RNA elongation inhibitor, which supports the existence of an RNA polymerase activity different from polymerases II and III; the detection of radiolabelled RNA comigrating at the same length as the exogenous transcript added to the extracts allowed us to show that iii the RNA polymerization is not a 3' end labelling and that iv the radiolabelled RNA is single rather than double stranded. In vitro cell-free systems derived from amphibian UFE therefore validate our previous in vivo results hypothesizing the existence of an evolutionary conserved enzymatic activity with the properties of an RNA dependent RNA polymerase (RdRp.

De novo transcriptome sequencing of axolotl blastema for identification of differentially expressed genes during limb regeneration

Science.gov (United States)

2013-01-01

Background Salamanders are unique among vertebrates in their ability to completely regenerate amputated limbs through the mediation of blastema cells located at the stump ends. This regeneration is nerve-dependent because blastema formation and regeneration does not occur after limb denervation. To obtain the genomic information of blastema tissues, de novo transcriptomes from both blastema tissues and denervated stump ends of Ambystoma mexicanum (axolotls) 14 days post-amputation were sequenced and compared using Solexa DNA sequencing. Results The sequencing done for this study produced 40,688,892 reads that were assembled into 307,345 transcribed sequences. The N50 of transcribed sequence length was 562 bases. A similarity search with known proteins identified 39,200 different genes to be expressed during limb regeneration with a cut-off E-value exceeding 10-5. We annotated assembled sequences by using gene descriptions, gene ontology, and clusters of orthologous group terms. Targeted searches using these annotations showed that the majority of the genes were in the categories of essential metabolic pathways, transcription factors and conserved signaling pathways, and novel candidate genes for regenerative processes. We discovered and confirmed numerous sequences of the candidate genes by using quantitative polymerase chain reaction and in situ hybridization. Conclusion The results of this study demonstrate that de novo transcriptome sequencing allows gene expression analysis in a species lacking genome information and provides the most comprehensive mRNA sequence resources for axolotls. The characterization of the axolotl transcriptome can help elucidate the molecular mechanisms underlying blastema formation during limb regeneration. PMID:23815514

Excretory nitrogen metabolism in the juvenile axolotl Ambystoma mexicanum: differences in aquatic and terrestrial environments.

Science.gov (United States)

Loong, Ai M; Chew, Shit F; Ip, Yuen K

2002-01-01

The fully grown but nonmetamorphosed (juvenile) axolotl Ambystoma mexicanum was ureogenic and primarily ureotelic in water. A complete ornithine-urea cycle (OUC) was present in the liver. Aerial exposure impeded urea (but not ammonia) excretion, leading to a decrease in the percentage of nitrogen excreted as urea in the first 24 h. However, urea and not ammonia accumulated in the muscle, liver, and plasma during aerial exposure. By 48 h, the rate of urea excretion recovered fully, probably due to the greater urea concentration gradient in the kidney. It is generally accepted that an increase in carbamoyl phosphate synthetase activity is especially critical in the developmental transition from ammonotelism to ureotelism in the amphibian. Results from this study indicate that such a transition in A. mexicanum would have occurred before migration to land. Aerial exposure for 72 h exhibited no significant effect on carbamoyl phosphate synthetase-I activity or that of other OUC enzymes (with the exception of ornithine transcarbamoylase) from the liver of the juvenile A. mexicanum. This supports our hypothesis that the capacities of OUC enzymes present in the liver of the aquatic juvenile axolotl were adequate to prepare it for its invasion of the terrestrial environment. The high OUC capacity was further supported by the capability of the juvenile A. mexicanum to survive in 10 mM NH(4)Cl without accumulating amino acids in its body. The majority of the accumulating endogenous and exogenous ammonia was detoxified to urea, which led to a greater than twofold increase in urea levels in the muscle, liver, and plasma and a significant increase in urea excretion by hour 96. Hence, it can be concluded that the juvenile axolotl acquired ureotelism while submerged in water, and its hepatic capacity of urea synthesis was more than adequate to handle the toxicity of endogenous ammonia during migration to land.

Cutaneous mastocytomas in the neotenic caudate amphibians Ambystoma mexicanum (axolotl) and Ambystoma tigrinun (tiger salamander)

Science.gov (United States)

Harshbarger, J.C.; Chang, S.C.; DeLanney, L.E.; Rose, F.L.; Green, D.E.

1999-01-01

Spontaneous mastocytomas studied in 18 axolotls (Ambystoma mexicanum) and six tiger salamanders (Ambystoma tigrinum) were gray-white, uni- to multilobular cutaneous protrusions from 2mm to 2cm in diameter. Tumors were moderately cellular unencapsulated masses that usually infiltrated the dermis and hypodermis with the destruction of intervening tissues. Some tumors were invading superficial bundles of the underlying skeletal muscle. Tumors consisted of mitotically active cells derived from a single lineage but showing a range of differentiation. Immature cells had nearly smooth to lightly cleft or folded basophilic nuclei bordered by a band of cytoplasm with few cytoplasmic processes and containing a few small uniform eccentric granules. Mature cells had basophilic nuclei with deep clefts or folds and abundant eosinophilic cytoplasm with multiple long intertwining cytoplasmic extensions packed with metachromatic granules. The axolotls were old individuals from an inbred laboratory colony. The tiger salamanders were wild animals from a single polluted pond. They could have been old and inbred. Both groups were neotenic. These are the first mastocytomas discovered in cold-blooded animals.

Probability of Regenerating a Normal Limb After Bite Injury in the Mexican Axolotl (Ambystoma mexicanum).

Science.gov (United States)

Thompson, Sierra; Muzinic, Laura; Muzinic, Christopher; Niemiller, Matthew L; Voss, S Randal

2014-06-01

Multiple factors are thought to cause limb abnormalities in amphibian populations by altering processes of limb development and regeneration. We examined adult and juvenile axolotls ( Ambystoma mexicanum ) in the Ambystoma Genetic Stock Center (AGSC) for limb and digit abnormalities to investigate the probability of normal regeneration after bite injury. We observed that 80% of larval salamanders show evidence of bite injury at the time of transition from group housing to solitary housing. Among 717 adult axolotls that were surveyed, which included solitary-housed males and group-housed females, approximately half presented abnormalities, including examples of extra or missing digits and limbs, fused digits, and digits growing from atypical anatomical positions. Bite injury likely explains these limb defects, and not abnormal development, because limbs with normal anatomy regenerated after performing rostral amputations. We infer that only 43% of AGSC larvae will present four anatomically normal looking adult limbs after incurring a bite injury. Our results show regeneration of normal limb anatomy to be less than perfect after bite injury.

Effect of thyroid hormone concentration on the transcriptional response underlying induced metamorphosis in the Mexican axolotl (Ambystoma).

Science.gov (United States)

Page, Robert B; Voss, Stephen R; Samuels, Amy K; Smith, Jeramiah J; Putta, Srikrishna; Beachy, Christopher K

2008-02-11

Thyroid hormones (TH) induce gene expression programs that orchestrate amphibian metamorphosis. In contrast to anurans, many salamanders do not undergo metamorphosis in nature. However, they can be induced to undergo metamorphosis via exposure to thyroxine (T4). We induced metamorphosis in juvenile Mexican axolotls (Ambystoma mexicanum) using 5 and 50 nM T4, collected epidermal tissue from the head at four time points (Days 0, 2, 12, 28), and used microarray analysis to quantify mRNA abundances. Individuals reared in the higher T4 concentration initiated morphological and transcriptional changes earlier and completed metamorphosis by Day 28. In contrast, initiation of metamorphosis was delayed in the lower T4 concentration and none of the individuals completed metamorphosis by Day 28. We identified 402 genes that were statistically differentially expressed by > or = two-fold between T4 treatments at one or more non-Day 0 sampling times. To complement this analysis, we used linear and quadratic regression to identify 542 and 709 genes that were differentially expressed by > or = two-fold in the 5 and 50 nM T4 treatments, respectively. We found that T4 concentration affected the timing of gene expression and the shape of temporal gene expression profiles. However, essentially all of the identified genes were similarly affected by 5 and 50 nM T4. We discuss genes and biological processes that appear to be common to salamander and anuran metamorphosis, and also highlight clear transcriptional differences. Our results show that gene expression in axolotls is diverse and precise, and that axolotls provide new insights about amphibian metamorphosis.

MRI tracking of SPIO labelled stem cells in a true regenerative environment, the regenerating limb of the axolotl

DEFF Research Database (Denmark)

Lauridsen, Henrik; Foldager, Casper Bindzus; Hagensen, Mette

are generally restricted by their limited regenerative potential. Conversely, excellent animal models for regenerative studies exist in lower vertebrates such as the urodele amphibians (salamanders and newts), exemplified in the iconic Mexican axolotl (Ambystoma mexicanum) capable of regenerating whole limbs...

Axolotl hemoglobin: cDNA-derived amino acid sequences of two alpha globins and a beta globin from an adult Ambystoma mexicanum.

Science.gov (United States)

Shishikura, Fumio; Takeuchi, Hiro-aki; Nagai, Takatoshi

2005-11-01

Erythrocytes of the adult axolotl, Ambystoma mexicanum, have multiple hemoglobins. We separated and purified two kinds of hemoglobin, termed major hemoglobin (Hb M) and minor hemoglobin (Hb m), from a five-year-old male by hydrophobic interaction column chromatography on Alkyl Superose. The hemoglobins have two distinct alpha type globin polypeptides (alphaM and alpham) and a common beta globin polypeptide, all of which were purified in FPLC on a reversed-phase column after S-pyridylethylation. The complete amino acid sequences of the three globin chains were determined separately using nucleotide sequencing with the assistance of protein sequencing. The mature globin molecules were composed of 141 amino acid residues for alphaM globin, 143 for alpham globin and 146 for beta globin. Comparing primary structures of the five kinds of axolotl globins, including two previously established alpha type globins from the same species, with other known globins of amphibians and representatives of other vertebrates, we constructed phylogenetic trees for amphibian hemoglobins and tetrapod hemoglobins. The molecular trees indicated that alphaM, alpham, beta and the previously known alpha major globin were adult types of globins and the other known alpha globin was a larval type. The existence of two to four more globins in the axolotl erythrocyte is predicted.

Hopp, hopp, hopp im Schweinsgalopp? Klauen- und Gliedmaßengesundheit beim Schwein

OpenAIRE

Leeb, Christine; Bernardi, Florian; Winckler, Christoph

2009-01-01

Immer wieder kommen aus der Praxis Anfragen, über Lahmheitbeim Schwein zu berichten, auch ein Klauenpflegekurs wurde bereits durchgeführt, um akute Probleme lösen zu können. Doch was sind die Ursachen für Lahmheiten beim Schwein? Dieser Beitrag soll nicht nur die klinischen Symptome aufzählen und rasche Lösungen vermitteln (die es selten gibt), sondern Fragen stellen und zum selbst Beobachten und Nachdenken anregen. Dazu wird vom Wildschwein ausgehend das Normalverhalten betrac...

Untersuchungen ausgewählter Nierenkrankheiten beim Frettchen (Mustela putorius f. furo L. 1758)

OpenAIRE

Riechert, Maren

2005-01-01

Um Häufigkeit, Bedeutung und diätetische Ursachen veränderter Nieren beim Frettchen zu erarbeiten, wurden die Nieren von 63 Heimtieren und 120 Labortieren sonographisch untersucht und Fütterungsanalysen durchgeführt. Anatomische Studien an gesunden Nieren wurden für den Vergleich mit den veränderten Nieren angefertigt. Die Untersuchungen zur Anatomie ergaben für das Frettchen Nieren vom einfachen glatten und einwarzigen Typ. Des Weiteren konnten mithilfe von anatomischen ...

Effect of thyroid hormone concentration on the transcriptional response underlying induced metamorphosis in the Mexican axolotl (Ambystoma

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Samuels Amy K

2008-02-01

Full Text Available Abstract Background Thyroid hormones (TH induce gene expression programs that orchestrate amphibian metamorphosis. In contrast to anurans, many salamanders do not undergo metamorphosis in nature. However, they can be induced to undergo metamorphosis via exposure to thyroxine (T4. We induced metamorphosis in juvenile Mexican axolotls (Ambystoma mexicanum using 5 and 50 nM T4, collected epidermal tissue from the head at four time points (Days 0, 2, 12, 28, and used microarray analysis to quantify mRNA abundances. Results Individuals reared in the higher T4 concentration initiated morphological and transcriptional changes earlier and completed metamorphosis by Day 28. In contrast, initiation of metamorphosis was delayed in the lower T4 concentration and none of the individuals completed metamorphosis by Day 28. We identified 402 genes that were statistically differentially expressed by ≥ two-fold between T4 treatments at one or more non-Day 0 sampling times. To complement this analysis, we used linear and quadratic regression to identify 542 and 709 genes that were differentially expressed by ≥ two-fold in the 5 and 50 nM T4 treatments, respectively. Conclusion We found that T4 concentration affected the timing of gene expression and the shape of temporal gene expression profiles. However, essentially all of the identified genes were similarly affected by 5 and 50 nM T4. We discuss genes and biological processes that appear to be common to salamander and anuran metamorphosis, and also highlight clear transcriptional differences. Our results show that gene expression in axolotls is diverse and precise, and that axolotls provide new insights about amphibian metamorphosis.

Activation of germline-specific genes is required for limb regeneration in the Mexican axolotl

OpenAIRE

Zhu, Wei; Pao, Gerald M; Satoh, Akira; Cummings, Gillian; Monaghan, James R; Harkins, Timothy T; Bryant, Susan V; Voss, S Randal; Gardiner, David M; Hunter, Tony

2012-01-01

The capacity for tissue and organ regeneration in humans is dwarfed by comparison to that of salamanders. Emerging evidence suggests that mechanisms learned from the early phase of salamander limb regeneration-wound healing, cellular dedifferentiation and blastemal formation-will reveal therapeutic approaches for tissue regeneration in humans. Here we describe a unique transcriptional fingerprint of regenerating limb tissue in the Mexican axolotl (Ambystoma mexicanum) that is indicative of ce...

Axolotl/Bichos Raros Crónica

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Susana Chávez-Silverman

2012-11-01

Full Text Available In this crónica, I pay homage (and talk back to! one of my favourite authors, Julio Cortázar, who I had the great privilege and pleasure of befriending in 1980, when he was a visiting professor at UC-Berkeley. I have been obsessed with time-travel, doubling, and interstitiality since I was very young; even the most casual Cortázar reader (if such a thing is possible will immediately recognise these as recurrent themes in his work. Here, faced with several actual axolotl in a Buenos Aires aquarium, I explore and comment on Cortázar’s strangely mesmerising meditation on identity and transformation. My personal connection is (as in much of my writing concerned with aspects of gender and sexuality suppressed or (more likely ignored in Cortázar’s version. I identify, too, with a poignant in-betweenness and ambiguity I read in the figure of the axolotl—and in the work of Cortázar and Alejandra Pizarnik.

The effects of rotation and positional change of stump tissues upon morphogenesis of the regenerating axolotl limb

NARCIS (Netherlands)

Carlson, Bruce M.

1972-01-01

Rotation of a skin cuff 180° around the proximodistal axis of the upper arm in the axolotl results in the formation of multiple regenerates in about 80° of cases after amputation of the limb through the rotated skin. Rotation of the dermis or the flexor and extensor muscles folowed by amputation

Induction of Metamorphosis Causes Differences in Sex-Specific Allocation Patterns in Axolotls (Ambystoma mexicanum) that Have Different Growth Histories.

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Clarkson, Pamela M; Beachy, Christopher K

2015-12-01

We tested the hypothesis that salamanders growing at different rates would have allocation patterns that differ among male and female metamorphic and larval salamanders. We raised individual axolotls, Ambystoma mexicanum , on four food regimes: constant high growth (throughout the experiment), constant low growth (restricted throughout the experiment), high growth switched to low growth (ad libitum switched after 140 d to restricted), and low growth switched to high growth (restricted switched after 140 d to ad libitum). Because axolotls are obligate paedomorphs, we exposed half of the salamanders to thyroid hormone to induce metamorphosis. We assayed growth and dissected and weighed gonads and fat bodies. Salamanders that were switched from restricted to ad libitum food regime delayed metamorphosis. In all treatment groups, females had larger gonads than males and males had larger fat bodies than females. The association between storage and reproduction differed between larvae and metamorphs and depended on sex.

Handlungsmuster von Lehrerinnen und Lehrern beim Einsatz neuer Medien. Grundlagen eines Projekts zur empirischen Unterrichtsforschung

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Sigrid Blömeke

2017-08-01

Full Text Available Ziel des vorzustellenden Projekts ist es in einem ersten Schritt, Handlungsmuster von Lehrpersonen beim Einsatz von neuen Medien im Unterricht der Fächer Deutsch, Mathematik und Informatik der Sekundarstufe II zu identifizieren. Zu diesem Zweck werden Videoaufnahmen von 30 Unterrichtsstunden im Hinblick auf zugrunde liegende ‚Unterrichtsscripts’ (i.e. didaktische Routinen analysiert und die subjektiven Theorien der Lehrkräfte zum Lehren und Lernen erhoben. Bei der Zusammensetzung der Stichprobe findet neben der Variation der Fachzugehörigkeit der Expertisegrad der Lehrpersonen bezogen auf den Einsatz neuer Medien Berücksichtigung, und zwar in zwei Abstufungen (hoch – niedrig. Auf diese Weise wird ermöglicht, in einem zweiten Schritt begründet Hypothesen zu Zusammenhängen zwischen Handlungsmustern sowie Fach und Expertise als Kontextfaktoren zu generieren und mögliche Geltungsbereiche zu beschreiben. Über diese Grundlagenforschung hinausgehend sollen in einem dritten Schritt anhand der gewonnenen Erkenntnisse Interventionen entwickelt werden, die eine Weiterentwicklung von Lehrerhandeln beim Einsatz neuer Medien im Unterricht ermöglichen. Hier stellt sich allerdings die Frage, wie sich Handeln grundsätzlich verändern lässt.

Functional characterization of the vertebrate primary ureter: Structure and ion transport mechanisms of the pronephric duct in axolotl larvae (Amphibia)

DEFF Research Database (Denmark)

Haugan, Birgitte M; Halberg, Kenneth Agerlin; Jespersen, Åse

2010-01-01

whether the duct is involved in urine modification using larvae of the freshwater amphibian Ambystoma mexicanum (axolotl) as model. Results We investigated structural as well as physiological properties of the pronephric duct. The key elements of our methodology were: using histology, light...

Zum Erleben von Thrills und anderen starken emotionalen Reaktionen beim Musikhören

OpenAIRE

Schönberger, Jörg

2003-01-01

Obwohl unbestritten ist, dass Musik in der Lage ist, starke emotionale Reaktionen auszulösen, hat sich die Musikpsychologie wenig mit den Emotionen beschäftigt, die Menschen beim Musikhören erleben. Zwei mögliche Zugänge zum Erfassen solch starker emotionaler Reaktionen sind die Ansätze von John A. Sloboda und Alf Gabrielsson. Sloboda nutzt für seinen Ansatz das Phänomen der "Thrills" — physiologische Begleiterscheinungen starker emotionaler Reaktionen wie z.B. Gänsehaut, Schauer, die ü...

Pathological changes of Golgi complex in hemocytoblasts of spleen of young axolotls after x-irradiation

Energy Technology Data Exchange (ETDEWEB)

Turska, R.

1975-01-01

The data available up to now concerning the structure of Golgi complex in different types of normal and pathologically changed cells are very divergent. Results are reported from detailed studies on changes occurring within the Golgi complex in the spleen of three-month old axolotls after x-ray irradiation with a single dose of 1,200 R and killed by decapitation 15, 30, 60 minutes and 3, 6, and 12 hours after irradiation.

Resegmentation in the Mexican axolotl, Ambystoma mexicanum.

Science.gov (United States)

Piekarski, Nadine; Olsson, Lennart

2014-02-01

The segmental series of somites in the vertebrate embryo gives rise to the axial skeleton. In amniote models, single vertebrae are derived from the sclerotome of two adjacent somites. This process, known as resegmentation, is well-studied using the quail-chick chimeric system, but the presumed generality of resegmentation across vertebrates remains poorly evaluated. Resegmentation has been questioned in anamniotes, given that the sclerotome is much smaller and lacks obvious differentiation between cranial and caudal portions. Here, we provide the first experimental evidence that resegmentation does occur in a species of amphibian. Fate mapping of individual somites in the Mexican axolotl (Ambystoma mexicanum) revealed that individual vertebrae receive cells from two adjacent somites as in the chicken. These findings suggest that large size and segmentation of the sclerotome into distinct cranial and caudal portions are not requirements for resegmentation. Our results, in addition to those for zebrafish, indicate that resegmentation is a general process in building the vertebral column in vertebrates, although it may be achieved in different ways in different groups. Copyright © 2013 Wiley Periodicals, Inc.

Regulation of Regenerative Responses by Factors in the Extracellular Matrix during Axolotl (Ambystoma mexicanum) Limb Regeneration

OpenAIRE

Phan, Anne Quy

2014-01-01

Salamanders are unique among adult vertebrates in their ability to regenerate complex body structures after traumatic injury. Axolotl limb regeneration is a stepwise sequence of three requisite processes: (1) scarless wound healing to generate a regenerative wound epithelium, (2) blastema formation by migration, proliferation and dedifferentiation to create a mass of multipotent regeneration-competent progenitor cells, and (3) induction of pattern formation by interaction of cells with opposi...

Ultrastructure of the external gill epithelium of the axolotl, Ambystoma mexicanum with reference to ionic transport.

Science.gov (United States)

Jarial, M S; Wilkins, J H

2003-10-01

The ultrastructure of the external gill epithelium of the axolotl, Ambystoma mexicanum, has been examined using conventional transmission electron microscopy to elucidate its role in ionic transport. Four cell types are identified in the gill filament and primary gill bar epithelium. These are granular, ciliated, Leydig and basal cells. A fifth cell type, the flat mitochondria-rich cell is only found in the gill bar epithelium. The predominant granular cells display microvilli at their surface and their cytoplasm contains abundant mitochondria, rough endoplasmic reticulum, Golgi complexes, vesicles and PAS+ secretory granules that are extruded at the surface, which along with secretions from the Leydig cells form a mucous coat. The granular cells are joined apically by junctional complexes consisting of zonulae occludens, zonulae adherens and desmosomes. The lateral membranes of granular cells enclose large intercellular spaces that are closed at the apical ends but remain open at the basal ends adjoining capillaries. In AgNO3-treated axolotl, the gills become darkly stained, the silver grains penetrate apical membranes and appear in the cytoplasm, accumulating near the lateral membranes and also enter the intercellular spaces. These findings are consistent with the dual role of the gill epithelium in mucus production and active ionic transport.

Early regulation of axolotl limb regeneration.

Science.gov (United States)

Makanae, Aki; Satoh, Akira

2012-10-01

Amphibian limb regeneration has been studied for a long time. In amphibian limb regeneration, an undifferentiated blastema is formed around the region damaged by amputation. The induction process of blastema formation has remained largely unknown because it is difficult to study the induction of limb regeneration. The recently developed accessory limb model (ALM) allows the investigation of limb induction and reveals early events of amphibian limb regeneration. The interaction between nerves and wound epidermis/epithelium is an important aspect of limb regeneration. During early limb regeneration, neurotrophic factors act on wound epithelium, leading to development of a functional epidermis/epithelium called the apical epithelial cap (AEC). AEC and nerves create a specific environment that inhibits wound healing and induces regeneration through blastema formation. It is suggested that FGF-signaling and MMP activities participate in creating a regenerative environment. To understand why urodele amphibians can create such a regenerative environment and humans cannot, it is necessary to identify the similarities and differences between regenerative and nonregenerative animals. Here we focus on ALM to consider limb regeneration from a new perspective and we also reported that focal adhesion kinase (FAK)-Src signaling controlled fibroblasts migration in axolotl limb regeneration. Copyright © 2012 Wiley Periodicals, Inc.

Visualisation of axolotl blastema cells and pig endothelial progenitor cells using very small super paramagnetic iron oxide particles in MRI: A technique with applications for non invasive visualisation of regenerative processes

DEFF Research Database (Denmark)

Lauridsen, Henrik; Kjær, N.B.; Bek, Maria

oxide particles (VSOP) in animal cells enable non invasive cell tracking using magnetic resonance imaging (MRI) and can prove useful, when visualising regenerative processes. This study examines the possibility of labelling limited numbers of axolotl blastema cells (aBC) and pig endothelial progenitor...... implanted in live axolotl tail and dead porcine heart, respectively. Cellular iron uptake was determined using inductively coupled plasma optical emission spectrometry (ICP-OES). Results: T2*-weighted 2D gradient-echo sequences on samples of 10˄5 cells yielded at significant linear correlations between...

Low submetamorphic doses of dexamethasone and thyroxine induce complete metamorphosis in the axolotl (Ambystoma mexicanum) when injected together.

Science.gov (United States)

Kühn, Eduard R; De Groef, Bert; Grommen, Sylvia V H; Van der Geyten, Serge; Darras, Veerle M

2004-06-01

Entanglement of functions between the adrenal (or interrenal) and thyroid axis has been well described for all vertebrates and can be tracked down up to the level of gene expression. Both thyroid hormones and corticosteroids may induce morphological changes leading to metamorphosis climax in the neotenic Mexican axolotl (Ambystoma mexicanum). In a first series of experiments, metamorphosis was induced with an injection of 25 microg T(4) on three alternate days as judged by a decrease in body weight and tail height together with complete gill resorption. This injection also resulted in elevated plasma concentrations of T(3) and corticosterone. Previous results have indicated that the same dose of dexamethasone (DEX) is ineffective in this regard (Gen. Comp. Endocrinol. 127 (2002) 157). In a second series of experiments low doses of T(4) (0.5 microg) or DEX (5 microg) were ineffective to induce morphological changes. However, when these submetamorphic doses were injected together, morphological changes were observed within one week leading to complete metamorphosis. It is concluded that thyroid hormones combined with corticosteroids are essential for metamorphosis in the axolotl and that only high doses of either thyroid hormone or corticosteroid can induce morphological changes when injected separately.

[Specific growth rate and the rate of energy metabolism in the ontogenesis of axolotl, Ambystoma mexicanum (Amphibia: Ambystomatidae)].

Science.gov (United States)

Vladimirova, I G; Kleĭmenov, S Iu; Alekseeva, T A; Radzinskaia, L I

2003-01-01

Concordant changes in the rate of energy metabolism and specific growth rate of axolotls have been revealed. Several periods of ontogeny are distinguished, which differ in the ratio of energy metabolism to body weight and, therefore, are described by different allometric equations. It is suggested that the specific growth rate of an animal determines the type of dependence of energy metabolism on body weight.

Absence of mutation at the 5'-upstream promoter region of the TPM4 gene from cardiac mutant axolotl (Ambystoma mexicanum).

Science.gov (United States)

Denz, Christopher R; Zhang, Chi; Jia, Pingping; Du, Jianfeng; Huang, Xupei; Dube, Syamalima; Thomas, Anish; Poiesz, Bernard J; Dube, Dipak K

2011-09-01

Tropomyosins are a family of actin-binding proteins that show cell-specific diversity by a combination of multiple genes and alternative RNA splicing. Of the 4 different tropomyosin genes, TPM4 plays a pivotal role in myofibrillogenesis as well as cardiac contractility in amphibians. In this study, we amplified and sequenced the upstream regulatory region of the TPM4 gene from both normal and mutant axolotl hearts. To identify the cis-elements that are essential for the expression of the TPM4, we created various deletion mutants of the TPM4 promoter DNA, inserted the deleted segments into PGL3 vector, and performed promoter-reporter assay using luciferase as the reporter gene. Comparison of sequences of the promoter region of the TPM4 gene from normal and mutant axolotl revealed no mutations in the promoter sequence of the mutant TPM4 gene. CArG box elements that are generally involved in controlling the expression of several other muscle-specific gene promoters were not found in the upstream regulatory region of the TPM4 gene. In deletion experiments, loss of activity of the reporter gene was noted upon deletion which was then restored upon further deletion suggesting the presence of both positive and negative cis-elements in the upstream regulatory region of the TPM4 gene. We believe that this is the first axolotl promoter that has ever been cloned and studied with clear evidence that it functions in mammalian cell lines. Although striated muscle-specific cis-acting elements are absent from the promoter region of TPM4 gene, our results suggest the presence of positive and negative cis-elements in the promoter region, which in conjunction with positive and negative trans-elements may be involved in regulating the expression of TPM4 gene in a tissue-specific manner.

Pathological features of olfactory neuroblastoma in an axolotl (Ambystoma mexicanum).

Science.gov (United States)

Shioda, Chieko; Uchida, Kazuyuki; Nakayama, Hiroyuki

2011-08-01

A one-year-old, female Mexican axolotl (Ambystoma mexicanum) had a rough-surfaced, polypoid, pink tumor mass of approximately 10 mm in diameter in the oral cavity. Histologically, the tumor extended from the ethmoturbinate region and into the oral cavity and had replaced some of the maxillary bone tissue. The tumor mass was composed of a lobular architecture of small round-shaped tumor cells with occasional Flexner-Wintersteiner-like rosette formation. There were no metastatic lesions in the other organs. Immunohistochemically, the tumor cells were partly positive for several neural markers (class III beta-tubulin, S-100 protein, and doublecortin) and intensely positive for an epithelial marker (cytokeratin AE1/AE3). These results suggest that the present tumor originated from neuroectodermal tissue. Considering the location and histological and immunohistochemical features of the tumor, a diagnosis of olfactory neuroblastoma was made.

Lineage tracing of genome-edited alleles reveals high fidelity axolotl limb regeneration.

Science.gov (United States)

Flowers, Grant Parker; Sanor, Lucas D; Crews, Craig M

2017-09-16

Salamanders are unparalleled among tetrapods in their ability to regenerate many structures, including entire limbs, and the study of this ability may provide insights into human regenerative therapies. The complex structure of the limb poses challenges to the investigation of the cellular and molecular basis of its regeneration. Using CRISPR/Cas, we genetically labelled unique cell lineages within the developing axolotl embryo and tracked the frequency of each lineage within amputated and fully regenerated limbs. This allowed us, for the first time, to assess the contributions of multiple low frequency cell lineages to the regenerating limb at once. Our comparisons reveal that regenerated limbs are high fidelity replicas of the originals even after repeated amputations.

The axolotl limb blastema: cellular and molecular mechanisms driving blastema formation and limb regeneration in tetrapods

Science.gov (United States)

McCusker, Catherine; Bryant, Susan V.

2015-01-01

Abstract The axolotl is one of the few tetrapods that are capable of regenerating complicated biological structures, such as complete limbs, throughout adulthood. Upon injury the axolotl generates a population of regeneration‐competent limb progenitor cells known as the blastema, which will grow, establish pattern, and differentiate into the missing limb structures. In this review we focus on the crucial early events that occur during wound healing, the neural−epithelial interactions that drive the formation of the early blastema, and how these mechanisms differ from those of other species that have restricted regenerative potential, such as humans. We also discuss how the presence of cells from the different axes of the limb is required for the continued growth and establishment of pattern in the blastema as described in the polar coordinate model, and how this positional information is reprogrammed in blastema cells during regeneration. Multiple cell types from the mature limb stump contribute to the blastema at different stages of regeneration, and we discuss the contribution of these types to the regenerate with reference to whether they are “pattern‐forming” or “pattern‐following” cells. Lastly, we explain how an engineering approach will help resolve unanswered questions in limb regeneration, with the goal of translating these concepts to developing better human regenerative therapies. PMID:27499868

Metamorfosis: La animalidad y el mito en La Metamorfosis de Kafka y Axolotl de Cortázar

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Catalina Villalobos Díaz

2017-07-01

Full Text Available El presente artículo propone una lectura de la animalidad, principalmente de la metamorfosis, por medio de dos relatos de dos grandes escritores de la literatura: Axolotl, de Julio Cortázar, y La Metamorfosis, de Franz Kafka. A través de estos textos, se plantea un análisis con respecto a lo que representa una transformación y el mito tras la metamorfosis como tal.

Dual embryonic origin and patterning of the pharyngeal skeleton in the axolotl (Ambystoma mexicanum).

Science.gov (United States)

Sefton, Elizabeth M; Piekarski, Nadine; Hanken, James

2015-01-01

The impressive morphological diversification of vertebrates was achieved in part by innovation and modification of the pharyngeal skeleton. Extensive fate mapping in amniote models has revealed a primarily cranial neural crest derivation of the pharyngeal skeleton. Although comparable fate maps of amphibians produced over several decades have failed to document a neural crest derivation of ventromedial elements in these vertebrates, a recent report provides evidence of a mesodermal origin of one of these elements, basibranchial 2, in the axolotl. We used a transgenic labeling protocol and grafts of labeled cells between GFP+ and white embryos to derive a fate map that describes contributions of both cranial neural crest and mesoderm to the axolotl pharyngeal skeleton, and we conducted additional experiments that probe the mechanisms that underlie mesodermal patterning. Our fate map confirms a dual embryonic origin of the pharyngeal skeleton in urodeles, including derivation of basibranchial 2 from mesoderm closely associated with the second heart field. Additionally, heterotopic transplantation experiments reveal lineage restriction of mesodermal cells that contribute to pharyngeal cartilage. The mesoderm-derived component of the pharyngeal skeleton appears to be particularly sensitive to retinoic acid (RA): administration of exogenous RA leads to loss of the second basibranchial, but not the first. Neural crest was undoubtedly critical in the evolution of the vertebrate pharyngeal skeleton, but mesoderm may have played a central role in forming ventromedial elements, in particular. When and how many times during vertebrate phylogeny a mesodermal contribution to the pharyngeal skeleton evolved remain to be resolved. © 2015 Wiley Periodicals, Inc.

Collection of gametes from live axolotl, Ambystoma mexicanum, and standardization of in vitro fertilization.

Science.gov (United States)

Mansour, N; Lahnsteiner, F; Patzner, R A

2011-01-15

This study established the first protocol for collection of gametes from live axolotl, Ambystoma mexicanum, by gentle abdominal massage and in vitro fertilization. To stimulate spermiation and ovulation, human chorionic gonadotrophin (hCG) and Ovopel pellets, which are commercially used to stimulate spawning in fish, were tested. The hCG was more effective than Ovopel pellets and yielded a higher semen volume in the injected males and a shorter response time in the females. Collected semen by this method was already motile and fertile. Fertile eggs could be collected in 3-4 successive collection times after the female has started the typical spawning behaviour. The fertilization condition that yielded the highest hatching rate was mixing semen with eggs before the addition of a fertilization saline solution (20 mmol/l NaCl, 1 mmol/l KCl, 1 mmol/l Mg(2)SO(4), 1 mmol Ca(2)Cl, 3 mmol NaHCO(3), 10 mmol/l Tris, pH 8.5 - Osmolality = 65 mosmol/kg). When the pH of the fertilization solution was increased to ≥ 10, the hatching rate was significantly increased. The use of fertilization solutions with osmolalities of ≥ 150 and ≥ 182 were accompanied with a significant decrease in hatching rates and the appearance of deformed larvae, respectively. In conclusion, a reliable protocol for gamete collection from live axolotl is established as a laboratory model of in vitro fertilization for urodele amphibians. This protocol may be transferable to endangered urodeles. Copyright © 2011 Elsevier Inc. All rights reserved.

Proliferation zones in the axolotl brain and regeneration of the telencephalon

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Maden Malcolm

2013-01-01

Full Text Available Abstract Background Although the brains of lower vertebrates are known to exhibit somewhat limited regeneration after incisional or stab wounds, the Urodele brain exhibits extensive regeneration after massive tissue removal. Discovering whether and how neural progenitor cells that reside in the ventricular zones of Urodeles proliferate to mediate tissue repair in response to injury may produce novel leads for regenerative strategies. Here we show that endogenous neural progenitor cells resident to the ventricular zone of Urodeles spontaneously proliferate, producing progeny that migrate throughout the telencephalon before terminally differentiating into neurons. These progenitor cells appear to be responsible for telencephalon regeneration after tissue removal and their activity may be up-regulated by injury through an olfactory cue. Results There is extensive proliferation of endogenous neural progenitor cells throughout the ventricular zone of the adult axolotl brain. The highest levels are observed in the telencephalon, especially the dorsolateral aspect, and cerebellum. Lower levels are observed in the mesencephalon and rhombencephalon. New cells produced in the ventricular zone migrate laterally, dorsally and ventrally into the surrounding neuronal layer. After migrating from the ventricular zone, the new cells primarily express markers of neuronal differentiative fates. Large-scale telencephalic tissue removal stimulates progenitor cell proliferation in the ventricular zone of the damaged region, followed by proliferation in the tissue that surrounds the healing edges of the wound until the telencephalon has completed regeneration. The proliferative stimulus appears to reside in the olfactory system, because telencephalic regeneration does not occur in the brains of olfactory bulbectomized animals in which the damaged neural tissue simply heals over. Conclusion There is a continual generation of neuronal cells from neural progenitor cells

Role of thyroid hormones in the normal and glucocorticosteroid hormone-induced evolution of carbamoyl-phosphate synthase (ammonia) activity in axolotl liver

NARCIS (Netherlands)

Lamers, W. H.; Vink, C.; Charles, R.

1978-01-01

1. In axolotl liver, the activity of carbamoyl-phosphate synthase (ammonia), expressed per mg liver protein, decreases to a minimum at 5 months of age, then increases to a maximum at 8 months of age which is followed by a decrease again. The initial decrease between 3 and 5 months of age appears to

The Axolotl Fibula as a Model for the Induction of Regeneration across Large Segment Defects in Long Bones of the Extremities

Science.gov (United States)

Chen, Xiaoping; Song, Fengyu; Jhamb, Deepali; Li, Jiliang; Bottino, Marco C.; Palakal, Mathew J.; Stocum, David L.

2015-01-01

We tested the ability of the axolotl (Ambystoma mexicanum) fibula to regenerate across segment defects of different size in the absence of intervention or after implant of a unique 8-braid pig small intestine submucosa (SIS) scaffold, with or without incorporated growth factor combinations or tissue protein extract. Fractures and defects of 10% and 20% of the total limb length regenerated well without any intervention, but 40% and 50% defects failed to regenerate after either simple removal of bone or implanting SIS scaffold alone. By contrast, scaffold soaked in the growth factor combination BMP-4/HGF or in protein extract of intact limb tissue promoted partial or extensive induction of cartilage and bone across 50% segment defects in 30%-33% of cases. These results show that BMP-4/HGF and intact tissue protein extract can promote the events required to induce cartilage and bone formation across a segment defect larger than critical size and that the long bones of axolotl limbs are an inexpensive model to screen soluble factors and natural and synthetic scaffolds for their efficacy in stimulating this process. PMID:26098852

Neodadjuvante und adjuvante Kurzzeit-Hormontherapie in Kombination mit konformaler HDR-Brachytherapie beim Prostatakarzinom

Directory of Open Access Journals (Sweden)

Martin T

2004-01-01

Full Text Available Zielsetzung: Auswertung der Behandlungsergebnisse der neoadjuvanten und adjuvanten Kurzzeit-Hormontherapie kombiniert mit konformaler HDR-Brachytherapie und externer Radiotherapie beim Prostatakarzinom. Patienten und Methoden: Von 01/97 bis 09/99 behandelten wir 102 Patienten mit Prostatakarzinomen im Stadium T1–3 N0 M0. Im Stadium T1–2 befanden sich 71, im Stadium T3 31 Patienten. Der mediane prätherapeutische PSA-Wert betrug 15,3 ng/ml. Nach ultraschallgesteuerter transrektaler Implantation von vier Afterloadingnadeln erfolgte die CT-gestützte 3D-Brachytherapie- Planung. Alle Patienten erhielten vier HDR-Implantate mit einer Referenzdosis von 5 Gy oder 7 Gy pro Implantat. Die Zeit zwischen jedem Implantat betrug jeweils 14 Tage. Nach der Brachytherapie folgte die externe Radiotherapie bis 39,6 Gy oder 45,0 Gy. Alle Patienten erhielten eine neoadjuvante und adjuvante Kurzzeit-Hormontherapie, die 2–19 Monate vor der Brachytherapie eingeleitet und 3 Monate nach Abschluß der externen Radiotherapie abgesetzt wurde (mediane Dauer: 9 Monate. Ergebnisse: Die mediane Nachbeobachtungszeit war 2,6 Jahre (range: 2,0–4,1 Jahre. Die biochemische Kontrollrate betrug 82 % nach 3 Jahren. Bei 14/102 Patienten registrierten wir ein biochemisches Rezidiv, bei 5/102 Patienten ein klinisches Rezidiv. Das Gesamtüberleben betrug 90 %, das krankheitsspezifische Überleben 98,0 % nach 3 Jahren. Ein Patient entwickelte eine prostato-urethro-rektale Fistel als späte Grad 4-Toxizität. Akute Grad-3 Toxizitäten traten bei 4 %, späte Grad-3 Toxizitäten bei 5 % der Patienten auf. Schlußfolgerung: Die neoadjuvante und adjuvante Kurzzeit-Hormontherapie kombiniert mit konformaler HDR-Brachytherapie und externer Radiotherapie erweist sich als sichere und wirksame Behandlungsmodalität beim Prostatakarzinom mit minimalen behandlungsbedingten Toxizitäten und einer vielversprechenden biochemischen Kontrollrate nach medianer Nachbeobachtungszeit von 2,6 Jahren.

Untersuchungen zur Involution der Vagina and Zervix beim Rind post partum unter Berücksichtigung der Zervix als Geburtshindernis

OpenAIRE

Wehrend, Axel

2002-01-01

Ziel der vorliegenden Arbeit war es die physiologische Involution der Zervix im Vergleich zur Vagina beim Rind während der ersten zehn Tage post partum zu charakterisieren. Weiterhin sollte durch klinische Untersuchungen an Kühen nach Dystokie und einer retrospektiven Datenauswertung von Schwergeburten unterschiedlicher Tierarten der Anteil zervikal bedingter Geburtsstockungen im Interspeziesvergleich analysiert und Einflussfaktoren auf das Auftreten dieser Dystokieform sowie Störungen in der...

The Axolotl Fibula as a Model for the Induction of Regeneration across Large Segment Defects in Long Bones of the Extremities.

Directory of Open Access Journals (Sweden)

Xiaoping Chen

Full Text Available We tested the ability of the axolotl (Ambystoma mexicanum fibula to regenerate across segment defects of different size in the absence of intervention or after implant of a unique 8-braid pig small intestine submucosa (SIS scaffold, with or without incorporated growth factor combinations or tissue protein extract. Fractures and defects of 10% and 20% of the total limb length regenerated well without any intervention, but 40% and 50% defects failed to regenerate after either simple removal of bone or implanting SIS scaffold alone. By contrast, scaffold soaked in the growth factor combination BMP-4/HGF or in protein extract of intact limb tissue promoted partial or extensive induction of cartilage and bone across 50% segment defects in 30%-33% of cases. These results show that BMP-4/HGF and intact tissue protein extract can promote the events required to induce cartilage and bone formation across a segment defect larger than critical size and that the long bones of axolotl limbs are an inexpensive model to screen soluble factors and natural and synthetic scaffolds for their efficacy in stimulating this process.

CRISPR-Mediated Genomic Deletion of Sox2 in the Axolotl Shows a Requirement in Spinal Cord Neural Stem Cell Amplification during Tail Regeneration

Directory of Open Access Journals (Sweden)

Ji-Feng Fei

2014-09-01

Full Text Available The salamander is the only tetrapod that functionally regenerates all cell types of the limb and spinal cord (SC and thus represents an important regeneration model, but the lack of gene-knockout technology has limited molecular analysis. We compared transcriptional activator-like effector nucleases (TALENs and clustered regularly interspaced short palindromic repeats (CRISPRs in the knockout of three loci in the axolotl and find that CRISPRs show highly penetrant knockout with less toxic effects compared to TALENs. Deletion of Sox2 in up to 100% of cells yielded viable F0 larvae with normal SC organization and ependymoglial cell marker expression such as GFAP and ZO-1. However, upon tail amputation, neural stem cell proliferation was inhibited, resulting in spinal-cord-specific regeneration failure. In contrast, the mesodermal blastema formed normally. Sox3 expression during development, but not regeneration, most likely allowed embryonic survival and the regeneration-specific phenotype. This analysis represents the first tissue-specific regeneration phenotype from the genomic deletion of a gene in the axolotl.

Fine structure of the epidermal Leydig cells in the axolotl Ambystoma mexicanum in relation to their function.

Science.gov (United States)

Jarial, M S

1989-01-01

The fine structure of the Leydig cells in the epidermis of the strictly aquatic adult axolotl Ambystoma mexicanum resembles that of similar cells in larval salamanders. The major finding of this study is that the mucous secretion of the Leydig cells is released into the intercellular spaces from which it is discharged through pores onto the surface of the epidermis where it forms a mucous layer to protect the skin. Images Figs. 1-2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Figs. 11-13 PMID:2630544

Radiotherapeutic concepts in cancer of unknown primary site; Strahlentherapeutische Konzepte beim CUP-Syndrom

Energy Technology Data Exchange (ETDEWEB)

Krug, D.; Debus, J.; Sterzing, F. [Universitaetsklinikum Heidelberg, Klinik fuer Radioonkologie und Strahlentherapie, Heidelberg (Germany)

2014-02-15

The term cancer of unknown primary (CUP) encompasses a group of entities which differ to a great extent regarding etiology, prognosis and therapeutic management. The aim of the study was an elaboration of the role of radiotherapy in CUP syndrome. Systematic literature search and specification of the available treatment options. Radiotherapy is an integral part of interdisciplinary management approaches for patients with CUP in both curative and palliative situations. Radio-oncological techniques, such as intensity-modulated radiotherapy and stereotactic body radiotherapy increase the therapeutic window. Modern diagnostic modalities from radiology and nuclear medicine are the cornerstone of radiotherapeutic interventions, especially in terms of target volume definition and pretherapeutic staging. In the interdisciplinary setting radiation oncology offers the possibility of curative and often organ preserving approaches in patients with axillary and cervical CUP. In addition, improvement and preservation of quality of life can be achieved in patients with metastatic disease. Radiation oncology is a crucial component of the interdisciplinary management of patients with CUP. Therapeutic decisions in patients with CUP should be made in an interdisciplinary setting. (orig.) [German] Das Cancer-of-unknown-primary(CUP)-Syndrom fasst eine Gruppe von Erkrankungen zusammen, die durch eine ausgepraegte Heterogenitaet hinsichtlich Aetiologie, Therapie und Prognose gepraegt sind. Darstellung der Rolle der Strahlentherapie beim CUP-Syndrom. Systematische Literaturrecherche und Erlaeuterung der Behandlungsoptionen. Die Strahlentherapie ist beim CUP-Syndrom sowohl in adjuvanten und definitiven Therapiekonzepten wie auch in palliativer Intention etabliert. Technisch innovative Verfahren wie die intensitaetsmodulierte Radiotherapie und die stereotaktische Bestrahlung im Koerperstammbereich ermoeglichen eine Vergroesserung der therapeutischen Breite. Eine leistungsfaehige und moderne

Comparative pelvic development of the axolotl (Ambystoma mexicanum) and the Australian lungfish (Neoceratodus forsteri): conservation and innovation across the fish-tetrapod transition.

Science.gov (United States)

Boisvert, Catherine Anne; Joss, Jean Mp; Ahlberg, Per E

2013-01-23

The fish-tetrapod transition was one of the major events in vertebrate evolution and was enabled by many morphological changes. Although the transformation of paired fish fins into tetrapod limbs has been a major topic of study in recent years, both from paleontological and comparative developmental perspectives, the interest has focused almost exclusively on the distal part of the appendage and in particular the origin of digits. Relatively little attention has been paid to the transformation of the pelvic girdle from a small unipartite structure to a large tripartite weight-bearing structure, allowing tetrapods to rely mostly on their hindlimbs for locomotion. In order to understand how the ischium and the ilium evolved and how the acetabulum was reoriented during this transition, growth series of the Australian lungfish Neoceratodus forsteri and the Mexican axolotl Ambystoma mexicanum were cleared and stained for cartilage and bone and immunostained for skeletal muscles. In order to understand the myological developmental data, hypotheses about the homologies of pelvic muscles in adults of Latimeria, Neoceratodus and Necturus were formulated based on descriptions from the literature of the coelacanth (Latimeria), the Australian Lungfish (Neoceratodus) and a salamander (Necturus). In the axolotl and the lungfish, the chondrification of the pelvic girdle starts at the acetabula and progresses anteriorly in the lungfish and anteriorly and posteriorly in the salamander. The ilium develops by extending dorsally to meet and connect to the sacral rib in the axolotl. Homologous muscles develop in the same order with the hypaxial musculature developing first, followed by the deep, then the superficial pelvic musculature. Development of the pelvic endoskeleton and musculature is very similar in Neoceratodus and Ambystoma. If the acetabulum is seen as being a fixed landmark, the evolution of the ischium only required pubic pre-chondrogenic cells to migrate posteriorly. It

Feinkartierung von Loss of Heterozygosity-Intervallen auf Chromosom 11p und Untersuchungen zum Expressions- und Methylierungsstatus von FANCF beim Ovarialkarzinom

OpenAIRE

Schulze, Kathrin

2011-01-01

Um Tumorsuppressorgene beim Ovarialkarzinom zu identifizieren wurde eine Kartierung von LOH-Intervallen der Region 11p15.5 - 11p11.2 mittels 11 Mikrosatellitenmarkern an 47 Ovarialtumorproben vorgenommen. Im Bereich des ST5- und AFM255/KAI1-Locus konnten potentielle Intervalle abgegrenzt werden. Das Fanconi Anämie Gen FANCF wurde für Untersuchungen zum Expressions- und Methylierungsstatus ausgewählt, da dessen Abschaltung mit einem besseren Ansprechen auf Cisplatin bei Ovarialkarzinompatienti...

Clinical importance and significance of early evaluation of therapy response in lung cancer; Klinische Notwendigkeit und Bedeutung der Frueherfassung der Therapie-Response beim Bronchialkarzinom

Energy Technology Data Exchange (ETDEWEB)

Griesinger, F. [Universitaetsklinik Goettingen (Germany). Abt. Haematologie und Onkologie; Baum, R.P. [Zentralklinik Bad Berka (Germany). Klinik fuer Nuklearmedizin/PET-Zentrum

2001-04-01

In solid tumors, especially in non-small cell lung cancer (NSCLC), the TNM staging is the only well defined pretherapeutic risk factor. TNM-staging has a significant impact on prognosis and survival and is used to determine therapeutic stratification. Although numerous molecular and immunologic pretherapeutic risk factors have been described in NSCLC, none of them has been translated into therapeutic stratification. Therefore, the identification of posttherapeutic risk factors in NSCLC is essential. Locally advanced NSCLC are currently treated with preoperative (neoadjuvant) induction regimens. It has been shown that systemic tumor control and long-term disease free survival is correlated with histologic tumor regression. First results are presented in this paper that PET may be highly predictive for histologic tumor regression and long term outcome in NSCLC stage III. These results may establish PET as the first noninvasive posttherapeutic risk factor in locally advanced NSCLC. (orig.) [German] Bei soliden Tumoren, insbesondere beim nichtkleinzelligen Bronchialkarzinom (NSCLC), sind praetherapeutische Risikofaktoren im Westlichen durch das Tumorstadium (TNM-Klassifikation) definiert. Diese Tumorstadien haben eine erhebliche prognostische Relevanz und sind entscheidend fuer die Therapiestratifikation. Obwohl eine Reihe praetherapeutischer molekularer und immunologischer Risikofaktoren beim NSCLC beschrieben wurden, hat keiner von ihnen Eingang in die prospektive Risikostratifikation oder Therapieplanung gefunden. Daher ist die Identifikation posttherapeutischer Risikofaktoren zur Therapiestratifikation des NSCLC essenziell wichtig. Ein innovativer Therapieansatz bei lokal fortgeschrittenen NSCLC ist die neoadjuvante (praeoperative) Induktionstherapie. Hier konnte gezeigt werden, dass die systemische Tumorkontrolle und das Langzeitueberleben mit dem histologischen Ansprechen korrelierte. Erste Untersuchungen zeigen jetzt, dass die FDG-PET vermutlich einen hohen

Positional information in axolotl and mouse limb extracellular matrix is mediated via heparan sulfate and fibroblast growth factor during limb regeneration in the axolotl (Ambystoma mexicanum).

Science.gov (United States)

Phan, Anne Q; Lee, Jangwoo; Oei, Michelle; Flath, Craig; Hwe, Caitlyn; Mariano, Rachele; Vu, Tiffany; Shu, Cynthia; Dinh, Andrew; Simkin, Jennifer; Muneoka, Ken; Bryant, Susan V; Gardiner, David M

2015-08-01

Urodele amphibians are unique among adult vertebrates in their ability to regenerate complex body structures after traumatic injury. In salamander regeneration, the cells maintain a memory of their original position and use this positional information to recreate the missing pattern. We used an in vivo gain-of-function assay to determine whether components of the extracellular matrix (ECM) have positional information required to induce formation of new limb pattern during regeneration. We discovered that salamander limb ECM has a position-specific ability to either inhibit regeneration or induce de novo limb structure, and that this difference is dependent on heparan sulfates that are associated with differential expression of heparan sulfate sulfotransferases. We also discovered that an artificial ECM containing only heparan sulfate was sufficient to induce de novo limb pattern in salamander limb regeneration. Finally, ECM from mouse limbs is capable of inducing limb pattern in axolotl blastemas in a position-specific, developmental-stage-specific, and heparan sulfate-dependent manner. This study demonstrates a mechanism for positional information in regeneration and establishes a crucial functional link between salamander regeneration and mammals.

Corticotropin-releasing hormone-mediated metamorphosis in the neotenic axolotl Ambystoma mexicanum: synergistic involvement of thyroxine and corticoids on brain type II deiodinase.

Science.gov (United States)

Kühn, Eduard R; De Groef, Bert; Van der Geyten, Serge; Darras, Veerle M

2005-08-01

In the present study, morphological changes leading to complete metamorphosis have been induced in the neotenic axolotl Ambystoma mexicanum using a submetamorphic dose of T(4) together with an injection of corticotropin-releasing hormone (CRH). An injection of CRH alone is ineffective in this regard presumably due to a lack of thyrotropic stimulation. Using this low hormone profile for induction of metamorphosis, the deiodinating enzymes D2 and D3 known to be present in amphibians were measured in liver and brain 24h following an intraperitoneal injection. An injection of T(4) alone did not influence liver nor brain D2 and D3, but dexamethasone (DEX) or CRH alone or in combination with T(4) decreased liver D2 and D3. Brain D2 activity was slightly increased with a higher dose of DEX, though CRH did not have this effect. A profound synergistic effect occurred when T(4) and DEX or CRH were injected together, in the dose range leading to metamorphosis, increasing brain D2 activity more than fivefold. This synergistic effect was not found in the liver. It is concluded that brain T(3) availability may play an important role for the onset of metamorphosis in the neotenic axolotl.

The yeast two hybrid system in a screen for proteins interacting with axolotl (Ambystoma mexicanum) Msx1 during early limb regeneration.

Science.gov (United States)

Abuqarn, Mehtap; Allmeling, Christina; Amshoff, Inga; Menger, Bjoern; Nasser, Inas; Vogt, Peter M; Reimers, Kerstin

2011-07-01

Urodele amphibians are exceptional in their ability to regenerate complex body structures such as limbs. Limb regeneration depends on a process called dedifferentiation. Under an inductive wound epidermis terminally differentiated cells transform to pluripotent progenitor cells that coordinately proliferate and eventually redifferentiate to form the new appendage. Recent studies have developed molecular models integrating a set of genes that might have important functions in the control of regenerative cellular plasticity. Among them is Msx1, which induced dedifferentiation in mammalian myotubes in vitro. Herein, we screened for interaction partners of axolotl Msx1 using a yeast two hybrid system. A two hybrid cDNA library of 5-day-old wound epidermis and underlying tissue containing more than 2×10⁶ cDNAs was constructed and used in the screen. 34 resulting cDNA clones were isolated and sequenced. We then compared sequences of the isolated clones to annotated EST contigs of the Salamander EST database (BLASTn) to identify presumptive orthologs. We subsequently searched all no-hit clone sequences against non redundant NCBI sequence databases using BLASTx. It is the first time, that the yeast two hybrid system was adapted to the axolotl animal model and successfully used in a screen for proteins interacting with Msx1 in the context of amphibian limb regeneration. 2011 Elsevier B.V. All rights reserved.

Role of cranial neural crest cells in visceral arch muscle positioning and morphogenesis in the Mexican axolotl, Ambystoma mexicanum.

Science.gov (United States)

Ericsson, Rolf; Cerny, Robert; Falck, Pierre; Olsson, Lennart

2004-10-01

The role of cranial neural crest cells in the formation of visceral arch musculature was investigated in the Mexican axolotl, Ambystoma mexicanum. DiI (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine, perchlorate) labeling and green fluorescent protein (GFP) mRNA injections combined with unilateral transplantations of neural folds showed that neural crest cells contribute to the connective tissues but not the myofibers of developing visceral arch muscles in the mandibular, hyoid, and branchial arches. Extirpations of individual cranial neural crest streams demonstrated that neural crest cells are necessary for correct morphogenesis of visceral arch muscles. These do, however, initially develop in their proper positions also in the absence of cranial neural crest. Visceral arch muscles forming in the absence of neural crest cells start to differentiate at their origins but fail to extend toward their insertions and may have a frayed appearance. Our data indicate that visceral arch muscle positioning is controlled by factors that do not have a neural crest origin. We suggest that the cranial neural crest-derived connective tissues provide directional guidance important for the proper extension of the cranial muscles and the subsequent attachment to the insertion on the correct cartilage. In a comparative context, our data from the Mexican axolotl support the view that the cranial neural crest plays a fundamental role in the development of not only the skeleton of the vertebrate head but also in the morphogenesis of the cranial muscles and that this might be a primitive feature of cranial development in vertebrates. 2004 Wiley-Liss, Inc.

Leucine-enkephalin-like immunoreactivity is localized in luteinizing hormone-producing cells in the axolotl (Ambystoma mexicanum) pituitary.

Science.gov (United States)

Suzuki, Hirohumi; Yamamoto, Toshiharu

2014-02-01

In this study, we used immunohistochemical techniques to determine the cell type of leucine-enkephalin (Leu-ENK)-immunoreactive cells in the axolotl (Ambystoma mexicanum) pituitary. Immunoreactive cells were scattered throughout the pars distalis except for the dorso-caudal portion. These cells were immuno-positive for luteinizing hormone (LH), but they were immuno-negative for adrenocorticotrophic, growth, and thyroid-stimulating hormones, as well as prolactin. Immunoelectron microscopy demonstrated that Leu-ENK-like substance and LH co-localized within the same secretory granules. Leu-ENK secreted from gonadotrophs may participate in LH secretion in an autocrine fashion, and/or may participate in the release of sex steroids together with LH. Copyright © 2013 Elsevier Ltd. All rights reserved.

Severe necrotizing myocarditis caused by serratia marcescens infection in an axolotl (Ambystoma mexicanum).

Science.gov (United States)

Del-Pozo, J; Girling, S; Pizzi, R; Mancinelli, E; Else, R W

2011-05-01

This report provides the first account of the pathological changes associated with infection by Serratia marcescens in an adult male axolotl. The infection resulted in septicaemia with severe multifocal necrotizing myocarditis. The latter lesion evolved to cardiac rupture, haemopericardium and death resulting from cardiac tamponade. This animal was exposed to higher than usual temperatures (24-25 °C) 2 weeks before the onset of disease and this may have resulted in immunocompromise and opportunistic bacterial infection. S. marcescens was isolated from the coelomic and pericardial cavity. Both isolates were identical and were resistant to β-lactam antibiotics, but not to aminoglycosides or fluoroquinolones. The production of red prodigiosin pigment by the bacterium suggested an environmental origin. Overall, the clinical and histopathological presentation suggests that S. marcescens should be included in the list of aetiological agents of the 'red-leg'/bacterial dermatosepticaemia syndrome of amphibians. Copyright © 2010 Elsevier Ltd. All rights reserved.

Modern imaging technology for childhood urinary tract infection; Moderne Bildgebung beim Harnweginfekt im Kindesalter

Energy Technology Data Exchange (ETDEWEB)

Riccabona, M.; Fotter, R. [Radiologische Universitaetsklinik Graz (Germany). Abteilung Kinderradiologie

2005-12-01

Imaging in childhood urinary tract infection (UTI) is still a matter of debate. There are established guidelines, however new knowledge and the changed medical environment have enhanced this ongoing discussion. These new insights have impacted therapy and consequently the imaging algorithm. Modern imaging methods - particularly MRI and modern ultrasound (US) - are less invasive with a lower radiation burden. Additionally, it has been shown that VUR is a poor predictor for renal scarring out, which affects long-term results. Furthermore, the majority of UT malformations is depicted by prenatal US. The most crucial aspect of improving long-term outcome appears to be the early and reliable depiction of UTI and effective treatment to prevent renal scarring. This review tries to present this new knowledge and to discuss the potential of modern imaging. Recent changes in imaging algorithms are highlighted and an outcome-oriented algorithm that addresses these recent developments is proposed, without lightly abandoning established standards. It consists of an orienting US and - for depiction of renal involvement - amplitude coded color Doppler sonography or renal static scintigraphy (considered the gold standard, particularly for evaluating scars); in future MRI may play a role. Based on this concept, only patients with renal damage as well as patients with complex urinary tract malformations or intractable recurrent UTI may have to undergo VCUG. (orig.) [German] Die bildgebende Diagnostik beim kindlichen Harnweginfekt (HWI) wird weiterhin heftig diskutiert. Zwar existieren etablierte Bildgebungsalgorithmen, insbesondere fuer das Kleinkindesalter; neue Erkenntnisse bzw. Aufgabenstellungen haben aber zu einer Aenderung des Therapiekonzepts mit Auswirkungen auf die Bildgebung gefuehrt. Zusaetzlich haben technische (Weiter)Entwicklungen das Potenzial der Bildgebung erweitert; v. a. MRT und moderne Ultraschallverfahren versprechen eine weniger invasive und strahlenfreie

Localization of amylin-like immunoreactivity in melanocyte-stimulating hormone-containing cells of the pars intermedia but not those of the pars distalis in the axolotl (Ambystoma mexicanum) pituitary.

Science.gov (United States)

Suzuki, Hirohumi; Yamamoto, Toshiharu

2016-04-01

Immunohistochemical techniques were employed to investigate the distribution of amylin-like immunoreactivity in the axolotl (Ambystoma mexicanum) pituitary. Amylin-immunoreactive cells were observed in the pars intermedia, and these cells were found to be immunoreactive for α-melanocyte-stimulating hormone (αMSH) as well. In contrast, αMSH-immunoreactive cells in the pars distalis were immuno-negaitive for amylin. These light microscopic findings were confirmed by immunoelectron microscopy. Amylin-immunoreactive signals were located on the haloes of presumable secretory granules in association with αMSH-immunoreactive signals in the amylin-positive cells. However, in the pars distalis, the αMSH-positive cells did not contain amylin-immunoreactive secretory granules. Western blot analysis of axolotl pituitary extracts revealed the labeling of a protein band at approximately 10.5-kDa by the anti-rat amylin serum, which was not labeled by the anti-αMSH antibody. These findings indicate that amylin secreted from MSH-producing cells in the pars intermedia may modulate MSH secretion in an autocrine fashion and may participate in MSH functions such as fatty homeostasis together with MSH. Copyright © 2016 Elsevier GmbH. All rights reserved.

Oxygen consumption and cytochrome exidase activity of axolotl limbs muscle tissue in restoration of regenerative ability suprressed by X-irradiation

International Nuclear Information System (INIS)

Teplits, N.A.

1975-01-01

The rate of oxygen use and activity of cytochrome oxidase in a homogenate of mitochondria and nuclei of muscle tissue of axolotl limbs after suppression of their regenerative capability by x irradiation and their restoration was studied experimentally. With suppression of the regenative capability the use of oxygen was depressed. Cytochrome oxidase activity in the homogenate and mitochondria decreased compared to that of the intact limb, in the nuclei of muscle tissue it was the same or greater. With restoration of the regenerative capability of the limbs the respiration rate of the homogenate and the mitochondria increased, accompanied by increased cytochrome oxidase activity. In the nuclei the cytochrome oxidase activity did not change in the blastema stage and sharply decreased in the limb formation state. (E.T.)

Oxygen consumption and cytochrome exidase activity of axolotl limbs muscle tissue in restoration of regenerative ability suppressed by X-irradiation

Energy Technology Data Exchange (ETDEWEB)

Teplits, N A [AN SSSR, Moscow. Inst. Biologii Razvitiya

1975-01-01

The rate of oxygen use and activity of cytochrome oxidase in a homogenate of mitochondria and nuclei of muscle tissue of axolotl limbs after suppression of their regenerative capability by x irradiation and their restoration was studied experimentally. With suppression of the regenative capability the use of oxygen was depressed. Cytochrome oxidase activity in the homogenate and mitochondria decreased compared to that of the intact limb, in the nuclei of muscle tissue it was the same or greater. With restoration of the regenerative capability of the limbs the respiration rate of the homogenate and the mitochondria increased, accompanied by increased cytochrome oxidase activity. In the nuclei the cytochrome oxidase activity did not change in the blastema stage and sharply decreased in the limb formation state.

Ex vivo generation of a functional and regenerative wound epithelium from axolotl (Ambystoma mexicanum) skin.

Science.gov (United States)

Ferris, Donald R; Satoh, Akira; Mandefro, Berhan; Cummings, Gillian M; Gardiner, David M; Rugg, Elizabeth L

2010-10-01

Urodele amphibians (salamanders) are unique among adult vertebrates in their ability to regenerate structurally complete and fully functional limbs. Regeneration is a stepwise process that requires interactions between keratinocytes, nerves and fibroblasts. The formation of a wound epithelium covering the amputation site is an early and necessary event in the process but the molecular mechanisms that underlie the role of the wound epithelium in regeneration remain unclear. We have developed an ex vivo model that recapitulates many features of in vivo wound healing. The model comprises a circular explant of axolotl (Ambystoma mexicanum) limb skin with a central circular, full thickness wound. Re-epithelialization of the wound area is rapid (typically <11 h) and is dependent on metalloproteinase activity. The ex vivo wound epithelium is viable, responds to neuronal signals and is able to participate in ectopic blastema formation and limb regeneration. This ex vivo model provides a reproducible and tractable system in which to study the cellular and molecular events that underlie wound healing and regeneration. © 2010 The Authors. Journal compilation © 2010 Japanese Society of Developmental Biologists.

Comparative transcriptional profiling of the axolotl limb identifies a tripartite regeneration-specific gene program.

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Dunja Knapp

Full Text Available Understanding how the limb blastema is established after the initial wound healing response is an important aspect of regeneration research. Here we performed parallel expression profile time courses of healing lateral wounds versus amputated limbs in axolotl. This comparison between wound healing and regeneration allowed us to identify amputation-specific genes. By clustering the expression profiles of these samples, we could detect three distinguishable phases of gene expression - early wound healing followed by a transition-phase leading to establishment of the limb development program, which correspond to the three phases of limb regeneration that had been defined by morphological criteria. By focusing on the transition-phase, we identified 93 strictly amputation-associated genes many of which are implicated in oxidative-stress response, chromatin modification, epithelial development or limb development. We further classified the genes based on whether they were or were not significantly expressed in the developing limb bud. The specific localization of 53 selected candidates within the blastema was investigated by in situ hybridization. In summary, we identified a set of genes that are expressed specifically during regeneration and are therefore, likely candidates for the regulation of blastema formation.

Ontogeny of the VIP system in the gastro-intestinal tract of the Axolotl, Ambystoma mexicanum: successive appearance of co-existing PACAP and NOS.

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Badawy, Gamal; Reinecke, Manfred

2003-03-01

Evidence for the presence and potential co-existence of vasoactive intestinal polypeptide (VIP), pituitary adenylate cyclase-activating polypeptide (PACAP) and nitric oxide synthase (NOS) in gastro-intestinal endocrine cells and/or nerve fibers is conflicting and very few results exist on development. This immunofluorescence study aims to clarify the appearance and localization of VIP, PACAP and NOS in the gastro-intestinal tract of the Axolotl, Ambystoma mexicanum, during ontogeny. VIP-immunoreactivity appeared in nerve fibers as early as on day 3 after hatching likely indicating a particular role, such as a trophic action, of VIP in very early development. PACAP-immunoreactivity was observed 3 days later within the VIP-immunoreactive (-IR) fibers. From this time on, VIP- and PACAP-immunoreactivity exhibited complete co-existence. VIP/PACAP-IR fibers were found throughout the gastro-intestinal tract. They were most prominent in the myenteric plexus and the muscle layers and less frequent in the submucosa. NOS-immunoreactivity appeared as late as at the 1st (64 days) juvenile stage in a subpopulation of the VIP/PACAP-IR fibers that contacted submucosal arteries. We found only very few VIP/PACAP-IR perikarya, indicating that part of the VIP/PACAP-IR fibers is of extrinsic origin. On day 12 and in the 1st and 2nd (104 days) juvenile stage, infrequent PACAP-IR entero-endocrine cells were noted, while neither VIP- nor NOS-immunoreactivity occurred in endocrine cells at any stage of development. The complete coexistence of neuronal PACAP- and VIP-immunoreactivities and their very early appearance in ontogeny may suggest important and coordinated roles of both peptides in the control of Axolotl gastro-intestinal activity, while the VIP/ PACAP/NOS-IR fibers may be involved in the regulation of submucosal blood flow.

Patterns of spatial and temporal visceral arch muscle development in the Mexican axolotl (Ambystoma mexicanum).

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Ericsson, Rolf; Olsson, Lennart

2004-08-01

Vertebrate head development is a classical topic that has received renewed attention during the last decade. Most reports use one of a few model organisms (chicken, mouse, zebrafish) and have focused on molecular mechanisms and the role of the neural crest, while cranial muscle development has received less attention. Here we describe cranial muscle differentiation and morphogenesis in the Mexican axolotl, Ambystoma mexicanum. To determine the onset of differentiation we use antibodies against desmin and optical sectioning using confocal laser scanning microscopy on whole-mount immunostained embryos. This technique makes it possible to document the cranial muscle in three dimensions while keeping the specimens intact. Desmin expression starts almost simultaneously in the first, second, and third visceral arch muscles (as in other amphibians studied). Muscle anlagen divide up early into the different elements which constitute the larval cranial musculature. We extend and refine earlier findings, e.g., by documenting a clear division between interhyoideus and interhyoideus posterior. The timing of cranial muscle differentiation differs among vertebrate groups, but seems to be constant within each group. This study provides a morphological foundation for further studies of muscle cell fate and early differentiation. Copyright 2004 Wiley-Liss, Inc.

DNA Methylation Dynamics Regulate the Formation of a Regenerative Wound Epithelium during Axolotl Limb Regeneration.

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Cristian Aguilar

Full Text Available The formation of a blastema during regeneration of an axolotl limb involves important changes in the behavior and function of cells at the site of injury. One of the earliest events is the formation of the wound epithelium and subsequently the apical epidermal cap, which involves in vivo dedifferentiation that is controlled by signaling from the nerve. We have investigated the role of epigenetic modifications to the genome as a possible mechanism for regulating changes in gene expression patterns of keratinocytes of the wound and blastema epithelium that are involved in regeneration. We report a modulation of the expression DNMT3a, a de novo DNA methyltransferase, within the first 72 hours post injury that is dependent on nerve signaling. Treatment of skin wounds on the upper forelimb with decitabine, a DNA methyltransferase inhibitor, induced changes in gene expression and cellular behavior associated with a regenerative response. Furthermore, decitabine-treated wounds were able to participate in regeneration while untreated wounds inhibited a regenerative response. Elucidation of the specific epigenetic modifications that mediate cellular dedifferentiation likely will lead to insights for initiating a regenerative response in organisms that lack this ability.

Neurotrophic regulation of fibroblast dedifferentiation during limb skeletal regeneration in the axolotl (Ambystoma mexicanum).

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Satoh, Akira; Cummings, Gillian M C; Bryant, Susan V; Gardiner, David M

2010-01-15

The ability of animals to repair tissue damage is widespread and impressive. Among tissues, the repair and remodeling of bone occurs during growth and in response to injury; however, loss of bone above a threshold amount is not regenerated, resulting in a "critical-size defect" (CSD). The development of therapies to replace or regenerate a CSD is a major focus of research in regenerative medicine and tissue engineering. Adult urodeles (salamanders) are unique in their ability to regenerate complex tissues perfectly, yet like mammals do not regenerate a CSD. We report on an experimental model for the regeneration of a CSD in the axolotl (the Excisional Regeneration Model) that allows for the identification of signals to induce fibroblast dedifferentiation and skeletal regeneration. This regenerative response is mediated in part by BMP signaling, as is the case in mammals; however, a complete regenerative response requires the induction of a population of undifferentiated, regeneration-competent cells. These cells can be induced by signaling from limb amputation to generate blastema cells that can be grafted to the wound, as well as by signaling from a nerve and a wound epithelium to induce blastema cells from fibroblasts within the wound environment. Copyright 2009 Elsevier Inc. All rights reserved.

Crystal structure of axolotl (Ambystoma mexicanum) liver bile acid-binding protein bound to cholic and oleic acid.

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Capaldi, Stefano; Guariento, Mara; Perduca, Massimiliano; Di Pietro, Santiago M; Santomé, José A; Monaco, Hugo L

2006-07-01

The family of the liver bile acid-binding proteins (L-BABPs), formerly called liver basic fatty acid-binding proteins (Lb-FABPs) shares fold and sequence similarity with the paralogous liver fatty acid-binding proteins (L-FABPs) but has a different stoichiometry and specificity of ligand binding. This article describes the first X-ray structure of a member of the L-BABP family, axolotl (Ambystoma mexicanum) L-BABP, bound to two different ligands: cholic and oleic acid. The protein binds one molecule of oleic acid in a position that is significantly different from that of either of the two molecules that bind to rat liver FABP. The stoichiometry of binding of cholate is of two ligands per protein molecule, as observed in chicken L-BABP. The cholate molecule that binds buried most deeply into the internal cavity overlaps well with the analogous bound to chicken L-BABP, whereas the second molecule, which interacts with the first only through hydrophobic contacts, is more external and exposed to the solvent. (c) 2006 Wiley-Liss, Inc.

Proteomic analysis of blastema formation in regenerating axolotl limbs

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Nye Holly LD

2009-11-01

Full Text Available Abstract Background Following amputation, urodele salamander limbs reprogram somatic cells to form a blastema that self-organizes into the missing limb parts to restore the structure and function of the limb. To help understand the molecular basis of blastema formation, we used quantitative label-free liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS-based methods to analyze changes in the proteome that occurred 1, 4 and 7 days post amputation (dpa through the mid-tibia/fibula of axolotl hind limbs. Results We identified 309 unique proteins with significant fold change relative to controls (0 dpa, representing 10 biological process categories: (1 signaling, (2 Ca2+ binding and translocation, (3 transcription, (4 translation, (5 cytoskeleton, (6 extracellular matrix (ECM, (7 metabolism, (8 cell protection, (9 degradation, and (10 cell cycle. In all, 43 proteins exhibited exceptionally high fold changes. Of these, the ecotropic viral integrative factor 5 (EVI5, a cell cycle-related oncoprotein that prevents cells from entering the mitotic phase of the cell cycle prematurely, was of special interest because its fold change was exceptionally high throughout blastema formation. Conclusion Our data were consistent with previous studies indicating the importance of inositol triphosphate and Ca2+ signaling in initiating the ECM and cytoskeletal remodeling characteristic of histolysis and cell dedifferentiation. In addition, the data suggested that blastema formation requires several mechanisms to avoid apoptosis, including reduced metabolism, differential regulation of proapoptotic and antiapoptotic proteins, and initiation of an unfolded protein response (UPR. Since there is virtually no mitosis during blastema formation, we propose that high levels of EVI5 function to arrest dedifferentiated cells somewhere in the G1/S/G2 phases of the cell cycle until they have accumulated under the wound epidermis and enter mitosis in response to

Hilfe oder Hindernis? Meinungen finnischer Sprachstudierender über Mehrsprachigkeit als Ressource beim Deutschlernen

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Sabine Grasz

2017-10-01

Full Text Available Der Fremdsprachenunterricht in Finnland befindet sich gerade in einer Umbruchphase, denn mit der Einführung neuer Lehrpläne im Jahr 2016 werden Verfahren der Mehrsprachigkeitsdidaktik in Zukunft eine zentrale Rolle spielen. In diesem Beitrag wird untersucht, ob und wie finnische Universitätsstudierende, die selbst von einer eher monolingual ausgerichteten Lerntradition geprägt sind, ihr mehrsprachiges Repertoire als Ressource beim Lernen weiterer Fremdsprachen sehen. Zu diesem Zweck wurde eine Befragung unter Lehramtsstudierenden der Fächer Anglistik und Skandinavistik, die Germanistik als Nebenfach studieren möchten, durchgeführt. Die Analyse zeigt, dass die Studierenden zwar mehrheitlich positive Einstellungen gegenüber Mehrsprachigkeit aufweisen, dass es aber Entwicklungsbedarf im Hinblick auf Sprachbewusstheit, multilinguale Fähigkeiten und bei den Einstellungen gegenüber Sprachmischungen gibt. Foreign language education in Finland is currently undergoing a period of change, as the introduction of new curricula in 2016 will lead to a central role of multilingualism in teaching. This article examines whether and how Finnish university students, who themselves were influenced by a more monolingual learning tradition, consider their multilingual repertoire as a resource for learning other foreign languages. For this purpose, a survey was conducted among teacher students of English and Swedish, who would like to study German as a minor. The analysis shows that while the majority of students have positive attitudes towards multilingualism, there is a need for development in terms of language awareness, multilingual skills, and attitudes towards language mixes.

Aktuelle Technik der Bruststraffung beim Mann nach Gewichtsverlust [Modern technique in male breast contouring after weight loss

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Stoff, Alexander

2013-08-01

Full Text Available [english] The morbid adiposity and its medical consequences demonstrates a growing problem of our current prosperous society. Due to a significant improvement of bariatric techniques and a reduplication of adipose patients during the 20 century, the number of patients, who present to plastic surgeons with a new degree of suffering, has been growing steadily. Initially, the female patients were in the majority, which has been more balanced nowadays.The male breast is a body region that primarily symbolizes masculinity and strenght. In male patients after massive weight loss, this body region remains as an extremly deflated breast envelope without any sign of possible retraction. The plastic surgeon may choose from different single or combinated ltechniques, which are indicated depending on the local and adjacent tissue characteristics.We are presenting our modified technique of male breast reshaping, referring to the technique of Aly, except for a NAC transposition on a central pedicle. The central pedicle is hereby preserved from resection after tremendous liposuction. This central pedicle technique allows a safe and uncomplicated NAC transposition with significant advantages compared to free NAC-Transposition techniques in terms of aesthetical and functional outcome. [german] Die morbide Adipositas mit ihren Langzeitfolgen ist ein zunehmendes Problem unserer heutigen Wohlstandsgesellschaft. Mit einer Verdoppelung der betroffenen Patienten im Laufe des 20. Jahrhunderts ist gleichzeitig durch rasante Verbesserung der bariatrischen Eingriffe auch die Zahl der Patienten signifikant und stetig gestiegen, die sich nach massiver Gewichtsreduktion nun mit neuem Leidensdruck beim Plastischen Chirurgen vorstellen. Hierbei ist die anfängliche Überzahl der weiblichen Patienten in ein ausgewogenes Verhältnis der betroffenen Geschlechter übergegangen. Die männliche Brust, eine Körperregion, die in erster Linie Männlichkeit und Stärke symbolisiert und

Dual embryonic origin of the hyobranchial apparatus in the Mexican axolotl (Ambystoma mexicanum).

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Davidian, Asya; Malashichev, Yegor

2013-01-01

Traditionally, the cartilaginous viscerocranium of vertebrates is considered as neural crest (NC)-derived. Morphological work carried out on amphibian embryos in the first half of the XX century suggested potentially mesodermal origin for some hyobranchial elements. Since then, the embryonic sources of the hyobranchial apparatus in amphibians has not been investigated due to lack of an appropriate long-term labelling system. We performed homotopic transplantations of neural folds along with the majority of cells of the presumptive NC, and/or fragments of the head lateral plate mesoderm (LPM) from transgenic GFP+ into white embryos. In these experiments, the NC-derived GFP+ cells contributed to all hyobranchial elements, except for basibranchial 2, whereas the grafting of GFP+ head mesoderm led to a reverse labelling result. The grafting of only the most ventral part of the head LPM resulted in marking of the basibranchial 2 and the heart myocardium, implying their origin from a common mesodermal region. This is the first evidence of contribution of LPM of the head to cranial elements in any vertebrate. If compared to fish, birds, and mammals, in which all branchial skeletal elements are NC-derived, the axolotl (probably this is true for all amphibians) demonstrates an evolutionary deviation, in which the head LPM replaces NC cells in a hyobranchial element. This implies that cells of different embryonic origin may have the same developmental program, leading to the formation of identical (homologous) elements of the skeleton.

Regulation of Axolotl (Ambystoma mexicanum) Limb Blastema Cell Proliferation by Nerves and BMP2 in Organotypic Slice Culture.

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Lehrberg, Jeffrey; Gardiner, David M

2015-01-01

We have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. Blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. Because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possible to test the response of blastema cells to signaling molecules present in serum, as well as those produced by nerves. We also were able to investigate the response of blastema cells to experimentally regulated changes in BMP signaling. Blastema cells responded to all of these signals by increasing the rate of proliferation and the level of expression of the blastema marker gene, Prrx-1. The organotypic slice culture model provides the opportunity to identify and characterize the spatial and temporal co-regulation of pathways in order to induce and enhance a regenerative response.

Regulation of Axolotl (Ambystoma mexicanum Limb Blastema Cell Proliferation by Nerves and BMP2 in Organotypic Slice Culture.

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Jeffrey Lehrberg

Full Text Available We have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. Blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. Because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possible to test the response of blastema cells to signaling molecules present in serum, as well as those produced by nerves. We also were able to investigate the response of blastema cells to experimentally regulated changes in BMP signaling. Blastema cells responded to all of these signals by increasing the rate of proliferation and the level of expression of the blastema marker gene, Prrx-1. The organotypic slice culture model provides the opportunity to identify and characterize the spatial and temporal co-regulation of pathways in order to induce and enhance a regenerative response.

Effect of water quality on the feeding ecology of axolotl Ambystoma mexicanum

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Diego de Jesus Chaparro-Herrera

2013-10-01

Full Text Available Ambystoma mexicanum, a highly endangered species, is endemic to lake Xochimilco (Mexico City, Mexico which currently is being negatively affected by the introduction of Oreochromis niloticus (Tilapia and water pollution. During the first weeks of development, when mortality is the highest, Ambystoma mexicanumdepends on a diet of zooplankton. The aim of this study was to check whether contamination levels in lake Xochimilco influence zooplankton consumption by similar size classes of A. mexicanum and Oreochromis niloticus. In this study, we analysed changes in the functional responses and prey preference of A. mexicanum and larval Tilapia in two media, one with filtered lake Xochimilco water and another one with reconstituted water. As prey we used cladocerans (Moina macrocopa, Alona glabra, Macrothrix triserialis and Simocephalus vetulus and ostracods (Heterocypris incongruens. Zooplankton was offered in 5 different densities, 10, 20, 40, 80, 160 ind./mL. Prey consumption by A. mexicanum varied in relation to the species offered and age of the larvae. From the first week to the eighth week prey consumption by A. mexicanum increased by 57%. Our functional response tests showed that regardless of the prey type, prey consumption by A. mexicanum was lower in the contaminated water from lake Xochimilco. Among the zooplankton offered in the contaminated environment predators preferred smaller and slower moving microcrustaceans such as Alona glabra and Heterocypris incongruens. Furthermore, O. niloticus preferred prey such as Moina macrocopa and Macrothrix triserialis in the contaminated medium and was more voracious than the axolotl. Our results indicate that both water quality of the lake and the presence of the more resistant exotic fish adversely impact the survival of this endangered amphibian.

A state-of-the-art review of built environment information modelling (BeIM

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Tah J.H.M.

2017-12-01

Full Text Available Elements that constitute the built environment are vast and so are the independent systems developed to model its various aspects. Many of these systems have been developed under various assumptions and approaches to execute functions that are distinct, complementary or sometimes similar. Furthermore, these systems are ever increasing in number and often assume similar nomenclatures and acronyms, thereby exacerbating the challenges of understanding their peculiar functions, definitions and differences. The current societal demand to improve sustainability per­formance through collaboration as well as whole-system and through-life thinking is driving the need to integrate independent systems associated with different aspects and scales of the built environment to deliver smart solutions and services that improve the well-being of citizens. The contemporary object-oriented digitization of real-world elements appears to provide a leeway for amalgamating the modelling systems of various domains in the built environment which we termed as built environment information modelling (BeIM. These domains include architecture, engineering, construction as well as urban planning and design. Applications such as building information modelling, geographic information systems and 3D city modelling systems are now being integrated for city modelling purposes. The various works directed at integrating these systems are examined, revealing that current research efforts on integration fall into three categories: (1 data/file conversion systems, (2 semantic mapping systems and (3 the hybrid of both. The review outcome suggests that good knowledge of these domains and how their respective systems operate is vital to pursuing holistic systems integration in the built environment.

Neurotrophic regulation of epidermal dedifferentiation during wound healing and limb regeneration in the axolotl (Ambystoma mexicanum).

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Satoh, A; Graham, G M C; Bryant, S V; Gardiner, D M

2008-07-15

Adult urodeles (salamanders) are unique in their ability to regenerate complex organs perfectly. The recently developed Accessory Limb Model (ALM) in the axolotl provides an opportunity to identify and characterize the essential signaling events that control the early steps in limb regeneration. The ALM demonstrates that limb regeneration progresses in a stepwise fashion that is dependent on signals from the wound epidermis, nerves and dermal fibroblasts from opposite sides of the limb. When all the signals are present, a limb is formed de novo. The ALM thus provides an opportunity to identify and characterize the signaling pathways that control blastema morphogenesis and limb regeneration. In the present study, we have utilized the ALM to identity the buttonhead-like zinc-finger transcription factor, Sp9, as being involved in the formation of the regeneration epithelium. Sp9 expression is induced in basal keratinocytes of the apical blastema epithelium in a pattern that is comparable to its expression in developing limb buds, and it thus is an important marker for dedifferentiation of the epidermis. Induction of Sp9 expression is nerve-dependent, and we have identified KGF as an endogenous nerve factor that induces expression of Sp9 in the regeneration epithelium.

Ion channel signaling influences cellular proliferation and phagocyte activity during axolotl tail regeneration.

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Franklin, Brandon M; Voss, S Randal; Osborn, Jeffrey L

2017-08-01

Little is known about the potential for ion channels to regulate cellular behaviors during tissue regeneration. Here, we utilized an amphibian tail regeneration assay coupled with a chemical genetic screen to identify ion channel antagonists that altered critical cellular processes during regeneration. Inhibition of multiple ion channels either partially (anoctamin1/Tmem16a, anoctamin2/Tmem16b, K V 2.1, K V 2.2, L-type Ca V channels and H/K ATPases) or completely (GlyR, GABA A R, K V 1.5 and SERCA pumps) inhibited tail regeneration. Partial inhibition of tail regeneration by blocking the calcium activated chloride channels, anoctamin1&2, was associated with a reduction of cellular proliferation in tail muscle and mesenchymal regions. Inhibition of anoctamin 1/2 also altered the post-amputation transcriptional response of p44/42 MAPK signaling pathway genes, including decreased expression of erk1/erk2. We also found that complete inhibition via voltage gated K + channel blockade was associated with diminished phagocyte recruitment to the amputation site. The identification of H + pumps as required for axolotl tail regeneration supports findings in Xenopus and Planaria models, and more generally, the conservation of ion channels as regulators of tissue regeneration. This study provides a preliminary framework for an in-depth investigation of the mechanistic role of ion channels and their potential involvement in regulating cellular proliferation and other processes essential to wound healing, appendage regeneration, and tissue repair. Copyright © 2017 Elsevier B.V. All rights reserved.

Activation of germline-specific genes is required for limb regeneration in the Mexican axolotl

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Zhu, Wei; Pao, Gerald M; Satoh, Akira; Cummings, Gillian; Monaghan, James R; Harkins, Timothy T; Bryant, Susan V; Voss, S Randal; Gardiner, David M; Hunter, Tony

2013-01-01

The capacity for tissue and organ regeneration in humans is dwarfed by comparison to that of salamanders. Emerging evidence suggests that mechanisms learned from the early phase of salamander limb regeneration – wound healing, cellular dedifferentiation and blastemal formation – will reveal therapeutic approaches for tissue regeneration in humans. Here we describe a unique transcriptional fingerprint of regenerating limb tissue in the Mexican axolotl (Ambystoma mexicanum) that is indicative of cellular reprogramming of differentiated cells to a germline-like state. Two genes that are required for self-renewal of germ cells in mice and flies, Piwi-like 1 (PL1) and Piwi-like 2 (PL2), are expressed in limb blastemal cells, the basal layer keratinocytes and the thickened apical epithelial cap in the wound epidermis in the regenerating limb. Depletion of PL1 and PL2 by morpholino oligonucleotides decreased cell proliferation and increased cell death in the blastema leading to a significant retardation of regeneration. Examination of key molecules that are known to be required for limb development or regeneration further revealed that FGF8 is transcriptionally downregulated in the presence of the morpholino oligos, indicating PL1 and PL2 might participate in FGF signaling during limb regeneration. Given the requirement for FGF signaling in limb development and regeneration, the results suggest that PL1 and PL2 function to establish a unique germline-like state that is associated with successful regeneration. PMID:22841627

Βιβλιοκρισία:P. SCHREINER-E. VOGT(eds., Karl Krumbacher. Leben und Werk, München, Verlag der Bayerischen Akademie der Wissenschaften in Kommission beim Verlag C. H. Beck, München 2011

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Walter PUCHNER

2013-04-01

Full Text Available Βιβλιοκρισία: P. Schreiner-E. Vogt (eds., Karl Krumbacher. Leben und Werk, München, Verlag der Bayerischen Akademie der Wissenschaften in Kommission beim Verlag C. H. Beck, München 2011 (Bayerische Akademie der Wissenschaften, Philosophisch-historische Klasse, Sitzungsberichte, Jahrgang 2011, Heft 4, σελ. 147, 5 εικ., ΙSBN 978 3 7696 1569 0.

Identification of differentially expressed thyroid hormone responsive genes from the brain of the Mexican Axolotl (Ambystoma mexicanum).

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Huggins, P; Johnson, C K; Schoergendorfer, A; Putta, S; Bathke, A C; Stromberg, A J; Voss, S R

2012-01-01

The Mexican axolotl (Ambystoma mexicanum) presents an excellent model to investigate mechanisms of brain development that are conserved among vertebrates. In particular, metamorphic changes of the brain can be induced in free-living aquatic juveniles and adults by simply adding thyroid hormone (T4) to rearing water. Whole brains were sampled from juvenile A. mexicanum that were exposed to 0, 8, and 18 days of 50 nM T4, and these were used to isolate RNA and make normalized cDNA libraries for 454 DNA sequencing. A total of 1,875,732 high quality cDNA reads were assembled with existing ESTs to obtain 5884 new contigs for human RefSeq protein models, and to develop a custom Affymetrix gene expression array (Amby_002) with approximately 20,000 probe sets. The Amby_002 array was used to identify 303 transcripts that differed statistically (p1.5) as a function of days of T4 treatment. Further statistical analyses showed that Amby_002 performed concordantly in comparison to an existing, small format expression array. This study introduces a new A. mexicanum microarray resource for the community and the first lists of T4-responsive genes from the brain of a salamander amphibian. Copyright © 2011 Elsevier Inc. All rights reserved.

Positive in vitro wound healing effects of functional inclusion bodies of a lipoxygenase from the Mexican axolotl.

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Stamm, Anne; Strauß, Sarah; Vogt, Peter; Scheper, Thomas; Pepelanova, Iliyana

2018-04-07

AmbLOXe is a lipoxygenase, which is up-regulated during limb-redevelopment in the Mexican axolotl, Ambystoma mexicanum, an animal with remarkable regeneration capacity. Previous studies have shown that mammalian cells transformed with the gene of this epidermal lipoxygenase display faster migration and wound closure rate during in vitro wound healing experiments. In this study, the gene of AmbLOXe was codon-optimized for expression in Escherichia coli and was produced in the insoluble fraction as protein aggregates. These inclusion bodies or nanopills were shown to be reservoirs containing functional protein during in vitro wound healing assays. For this purpose, functional inclusion bodies were used to coat cell culture surfaces prior cell seeding or were added directly to the medium after cells reached confluence. In both scenarios, AmbLOXe inclusion bodies led to faster migration rate and wound closure, in comparison to controls containing either no AmbLOXe or GFP inclusion bodies. Our results demonstrate that AmbLOXe inclusion bodies are functional and may serve as stable reservoirs of this enzyme. Nevertheless, further studies with soluble enzyme are also necessary in order to start elucidating the exact molecular substrates of AmbLOXe and the biochemical pathways involved in the wound healing effect.

Magnetic resonance imaging of complex congenital heart disease in aduits; Magnetresonanztomographie komplexer kongenitaler Herzerkrankungen beim Erwachsenen

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Bremerich, J. [San Francisco Univ, CA (United States). Dept. of Radiology]|[Universitaetsklinik Basel (Switzerland). Abt. fuer Medizinische Radiologie; Wyttenbach, R.; Higgins, C.B. [San Francisco Univ, CA (United States). Dept. of Radiology; Buser, P. [Universitaetsklinik Basel (Switzerland). Abt. fuer Kardiologie; Steinbrich, W. [Universitaetsklinik Basel (Switzerland). Abt. fuer Medizinische Radiologie

1999-04-01

An increasing number of patients with complex congenital heart disease reaches adulthood, because treatment and patient outcome have improved considerably in recent years. Monitoring of these patients requires both definition of cardiac anatomy and assessment of function with good reproducibility. Complications after surgical repair such as restenoses of pulmonary arteries after surgical repair of Tetralogy of Fallot, ventricular hypertrophy, stenoses or leakage of baffles, or stenosis and aneurysms of anastomoses have to be detected at an early stage. Magnetic Resonance Imaging (MRI) is an excellent tool to monitor these patients because of its noninvasive nature, its good interstudy and interobserver reproducibility, and because it allows assessment of both cardiac anatomy and function. This paper reviews the current applications of MRI in complex congenital heart disease in adults. (orig.) [Deutsch] Durch Verbesserungen in der Diagnose und Therapie komplexer kongenitaler Herzerkrankungen kann eine zunehmende Anzahl von betroffenen Patienten das Erwachsenenalter erreichen. Diese Patienten benoetigen regelmaessige postoperative Verlaufskontrollen, um Komplikationen wie z.B. Restenosen der grossen Arterien, Stenosen, Lecks und Aneurysmata von Anastomosen, Ventrikelhypertrophie und -dilatation oder Klappendysfunktionen fruehzeitig zu erkennen und zu behandeln. Fuer nichtinvasive regelmaessige Verlaufskontrollen bietet sich die Magnetresonanztomographie (MRT) des Herzens an, da sie eine umfassende Untersuchung sowohl der Morphologie als auch der Funktion des Herzens mit guter Reproduzierbarkeit erlaubt. Die gegenwaertigen klinischen Anwendungen der MRT bei komplexen kongenitalen Herzerkrankungen beim Erwachsenen werden in dieser Uebersicht beschrieben. (orig.)

Cerebral MR imaging of malignant melanoma; Zerebrale MR-Bildgebung beim malignen Melanom

Energy Technology Data Exchange (ETDEWEB)

Breckwoldt, M.; Bendszus, M. [Universitaetsklinikum Heidelberg, Abteilung Neuroradiologie, Neurologische Klinik, Heidelberg (Germany)

2015-01-16

Suszeptibilitaetssignale (ITSS), was sie von anderen Metastasen unterscheidet (Spezifitaet ca. 81-96 %). Die Diffusionsbildgebung spielt beim MM nur eine untergeordnete Rolle. Die suszeptibilitaetsgewichtete Bildgebung verbessert die Sensitivitaet der Metastasendetektion bei eingeschraenkter Spezifitaet. Eine Unterscheidung von Mikroblutungen oder Verkalkungen kann im Einzelfall unmoeglich sein. Kontrovers ist zudem, wie SWI-Signalausloeschungen zu werten sind, fuer die sich kein Korrelat in den anderen Sequenzen findet (Differenzialdiagnose: Metastase, Mikroblutung, Verkalkung). Der beim MM haeufig vorkommende ZNS-Befall ist ab Stadium IIc auch bei neurologisch asymptomatischen Patienten auszuschliessen. Ebenso sind im Stadium IV alle 3 Monate kraniale MRT-Untersuchungen indiziert. Die Unterscheidung von Metastasen und intrazerebralen Einblutungen ist nicht immer moeglich und muss im Einzelfall durch eine Verlaufsuntersuchung geklaert werden. Zusaetzliche diagnostische Sensitivitaet bei eingeschraenkter Spezifitaet bringt die SWI. (orig.)

Identification of Differentially Expressed Thyroid Hormone Responsive Genes from the Brain of the Mexican Axolotl (Ambystoma mexicanum) ✧

Science.gov (United States)

Huggins, P; Johnson, CK; Schoergendorfer, A; Putta, S; Bathke, AC; Stromberg, AJ; Voss, SR

2011-01-01

The Mexican axolotl (Ambystoma mexicanum) presents an excellent model to investigate mechanisms of brain development that are conserved among vertebrates. In particular, metamorphic changes of the brain can be induced in free-living aquatic juveniles and adults by simply adding thyroid hormone (T4) to rearing water. Whole brains were sampled from juvenile A. mexicanum that were exposed to 0, 8, and 18 days of 50 nM T4, and these were used to isolate RNA and make normalized cDNA libraries for 454 DNA sequencing. A total of 1,875,732 high quality cDNA reads were assembled with existing ESTs to obtain 5,884 new contigs for human RefSeq protein models, and to develop a custom Affymetrix gene expression array (Amby_002) with approximately 20,000 probe sets. The Amby_002 array was used to identify 303 transcripts that differed statistically (p 1.5) as a function of days of T4 treatment. Further statistical analyses showed that Amby_002 performed concordantly in comparison to an existing, small format expression array. This study introduces a new A. mexicanum microarray resource for the community and the first lists of T4-responsive genes from the brain of a salamander amphibian. PMID:21457787

Glucose transporter distribution in the vessels of the central nervous system of the axolotl Ambystoma mexicanum (Urodela: Ambystomatidae).

Science.gov (United States)

Lazzari, Maurizio; Bettini, Simone; Ciani, Franco; Franceschini, Valeria

2008-10-01

The GLUT-1 isoform of the glucose transporter is commonly considered a reliable molecular marker of blood-brain barrier endothelia in the neural vasculature organized in a three-dimensional network of single vessels. The central nervous system of the axolotl Ambystoma mexicanum is characterized by a vascular architecture that contains both single and paired vessels. The presence and distribution of the GLUT-1 transporter are studied in this urodele using both immunoperoxidase histochemistry and immunogold technique. Light microscopy reveals immunopositivity in both parenchymal and meningeal vessels. The transverse-sectioned pairs of vessels do not show the same size. Furthermore, in the same pair, the two elements often differ in diameter. The main regions of the central nervous system show a different percentage of the paired structures. Only immunogold cytochemistry reveals different staining intensity in the two adjoined elements of a vascular pair. Colloidal gold particles show an asymmetric distribution in the endothelia of both single and paired vessels. These particles are more numerous on the abluminal surface than on the luminal one. The particle density is calculated in both vascular types. The different values could indicate functional differences between single and paired vessels and between the two adjoined elements of a pair, regarding glucose transport.

49. and 50. annual meeting of the Civil Defence Commission of the Federal Ministry of the Interior. Proceedings; 49. und 50. Jahrestagung der Schutzkommission beim Bundesminister des Innern. Vortraege

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

The publication contains the proceedings of the 2000 and 2001 annual meetings. Subjects were: Disaster medicine, public alarm, proliferation of weapons of mass destruction, epidemic hygiene and control, therapy of organophosphate poisoning, airborne energy and dose equivalent profiles by microdosimetry, zoning system for floods, backwater, heavy rains, health services, information security in transition, heavy-duty concretes, building and infrastructure protection. [German] Der Band umfasst die Vortraege der Jahrestagungen 2000 und 2001 der Schutzkommission beim Bundesminister des Innern. Die Vortraege beschaeftigten sich mit folgenden Themen: Katastrophenmedizin, Warnung der Bevoelkerung, Proliferation von Massenvernichtungswaffen, Seuchenhygiene und Seuchenbekaempfung, Therapie von Organophosphatvergiftung, Energie- und Aequivalentdosisleistungsprofile mittels Microdosimetrie in Flugzeugen, Zonierungssystem Ueberschwemmung Rueckstau Starkregen, Gesundheitsdienst, Informationssicherheit im Wandel, Hochleistungsbetone, Baulicher Schutz und Schutz von Infrastruktur. (uke)

Muscular derivatives of the cranialmost somites revealed by long-term fate mapping in the Mexican axolotl (Ambystoma mexicanum).

Science.gov (United States)

Piekarski, Nadine; Olsson, Lennart

2007-01-01

The fate of single somites has not been analyzed from a comparative perspective with modern cell-marking methods. Most of what we know is based on work using quail-chick chimeras. Consequently, to what degree cell fate has been conserved despite the anatomical differences among vertebrates is unknown. We have analyzed the cell fate of the cranialmost somites, with the focus on somite two, in the Mexican axolotl (Ambystoma mexicanum). Somite cells were marked by injection of dextran-fluorescein and detected using immunofluorescence after 2 months of development in paraffin sections. Our data confirm and extend earlier studies based on classical histology in salamanders. We show that somite two contributes to different muscles, skeletal elements, and connective tissues of the head and cranial trunk region. Cells from somites two and three migrate latero-ventrally and contribute to the hypobranchial muscles mm. geniohyoideus and rectus cervicis. We provide evidence that the specific formation of the hypobranchial musculature from ventral processes of the somites might be variable in different classes of vertebrates. We further demonstrate that mm. cucullaris and dilatator laryngis, which were earlier thought to have a branchial origin, arise from somitic material in a manner very similar to the findings in quail-chick chimeras. Our findings indicate that the pattern of somitic derivatives is highly conserved within tetrapods.

The Center for Regenerative Biology and Medicine at Mount Desert Island Biological Laboratory

Science.gov (United States)

2015-08-01

TERMS limb regeneration Positional Memory Code Axolotl microRNAs Zebrafish Polypterus 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18...injury induced regeneration of limbs/appendage tissues in Ambystoma ( axolotl ) and Polypterus animals. The defining feature of limb/appendage...downregulated in UPREGULATED DOWNREGULATED Figure 1: Venn diagram of UniProt protein sequence IDs among Axolotl and Polypterus contigs that

Analysis of the expression and function of Wnt-5a and Wnt-5b in developing and regenerating axolotl (Ambystoma mexicanum) limbs.

Science.gov (United States)

Ghosh, Sukla; Roy, Stéphane; Séguin, Carl; Bryant, Susan V; Gardiner, David M

2008-05-01

Urodele amphibians are unique adult vertebrates because they are able to regenerate body parts after amputation. Studies of urodele limb regeneration, the key model system for vertebrate regeneration, have led to an understanding of the origin of blastema cells and the importance of positional interactions between blastema cells in the control of growth and pattern formation. Progress is now being made in the identification of the signaling pathways that regulate dedifferentiation, blastema morphogenesis, growth and pattern formation. Members of the Wnt family of secreted proteins are expressed in developing and regenerating limbs, and have the potential to control growth, pattern formation and differentiation. We have studied the expression of two non-canonical Wnt genes, Wnt-5a and Wnt-5b. We report that they are expressed in equivalent patterns during limb development and limb regeneration in the axolotl (Ambystoma mexicanum), and during limb development in other tetrapods, implying conservation of function. Our analysis of the effects of ectopic Wnt-5a expression is consistent with the hypothesis that canonical Wnt signaling functions during the early stages of regeneration to control the dedifferentiation of stump cells giving rise to the regeneration-competent cells of the blastema.

DiI Perfusion as a Method for Vascular Visualization in Ambystoma mexicanum.

Science.gov (United States)

Saltman, Anna J; Barakat, May; Bryant, Donald M; Brodovskaya, Anastasia; Whited, Jessica L

2017-06-16

Perfusion techniques have been used for centuries to visualize the circulation of tissues. Axolotl (Ambystoma mexicanum) is a species of salamander that has emerged as an essential model for regeneration studies. Little is known about how revascularization occurs in the context of regeneration in these animals. Here we report a simple method for visualization of the vasculature in axolotl via perfusion of 1,1'-Dioctadecy-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI). DiI is a lipophilic carbocyanine dye that inserts into the plasma membrane of endothelial cells instantaneously. Perfusion is done using a peristaltic pump such that DiI enters the circulation through the aorta. During perfusion, dye flows through the axolotl's blood vessels and incorporates into the lipid bilayer of vascular endothelial cells upon contact. The perfusion procedure takes approximately one hour for an eight-inch axolotl. Immediately after perfusion with DiI, the axolotl can be visualized with a confocal fluorescent microscope. The DiI emits light in the red-orange range when excited with a green fluorescent filter. This DiI perfusion procedure can be used to visualize the vascular structure of axolotls or to demonstrate patterns of revascularization in regenerating tissues.

Radiography of the equine thorax and its differential diagnosis relevance; Die differenzialdiagnostische Bedeutung der röntgenologischen Thoraxuntersuchung beim Pferd

Energy Technology Data Exchange (ETDEWEB)

Klein, H. J. [Klinik fuer Pferde, Tieraerztliche Hochschule Hannover (Germany); Offeney, F.

1990-07-01

Commonly chronic obstructive pulmonary disease (COPD) is the cause of dyspnoe or loss of performance in the horse. Tracheobronchoscopy, cytology of tracheobronchial aspirates, interpleural pressure measurement, and arterial blood gas analysis improved diagnosis of equine respiratory disorders. Yet some intrathoraeie diseases, especially chronic pneumonia, are differential diagnosis problems. Radiography of the thorax improves the diagnosis of pneumonia and some other intrathoraeie diseases. The technique of the radiography of the thorax is described and radiographic findings in 166 horses suffering from respiratory diseases are evaluated. Theses horses showed pathologic radiographic findings caused by COPD (n =61), pneumonia (67), pleuritis (12), exercise-induced pulmonary haemorrhage (8), aspiration pneumonia (7), hydrothorax (6), pneumothorax (2), lung abseess (1); mediastinal tumor (1), and diaphragmatie hernia (1) [German] Die chronisch obstruktive Bronchitis (COB) ist die häufigste Ursache von Atembeschwerden oder Leistungsmangel beim Pferd. Tracheobronchoskopie, Tracheobronchialsekretzytologie, interpleurale Druckmessung und arterielle Blutgasanalyse verbesserten die Diagnostik respiratorischer Erkrankungen. Dennoch bestehen Probleme hinsichtlich der Differentialdiagnose zur COB, und zwar insbesondere bei chronischen Pneumonien. Die röntgenologische Thoraxuntersuchung verbessert die Diagnose von Pneumonien und einigen anderen intrathorakalen Erkrankungen. Die Technik der röntgenologischen Thoraxuntersuchung wird beschrieben, und die Befunde von 166 Pferden mit Erkrankungen der Atemorgane werden ausgewertet. Diese Pferde zeigten pathologische Röntgenbefunde als Folge einer COB (n =61), einer Pneumonie (67), einer Pleuritis (12), eines belastungsinduzierten Lungenblutens (8), einer Aspirationspneumonie (7), eines Hydrothorax (6), eines Pneumothorax (2), eines Lungenabszesses (1), eines mediastinalen Tumors (1) und einer Zwerchfellhernie (1)

Ecological Risk Assessment of Perchlorate in Avian Species, Rodents, Amphibians and Fish

Science.gov (United States)

2003-04-01

http://www .indiana.edu/- axolotl ). 10.0 JUSTIFICATION OF TEST SYSTEM Perchlorate occurs in ground and surface waters in 44 states in the USA... axolotl ). * Sequentially numbered in order of the date that the change is effective Dept. of Biological Sciences (DBS) Box 43131 Lubbock, TX 79409...KCl, 0.025 giL; CaCh2 H20, 0.65 g/L; MgS04·7H20, 0.1 giL (http://www.indiana.edu/~ axolotl ). *Sequentially numbered in order of the date that the

Genic regions of a large salamander genome contain long introns and novel genes

Directory of Open Access Journals (Sweden)

Bryant Susan V

2009-01-01

Full Text Available Abstract Background The basis of genome size variation remains an outstanding question because DNA sequence data are lacking for organisms with large genomes. Sixteen BAC clones from the Mexican axolotl (Ambystoma mexicanum: c-value = 32 × 109 bp were isolated and sequenced to characterize the structure of genic regions. Results Annotation of genes within BACs showed that axolotl introns are on average 10× longer than orthologous vertebrate introns and they are predicted to contain more functional elements, including miRNAs and snoRNAs. Loci were discovered within BACs for two novel EST transcripts that are differentially expressed during spinal cord regeneration and skin metamorphosis. Unexpectedly, a third novel gene was also discovered while manually annotating BACs. Analysis of human-axolotl protein-coding sequences suggests there are 2% more lineage specific genes in the axolotl genome than the human genome, but the great majority (86% of genes between axolotl and human are predicted to be 1:1 orthologs. Considering that axolotl genes are on average 5× larger than human genes, the genic component of the salamander genome is estimated to be incredibly large, approximately 2.8 gigabases! Conclusion This study shows that a large salamander genome has a correspondingly large genic component, primarily because genes have incredibly long introns. These intronic sequences may harbor novel coding and non-coding sequences that regulate biological processes that are unique to salamanders.

Profiling neurotransmitter receptor expression in the Ambystoma mexicanum brain.

Science.gov (United States)

Reyes-Ruiz, Jorge Mauricio; Limon, Agenor; Korn, Matthew J; Nakamura, Paul A; Shirkey, Nicole J; Wong, Jamie K; Miledi, Ricardo

2013-03-22

Ability to regenerate limbs and central nervous system (CNS) is unique to few vertebrates, most notably the axolotl (Ambystoma sp.). However, despite the fact the neurotransmitter receptors are involved in axonal regeneration, little is known regarding its expression profile. In this project, RT-PCR and qPCR were performed to gain insight into the neurotransmitter receptors present in Ambystoma. Its functional ability was studied by expressing axolotl receptors in Xenopus laevis oocytes by either injection of mRNA or by direct microtransplantation of brain membranes. Oocytes injected with axolotl mRNA expressed ionotropic receptors activated by GABA, aspartate+glycine and kainate, as well as metabotropic receptors activated by acetylcholine and glutamate. Interestingly, we did not see responses following the application of serotonin. Membranes from the axolotl brain were efficiently microtransplanted into Xenopus oocytes and two types of native GABA receptors that differed in the temporal course of their responses and affinities to GABA were observed. Results of this study are necessary for further characterization of axolotl neurotransmitter receptors and may be useful for guiding experiments aimed at understanding activity-dependant limb and CNS regeneration. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

A Formal Approach to Discourse Anaphora

Science.gov (United States)

1978-05-01

was given a nut by Wendy, and Druce did 0 too. 0 = ? 41. The aardvark was given two peanuts for its birthday, and the axolotl was 0 too. 0...given two peanuts for its birthday 42. Wendy avoidf the aardvark, and the axolotl was 0 too. 0 = 7 In the case of multiple passives (such as are...the axolotl was 0 too. 0 = given an apple 45. Bert is a super dentist and his father was 0 too. 0 = (be) a super dentist Moreover, it appeals to me

Politik der Mikroentscheidungen: Edward Snowden, Netzneutralität und die Architekturen des Internets

OpenAIRE

Sprenger, Florian

2015-01-01

Ob beim Aufrufen einer Webseite, beim Versenden einer E-Mail oder beim Hochfrequenzhandel an der Börse: Auf ihrem Weg durch die Weiten digitaler Netze durchqueren Bits zahlreiche Knoten, an denen eine Reihe von Mikroentscheidungen getroffen werden. Diese Entscheidungen betreffen den besten Pfad zum Ziel, die Verarbeitungsgeschwindigkeit oder die Priorität zwischen den ankommenden Paketen. In ihrer vielschichtigen Gestalt bilden solche Mikroentscheidungen eine bislang nur marginal beachtete Di...

Urodele p53 tolerates amino acid changes found in p53 variants linked to human cancer

Directory of Open Access Journals (Sweden)

Villiard Éric

2007-09-01

Full Text Available Abstract Background Urodele amphibians like the axolotl are unique among vertebrates in their ability to regenerate and their resistance to develop cancers. It is unknown whether these traits are linked at the molecular level. Results Blocking p53 signaling in axolotls using the p53 inhibitor, pifithrin-α, inhibited limb regeneration and the expression of p53 target genes such as Mdm2 and Gadd45, suggesting a link between tumor suppression and regeneration. To understand this relationship we cloned the p53 gene from axolotl. When comparing its sequence with p53 from other organisms, and more specifically human we observed multiple amino acids changes found in human tumors. Phylogenetic analysis of p53 protein sequences from various species is in general agreement with standard vertebrate phylogeny; however, both mice-like rodents and teleost fishes are fast evolving. This leads to long branch attraction resulting in an artefactual basal emergence of these groups in the phylogenetic tree. It is tempting to assume a correlation between certain life style traits (e.g. lifespan and the evolutionary rate of the corresponding p53 sequences. Functional assays of the axolotl p53 in human or axolotl cells using p53 promoter reporters demonstrated a temperature sensitivity (ts, which was further confirmed by performing colony assays at 37°C. In addition, axolotl p53 was capable of efficient transactivation at the Hmd2 promoter but has moderate activity at the p21 promoter. Endogenous axolotl p53 was activated following UV irradiation (100 j/m2 or treatment with an alkylating agent as measured using serine 15 phosphorylation and the expression of the endogenous p53 target Gadd45. Conclusion Urodele p53 may play a role in regeneration and has evolved to contain multiple amino acid changes predicted to render the human protein defective in tumor suppression. Some of these mutations were probably selected to maintain p53 activity at low temperature. However

Microarray analysis of a salamander hopeful monster reveals transcriptional signatures of paedomorphic brain development

Science.gov (United States)

2010-01-01

Background The Mexican axolotl (Ambystoma mexicanum) is considered a hopeful monster because it exhibits an adaptive and derived mode of development - paedomorphosis - that has evolved rapidly and independently among tiger salamanders. Unlike related tiger salamanders that undergo metamorphosis, axolotls retain larval morphological traits into adulthood and thus present an adult body plan that differs dramatically from the ancestral (metamorphic) form. The basis of paedomorphic development was investigated by comparing temporal patterns of gene transcription between axolotl and tiger salamander larvae (Ambystoma tigrinum tigrinum) that typically undergo a metamorphosis. Results Transcript abundances from whole brain and pituitary were estimated via microarray analysis on four different days post hatching (42, 56, 70, 84 dph) and regression modeling was used to independently identify genes that were differentially expressed as a function of time in both species. Collectively, more differentially expressed genes (DEGs) were identified as unique to the axolotl (n = 76) and tiger salamander (n = 292) than were identified as shared (n = 108). All but two of the shared DEGs exhibited the same temporal pattern of expression and the unique genes tended to show greater changes later in the larval period when tiger salamander larvae were undergoing anatomical metamorphosis. A second, complementary analysis that directly compared the expression of 1320 genes between the species identified 409 genes that differed as a function of species or the interaction between time and species. Of these 409 DEGs, 84% exhibited higher abundances in tiger salamander larvae at all sampling times. Conclusions Many of the unique tiger salamander transcriptional responses are probably associated with metamorphic biological processes. However, the axolotl also showed unique patterns of transcription early in development. In particular, the axolotl showed a genome-wide reduction in mRNA abundance

Microarray analysis of a salamander hopeful monster reveals transcriptional signatures of paedomorphic brain development

Directory of Open Access Journals (Sweden)

Putta Srikrishna

2010-06-01

Full Text Available Abstract Background The Mexican axolotl (Ambystoma mexicanum is considered a hopeful monster because it exhibits an adaptive and derived mode of development - paedomorphosis - that has evolved rapidly and independently among tiger salamanders. Unlike related tiger salamanders that undergo metamorphosis, axolotls retain larval morphological traits into adulthood and thus present an adult body plan that differs dramatically from the ancestral (metamorphic form. The basis of paedomorphic development was investigated by comparing temporal patterns of gene transcription between axolotl and tiger salamander larvae (Ambystoma tigrinum tigrinum that typically undergo a metamorphosis. Results Transcript abundances from whole brain and pituitary were estimated via microarray analysis on four different days post hatching (42, 56, 70, 84 dph and regression modeling was used to independently identify genes that were differentially expressed as a function of time in both species. Collectively, more differentially expressed genes (DEGs were identified as unique to the axolotl (n = 76 and tiger salamander (n = 292 than were identified as shared (n = 108. All but two of the shared DEGs exhibited the same temporal pattern of expression and the unique genes tended to show greater changes later in the larval period when tiger salamander larvae were undergoing anatomical metamorphosis. A second, complementary analysis that directly compared the expression of 1320 genes between the species identified 409 genes that differed as a function of species or the interaction between time and species. Of these 409 DEGs, 84% exhibited higher abundances in tiger salamander larvae at all sampling times. Conclusions Many of the unique tiger salamander transcriptional responses are probably associated with metamorphic biological processes. However, the axolotl also showed unique patterns of transcription early in development. In particular, the axolotl showed a genome

Value of radiographic examination of the knee joint for the orthopedic surgeon; Wertigkeit der radiologischen Bildgebung beim Kniegelenk fuer den Orthopaeden

Energy Technology Data Exchange (ETDEWEB)

Pietsch, M.; Hofmann, S. [Allgemeines und Orthopaedisches LKH Stolzalpe (Austria). Abteilung fuer Orthopaedie und orthopaedische Chirurgie

2006-01-01

Extended radiographic examinations offer excellent options for diagnosis and strategy for treatment of the knee joint. The whole-leg radiograph is indispensable in measuring alignment for osteotomy or total knee arthroplasty (TKA). Fluoroscopically assisted varus-valgus stress radiographs provide the possibility for verifying mechanical function of the implanted knee prosthesis. Ultrasound examinations have been widely replaced by magnetic resonance imaging (MRI). MRI is the golden standard to examine intra-articular structures of the knee (meniscus, ligaments, cartilage) and surrounding soft tissue. For evaluating femoral and tibial torsion and determining axial rotation of TKA, computed tomography (CT) is best qualified. Imaging of the patellofemoral joint (patella instability) is difficult; CT scans in combination with true lateral radiographs seem to be helpful. (orig.) [German] Die erweiterte Roentgendiagnostik bietet gute Moeglichkeiten der Diagnose und Therapieplanung beim Kniegelenk. Das Ganzbeinroentgen ist unabdingbar zur Achsvermessung bei der Planung einer Umstellungsosteotomie oder der Implantation einer Knietotalendoprothese (KTEP). Varus-/Valgusaufnahmen unter Bildwandler gestatten die Ueberpruefung der Mechanik einer liegenden KTEP. Sonographische Untersuchungen des Kniegelenks sind weitgehend durch die Magnetresonanztomographie (MRT) ersetzt. Die MRT ist die Methode der Wahl zur Beurteilung der Kniebinnenstrukturen (Meniskus, Baender, Knorpel) und der umgebenden Weichteile. Zur Bestimmung der Torsion von Femur und Tibia sowie der Rotation der Komponenten einer KTEP ist die Computertomographie (CT) am besten geeignet. Die Beurteilung des Femorpatellargelenks (Patellainstabilitaet) ist schwierig, am vielversprechendsten erscheint die CT in Kombination mit streng seitlichen Roentgenbildern. (orig.)

Ion transport by the amphibian primary ureter

DEFF Research Database (Denmark)

Møbjerg, Nadja

2008-01-01

putative ion transport mechanisms in the primary ureter of the freshwater amphibian Ambystoma mexicanum (axolotl). Primary ureters isolated from axolotl larvae were perfused in vitro and single cells were impaled across the basal cell membrane with glass microelectrodes. In 42 cells the membrane potential......+] steps from 3 to 20 mmol/l and a hyperpolarization of Vm upon lowering [Na+] from 102 to 2 mmol/l, indicating the presence of luminal K+ and Na+ conductances. This study provides the first functional data on the vertebrate primary ureter. The data show that the primary ureter of axolotl larvae...

Transcriptome dynamics along axolotl regenerative development are consistent with an extensive reduction in gene expression heterogeneity in dedifferentiated cells

Directory of Open Access Journals (Sweden)

Carlos Díaz-Castillo

2017-11-01

Full Text Available Although in recent years the study of gene expression variation in the absence of genetic or environmental cues or gene expression heterogeneity has intensified considerably, many basic and applied biological fields still remain unaware of how useful the study of gene expression heterogeneity patterns might be for the characterization of biological systems and/or processes. Largely based on the modulator effect chromatin compaction has for gene expression heterogeneity and the extensive changes in chromatin compaction known to occur for specialized cells that are naturally or artificially induced to revert to less specialized states or dedifferentiate, I recently hypothesized that processes that concur with cell dedifferentiation would show an extensive reduction in gene expression heterogeneity. The confirmation of the existence of such trend could be of wide interest because of the biomedical and biotechnological relevance of cell dedifferentiation-based processes, i.e., regenerative development, cancer, human induced pluripotent stem cells, or plant somatic embryogenesis. Here, I report the first empirical evidence consistent with the existence of an extensive reduction in gene expression heterogeneity for processes that concur with cell dedifferentiation by analyzing transcriptome dynamics along forearm regenerative development in Ambystoma mexicanum or axolotl. Also, I briefly discuss on the utility of the study of gene expression heterogeneity dynamics might have for the characterization of cell dedifferentiation-based processes, and the engineering of tools that afforded better monitoring and modulating such processes. Finally, I reflect on how a transitional reduction in gene expression heterogeneity for dedifferentiated cells can promote a long-term increase in phenotypic heterogeneity following cell dedifferentiation with potential adverse effects for biomedical and biotechnological applications.

Transcriptome dynamics along axolotl regenerative development are consistent with an extensive reduction in gene expression heterogeneity in dedifferentiated cells

Science.gov (United States)

2017-01-01

Although in recent years the study of gene expression variation in the absence of genetic or environmental cues or gene expression heterogeneity has intensified considerably, many basic and applied biological fields still remain unaware of how useful the study of gene expression heterogeneity patterns might be for the characterization of biological systems and/or processes. Largely based on the modulator effect chromatin compaction has for gene expression heterogeneity and the extensive changes in chromatin compaction known to occur for specialized cells that are naturally or artificially induced to revert to less specialized states or dedifferentiate, I recently hypothesized that processes that concur with cell dedifferentiation would show an extensive reduction in gene expression heterogeneity. The confirmation of the existence of such trend could be of wide interest because of the biomedical and biotechnological relevance of cell dedifferentiation-based processes, i.e., regenerative development, cancer, human induced pluripotent stem cells, or plant somatic embryogenesis. Here, I report the first empirical evidence consistent with the existence of an extensive reduction in gene expression heterogeneity for processes that concur with cell dedifferentiation by analyzing transcriptome dynamics along forearm regenerative development in Ambystoma mexicanum or axolotl. Also, I briefly discuss on the utility of the study of gene expression heterogeneity dynamics might have for the characterization of cell dedifferentiation-based processes, and the engineering of tools that afforded better monitoring and modulating such processes. Finally, I reflect on how a transitional reduction in gene expression heterogeneity for dedifferentiated cells can promote a long-term increase in phenotypic heterogeneity following cell dedifferentiation with potential adverse effects for biomedical and biotechnological applications. PMID:29134148

Diagnostic radiology on multiple injured patients: interdisciplinary management; Radiologische Diagnostik beim Polytrauma: interdisziplinaeres Management

Energy Technology Data Exchange (ETDEWEB)

Linsenmaier, U.; Pfeifer, K.J. [Inst. fuer Radiologische Diagnostik, Klinikum der Univ. Muenchen (Germany); Kanz, K.G.; Mutschler, W. [Chirurgische Klinik Innenstadt, Klinikum der Univ. Muenchen, (Germany)

2001-06-01

The presence of a radiologist within the admitting area of an emergency department and his capability as a member of the trauma team have a major impact on the role of diagnostic radiology in trauma care. The knowledge of clinical decision criteria, algorithms, and standards of patient care are essential for the acceptance within a trauma team. We present an interdisciplinary management concept of diagnostic radiology for trauma patients, which comprises basic diagnosis, organ diagnosis, radiological ABC, and algorithms of early clinical care. It is the result of a prospective study comprising over 2000 documented multiple injured patients. The radiologist on a trauma team should support trauma surgery and anesthesia in diagnostic and clinical work-up. The radiological ABC provides a structured approach for diagnostic imaging in all steps of the early clinical care of the multiple injured patient. Radiological ABC requires a reevaluation in cases of equivocal findings or difficulties in the clinical course. Direct communication of radiological findings with the trauma team enables quick clinical decisions. In addition, the radiologist can priority-oriented influence the therapy by using interventional procedures. The clinical radiologist is an active member of the interdisciplinary trauma team, not only providing diagnostic imaging but also participating in clinical decisions. (orig.) [German] Die Anwesenheit des Radiologen im Schockraum und dessen Teamfaehigkeit bestimmen den Status der diagnostischen Radiologie in der Traumaversorgung. Voraussetzung zur Mitarbeit im interdisziplinaeren Traumateam ist die detaillierte Kenntnis der wesentlichen Entscheidungskriterien, Algorithmen und Behandlungsablaeufe. Das hier vorgestellte interdisziplinaere Managementkonzept der radiologischen Diagnostik beim Polytrauma mit Basisdiagnostik, Organdiagnostik, radiologischer ABC-Regel und Algorithmen zur fruehklinischen Behandlung beruht auf einer prospektiven Polytraumastudie mit

Dicty_cDB: Contig-U11847-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available 00512_699( AE000512 |pid:none) Thermotoga maritima MSB8, comple... 42 0.065 JC2551( JC2551 ) tropomyosin alpha chain - axolotl...AltName: Full=Myosin heavy chai... 42 0.11 JC6199( JC6199 ) alpha-tropomyosin S-1 - axolotl &U33450_1(U33450

Volumetry of metastases from renal cell carcinoma. Comparison with the RECIST criteria; Volumetrie von Metastasen beim Nierenzellkarzinom. Vergleich mit den RECIST-Kriterien

Energy Technology Data Exchange (ETDEWEB)

Graser, A.; Becker, C.R.; Reiser, M.F. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany); Stief, C.; Staehler, M. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen, Klinik und Poliklinik fuer Urologie, Muenchen (Germany)

2008-09-15

For patients with metastasized renal cell carcinoma (RCC), imaging techniques are of great importance. Currently, therapy widely relies on antiangiogenic factors, which frequently lead to relatively subtle changes in the size of lesions. From this aspect the commonly used RECIST criteria (response evaluation criteria in solid tumors) must be considered as imprecise for the evaluation of the response to therapy. This article gives a review on new software-based volumetric methods, which allow therapy-induced changes in the size of metastases from RCC to be detected with higher sensitivity and reproducibility. A comparison of RECIST and volumetry was carried out with data from patients with metastasized RCC to demonstrate the higher sensitivity of the 3D volumetric procedure. (orig.) [German] Bei Patienten mit metastasiertem Nierenzellkarzinom werden an die Bildgebung besondere Anforderungen gestellt. Die Therapie beruht heute in den meisten Faellen auf antiangiogenetischen Wirkstoffen, die im Verlauf teils zu relativ geringen Groessenaenderungen von Laesionen fuehren. Daher sind die oftmals verwendeten RECIST-Kriterien (''response evaluation criteria in solid tumors'') bei der Beurteilung des Therapieansprechens als ungenau anzusehen. In diesem Artikel wird ein Ueberblick ueber neue, softwarebasierte volumetrische Methoden gegeben, die es ermoeglichen, therapieinduzierte Groessenaenderungen von Metastasen beim Nierenzellkarzinom mit hoeherer Sensitivitaet und Reproduzierbarkeit zu detektieren. Anhand eigener Daten wird ein Vergleich von RECIST und Volumetrie bei Patienten mit metastasiertem Nierenzellkarzinom durchgefuehrt und die hoehere Sensitivitaet des automatisierten Verfahrens gezeigt. (orig.)

Intracellular Signalling in Retinal Ischemia

Science.gov (United States)

1990-07-01

spatial buffering capacity of the Miller cells of axolotl retina indicated that gap junctional coupling can increase the capacity of the Muller cell to...1974. 27 33. Mobbs P, Brew H, and Atwell D: A quantitative analysis of glial cell coupling in the retina of the axolotl (Ambystoma mexicanum). Brain

The value of radiotherapy in comparison with extracorporeal shockwave therapy for supraspinatus tendinitis; Die Wertigkeit der Strahlenbehandlung im Vergleich zur extrakorporalen Stosswellentherapie (ESWT) beim Supraspinatussehnensyndrom

Energy Technology Data Exchange (ETDEWEB)

Gross, M.W.; Engenhart-Cabillic, R. [Klinik fuer Strahlentherapie und Radioonkologie der Philipps-Univ. Marburg (Germany); Sattler, A.; Haake, M.; Schmitt, J.; Hildebrandt, R. [Orthopaedische Klinik der Philipps-Univ. Marburg (Germany); Mueller, H.H. [Inst. fuer Medizinische Biometrie und Epidemiologie, Philipps-Univ. Marburg (Germany)

2002-06-01

Background and Aim: Supraspinatus tendinitis is usually treated by antiinflammatoric drugs, local injections, physiotherapy or low-dose irradiation. A novel approach is the use of extracorporeal shock wave therapy (ESWT) if conservative therapies have failed. So far there has been no controlled study comparing the effectiveness of ESWT with an established conservative method of therapy such as X-ray stimulation radiotherapy. Patients and Methods: 30 patients with chronic supraspinatus tendinitis were admitted into the prospective randomized study. After randomization the patients were treated either with X-ray stimulation radiotherapy with 6 x 0.5 Gy on the ICRU reference point (1 fraction/day) with cobalt 60 gamma rays or three times with 2000 pulses (energy flux density ED+ 0.1 mJ/mm{sup 2}) in 1 week intervals using a Storz Minilith SL1. Primary endpoint was the age-corrected constant score 3 months after intervention. Results: Acute side effects caused by the irradiation were not observed, as expected. One patient described pain and one patient showed a moderate skin irritation after ESWT. In the radiotherapy group average the age-corrected constant score improved from 47.6 through 79.5 points to 87.4 points. In the ESWT group it rose from 50.1 points before ESWT to 91.4 points after 12 weeks and 97.8 after 52 weeks. Conclusion: No statistically significant differences were proven between ESWT and radiotherapy. ESWT appears to be equivalent but not superior to radiotherapy in treating chronic supraspinatus tendinitis syndrome. A comprehensive randomized study is, however, necessary to ensure the equivalence of ESWT. (orig.) [German] Hintergrund und Studienziel: Neben den medikamentoesen Therapieverfahren stehen beim Supraspinatussehnensyndrom die niedrig dosierte Strahlentherapie und, als neuere Methode, die extrakorporale Stosswellentherapie (ESWT) zur Verfuegung. Bislang fehlt jedoch eine kontrollierte Studie, die die Wirksamkeit der ESWT im Vergleich zur

Electrically Mediated Trauma Repair

Science.gov (United States)

1994-07-07

potential (TEP) (Johnston and Hoshiko, 1971; Rick et al., 1988; Shi and Borgens, 1994). In the axolotl neurulae, a gradient of 10 - 20 mV/mm is...reach 60-80 mV/mm. A more shallow voltage gradient is observed in the transverse plane of axolotl neurulae associated with mirror image outwardly

Clostridium perfringens challenge and dietary fat type modifies performance, microbiota composition and histomorphology of the broiler chicken gastrointestinal tract

DEFF Research Database (Denmark)

Josefiak, Damian; Swiatkiewicz, S; Kieronczyk, B

2016-01-01

Belastung mit Clostridium perfringens und Futterfettquelle modifizieren die Leistung, die Zusammensetzung der Microbiota und die Histomorphologie des Verdauungstraktes beim Broiler......Belastung mit Clostridium perfringens und Futterfettquelle modifizieren die Leistung, die Zusammensetzung der Microbiota und die Histomorphologie des Verdauungstraktes beim Broiler...

Functional characterization of the vertebrate primary ureter: Structure and ion transport mechanisms of the pronephric duct in axolotl larvae (Amphibia

Directory of Open Access Journals (Sweden)

Prehn Lea R

2010-05-01

Full Text Available Abstract Background Three kidney systems appear during vertebrate development: the pronephroi, mesonephroi and metanephroi. The pronephric duct is the first or primary ureter of these kidney systems. Its role as a key player in the induction of nephrogenic mesenchyme is well established. Here we investigate whether the duct is involved in urine modification using larvae of the freshwater amphibian Ambystoma mexicanum (axolotl as model. Results We investigated structural as well as physiological properties of the pronephric duct. The key elements of our methodology were: using histology, light and transmission electron microscopy as well as confocal laser scanning microscopy on fixed tissue and applying the microperfusion technique on isolated pronephric ducts in combination with single cell microelectrode impalements. Our data show that the fully differentiated pronephric duct is composed of a single layered epithelium consisting of one cell type comparable to the principal cell of the renal collecting duct system. The cells are characterized by a prominent basolateral labyrinth and a relatively smooth apical surface with one central cilium. Cellular impalements demonstrate the presence of apical Na+ and K+ conductances, as well as a large K+ conductance in the basolateral cell membrane. Immunolabeling experiments indicate heavy expression of Na+/K+-ATPase in the basolateral labyrinth. Conclusions We propose that the pronephric duct is important for the subsequent modification of urine produced by the pronephros. Our results indicate that it reabsorbs sodium and secretes potassium via channels present in the apical cell membrane with the driving force for ion movement provided by the Na+/K+ pump. This is to our knowledge the first characterization of the pronephric duct, the precursor of the collecting duct system, which provides a model of cell structure and basic mechanisms for ion transport. Such information may be important in understanding

Dimensioning of activation systems using submerged membranes at municipal sewage treatment plants; Bemessung von Membranbelebungsanlagen beim Einsatz zur Reinigung kommunaler Abwaesser

Energy Technology Data Exchange (ETDEWEB)

Ohle, P.; Dorgeloh, E. [Technische Hochschule Aachen (DE). Inst. fuer Siedlungswasserwirtschaft (ISA)

1999-07-01

Dimensioning of conventional activation systems in Germany as a rule relies on instruction sheet A131 of the Abwassertechnische Vereinigung or follows the Hochschulgruppen approach (HSG). They contain recommendations as to the size of the nitrification and denitrification zones, the amount of oxygen supplied and sludge production, and the size of the final sedimentation tank. For the use of sludge activation techniques by means of submerged membranes at municipal sewage treatment plant there so far do not exist any clues to dimensioning that make allowance for the modified boundary conditions. The present paper analyses instruction sheet A131 for its suitability as a basis in the dimensioning of sludge activation systems with submerged membranes at municipal sewage treatment plant. Then the dimensioning instructions are modified to suit the changed boundary conditions, and recommendations for the dimensioning of activation systems with submerged membranes on the basis of extensive studies carried out at the Institut fuer Siedlungswasserwirtschaft ISA of Aachen Technical University RWTH are given. (orig.) [German] Die Bemessung konventioneller Belebungsverfahren erfolgt in Deutschland i.d.R. auf der Grundlage des Arbeitsblatts A 131 der Abwassertechnischen Vereinigung bzw. nach dem Hochschulgruppenansatz (HSG). Sie enthalten Empfehlungen bezueglich der Dimensionierung von Nitrifikations- und Denitrifikationszone, Sauerstoffversorgung, Schlammproduktion und Nachklaerbecken. Fuer den Einsatz von Membranbelebungsanlagen in kommunalen Klaeranlagen existieren bislang keine Bemessungshinweise, die den veraenderten Randbedingungen Rechnung tragen. Der vorliegende Beitrag analysiert das Arbeitsblatt A 131 in Hinsicht auf die Moeglichkeit zur Anwendung fuer die Bemessung von Membranbelebungsanlagen beim Einsatz zur kommunalen Abwasserreinigung. Im Weiteren erfolgt die Modifikation der Bemessungshinweise hinsichtlich der geaenderten Randbedingungen und die Angabe von

Senescence gives insights into the morphogenetic evolution of anamniotes

Directory of Open Access Journals (Sweden)

Éric Villiard

2017-06-01

Full Text Available Senescence represents a mechanism to avoid undesired cell proliferation that plays a role in tumor suppression, wound healing and embryonic development. In order to gain insight on the evolution of senescence, we looked at its presence in developing axolotls (urodele amphibians and in zebrafish (teleost fish, which are both anamniotes. Our data indicate that cellular senescence is present in various developing structures in axolotls (pronephros, olfactory epithelium of nerve fascicles, lateral organs, gums and in zebrafish (epithelium of the yolk sac and in the lower part of the gut. Senescence was particularly associated with transient structures (pronephros in axolotls and yolk sac in zebrafish suggesting that it may play a role in the elimination of these tissues. Our data supports the notion that cellular senescence evolved early in vertebrate evolution to influence embryonic development.

Anatomy of the pectoral and forelimb muscles of wildtype and green fluorescent protein-transgenic axolotls and comparison with other tetrapods including humans: a basis for regenerative, evolutionary and developmental studies

Science.gov (United States)

Diogo, R; Tanaka, E M

2012-01-01

The axolotl Ambystoma mexicanum is one of the most used model organisms in evolutionary, developmental and regenerative studies, particularly because it can reconstitute a fully functional and complete forelimb/hindlimb. Surprisingly, there is no publication that describes all the pectoral and forelimb muscles of this species or provides a comparative framework between these muscles and those of other model organisms and of modern humans. In the present paper we describe and illustrate all these muscles in A. mexicanum and provide the first report about the myology of adults of a model organism that is based on analyses and dissections of both wildtype animals and transgenic animals that express green fluorescent protein (GFP) in muscle fibers. On the one hand, the inclusion of GFP-transgenic animals allows us to show the muscles as more commonly seen, and thus easier to understand, by current developmental and regenerative biologists. On the other hand, by including wildtype and GFP-transgenic animals and by visualizing these latter animals with and without a simultaneous transmission laser light, we were able to obtain a more complete and clearer understanding of the exact limit of the fleshy and tendinous parts of the muscles and their specific connections with the skeletal elements. This in turn allowed us to settle some controversies in previous anatomical and comparative studies. As most developmental, regenerative and evolutionary biologists are interested in comparing their observations of A. mexicanum with observations in other model organisms, and ultimately in using this information to increase the understanding of human evolution and medicine, we also provide tables showing the homologies between the pectoral and forelimb muscles of axolotls, of model organisms such as mice, frogs and chicken, and of Homo sapiens. An example illustrating the outcomes of using our methodology and of our observations is that they revealed that, contrary to what is often

Anatomy of the pectoral and forelimb muscles of wildtype and green fluorescent protein-transgenic axolotls and comparison with other tetrapods including humans: a basis for regenerative, evolutionary and developmental studies.

Science.gov (United States)

Diogo, R; Tanaka, E M

2012-12-01

The axolotl Ambystoma mexicanum is one of the most used model organisms in evolutionary, developmental and regenerative studies, particularly because it can reconstitute a fully functional and complete forelimb/hindlimb. Surprisingly, there is no publication that describes all the pectoral and forelimb muscles of this species or provides a comparative framework between these muscles and those of other model organisms and of modern humans. In the present paper we describe and illustrate all these muscles in A. mexicanum and provide the first report about the myology of adults of a model organism that is based on analyses and dissections of both wildtype animals and transgenic animals that express green fluorescent protein (GFP) in muscle fibers. On the one hand, the inclusion of GFP-transgenic animals allows us to show the muscles as more commonly seen, and thus easier to understand, by current developmental and regenerative biologists. On the other hand, by including wildtype and GFP-transgenic animals and by visualizing these latter animals with and without a simultaneous transmission laser light, we were able to obtain a more complete and clearer understanding of the exact limit of the fleshy and tendinous parts of the muscles and their specific connections with the skeletal elements. This in turn allowed us to settle some controversies in previous anatomical and comparative studies. As most developmental, regenerative and evolutionary biologists are interested in comparing their observations of A. mexicanum with observations in other model organisms, and ultimately in using this information to increase the understanding of human evolution and medicine, we also provide tables showing the homologies between the pectoral and forelimb muscles of axolotls, of model organisms such as mice, frogs and chicken, and of Homo sapiens. An example illustrating the outcomes of using our methodology and of our observations is that they revealed that, contrary to what is often

Diagnostic imaging in polytrauma: comparison of radiation exposure from whole-body MSCT and conventional radiography with organ-specific CT; Radiologische Bildgebung beim Polytrauma: Dosisvergleich von Ganzkoerper-MSCT und konventionellem Roentgen mit organspezifischer CT

Energy Technology Data Exchange (ETDEWEB)

Wedegaertner, U.; Lorenzen, M.; Weber, C.; Adam, G. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Nagel, H.D. [Philips Medizin Systeme GmbH, Hamburg (Germany)

2004-07-01

Purpose: To compare the radiation dose of whole-body multislice CT (MSCT) and conventional radiography with organ-specific CT in polytrauma. Materials and Methods: The whole-body MSCT encompassing brain, neck and midface, chest, abdomen and pelvis was performed on a Somatom Volume Zoom (Siemens). Conventional radiography consisted of chest and cervical, thoracic and lumbar spine in two views as well as pelvis. Polymat, Siemens. Three combinations of organ specific CT were chosen: CT examination of (1) head and cervical spine, (2) head, cervical spine and chest, (3) head, cervical spine and abdomen. The effective doses of whole-body MSCT and conventional radiography with organ-specific CT were calculated. Results: Effective doses were 20 mSv for whole-body MSCT, 2 mSv for conventional x-ray, and 5 mSv for combination (1), 8 mSv for combination (2) and (3) 16 mSv for combination (3) of the organ-specific CT. The ratio of radiation dose between whole-body MSCT and radiography was 10: 1. This ratio was reduced to 3: 1, 2: 1 and 1: 1 when a combination of radiography and CT was performed. Conclusions: Whole-body MSCT in polytrauma compared to conventional radiography with organ-specific CT induces a threefold increased dose in unfavorable situations and no increased dose in favorable situations. Nevertheless, routine use of whole-body MSCT should be critically evaluated and should be adapted to the clinical benefit. (orig.) [German] Ziel: Dosisvergleich von Ganzkoerper-MSCT und konventioneller Basisdiagnostik mit organspezifischen Ct-Untersuchungen beim Polytrauma. Material und Methoden: Die Ganzkoerper-MSCT-Untersuchung von Schaedel, Mittelgesicht, HWS sowie Thorax, Abdomen und Becken erfolgte an einem Somatom-Volume-Zoom (Siemens). Die konventionelle Bildgebung, bestehend aus Thorax, Becken, HWS, BWS und LWs, wurde an einem Siemens-Polymat durchgefuehrt. Fuer die organspezifischen CT-Untersuchungen wurden 3 Kombinationen ausgewaehlt: (1) CCT + HWS, (2) CCT + HWS

An Aryl Hydrocarbon Receptor from the Salamander Ambystoma mexicanum Exhibits Low Sensitivity to 2,3,7,8-Tetrachlorodibenzo-p-dioxin.

Science.gov (United States)

Shoots, Jenny; Fraccalvieri, Domenico; Franks, Diana G; Denison, Michael S; Hahn, Mark E; Bonati, Laura; Powell, Wade H

2015-06-02

Structural features of the aryl hydrocarbon receptor (AHR) can underlie species- and population-specific differences in its affinity for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). These differences often explain variations in TCDD toxicity. Frogs are relatively insensitive to dioxin, and Xenopus AHRs bind TCDD with low affinity. Weak TCDD binding results from the combination of three residues in the ligand-binding domain: A354 and A370, and N325. Here we sought to determine whether this mechanism of weak TCDD binding is shared by other amphibian AHRs. We isolated an AHR cDNA from the Mexican axolotl (Ambystoma mexicanum). The encoded polypeptide contains identical residues at positions that confer low TCDD affinity to X. laevis AHRs (A364, A380, and N335), and homology modeling predicts they protrude into the binding cavity. Axolotl AHR bound one-tenth the TCDD of mouse AHR in velocity sedimentation analysis, and in transactivation assays, the EC50 for TCDD was 23 nM, similar to X. laevis AHR1β (27 nM) and greater than AHR containing the mouse ligand-binding domain (0.08 nM). Sequence, modeled structure, and function indicate that axolotl AHR binds TCDD weakly, predicting that A. mexicanum lacks sensitivity toTCDD toxicity. We hypothesize that this characteristic of axolotl and Xenopus AHRs arose in a common ancestor of the Caudata and Anura.

Virtual Genome Walking across the 32 Gb Ambystoma mexicanum genome; assembling gene models and intronic sequence.

Science.gov (United States)

Evans, Teri; Johnson, Andrew D; Loose, Matthew

2018-01-12

Large repeat rich genomes present challenges for assembly using short read technologies. The 32 Gb axolotl genome is estimated to contain ~19 Gb of repetitive DNA making an assembly from short reads alone effectively impossible. Indeed, this model species has been sequenced to 20× coverage but the reads could not be conventionally assembled. Using an alternative strategy, we have assembled subsets of these reads into scaffolds describing over 19,000 gene models. We call this method Virtual Genome Walking as it locally assembles whole genome reads based on a reference transcriptome, identifying exons and iteratively extending them into surrounding genomic sequence. These assemblies are then linked and refined to generate gene models including upstream and downstream genomic, and intronic, sequence. Our assemblies are validated by comparison with previously published axolotl bacterial artificial chromosome (BAC) sequences. Our analyses of axolotl intron length, intron-exon structure, repeat content and synteny provide novel insights into the genic structure of this model species. This resource will enable new experimental approaches in axolotl, such as ChIP-Seq and CRISPR and aid in future whole genome sequencing efforts. The assembled sequences and annotations presented here are freely available for download from https://tinyurl.com/y8gydc6n . The software pipeline is available from https://github.com/LooseLab/iterassemble .

Gender-Pay-Gap

OpenAIRE

Eicker, Jannis

2017-01-01

Der Gender-Pay-Gap ist eine statistische Kennzahl zur Messung der Ungleichheit zwischen Männern* und Frauen* beim Verdienst. Es gibt zwei Versionen: einen "unbereinigten" und einen "bereinigten". Der "unbereinigte" Gender-Pay-Gap berechnet den geschlechtsspezifischen Verdienstunterschied auf Basis der Bruttostundenlöhne aller Männer* und Frauen* der Grundgesamtheit. Beim "bereinigten" Wert hingegen werden je nach Studie verschiedene Faktoren wie Branche, Position und Berufserfahrung herausger...

Hibridez y metamorfosis en Juan Villoro: el universo mágico-mitológico del ajolote

Directory of Open Access Journals (Sweden)

An Van Hecke

2014-06-01

This study focuses on the symbolic meanings of the axolotl in Juan Villoro’s novel Materia dispuesta and the way the author approaches the concept of identity from both, the adolescent protagonist and Mexicans in general. This novel will be read in light of Roger Bartra’s essay, La jaula de la melancolía. Bartra uses the metaphor of the axolotl to analyse the concept of metamorphosis in the Mexican identity. Thereafter, Villoro’s novel will be compared with Julio Cortazar’s short story “Axolotl”, and Octavio Paz’s poem “Salamandra”. This comparison will allow to amplify the perspective and deepen the analysis of this hybrid animal by Villoro. The study of the axolotl demonstrates that Villoro revives the ancient aztec mythology about this amphibian, that was the representation of the god Xolotl, and that he introduces at the same time new meanings. It is in that combination of both perspectives that the richness of Villoro’s literary universe will be revealed.

About the effect of melted zinc mass additives on the formation on layers during hot galvanizing; Zur Wirkung von Zusaetzen zur Zinkschmelze auf die Schichtbildung beim Feuerverzinken

Energy Technology Data Exchange (ETDEWEB)

Schubert, P.; Schulz, W.D. [Institut fuer Korrosionsschutz Dresden GmbH, Gostritzer Str. 61-63, D-01217 Dresden (Germany)

2002-09-01

The influence of various melted zinc mass additives on the galvanizing behaviour of steels is examined by way of comparison. The mechanisms influencing the formation of layers are very different. In case tin is added, a material barrier of enriched tin develops in the zinc coating, which inhibits the iron transport. The mechanisms of Ni, Ti and Al in the melted zinc mass are explained by means of a new theory on the formation of layers, which is based on the influence of the growth of layers via hydrogen escaping from the steel surface during hot galvanizing. This behaviour makes it clear why the single melted mass additives only have a layer-thickness reducing effect on steels with very definite Si contents. The different inhibitions of the growth of the layer during hot galvanizing are discussed. (Abstract Copyright[2002], Wiley Periodicals, Inc.) [German] Der Einfluss unterschiedlicher Zinkschmelzezusaetze auf das Verzinkungsverhalten der Staehle wird vergleichend untersucht. Die Mechanismen der Einflussnahme auf die Schichtbildung sind sehr unterschiedlich. Bei Zusatz von Zinn entsteht im Zinkueberzug eine Materialbarriere aus angereichertem Zinn, die den Eisentransport hemmt. Die Wirkungsweise von Ni, Ti und Al in der Zinkschmelze wird mit Hilfe einer neuen Theorie der Schichtbildung erklaert. Diese beruht auf der Beeinflussung des Schichtwachstums durch Wasserstoff, der waehrend des Feuerverzinkens aus der Stahloberflaeche austritt. Diese Erklaerung macht verstaendlich, warum die einzelnen Schmelzezusaetze nur bei Staehlen mit ganz bestimmten Si-Gehalten schichtdickenreduzierend wirken. Die unterschiedlichen Hemmungen des Schichtwachstums beim Feuerverzinken werden diskutiert. (Abstract Copyright[2002], Wiley Periodicals, Inc.)

Phylogenetische und funktionelle Analysen zur Kapsel O-Acetyltransferase NeuO von Escherichia coli K1

OpenAIRE

Mordhorst, Ines Louise

2010-01-01

Escherichia coli ist ein Kommensale des menschlichen und tierischen Gastrointestinaltraktes. Einige E. coli-Stämme sind in der Lage, extraintestinale Erkrankungen beim Menschen wie Harnwegsinfekte, Neugeborenen-Meningitis und Sepsis, sowie beim Tier aviäre Coliseptikämien, hervorzurufen. Ein wichtiger Virulenzfaktor des Bakteriums ist dabei die aus α-2,8-verknüpften Sialinsäuremonomeren aufgebaute K1-Kapsel, die phasenvariabel mit einer hohen Frequenz O-acetyliert werden kann. Im Jahr 20...

Investigations on avoidance of hot cracks during laser welding of austenitic Cr-Ni steels and nickel-based alloys using temperature field tailoring. Final report; Untersuchungen zur Vermeidung von Heissrissen beim Laserstrahlschweissen von austenitischen Cr-Ni-Staehlen und Nickelbasislegierungen mittels Temperaturfeld-Tailoring. Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-08-08

. Zweitens wird bei rotationssymmetrischen Bauteilen, die mittels einer Axial-Rundnaht zu verschweissen sind, mit einem relativ einfachen Temperaturfeld, das durch Erwaermung des innen liegenden Fuegepartners vor und waehrend des Schweissens aufgebaut wird, ein Spannungsfeld erzeugt, das die Bildung von Heissrissen verhindert. Schliesslich konnte drittens ein heissrissfreies Laserstrahlschweissen des Stahls 1.4305 und der Nickelbasislegierung Udimet 720 bereits ohne den Einsatz zusaetzlicher Temperaturfelder erreicht werden. Die Grenzen der Einsetzbarkeit des Verfahrens bei Cr-Ni-Staehlen werden dann erreicht, wenn Quer-Heissrisse oder parallel zur Blechoberflaeche liegende Heissrisse entstehen. Die zur Vermeidung dieser Risse noetigen Druckspannungen in den Richtungen parallel zur Schweissnaht bzw. senkrecht zur Blechoberflaeche koennen mittels induktiver Erwaermung von der Blechoberseite aus nicht in der erforderlichen Groesse erzeugt werden. Ebenso stoesst das Verfahren an seine Grenzen, wenn Wiederaufschmelzungsrisse auftreten, was beim hier verwendeten Stahl 1.4435 der Fall war. Die Spannungen, die zur Verhinderung einer Rissoeffnung an den Korngrenzen der Waermeeinflusszone erforderlich waeren, konnten durch Temperaturfeld-Tailoring nicht erreicht werden. Die Moeglichkeit des heissrissfreien Schweissens des Stahls 1.4305 auch ohne Temperaturfeld-Tailoring ergibt sich hauptsaechlich aus dem primaer ferritischen Erstarrungsmodus des Stahls in der vorliegenden Legierungszusammensetzung. Ein industrieller Einsatz des Laserstrahlschweissens fuer diesen oft als nicht schweissbar klassifizierten Stahl erscheint moeglich, wenn bei der Legierungszusammensetzung auf niedrige Anteile der Austenitbildner Nickel, Kohlenstoff und Stickstoff Wert gelegt wird und damit eine stabil primaer ferritische Erstarrung erreicht wird. Fuer diesen Fall kommt es nicht zur Schwefelanreicherung an den Korngrenzen, wodurch die Bildung niedrigschmelzender Phasen und damit die Heissrissentstehung

Der Preis als Kaufbarriere?

DEFF Research Database (Denmark)

Mueller Loose, Simone

2012-01-01

Konsumenten im benachbarten europäischen Ausland (vgl. BVE 2011). Auch der im europäischen Vergleich hohe Marktanteil von Discountern ist ein Indi-kator dafür, dass die Deutschen beim Einkauf von Lebensmitteln weniger qualitäts- und stärker preisorientiert sind (vgl. Zühlsdorf/Spiller 2012). Nicht nur durch......-braucher beim Einkauf von Lebensmitteln hat und gibt einen Überblick über vorhandene empirische Ergebnisse zur Preisbereitschaft für gesunde Lebensmittel....

Ungleiche Ungleichheiten:Zu den Gemeinsamkeiten und Unterschieden von Sexismus und Rassismus

OpenAIRE

Späte, K. (Katrin)

2011-01-01

Sexismus durchzieht fast alle gesellschaftlichen Teilbereiche und deren Grundlagen, im Kern ging es schon Jahrtausende lang um die Rechtfertigung der Herrschaft von Männern über Frauen. Die Minderwertigkeit „der Frau“ wurde unter Rückgriff auf natürliche Begebenheiten bewiesen. Die Grundlage sowohl von Sexismus als auch von Rassismus ist eine Konstruktion: Beim Sexismus die des „weiblichen Geschlechts“, beim Rassismus die der „Rasse“. Während sich die Benennung des Objekts von Rassismus im...

Radioautographic investigation of retinal growth in mature amphibians

International Nuclear Information System (INIS)

Svistunov, S.A.; Mitashov, V.I.

1986-01-01

Growth of the retina was studied in mature intact amphibians, tritons, axolotls, ambystomas and clawed frogs, for six months using multiple injection of 3 H-thymidine. It was established that the source of replenishment of the retina by new cells is its terminal zone in all animals investigated. This is attested to by the gradual migration of labeled cells from the growth zone into differentiated layers of the retina. The most intensely labeled cells occupy a distal position relative to other labeled cells, therefore marking the boundary between the initial part of the retina, not containing labeled nuclei, and the part being augmented. For each species studied, a level of proliferative activity is characteristic for cells of the terminal zone, which decreases in the order axolotl-clawed frog-triton -ambystoma. In the axolotl and additional growth zone is noted in the retina, in addition to the terminal, which is located in the area of the unclosed section of the embryonic fissure. Results obtained serve as a basis for the regenerative potentials of eye tissues revealed previously in these amphibian species

Gruppenleistungen beim Review von Multiple-Choice-Fragen - Ein Vergleich von face-to-face und virtuellen Gruppen mit und ohne Moderation [Review of multiple-choice-questions and group performance - A comparison of face-to-face and virtual groups with and without facilitation

Directory of Open Access Journals (Sweden)

Schüttpelz-Brauns, Katrin

2010-11-01

Full Text Available [english] Background: Multiple choice questions (MCQs are often used in exams of medical education and need careful quality management for example by the application of review committees. This study investigates whether groups communicating virtually by email are similar to face-to-face groups concerning their review process performance and whether a facilitator has positive effects.Methods: 16 small groups of students were examined, which had to evaluate and correct MCQs under four different conditions. In the second part of the investigation the changed questions were given to a new random sample for the judgement of the item quality.Results: There was no significant influence of the variables “form of review committee” and “facilitation”. However, face-to-face and virtual groups clearly differed in the required treatment times. The test condition “face to face without facilitation” was generally valued most positively concerning taking over responsibility, approach to work, sense of well-being, motivation and concentration on the task.Discussion: Face-to-face and virtual groups are equally effective in the review of MCQs but differ concerning their efficiency. The application of electronic review seems to be possible but is hardly recommendable because of the long process time and technical problems.[german] Einleitung: Multiple-Choice-Fragen (MCF werden in vielen Prüfungen der medizinischen Ausbildung verwendet und bedürfen aus diesem Grund einer sorgfältigen Qualitätssicherung, beispielsweise durch den Einsatz von Review-Komitees. Anhand der vorliegenden empirischen Studie soll erforscht werden, ob virtuell per E-Mail kommunizierende Review-Komitees vergleichbar sind mit face-to-face Review-Komitees hinsichtlich ihrer Leistung beim Review-Prozess und ob sich Moderation positiv auswirkt.Methodik: 16 Kleingruppen von Psychologie-Studenten hatten die Aufgabe unter vier verschiedenen Versuchsbedingungen MCF zu bewerten und zu

Cycles of selected trace elements in the South Atlantic: Vertical transport and interactions between particulates and solution; Zum Kreislauf ausgewaehlter Spurenmetalle im Suedatlantik: Vertikaltransport und Wechselwirkung zwischen Partikeln und Loesung

Energy Technology Data Exchange (ETDEWEB)

Dierssen, H

1999-07-01

Subjects: Concentrations, vertical and regional distributions of dissolved and suspended particulate trace elements; Trace element fluxes - vertical, regional, seasonal; The role of particulate organic carbon and atmospheric dust in vertical transport; Fractionation of trace elements in particulate material during transport. [German] Themen dieser Arbeit sind: Konzentrationen, vertikale und regionale Verteilungen von geloesten und suspendierten partikulaeren Spurenelementem (SE); SE-Fluesse vertikal, regional und saisonal; die Rolle des partikulaeren organischen Kohlenstoffs und des atmosphaerischen Staubeintrags beim Vertikaltransport; Fraktionierung von SE im partikulaeren Material beim Transport. (orig./SR)

Clinical value of FDG hybrid-PET in staging and restaging of malignant lymphoma. Compared with conventional diagnostic methods; Klinische Wertigkeit der Befunde von FDG-PET mittels Koinzidenz-Gammakamera beim Staging und Restaging maligner Lymphome. Ein Vergleich zu konventioneller Diagnostik

Energy Technology Data Exchange (ETDEWEB)

Pichler, R.; Maschek, W.; Hatzl-Griesenhofer, M.; Huber, H. [Allgemeines Krankenhaus Linz (Austria). Inst. fuer Nuklearmedizin; Wimmer, G.; Wahl, G.; Fridrik, M. [Allgemeines Krankenhaus Linz (Austria). I. Medizinische Abt.

2000-09-01

Therapieplan. Insgesamt wurden 29 Personen zwecks posttherapeutischem Restaging untersucht. Bei allen wurden Computertomographie- und Lymphknoten-Ultraschalluntersuchungen angewendet. Die Ergebnisse wurden durch den klinischen Verlauf validiert, in drei Faellen wurde ein Rezidiv durch Biopsie bestaetigt. Ergebnisse: CT und US zeigten beim praetherapeutischen Staging 77 Herde verglichen mit 100 durch Doppelkopf-(DK-)PET dargestellten, dieser Unterschied war im Fisher-T-Test jedoch nicht signifikant (p>0,05). Bei der Erkennung residualer Erkrankungsaktivitaet erzielte DK-Koinzidenz-PET eine Sensitivitaet von 93%, eine Spezifitaet von 79%, einen positiven von 82% und einen negativen praediktiven Wert von 92%. Fuer CT+US ergaben sich entsprechend 87%, 64%, 72% und 88%. Schlussfolgerung: FDG-DK-PET erzielt beim Prestaging maligner Lymphome mindestens so genaue Ergebnisse wie ueblicherweise eingesetzte morphologische Diagnoseverfahren. Zusaetzlich ergibt sich ein erkennbarer Vorteil im therapeutischen Monitoring residualer Lymphome durch den Einsatz von Positronen-Koinzidenz-Detektion mittels einer 3/4-Zoll-Kristall-Gammakamera. (orig.)

Theory of rubber friction and traction properties of car tyres; Theorie der Gummireibung und Traktionseigenschaften von Reifen

Energy Technology Data Exchange (ETDEWEB)

Klueppel, M.; Alshuth, T.; Schuster, R.H. [Deutsches Inst. fuer Kautschuktechnologie e.V., Hannover (Germany)

1998-12-31

ABS braking on dry and wet roads involves different mechanisms of rubber friction on rough surfaces. This improves car safety in terms of higher manoeuvrability and shorter braking lengths especially on wet roads. Current research focuses on optimisation of tyrecontact surface materials with better traction characteristics and lower rolling resistance. Laboratory predictions of the traction properties of tyre faces must be based on fundamental knowledge of the local sliding phenomena in the tyre contact surface and the resulting energy dissipation during ABS braking. This contribution therefore attempts to relate the elementary mechanisms of tyre mechanics in ABS braking processes to theoretical concepts of rubber friction on rough surfaces. [Deutsch] Beim ABS-Bremsen auf trockenen und nassen Strassen werden unterschiedliche Mechanismen der Gummireibung auf rauhen Oberflaechen wirksam. In der Summe bewirkt dies eine hoehere Fahrsicherheit, da neben der Manoevrierfaehigkeit des Autos auch der Bremsweg, vor allem auf nassen Strassen, verkuerzt sein kann. In diesem Zusammenhang wird zur Zeit verstaerkt an einer Optimierung von Laufflaechenmaterialien durch den Einsatz von massgeschneiderten Loesungs-SBR-Typen in Verbindung mit gefaellten Kieselsaeuren gearbeitet, wodurch neben einer Verbesserung der Traktionseigenschaften beim ABS-Bremsen auch eine Verringerung des Rollwiderstandes erreicht wird. Fuer Laborvorhersagen der Traktionseigenschaften von Reifenlaufflaechen ist ein grundlegendes Verstaendnis der lokalen Gleitphaenomene in der Reifenaufstandsflaeche und der damit verbundenen Energiedissipation beim ABS-Bremsen erforderlich. In dieser Arbeit wird deshalb angestrebt, die elementaren Mechanismen der Reifenmechanik beim ABS-Bremsen mit theoretischen Konzepten der Gummireibung auf rauhen Oberflaechen in Verbindung zu bringen. (orig.)

Infektion beim Menschen und beim Hund mit der Milbe Cheyletiella yasguri Smiley

DEFF Research Database (Denmark)

Brandrup, F; Andersen, Klaus Ejner; Kristensen, S

1979-01-01

The infection with the mite Cheyletiella yasguri Smiley in 3 dogs and 5 out of 6 persons exposed to infestation is reported. Two of the dogs appeared to have been infected during a stay in a kennel. The dogs presented with moderate itching and slight to massive floury squamation on the back. In t...

Germany's first CO{sub 2} skating rink. Axima Kaeltetechnik builds new skating rink at Ravensburg; Die erste CO{sub 2}-Kunsteisbahn Deutschlands. Axima Kaeltetechnik baut in Ravensburg

Energy Technology Data Exchange (ETDEWEB)

Anon.

2004-04-01

Natural refrigerants are frequently used in skating rinks. Increasingly, CO2 is preferred to brine, as in the new Ravensburg skating rink. It is the first time this technology is applied in Germany, but more systems of this kind are sure to come. [German] Beim Bau von Kunsteisbahnen sind natuerliche Kaeltemittel kein Novum. Immer haeufiger erhaelt allerdings der Kaeltetraeger CO{sub 2} den Vorzug vor einer Sole, so auch beim Bau der neuen Kunsteisbahn in Ravensburg. Damit wurde erstmals in Deutschland in diesem Bereich der Schritt hin zu einer Systemtechnologie gemacht, die aller Voraussicht nach noch zahlreiche weitere Anwendungen nach sich ziehen wird. (orig.)

Immunocytochemical localization and immunochemical characterization of an insulin-related peptide in the pancreas of the urodele amphibian, Ambystoma mexicanum

DEFF Research Database (Denmark)

Hansen, G N; Hansen, B L; Jørgensen, P N

1989-01-01

The pancreas of the axolotl, Ambystoma mexicanum, was investigated by immunocytochemical methods for the presence of immunoreactivity to a number of antisera raised against mammalian insulins. All anti-insulin antisera tested revealed substantial amounts of reaction products confined solely...

Interdisciplinary consensus on diagnosis and treatment of testicular germ cell tumors. Results of an update conference based on evidence-based medicine (EBM); Interdisziplinaerer Konsensus zur Diagnostik und Therapie von Hodentumoren. Ergebnisse einer Update-Konferenz auf Grundlage evidenzbasierter Medizin (EBM)

Energy Technology Data Exchange (ETDEWEB)

Souchon, R. [Deutsche Gesellschaft fuer Radioonkologie (DEGRO) (Germany); Arbeitsgemeinschaft Radiologische Onkologie (ARO), Strahlenklinik AKH Hagen (Germany); Krege, S. [Deutsche Gesellschaft fuer Urologie (DGU) (Germany); Essen Univ. (Gesamthochschule) (Germany). Klinik und Poliklinik fuer Urologie; Schmoll, H.J. [Arbeitsgemeinschaft Internistische Onkologie (AIO), Zentrum fuer innere Medizin IV der Martin-Luther-Univ. Halle-Wittenberg (Germany); Albers, P. [Bonn Univ. (Germany). Urologische Klinik; Beyer, J. [Marburg Univ. (Germany). Medizinisches Zentrum fuer Innere Medizin; Bokemeyer, C. [Tuebingen Univ. (Germany). Abt. fuer Innere Medizin 2; Classen, J. [Tuebingen Univ. (Germany). Medizinisches Strahleninstitut und Roentgenabteilung; Dieckmann, K.P. [Albertinen-Krankenhaus, Hamburg (Germany). Urologische Abt.; Hartmann, M. [Bundeswehrkrankenhaus, Hamburg (Germany). Urologische Abt.; Heidenreich, A. [Marburg Univ. (Germany). Urologische Klinik; Hoeltl, W. [Kaiser-Franz-Josef-Spital Wien (Austria). Urologische Klinik; Kliesch, S. [Muenster Univ. (Germany). Klinik fuer Urologie; Koehrmann, K.U. [Urologische Klinik des Klinikums der Stadt Mannheim (Germany); Kuczyk, M. [Medizinische Hochschule Hannover (Germany). Klinik fuer Urologie; Schmidberger, H. [Goettingen Univ. (Germany). Klinik fuer Strahlentherapie und Radioonkologie; Weinknecht, S. [Krankenhaus am Urban Berlin (Germany). Urologische Abt.; Winter, E. [Klinikum Schwerin (Germany). Urologische Klinik; Wittekind, C. [Leipzig Univ. (Germany). Inst. fuer Pathologie; Bamberg, M. [Tuebingen Univ. (Germany). Abt. fuer Strahlentherapie

2000-09-01

An 'Interdisciplinary Update Consensus Statement' summarizes and defines the diagnostic and therapeutic standards according to the current scientific practices in testicular cancer. For 21 separate areas scientifically based decision criteria are suggested. For treatment areas where more than one option exist without a consensus being reached for a preferred strategy, such as in seminoma in clinical Stage I or in non-seminoma Stages CS I or CS IIA/B, all acceptable alternative strategies with their respecitve advantages and disadvantages are presented. This 'Interdisciplinary Update Consensus' was presented at the 24th National Congress of the German Cancer Society on March 21st and subsequently evaluated and approved by the various German scientific medical societies. (orig.) [German] Der zu 21 Themenkomplexen anhand wissenschaftlich begruendeter Entscheidungskriterien erarbeitete 'Interdisziplinaere Update-Konsensus' praezisiert und definiert diagnostische und therapeutische Standards entsprechend dem aktuellen Wissensstand ueber die Tumorentitaet. Fuer Therapiesituationen, bei denen mehrere Optionen bestehen und kein Konsens ueber die favorisierte Strategie erzielt wurde wie beim Seminom im klinischen Stadium I oder beim Nichtseminom in den Stadien CS I bzw. CS IIA/B, wurden jeweilige Alternativen mit deren Vor- und Nachteilen dargestellt. Der 'Interdisziplinaere Update-Konsensus' wurde beim 24. Deutschen Krebskongress am 21.3.2000 vorgestellt, nachfolgend von den daran beteiligten wissenschaftlichen Fachgesellschaften geprueft und gebilligt. (orig.)

Enzyme clusters during the metamorphic period of Ambystoma mexicanum: role of thyroid hormone

NARCIS (Netherlands)

Lamers, W. H.; Mooren, P. G.; de Graaf, A.

1982-01-01

Enzyme activities and DNA content have been measure in axolotl liver during the metamorphic period (4-8 months after spawning). Three different types of enzyme activity profiles were observed. In the type I profile (carbamoyl-phosphate synthase, arginase, ornithine transcarbamoylase, and glutamate

Development and regulation of response properties in spinal cord motoneurons

DEFF Research Database (Denmark)

Perrier, J F; Hounsgaard, J

2000-01-01

vertebrates in terms of both phylogeny and ontogeny. Spinal motoneurons in adults are remarkably similar in many respects ranging from the resting membrane potential to pacemaker properties. Apart from the axolotls, spinal motoneurons from all species investigated have latent intrinsic response properties...

Cartilage and bone cells do not participate in skeletal regeneration in Ambystoma mexicanum limbs.

Science.gov (United States)

McCusker, Catherine D; Diaz-Castillo, Carlos; Sosnik, Julian; Q Phan, Anne; Gardiner, David M

2016-08-01

The Mexican Axolotl is one of the few tetrapod species that is capable of regenerating complete skeletal elements in injured adult limbs. Whether the skeleton (bone and cartilage) plays a role in the patterning and contribution to the skeletal regenerate is currently unresolved. We tested the induction of pattern formation, the effect on cell proliferation, and contributions of skeletal tissues (cartilage, bone, and periosteum) to the regenerating axolotl limb. We found that bone tissue grafts from transgenic donors expressing GFP fail to induce pattern formation and do not contribute to the newly regenerated skeleton. Periosteum tissue grafts, on the other hand, have both of these activities. These observations reveal that skeletal tissue does not contribute to the regeneration of skeletal elements; rather, these structures are patterned by and derived from cells of non-skeletal connective tissue origin. Copyright © 2016 Elsevier Inc. All rights reserved.

TRACKING STEM CELLS IN AN INHERENTLY REGENRATIVE ENVIRONMENT

DEFF Research Database (Denmark)

Lauridsen, Henrik; Foldager, Casper Bindzus; Hagensen, Mette

2012-01-01

of such therapies. The objective of this study was to non-invasively evaluate regeneration over time in a truly regenerative process, the regeneration of an axolotl limb, employing superparamagnetic iron oxide particles (SPIO) contrast agents for stem cell tracking in MRI. Materials and Methods: Amputation of one...... in conjugation with the transfection agent poly-L-lysin (PLL) was tested on cultures of axolotl blastema cells from 7 animals in vitro. PicoGreen-DNA quantification following 3 weeks of culturing was performed to quantify cell viability. MRI-tracking of SPIO labelled blastema cells in the regenerating limb of 5....... Results: SPIO labelling with neither VSOP-C200, Resovist nor Resovist/PLL had any significant effect on blastema cell viability in vitro. Labelled tissue was clearly detectable in vivo 49 days after amputation using MRI (Fig. 1) and a significant decline in signal intensity of labelled limbs versus sham...

Cranial muscle development in the model organism ambystoma mexicanum: implications for tetrapod and vertebrate comparative and evolutionary morphology and notes on ontogeny and phylogeny.

Science.gov (United States)

Ziermann, Janine M; Diogo, Rui

2013-07-01

There is still confusion about the homology of several cranial muscles in salamanders with those of other vertebrates. This is true, in part, because of the fact that many muscles present in early ontogeny of amphibians disappear during development and specifically during metamorphosis. Resolving this confusion is important for the understanding of the comparative and evolutionary morphology of vertebrates and tetrapods because amphibians are the phylogenetically most plesiomorphic tetrapods, concerning for example their myology, and include two often used model organisms, Xenopus laevis (anuran) and Ambystoma mexicanum (urodele). Here we provide the first detailed report of the cranial muscle development in axolotl from early ontogenetic stages to the adult stage. We describe different and complementary types of general muscle morphogenetic gradients in the head: from anterior to posterior, from lateral to medial, and from origin to insertion. Furthermore, even during the development of neotenic salamanders such as axolotls, various larval muscles become indistinct, contradicting the commonly accepted view that during ontogeny the tendency is mostly toward the differentiation of muscles. We provide an updated comparison between these muscles and the muscles of other vertebrates, a discussion of the homologies and evolution, and show that the order in which the muscles appear during axolotl ontogeny is in general similar to their appearance in phylogeny (e.g. differentiation of adductor mandibulae muscles from one anlage to four muscles), with only a few remarkable exceptions, as for example the dilatator laryngis that appears evolutionary later but in the development before the intermandibularis. Copyright © 2013 Wiley Periodicals, Inc.

Das biochemische Rezidiv beim Prostatakarzinom

Directory of Open Access Journals (Sweden)

Rauchenwald M

2010-01-01

Full Text Available Als biochemisches Rezidiv (BCR wird der Wiederanstieg des nach kurativer Therapie des Prostatakarzinoms (PCa abgefallenen PSA-Werts bezeichnet. Der PSA-Verlauf nach kurativer Therapie ist von der primären Behandlungsmethode abhängig, weshalb auch unterschiedliche Definitionen dafür vorliegen. Der Verlauf selbst scheint prognostische Bedeutung zu haben. Ein Wiederanstieg des PSA-Werts geht der klinischen Progression voraus, wodurch frühzeitig eine Therapie eingeleitet werden kann. Der ideale Zeitpunkt für eine Sekundärbehandlung ist allerdings noch ungenügend definiert. Fast die Hälfte der BCR treten innerhalb der ersten 2 Jahre, ¾ innerhalb der ersten 5 Jahre nach Primärtherapie auf. Als Risikofaktoren für einen BCR werden ein primäres Tumorstadium ≥ T2c, PSA 15, Samenblaseninvasion, Lymphknotenbefall sowie Gleason-Score ≥ 8 angesehen. Von klinischer Bedeutung ist vor allem die Unterscheidung zwischen lokoregionärem und systemischem Rezidiv. Hierzu werden als Parameter neben dem primären Tumorstadium und Gleason-Score das posttherapeutische Intervall und die PSA-Dynamik empfohlen. Als diagnostische Maßnahmen erscheinen nur die Skelettszintigraphie und die Positronenemissionstomographie mit Acetat- oder Cholintracern und diese ebenfalls nur bei entsprechend hohen PSA-Werten sinnvoll. Therapeutisch kommt nach primärer Radikaloperation und Verdacht auf einen lokalen Progress in erster Linie die Salvagebestrahlung zur Anwendung, nach primärer Radiatio wird allerdings vorwiegend die hormonelle Manipulation einer Salvageoperation oder alter“nativen lokaltherapeutischen Maßnahmen vorgezogen.

Netzformen und VDE-Bestimmungen

Science.gov (United States)

Bernstein, Herbert

Der Verband Deutscher Elektrotechniker (VDE) hat eine Reihe von Vorschriften ausgearbeitet, die dem Schutz von Leben und Sachen beim Umgang mit elektrischer Energie dienen. Besonders wichtig sind die in den VDE-Bestimmungen 0100 und 0411 festgelegten Vorschriften.

Visualisation of animal anatomy using MRI and CT

DEFF Research Database (Denmark)

Lauridsen, Henrik; Hansen, Kasper; Pedersen, Michael

imaging (MRI) and CT. Various species (tarantula, horseshoe crab, carp, haddock, lungfish, axolotl) were subjected to multi-slice MRI and CT protocols to produce 2D images of body slices, followed by volume rendering producing 3D digital models of animal anatomy with applications for visualising specific...

Evolution of the head-trunk interface in tetrapod vertebrates

Science.gov (United States)

Sefton, Elizabeth M; Bhullar, Bhart-Anjan S; Mohaddes, Zahra; Hanken, James

2016-01-01

Vertebrate neck musculature spans the transition zone between head and trunk. The extent to which the cucullaris muscle is a cranial muscle allied with the gill levators of anamniotes or is instead a trunk muscle is an ongoing debate. Novel computed tomography datasets reveal broad conservation of the cucullaris in gnathostomes, including coelacanth and caecilian, two sarcopterygians previously thought to lack it. In chicken, lateral plate mesoderm (LPM) adjacent to occipital somites is a recently identified embryonic source of cervical musculature. We fate-map this mesoderm in the axolotl (Ambystoma mexicanum), which retains external gills, and demonstrate its contribution to posterior gill-levator muscles and the cucullaris. Accordingly, LPM adjacent to the occipital somites should be regarded as posterior cranial mesoderm. The axial position of the head-trunk border in axolotl is congruent between LPM and somitic mesoderm, unlike in chicken and possibly other amniotes. DOI: http://dx.doi.org/10.7554/eLife.09972.001 PMID:27090084

Vom Terrorismus zum Wandel durch Annäherung: Houellebecqs ‚Soumission‘

Directory of Open Access Journals (Sweden)

Wolfgang Asholt

2016-03-01

Full Text Available Es handelt sich um den Text eines Vortrags beim von Ursula Hennigfeld und Elmar Schafroth organisierten Workshop „Zensur, Political Correctness und Terrorismus“  (Universität Düsseldorf, 30.6. – 2.7. 2015.

Real-time detection of root zone-CO2 and its potential for irrigation scheduling

Directory of Open Access Journals (Sweden)

Klaus Spohrer

2015-08-01

Full Text Available Als Basis für die Bewässerungsplanung wurde die Eignung von CO2-Messungen im Wurzelraum (WR-CO2 untersucht und evaluiert. Die grundlegende Annahme war, dass Pflanzen als Reaktion auf eine defizitäre Wasserversorgung die Wurzelatmung reduzieren. Die Untersuchungen an Apfelbäumen konnten zeigen, dass das WR-CO2 zu großen Teilen (56–72 % seinen Ursprung in der pflanzenspezifischen CO2-Produktion (v. a. Wurzelatmung hat. Darüber hinaus reagierte das WR-CO2 deutlich auf Bewässerung und korrelierte bei der Austrocknung mit dem Bodenwassergehalt. Da Veränderungen beim WR-CO2 sich auch in Veränderungen beim Pflanzenwasserstatus widerspiegelten, besitzt das WR-CO2 Potenzial zur Ermittlung des Bewässerungsbedarfs der untersuchten Apfelbäume. Die Übertragbarkeit auf weitere Nutzpflanzen wird untersucht.

The MHC molecules of nonmammalian vertebrates

DEFF Research Database (Denmark)

Kaufman, J; Skjoedt, K; Salomonsen, J

1990-01-01

class II distribution. The axolotl has a very poor immune response (as though there are no helper T cells), a wide class II distribution and, for most animals, no cell surface class I molecule. It would be enlightening to understand both the mechanisms for the regulation of the MHC molecules during...

Stereotactic body radiotherapy for renal cell cancer and pancreatic cancer. Literature review and practice recommendations of the DEGRO Working Group on Stereotactic Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Panje, Cedric; Andratschke, Nikolaus; Guckenberger, Matthias [Zurich University Hospital, Department of Radiation Oncology, Zurich (Switzerland); Brunner, Thomas B. [Freiburg University Hospital, Department of Radiation Oncology, Freiburg (Germany); Niyazi, Maximilian [University of Munich, Department of Radiation Oncology, Munich (Germany)

2016-12-15

This report of the Working Group on Stereotactic Radiotherapy of the German Society of Radiation Oncology (DEGRO) aims to provide a literature review and practice recommendations for stereotactic body radiotherapy (SBRT) of primary renal cell cancer and primary pancreatic cancer. A literature search on SBRT for both renal cancer and pancreatic cancer was performed with focus on prospective trials and technical aspects for clinical implementation. Data on renal and pancreatic SBRT are limited, but show promising rates of local control for both treatment sites. For pancreatic cancer, fractionated SBRT should be preferred to single-dose treatment to reduce the risk of gastrointestinal toxicity. Motion-compensation strategies and image guidance are paramount for safe SBRT delivery in both tumor entities. SBRT for renal cancer and pancreatic cancer have been successfully evaluated in phase I and phase II trials. Pancreatic SBRT should be practiced carefully and only within prospective protocols due to the risk of severe gastrointestinal toxicity. SBRT for primary renal cell cancer appears a viable option for medically inoperable patients but future research needs to better define patient selection criteria and the detailed practice of SBRT. (orig.) [German] Die Arbeitsgruppe ''Stereotaktische Radiotherapie'' der Deutschen Gesellschaft fuer Radioonkologie (DEGRO) legt eine Zusammenfassung der aktuellen Literatur und daraus resultierende Empfehlungen zur Durchfuehrung der stereotaktischen Strahlentherapie (SBRT) beim Nierenzellkarzinom und beim Pankreaskarzinom vor. Es erfolgte eine Literaturrecherche zur Evidenz der SBRT beim Nierenzell- und Pankreaskarzinom, wobei der Schwerpunkt auf prospektive Studien und technische Aspekte fuer die klinische Umsetzung gelegt wurde. Fuer die SBRT beim Pankreaskarzinom und Nierenzellkarzinom sind bisher nur wenige Studien veroeffentlicht worden, die jedoch konsistent eine hohe Rate an lokaler Tumorkontrolle

Fourth report by the Federal German Government to the Bundestag on measures for the protection of the ozone layer; 4. Bericht der Bundesregierung an den Deutschen Bundestag ueber Massnahmen zum Schutz der Ozonschicht

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

This report, which relates the situation as of July 1997, again confirms the internationally leading role of the Federal German Republic in the phase-out of CFCs. No country has realised a more comprehensive concept for the phase-out of substances that deplete the ozone layer. Combining statutory and voluntary measures has proved a path-breaking approach. One of the most important driving forces in the CFC phase-out were the restrictions of use imposed by the Ordinance on the Prohibition of CFCs and Halon. (orig./SR) [Deutsch] Dieser Bericht - mit Stand vom Juli 1997 - bestaetigt erneut die internationale Fuehrungsrolle der Bundesrepublik Deutschland beim FCKW-Ausstieg. In keinem anderen Staaat wurde ein umfassenderes Konzept zum Ausstieg aus den ozonabbauenden Stoffen realisiert. Als wegweisend hat sich dabei die Verknuepfung ordnungsrechtlicher und freiwilliger Massnahem erwiesen. Insbesondere von den Verwendungsbeschraenkungen der FCKW-Halon-Verbots-Verordnung gingen wichtige Impulse beim FCKW-Ausstieg aus. (orig./SR)

Influence of antithyroid medication on effective half-life and uptake of {sup 131}I following radioiodine therapy; Einfluss thyreostatischer Medikation beim Morbus Basedow auf die Kinetik von 131-Iod waehrend einer Radiotherapie

Energy Technology Data Exchange (ETDEWEB)

Moka, D.; Voth, E.; Schicha, H. [Koeln Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin

1997-12-01

Aim of this study was to assess the influence of antithyroid drugs (ADT) on the kinetics of {sup 131}I. Therefore, 56 patients with Graves` disease and with shortened effective half-life of {sup 131}I were examined under stationary conditionary conditions. In 38 patients ATD was stopped three days after radioiodine therapy (RIT). The progress of the first RIT and of a second RIT, which still was necessary in 12 patients, was compared to 18 patients receiving ATD continuously. Values of effective half-life for {sup 131}I rose significantly from 3.4 to 5.7 days 2-3 days after stopping ATD. There was an increase of the {sup 131}I-uptake of a second RIT after stopping ATD from 29.0 to 38.4%. In contrast, {sup 131}I-uptake of a second RIT decreased significantly in patients receiving ATD continuously. Effective half-life and uptake of {sup 131}I were affected significantly by ATD. Interrupting ATD after RIT is useful to improve an apparantly insufficient RIT in thyrotoxic patients receiving ATD. (orig.) [Deutsch] Ziel dieser Studie war es, beim M. Basedow die Kinetik von {sup 131}I unter dem Einfluss thyreostatischer Medikation (tM) zu untersuchen. Dazu wurden die 56 Patienten mit immunogener Hyperthyreose M. Basedow (MB) und mit einem erhoehten `turn over` von {sup 131}I unter tM untersucht. Bei 38 Patienten wurde die tM am 3. Tag nach RITh abgesetzt. Der Verlauf der 1. RITh bzw. einer Nachtherapie wurde mit 18 Patienten unter fortlaufender tM verglichen. 2-3 Tage nach Absetzen der tM stieg die effektive Halbwertzeit (HWZ{sub eff.}) von {sup 131}I signifikant von 3,4 auf 5,7 Tage und der {sup 131}I-Uptake bei der Nachtherapie von 29,0 auf 38,4% an, waehrend er unter fortlaufender tM signifikant abfiel. Beide Effekte zeigen, dass tM die {sup 131}I-Kinetik der Schilddruese sehr schnell beeinflussen kann. Gezieltes Absetzen der tM eignet sich deshalb, um bei ausgewaehlten Patienten eine primaer unzureichende RITh noch waehrend des stationaeren Aufenthaltes zu steuern und

Electron microscopy of the amphibian model systems Xenopus laevis and Ambystoma mexicanum.

Science.gov (United States)

Kurth, Thomas; Berger, Jürgen; Wilsch-Bräuninger, Michaela; Kretschmar, Susanne; Cerny, Robert; Schwarz, Heinz; Löfberg, Jan; Piendl, Thomas; Epperlein, Hans H

2010-01-01

In this chapter we provide a set of different protocols for the ultrastructural analysis of amphibian (Xenopus, axolotl) tissues, mostly of embryonic origin. For Xenopus these methods include: (1) embedding gastrulae and tailbud embryos into Spurr's resin for TEM, (2) post-embedding labeling of methacrylate (K4M) and cryosections through adult and embryonic epithelia for correlative LM and TEM, and (3) pre-embedding labeling of embryonic tissues with silver-enhanced nanogold. For the axolotl (Ambystoma mexicanum) we present the following methods: (1) SEM of migrating neural crest (NC) cells; (2) SEM and TEM of extracellular matrix (ECM) material; (3) Cryo-SEM of extracellular matrix (ECM) material after cryoimmobilization; and (4) TEM analysis of hyaluronan using high-pressure freezing and HABP labeling. These methods provide exemplary approaches for a variety of questions in the field of amphibian development and regeneration, and focus on cell biological issues that can only be answered with fine structural imaging methods, such as electron microscopy. Copyright © 2010 Elsevier Inc. All rights reserved.

Praxis des Klebens

CERN Document Server

Theuerkauff, Petra

1989-01-01

Bei diesem Buch handelt es sich um einen Leitfaden fur Klebepraktiker. Es werden die verschiedenen Einzelschritte beim kleben beschrieben, als auch die vorbereitenden Massnahmen und anschliessenden Prufverfahren auf Festigkeit behandelt. Das Buch sollte an keinem Arbeitsplatz fehlen, wo man sich mit Problemen der Fugetechnik des Klebens beschaftigt.

New findings for the use of NMR- and computer tomography for gauging the potential of drilling fluids to cause damage to rocks; Neue Erkenntnisse bei der Anwendung von NMR- und Computertomografie-Methoden im Rahmen der Bewertung des Traegerschaedigungspotentiales von Bohrfluessigkeiten

Energy Technology Data Exchange (ETDEWEB)

Zwaag, C. van der [Reservoir Labs. AS, Trondheim (Norway); Stallmach, F. [Univ. Leipzig (Germany). Fakultaet fuer Physik und Geowissenschaften; Hanssen, J.E. [MI/Anchor Drilling Fluids AS, Stavanger (Norway); Soergaard, E. [Norsk Hydro AS, Bergen (Norway); Toennesen, R. [Saga Petroleum ASA, Stavanger (Norway)

1998-12-31

Polyanionic cellulose, xanthane and ppolyglycole are standard additives for water-based drilling fluids. These are added to drilling liquids to control water loss, provide viscosity and inhibit slating. Filtration losses, which are unavoidable when drilling, cause scavenging polymers to penetrate the area around the drilled hole. This causes a number of different reactions with the surrounding rocks and may ultimately have a permanent influence on the flow conditions of hydrocarbons. The study mentioned above aimed at determining the damage potential of these additives. [Deutsch] Polyanionische Cellulose, Xanthan und Polyglykol sind uebliche Zusatzstoffe von wasserbasischen Bohrspuelungen. Diese werden Bohrfluessigkeiten zur Wasserverlustkontrolle, zur Viskositaetsbildung und zur Schieferinhibierung zugesetzt. Die beim Bohrprozess unvermeidlichen Filtrationsverluste fuehren dazu, dass Spuelungspolymere beim Bohren in den Bohrlochnahbereich eindringen. Die Beschaffenheit dieser Stoffe fuehrt nach dem Eindringen zu unterschiedlichen Reaktionen mit dem Traegergestein. Diese koennen letzten Endes einen dauerhaften Einfluss auf die Zuflussbedingungen von Kohlenwasserstoffen haben. Das Ziel der vorliegenden Studie war es, das Traegerschaedigungspotential der obengenannten Spuelungszusaetze zu charakterisieren. (orig.)

Structural cladding /clad structures

DEFF Research Database (Denmark)

Beim, Anne

2012-01-01

Structural Cladding /Clad Structures: Studies in Tectonic Building Practice A. Beim CINARK – Centre for Industrialized Architecture, Institute of Architectural Technology, The Royal Danish Academy of Fine Arts School of Architecture, Copenhagen, Denmark ABSTRACT: With point of departure in the pr......Structural Cladding /Clad Structures: Studies in Tectonic Building Practice A. Beim CINARK – Centre for Industrialized Architecture, Institute of Architectural Technology, The Royal Danish Academy of Fine Arts School of Architecture, Copenhagen, Denmark ABSTRACT: With point of departure...... to analyze, compare, and discuss how these various construction solutions point out strategies for development based on fundamentally different mindsets. The research questions address the following issues: How to learn from traditional construction principles: When do we see limitations of tectonic maneuver......, to ask for more restrictive building codes. As an example, in Denmark there are series of increasing demands in the current building legislations that are focused at enhancing the energy performance of buildings, which consequently foster rigid insulation standards and ask for improvement of air...

Kognitive Prozesse der Adressatenantizipation beim Schreiben

OpenAIRE

Linnemann, Markus

2014-01-01

Im Fokus dieser Untersuchung stand die Textproduktion aus kognitiver Sicht. Diese umfasst im Wesentlichen vier Wissensbereiche. Neben dem thematischen und linguistischen Wissen, widmete sich die Arbeit vor allem dem pragmatischen, insbesondere dem Adressatenwissen und den dazugehörenden Prozessen. Es wurde dargestellt, dass der Adressat aufgrund seiner räumlichen und zeitlichen Distanz vom Schreiber antizipiert werden muss, wenn er erfolgreich kommunizieren will. Adressatenantizipation wurde ...

Körperliche Fitness beim alternden Mann

Directory of Open Access Journals (Sweden)

Rauchenwald M

2001-01-01

Full Text Available Die derzeitige Diskussion um die Substitution von Hormonen zur Therapie altersbedingter Leistungseinbußen und Befindlichkeitsstörungen führte zu der Frage, ob diese Veränderungen bzw. die entsprechenden Hormonspiegel nicht auch durch körperliches Training günstig beeinflußt werden können. Altern ist mit einem kontinuierlichen Abfall der körperlichen Fitness und der Erektionsfähigkeit verbunden. Die Risikofaktoren für Erektionsstörungen, wie z. B. Übergewicht, sind sehr ähnlich jenen von Herz-Kreislauf-Erkrankungen. Mehrere Studien konnten eine positive Korrelation von körperlicher Aktivität und Erektionsfähigkeit nachweisen. Regelmäßige Bewegung führt zu einer Gewichtsreduktion und zu einem Stressabbau. Die mit dem Alterungsprozeß assoziierten Hormone stehen untereinander als auch mit dem körperlichen Fitnesszustand in Zusammenhang. Ausdauertraining erhöht den Testosteronspiegel stärker als Krafttraining, zu hohe Belastungen führen zu einem Abfall desselben, v.a. in der Erholungsphase, und es besteht eine positive Korrelation von körperlicher Aktivität mit Testosteron und mit Wachstumshormon. Ältere Männer haben allerdings einen schlechteren Response als Jüngere (z. T. kein Effekt bei Krafttraining. Auch für Untrainierte scheint eine mäßige Kreislaufbelastung günstig zu sein und zumindest vorübergehend eine geringe Testosteron-Erhöhung zu bewirken. Ein Zusammenhang zwischen Fitness bzw. Lipidprofil einerseits und dem DHEAS-Spiegel andererseits ist in der Literatur bekannt. Körperliches Training führt auf physiologischem Wege zu Müdigkeit, besserem Schlaf und folglich zu höheren Wachstumshormonspiegeln. Weiters werden das Selbstbewußtsein, die Erektionsfähigkeit, die Muskelmasse und das Gefäßsystem günstig beeinflußt und Stress abgebaut. Regelmäßiges Training 3-5 x pro Woche für 30-60 Minuten mit einer Intensität von 60-80% des Maximalpulses wird als Ausdauertraining empfohlen. Regelmäßige körperliche Aktivität ist ein wichtiger Bestandteil erfolgreichen Alterns.

Radiation therapy for Morbus Ledderhose - indication and clinical results; Strahlentherapie beim Morbus Ledderhose - Indikation und klinische Ergebnisse

Energy Technology Data Exchange (ETDEWEB)

Seegenschmiedt, M.H.; Attassi, M. [Klinik fuer Radioonkologie, Strahlentherapie und Nuklearmedizin, Alfried-Krupp-Krankenhaus, Essen (Germany)

2003-12-01

were minimal: during and within 3 months of the RT course only a slight erythema (CTC 1 ) was seen in five treated lesions, while dry skin changes within the RT portal were observed in three cases (11%) in long term FU (> 12 months). Conclusions: radiotherapy is effective in treating ML and may prevent otherwise necessary surgical interventions. Nodules, cords and symptoms regress, but long-term outcome of at least 5 years has to be awaited. Prospective phase III studies should confirm these results. (orig.) [German] Hintergrund: Der morbus ledderhose (ML) ist eine hyperproliferative Erkrankung der Plantaraponeurose, die dem morbus dupuytren (MD) sehr aehnlich ist. Wir prueften, ob eine Bestrahlung die Symptome lindern und die Progression der Erkrankung aufhalten kann. Patienten und Methoden: Von Juni 1996 bis Dezember 2002 wurden zwoelf Frauen und 13 Maenner im Alter von 9-76 (median 56) Jahren mit symptomatischem ML bestrahlt und mindestens 1 Jahr kontrolliert. Insgesamt wurden 36 Fuesse (16 rechts, 20 links) bestrahlt, da elf Patienten beidseits einen Befall hatten. Zwoelf (48%) Patienten hatten auch einen MD. An 36 Fuessen lagen 63 Knoten (mit 0,5-6,5 cm Groesse) und an 13 (52%) Fuessen 20 Straenge (mit 1-4 cm Laenge) vor. Zusaetzlich bestanden 14-mai (56%) starke Fussschmerzen, achtmal (32%) Probleme beim Laufen, zwoelfmal (48%) andere Symptome (Druck, Schwellung, Spannung). Die Orthovolt-Radiotherapie erfasste alle tastbaren Knoten und Straenge. Es wurden zwei Serien zu je 5 x 3 Gy pro Woche (gesamt: 30 Gy) im Abstand von 8-12 Wochen gegeben. Die Auswertung erfolgte am Ende der RT, nach 3 und 12 Monaten und zuletzt im Dezember 2002. Primaerer Endpunkt war die Vermeidung einer Progression bzw. Operation; sekundaere Endpunkte waren mehrere objektive morphologisch-funktionelle sowie subjektive Parameter (visuelle analogskala (VAS)). Ergebnisse: Nach 38 (12-67) Monaten medianem FU war kein Fuss progredient oder musste operiert werden. Bei 11 von 36 (44%) Fuessen nahm

Die Brustflosse des Grönlandswales (Balaena mysticetus L.)

NARCIS (Netherlands)

Kükenthal, W.

1922-01-01

Das Studium der Brustflosse des Grönlandswales hat zu Fragen von allgemeinerem Interesse geführt. Ihre kurze und breite Form sowie ihre anscheinende Fünffingerigkeit, die ausserdem nur noch beim südlichen Glattwal (Balaena australis) vorkommt, liess sie ursprünglicher erscheinen als die schlankere

Verwendung von Polypropylen/Polyglactin 910- (PP910- und Polypropylen/Polyglecapron 25 (PP25- Netzen bei Beckenbodenprolaps - eine retrospektive Analyse

Directory of Open Access Journals (Sweden)

Schwegler Ch

2009-01-01

Full Text Available Die Entwicklung von Polypropylen- Implantaten zur Behandlung von Bauchwandhernien stellt einen Meilenstein in der Geschichte der Chirurgie dar. Mit einigen Jahren Verzug folgten die Urogynäkologen den Chirurgen und begannen, Polypropylen-Netze zur Behebung von Beckenbodenvorfällen einzusetzen. PP910-Netze (Vypro II®, Ethicon und PP25-Netze (Ultrapro®, Ethicon werden seit Langem mit gutem Erfolg bei Hernien-Operationen eingesetzt. Das Ziel dieser Studie war herauszufinden, inwieweit sich diese beiden Netze auch für den Einsatz beim Beckenbodenprolaps eignen. Hierzu wurden Fragebögen an Patientinnen versandt, denen in den Jahren 2003 und 2004 diese Netze im Beckenboden implantiert wurden. Die Hauptfragestellungen waren hierbei, inwiefern sich die Symptome des Vorfalles nach der Behandlung verändert hatten und welche Komplikationen nach der Operation aufgetreten waren. Beide Gruppen zeigten nach dem Netzeinsatz deutliche Verbesserungen der Symptomatik bei einer geringen Komplikationsquote. Beim Einsatz von PP910 zeigten sich in 6 % der Fälle Komplikationen, die auf die Implantation des Netzes zurückgeführt werden konnten. Beim Einsatz von PP25 zeigten sogar nur 1,5 % der operierten Frauen netzbedingte Komplikationen. Somit hat sich gezeigt, dass beide Netze gut für die Verwendung im Beckenboden geeignet sind. Vergleicht man die beiden Netze mit anderen Produkten, die derzeit als Implantate im Beckenboden genutzt werden, so zeigt sich ein sehr positives Ergebnis mit signifikant weniger postoperativen Komplikationen unter der Verwendung von PP25-Netzen. Im Rahmen dieser Analyse konnte festgestellt werden, dass PP25 ein sehr sicheres Netz mit ausgesprochen guten Ergebnissen für die Therapie des Beckenbodenprolaps ist.

Mechatronic Carlab - Eine System-Entwicklungsumgebung mit realen und virtuellen mechatronischen Fahrzeug-Komponenten

OpenAIRE

Bünte, Tilman

2004-01-01

Bei der Entwicklung mechatronischer Komponenten sind verschiedene Ingenieurdisziplinen beteiligt: Das Fachwissen auf dem Gebiet Mechanik, Elektronik und Informatik ist gefragt, wenn auf kleinem Raum die unterschiedlichsten Funktionen zu einem Produkt integriert werden. Beim DLR in Oberpfaffenhofen hat diese Technologie schon Tradition - ein großes Anwendungsfeld ist inzwischen die Fahrzeugtechnik

Mehrkörpersimulation eines ebenen Koppelgetriebes mittels Matlab / ADAMS -Co-Simulation

OpenAIRE

Gollee, Christian; Troll, Clemens

2017-01-01

Mit Hilfe der Matlab/ADAMS-Co-Simulation wird ein ebenes Koppelgetriebe (5- Gelenk) untersucht und anschließend die Wirkpaarung mit einem Stückgut betrachtet. Dabei werden verschiedene Modellierungsstufen angewendet und die Simulationsergebnisse Messergebnissen vom Versuchsstand gegenübergestellt. Daneben wird die grundlegende Herangehensweise beim Einsatz dieser Simulationswerkzeuge erläutert.

Resonance – Journal of Science Education | Indian Academy of ...

Indian Academy of Sciences (India)

Jürgen Drissner1 Hans-Martin Haase2 Mara Nikolajek1 Katrin Hille3. Botanical Garden, University of Ulm, D–89081 ULM, Germany. University of Education, Oberbettringer Str. 200, D–73525 Schwäbisch Gmünd, Germany. Transfercenter for Neuroscience and Learning, University of Ulm, Beim Alten Fritz 2 D–89075 ULM, ...

Crash tests with Smartcrash barriers, a technology with a future; Zukunftssichere Crashtests mit Smartcrash-Barrieren

Energy Technology Data Exchange (ETDEWEB)

Barz, D.; Evers, W. [Kistler Instrumente AG (Switzerland). Geschaeftsbereich Fahrzeugmesstechnik

2005-02-01

The Smartcrash barrier by Kistler is a completely new technology. State-of-the-art data processing with Microdau modules is combined with a singular mechanical modularity which meets all requirements of present and future crash standards. Together with a piezo measuring system perfectly tuned to the highly dynamic processes during crash tests, this provides a basis for making crash laboratories economically efficient, with safe and accurate data, and compatible with other measuring systems. The system is a 'must' for every modern crash laboratory. (orig.) [German] Die Smartcrash-Barriere von Kistler setzt in jeder Hinsicht Massstaebe. Neueste Technologie der Datenverarbeitung beim Crash mit Microdau-Modulen, wie sie auch in Dummys eingesetzt werden, wird mit einer einzigartigen mechanischen Modularitaet kombiniert, die alle erforderlichen Voraussetzungen fuer bestehende und zukuenftige Crash-Standards bietet. In Verbindung mit der fuer die Messung von hochdynamischen Kraftverlaeufen beim Crash praedestinierte Piezo-Messtechnik ist hiermit die Basis geschaffen, Crash-Laboratorien wirtschaftlich und hinsichtlich des Datenakquisition sicher und kompatibel mit anderen Messgroessen im Labor auszuruesten. Ein 'Muss' fuer jedes moderne Crash-Labor. (orig.)

High-resolution gamma spectroscopy with whole-body and partial-body counters. Experience, recommendations. Report; Hochaufloesende Gamma-Spektrometrie an Ganz- und Teilkoerperzaehlern. Erfahrungen, Empfehlungen. Bericht

Energy Technology Data Exchange (ETDEWEB)

Sahre, P. [comp.

1997-12-01

The application of high-resolution gamma spectroscopy with whole-body and partial-body counters shows a steadily rising upward trend over the last few years. This induced the ``Arbeitskreis Inkorporationsueberwachung`` of the association ``Fachverband fuer Strahlenschutz e.V.`` to organise a meeting for joint elaboration of a guide on recommended applications of this measuring technique, based on a review of existing experience and results. A key item on the agenda of the meeting was the comparative evaluation of the Ge semiconductor detector and the NaI solid scintillation detector. (orig./CB) [Deutsch] Der Einsatz der hochaufloesenden Gammaspektroskopie in Ganz- und Teilkoerperzaehlern hat in den letzten Jahren stetig zugenommen. Der ``Arbeitskreis Inkorporationsueberwachung`` des Fachverbandes fuer Strahlenschutz e.V. hat darum bisherige Erfahrungen zusammengetragen und Empfehlungen fuer den Einsatz dieser Messtechnik erarbeitet. Der Schwerpunkt der Tagung lag beim Vergleich von Germaniumhalbleiter- mit Natriumjodid-Festszintillationsdetektoren.Tl-Detektoren eignen sich v.a. beim Vorhandensein bekannter und zeitlich konstanter Nuklidvektoren (Kernkraftwerke, Nuklearmedizin). Bei unbekanntem bzw. variablem Nuklidvektor (Stoerfall, Unfall, Forschung) sollen Ge-Detektoren benutzt werden (orig./ABI)

Fresh-air cooling ceilings in an administration building; Frischluft-Kuehldecken in einem Verwaltungsgebaeude

Energy Technology Data Exchange (ETDEWEB)

Radtke, W

1995-06-01

In the construction of the new building of the Deutsche Innenbau GmbH in Muelheim much importance was attached to aesthetics and functionality. If the employees are enthusiastic after one year of operation this is mainly due to the ideal climatic conditions: Glazings with insulating glass (k=1,4 W/m{sup 2}k), high-quality thermal insulation of the breasts shading system with motor-driven screen at the outside, radiators with thermostatic valves and a fresh air cooling ceiling. The article describes the course of construction of the total air-conditioning and ventilation technique. (orig.) [Deutsch] Beim Neubau der DIG Deutsche Innenbau GmbH in Muelheim an der Ruhr legte man grossen Wert auf Aesthetik und Funktionalitaet. Wenn die Mitarbeiter nach einem Jahr Betrieb begeistert sind, so liegt dies grossenteils an idealen klimatechnischen Voraussetzungen: Verglasung mit Waermeschutzglas (K=1,4 W/m{sup 2}K), hochwertige Waermedaemmung der Bruestungen, aussenliegender Sonnenschutz mit motorbetaetigten Raffstoren, Radiatoren mit Thermostatventilen und einem Frischluft-Kuehldecken-System. Dieser Beitrag beschreibt die Vorgehensweise beim Bau der gesamten Klima- und Lueftungstechnik. (orig.)

Spatial distribution of prominin-1 (CD133-positive cells within germinative zones of the vertebrate brain.

Directory of Open Access Journals (Sweden)

József Jászai

Full Text Available In mammals, embryonic neural progenitors as well as adult neural stem cells can be prospectively isolated based on the cell surface expression of prominin-1 (CD133, a plasma membrane glycoprotein. In contrast, characterization of neural progenitors in non-mammalian vertebrates endowed with significant constitutive neurogenesis and inherent self-repair ability is hampered by the lack of suitable cell surface markers. Here, we have investigated whether prominin-1-orthologues of the major non-mammalian vertebrate model organisms show any degree of conservation as for their association with neurogenic geminative zones within the central nervous system (CNS as they do in mammals or associated with activated neural progenitors during provoked neurogenesis in the regenerating CNS.We have recently identified prominin-1 orthologues from zebrafish, axolotl and chicken. The spatial distribution of prominin-1-positive cells--in comparison to those of mice--was mapped in the intact brain in these organisms by non-radioactive in situ hybridization combined with detection of proliferating neural progenitors, marked either by proliferating cell nuclear antigen or 5-bromo-deoxyuridine. Furthermore, distribution of prominin-1 transcripts was investigated in the regenerating spinal cord of injured axolotl.Remarkably, a conserved association of prominin-1 with germinative zones of the CNS was uncovered as manifested in a significant co-localization with cell proliferation markers during normal constitutive neurogenesis in all species investigated. Moreover, an enhanced expression of prominin-1 became evident associated with provoked, compensatory neurogenesis during the epimorphic regeneration of the axolotl spinal cord. Interestingly, significant prominin-1-expressing cell populations were also detected at distinct extraventricular (parenchymal locations in the CNS of all vertebrate species being suggestive of further, non-neurogenic neural function

Visuelles in der wissenschaftlichen Kommunikation - z.B. Betrug und Fälschung

OpenAIRE

Fröhlich, Gerhard

2003-01-01

Visuelle Phänomene sind oft beim Aufdecken wissenschaftlichen Betrugs involviert. Wissenschaftliche und Massenmedien berichten von "vierdimensionalen" (Flusser) Manipulationen in Laboratorien (Moewus, Parapsychologie, Beneviste), "dreidimensionalen" Artefakten in Archäologie bzw. Geologie ("Lügensteine", Piltdown, Fujimura) und Biologie bzw. Medizin (Kammerers getuschte Geburtshelferkröte, Summerlins bemalte Mäuse, Illmensees Bluff-Klone). Inkriminierte zweidimensionale Repräsentationen (Bild...

Brain tumors in children; Hirntumoren beim Kind

Energy Technology Data Exchange (ETDEWEB)

Harting, I.; Seitz, A. [Universitaetsklinikum Heidelberg (Germany). Abt. Neuroradiologie

2009-06-15

Brain tumors are common in children; in Germany approximately 400 children are diagnosed every year. In the posterior fossa, cerebellar neoplasms outnumber brainstem gliomas. In contrast to their rarity in adults, brainstem gliomas are not uncommon in children. Supratentorial tumors can be subdivided by location into neoplasms of the cerebral hemispheres, suprasellar and pineal tumors. Astrocytoma is the most common pediatric brain tumor followed by medulloblastoma, ependymoma and craniopharyngeoma. The combination of imaging morphology, tumor localisation and patient age at manifestation form the basis of the neuroradiological differential diagnosis. (orig.)

Does selective pleural irradiation of malignant pleural mesothelioma allow radiation dose escalation. A planning study

Energy Technology Data Exchange (ETDEWEB)

Botticella, A.; Defraene, G. [KU Leuven - University of Leuven, Department of Oncology, Experimental Radiation Oncology, Leuven (Belgium); Nackaerts, K. [KU Leuven - University of Leuven, University Hospitals Leuven, Department of Respiratory Medicine, Leuven (Belgium); Deroose, C. [KU Leuven - University of Leuven, University Hospitals Leuven, Nuclear Medicine, Leuven (Belgium); Coolen, J. [KU Leuven - University of Leuven, University Hospitals Leuven, Radiology Department, Leuven (Belgium); Nafteux, P. [University Hospitals Leuven, Department of Thoracic Surgery, Leuven (Belgium); Vanstraelen, B. [University Hospitals Leuven, Department of Radiation Oncology, Leuven (Belgium); Joosten, S.; Michiels, L.A.W. [Fontys University of Applied Science, Institute Paramedical Studies, Medical Imaging and Radiotherapeutic Techniques, Eindhoven (Netherlands); Peeters, S. [KU Leuven - University of Leuven, Department of Oncology, Experimental Radiation Oncology, Leuven (Belgium); University Hospitals Leuven, Department of Radiation Oncology, Leuven (Belgium); Ruysscher, D. de [KU Leuven - University of Leuven, Department of Oncology, Experimental Radiation Oncology, Leuven (Belgium); Maastricht University Medical Center, GROW - School for Oncology and Developmental Biology, Department of Radiation Oncology (MAASTRO Clinic), Maastricht (Netherlands)

2017-04-15

After lung-sparing radiotherapy for malignant pleural mesothelioma (MPM), local failure at sites of previous gross disease represents the dominant form of failure. Our aim is to investigate if selective irradiation of the gross pleural disease only can allow dose escalation. In all, 12 consecutive stage I-IV MPM patients (6 left-sided and 6 right-sided) were retrospectively identified and included. A magnetic resonance imaging-based pleural gross tumor volume (GTV) was contoured. Two sets of planning target volumes (PTV) were generated for each patient: (1) a ''selective'' PTV (S-PTV), originating from a 5-mm isotropic expansion from the GTV and (2) an ''elective'' PTV (E-PTV), originating from a 5-mm isotropic expansion from the whole ipsilateral pleural space. Two sets of volumetric modulated arc therapy (VMAT) treatment plans were generated: a ''selective'' pleural irradiation plan (SPI plan) and an ''elective'' pleural irradiation plan (EPI plan, planned with a simultaneous integrated boost technique [SIB]). In the SPI plans, the average median dose to the S-PTV was 53.6 Gy (range 41-63.6 Gy). In 4 of 12 patients, it was possible to escalate the dose to the S-PTV to >58 Gy. In the EPI plans, the average median doses to the E-PTV and to the S-PTV were 48.6 Gy (range 38.5-58.7) and 49 Gy (range 38.6-59.5 Gy), respectively. No significant dose escalation was achievable. The omission of the elective irradiation of the whole ipsilateral pleural space allowed dose escalation from 49 Gy to more than 58 Gy in 4 of 12 chemonaive MPM patients. This strategy may form the basis for nonsurgical radical combined modality treatment of MPM. (orig.) [German] Beim malignen Pleuramesotheliom (MPM) ist nach lungenschonender Radiotherapie das lokale Scheitern an Stellen eines frueheren, sichtbaren Tumors die dominierende Form des Scheiterns. Unser Ziel ist es, zu untersuchen, ob die selektive

Smart Home, Smart Grid, Smart Meter - digitale Konzepte und das Recht an Daten

Science.gov (United States)

Spiecker genannt Döhmann, Indra

Modernes Energiemanagement setzt auf ein intelligent gesteuertes Energieinformationsnetz, das Smart Grid. In diesem ist der Smart Meter, die intelligente Messstelle beim Nutzer, ein zentrales Instrument für den wechselseitigen Austausch von Informationen. Allerdings werfen die über diverse Gesetze forcierten Informationsströme erhebliche datenschutzrechtliche Fragen auf. Der Beitrag stellt zentrale datenschutzrechtliche Leitlinien und Probleme vor und behandelt auch offene Fragestellungen.

Viertes LSDMA Symposium: Neue Entwicklungen im Bereich Big Data

OpenAIRE

Çayoğlu, Uğur

2015-01-01

Auch in diesem Jahr trafen sich zahlreiche Wissenschaftler aus unterschiedlichen Wissenschaftsgebieten beim internationalen Symposium „The Challenge of Big Data in Science“, der Helmholtz Initiative Large-Scale Data Management and Analysis (LSDMA). Das Steinbuch Centre for Computing veranstaltete diese Tagung nun das vierte Mal. Es waren über 90 Teilnehmer aus Deutschland, Frankreich, Spanien, China und den Vereinigten Staaten zu Gast.

Amphioxus and lamprey AP-2 genes: implications for neural crest evolution and migration patterns

Science.gov (United States)

Meulemans, Daniel; Bronner-Fraser, Marianne

2002-01-01

The neural crest is a uniquely vertebrate cell type present in the most basal vertebrates, but not in cephalochordates. We have studied differences in regulation of the neural crest marker AP-2 across two evolutionary transitions: invertebrate to vertebrate, and agnathan to gnathostome. Isolation and comparison of amphioxus, lamprey and axolotl AP-2 reveals its extensive expansion in the vertebrate dorsal neural tube and pharyngeal arches, implying co-option of AP-2 genes by neural crest cells early in vertebrate evolution. Expression in non-neural ectoderm is a conserved feature in amphioxus and vertebrates, suggesting an ancient role for AP-2 genes in this tissue. There is also common expression in subsets of ventrolateral neurons in the anterior neural tube, consistent with a primitive role in brain development. Comparison of AP-2 expression in axolotl and lamprey suggests an elaboration of cranial neural crest patterning in gnathostomes. However, migration of AP-2-expressing neural crest cells medial to the pharyngeal arch mesoderm appears to be a primitive feature retained in all vertebrates. Because AP-2 has essential roles in cranial neural crest differentiation and proliferation, the co-option of AP-2 by neural crest cells in the vertebrate lineage was a potentially crucial event in vertebrate evolution.

FGF and BMP derived from dorsal root ganglia regulate blastema induction in limb regeneration in Ambystoma mexicanum.

Science.gov (United States)

Satoh, Akira; Makanae, Aki; Nishimoto, Yurie; Mitogawa, Kazumasa

2016-09-01

Urodele amphibians have a remarkable organ regeneration ability that is regulated by neural inputs. The identification of these neural inputs has been a challenge. Recently, Fibroblast growth factor (Fgf) and Bone morphogenic protein (Bmp) were shown to substitute for nerve functions in limb and tail regeneration in urodele amphibians. However, direct evidence of Fgf and Bmp being secreted from nerve endings and regulating regeneration has not yet been shown. Thus, it remained uncertain whether they were the nerve factors responsible for successful limb regeneration. To gather experimental evidence, the technical difficulties involved in the usage of axolotls had to be overcome. We achieved this by modifying the electroporation method. When Fgf8-AcGFP or Bmp7-AcGFP was electroporated into the axolotl dorsal root ganglia (DRG), GFP signals were detectable in the regenerating limb region. This suggested that Fgf8 and Bmp7 synthesized in neural cells in the DRG were delivered to the limbs through the long axons. Further knockdown experiments with double-stranded RNA interference resulted in impaired limb regeneration ability. These results strongly suggest that Fgf and Bmp are the major neural inputs that control the organ regeneration ability. Copyright © 2016 Elsevier Inc. All rights reserved.

Entwicklung und Evaluation computerbasierter Trainingsaufgaben für das wissenschaftliche Schreiben

OpenAIRE

Proske, Antje

2006-01-01

Wissenschaftliches Schreiben ist eine sehr komplexe Aufgabe, die eine Vielzahl unterschiedlicher Aktivitäten umfasst. Viele Studierende haben jedoch Schwierigkeiten, die damit verbundenen Anforderungen selbständig zu bewältigen. Im Mittelpunkt des Interesses der vorliegenden Arbeit stand daher die Entwicklung und Evaluation interaktiver computerbasierter Trainingsaufgaben, die Studienanfänger beim Erwerb von Grundkompetenzen des wissenschaftlichen Schreibens unterstützen. Zentrale Anliegen di...

Kooperative Textproduktion : zur gemeinsamen Herstellung wissenschaftlicher Texte im Vergleich von ungeübten, fortgeschrittenen und sehr geübten SchreiberInnen

OpenAIRE

Lehnen, Katrin

2000-01-01

Was kennzeichnet wissenschaftliche Schreibkompetenz und wie manifestiert sie sich im Produktionsprozess? An welchen Normen orientieren sich SchreiberInnen beim Formulieren und welche Darstellungsstrategien machen sie sich zu eigen? Eine Möglichkeit, etwas darüber herauszubekommen, ist die Untersuchung kooperativer Textproduktionen. Dabei handelt es sich um Situationen, in denen mindestens zwei Personen gemeinsam einen Text planen, schreiben und/oder überarbeiten. Das Besondere ist, dass Proze...

Innovative Techniken und Algorithmen im Bereich Computational-Finance und Risikomanagement

OpenAIRE

Liang, Qian

2012-01-01

Diese Dissertation besteht aus zwei aktuellen Themen im Bereich Finanzmathematik, die voneinander unabhängig sind. Beim ersten Thema, "Flexible Algorithmen zur Bewertung komplexer Optionen mit mehreren Eigenschaften mittels der funktionalen Programmiersprache Haskell", handelt es sich um ein interdisziplinäres Projekt, in dem eine wissenschaftliche Brücke zwischen der Optionsbewertung und der funktionalen Programmierung geschlagen wurde. Im diesem Projekt wurde eine funktionale Biblio...

Augmented Reality als Vergleichswerkzeug am Beispiel der Automobilindustrie

OpenAIRE

Nölle, Stefan

2007-01-01

In der Automobilindustrie lässt sich am Markt ein starker Wettbewerb beobachten. Um Produktentwicklungskosten zu senken, kommen besonders Computer Aided Design Techniken zum Einsatz. Im Verlauf des Produktentstehungsprozess ergibt sich beim Prototypenbau ein Übergang von virtuellen zu realen Bauteilen. In dieser Phase sind wesentliche Arbeiten die Ver- und Abgleiche realer Bauteile mit ihren computergenerierten Konstruktionsvorgaben. Dieser so genannte Soll-/ Ist-Vergleich zwischen virtuellen...

Pitfalls in the MR diagnosis of primary malignant bone tumors; Pitfalls in der MR-Diagnostik primaer maligner Knochentumoren

Energy Technology Data Exchange (ETDEWEB)

Bader, T.R. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria). Abt. fuer Osteologie; Imhof, H.; Breitenseher, M.J. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria). Abt. fuer Osteologie]|[Wien Univ. (Austria). Einrichtung UOG Magnetic Resonanz; Dominkus, M. [Universitaetsklinik fuer Orthopaedie, Wien (Austria)

1998-06-01

MRI has gained an undisputed place in the evaluation of malignant bone tumors, not only for verifying results of conventional radiography and clarifying differential diagnoses; it has also become increasingly important for the assessment of the malignant/benign nature of the tumor, its growth rate, definition of adequate sites for biopsy, local preoperative staging, and evaluation of the response to chemotherapy. However, several pitfalls have to be observed regarding choice of technical parameters (coils, sequences, imaging planes), tissue differentiation, and tumor staging. When staging malignant tumors, critical aspects which have to be observed are tumor extension, integrity of the cortical bone, soft tissue components, infiltration of a joint or neurovascular bundle. The use of contrast agents provides important additional information but can also give rise to misinterpretations. Thus, all features of a tumor have to be observed in order to establish a final diagnosis. Particular difficulties can occur with the interpretation of MR images of osteomyelitis, osteoid osteoma, stress and insufficiency fractures, bone infarcts, myositis ossificans, hemangiomas, and aneurysmal bone cysts. (orig.) [Deutsch] Bei der Diagnostik von malignen Knochentumoren hat die MRT einen fixen Platz nicht nur in der Verifikation der Nativdiagnostik und der Differentialdiagnostik, sondern zunehmende Bedeutung bei der primaeren Beurteilung von Dignitaet und Wachstumsgeschwindigkeit, Definition einer geeigneten Biopsiestelle, beim lokoregionaeren, praeoperativen Staging und der Evaluation des Ansprechens auf Chemotherapie. Zahlreiche Pitfalls finden sich jedoch bei der Wahl der technischen Parameter (Spulen, Sequenzen, Schichtebenen), der Tumordifferenzierung und beim Staging von malignen Tumoren. Beim Staging sind die kritischen Punkte die Beurteilung von Tumorausdehnung, Integritaet der Kortikalis, Vorhandensein einer Weichteilkomponente, Infiltration eines Gelenks oder des

Open Source Software Projects Needing Security Investments

Science.gov (United States)

2015-06-19

modtls, BouncyCastle, gpg, otr, axolotl. 7. Static analyzers: Clang, Frama-C. 8. Nginx. 9. OpenVPN . It was noted that the funding model may be similar...to OpenSSL, where consulting funds the company. It was also noted that OpenVPN needs to correctly use OpenSSL in order to be secure, so focusing on...Dovecot 4. Other high-impact network services: OpenSSH, OpenVPN , BIND, ISC DHCP, University of Delaware NTPD 5. Core infrastructure data parsers

Normzahlen, Toleranzen, Passungen

Science.gov (United States)

Böge, Gert; Böge, Wolfgang

Vor allem wegen der Kosten ist es sinnvoll, sich beim Festlegen von Maßen aller Art auf Vorzugszahlen zu beschränken (Baugrößen, Drehzahlen, Drehmomente, Leistungen, Drücke usw.). Man verwendet dazu eine geometrisch gestufte Zahlenfolge (siehe Teil Mathematik). Abb. 40.1 zeigt, dass bei der geometrischen Stufung die Werte im unteren Bereich fein, im oberen grob gestuft sind. Das ist nicht nur technisch sinnvoll.

Synthese und Charakterisierung wasserfreier Seltenerdmetall-Nitrate, -Acetate und -Oxyacetate

OpenAIRE

Heinrichs, Christina

2013-01-01

Durch thermische Entwässerung der Seltenerdmetall(SE)-Nitrat-Hydrate und der SE-Acetat-Hydrate im Argon-Strom/Vakuum konnten wasserfreie SE-Nitrate und SE-Nitrat-Monohydrate bzw. wasserfreie SE-Acetate erhalten werden. Es gelang zudem, SE-Oxyacetate durch thermische Zersetzung der SE-Acetate darzustellen. Des Weiteren wurde beim Erhitzen von Praseodym-Carbonat-Hydrat ein Pr-Carbonat-Hydroxid erhalten. Die Verbindungen wurden mittels Röntgenpulverdiffraktometrie und an ausgewählten Beispielen ...

Wissenschaftliches Schreiben in der Fremdsprache Deutsch : am Beispiel von Abschlussarbeiten französischer Studierender

OpenAIRE

François, Audrey

2006-01-01

Die vorliegende Arbeit befasst sich mit dem wissenschaftlichen Schreiben in der Fremdsprache Deutsch am Beispiel von Abschlussarbeiten französischer Studierender. Das Ziel der Dissertation ist herauszufinden, wie französische Germanistikstudierende die innere und äußere Form ihrer universitären Abschlussarbeit gestalten. Dabei soll untersucht werden, ob französische fortgeschrittene DaF-Lernende beim wissenschaftlichen Schreiben bestimmte Schwierigkeiten haben, die nicht allen DaF-Lerne...

3D-Druck von Kunststoff-Medizinprodukten

OpenAIRE

Polzin, Christian; Seitz, Hermann

2012-01-01

Das Additive Manufacturing gewinnt im Bereich der Medizintechnik zur Herstellung von Prototypen bis hin zu Endprodukten zunehmend an Bedeutung. Ein großes Hemmnis stellen allerdings die relativ hohen Fertigungskosten dar. Hier bietet der verstärkte Einsatz der 3D-Drucktechnologie (3D Printing) ein erhebliches Potential zur Reduktion der Kosten. Aus dieser Motivation heraus wurde ein 3D-Druckverfahren zur Herstellung biokompatibler, sterilisierbarer Kunststoffmodelle entwickelt. Beim 3D-Druck-...

Concrete core tempering in a passive house. Simulation behaviour of a single-family house; Betonkerntemperierung im Passivhaus. Simulationsverhalten eines Einfamilienhauses

Energy Technology Data Exchange (ETDEWEB)

Mahler, B; Seiwald, H [Steinbeis-Transferzentrum Energie-, Gebaeude- und Solartechnik; Koch, K P [Rehau AG und Co., Erlangen-Eltersdorf (Germany)

2004-07-01

New office buildings often have concrete core tempering systems for combined heating and cooling. The technology may be applied to well-insulated domestic buildings as well, provided that certain boundary conditions are met. [German] Beim Neubau von Buerogebaeuden findet die Betonkerntemperierung fuer kombinierte Heiz- und Kuehlsysteme immer mehr Verbreitung. Im Zuge des stark reduzierten Heizleistungsbedarfs hochgedaemmter Wohngebaeude bietet sich die Betonkerntemperierung unter bestimmten Voraussetzungen auch hier als Heizsystem an. (orig.)

Optimization of radiotherapy planning for Non-Small Cell Lung Cancer (NSCLC) by {sup 18}FDG-PET; Optimierung der Bestrahlungsplanung beim nicht-kleinzelligen bronchialkarzinom (NSCLC) mit Hilfe von {sup 18}FDG-PET

Energy Technology Data Exchange (ETDEWEB)

Schmidt, S.; Nestle, U.; Kirsch, C.M. [Abt. fuer Nuklearmedizin, Universitaetskliniken des Saarlandes, Homburg/Saar (Germany); Walter, K. [Abt. fuer Strahlentherapie, Marienkrankenhaus Amberg (Germany); Licht, N.; Schnabel, K. [Abt. fuer Strahlentherapie, Universitaetskliniken des Saarlandes, Homburg/Saar (Germany); Ukena, D. [Innere Medizin V, Universitaetskliniken des Saarlandes, Homburg/Saar (Germany)

2002-10-01

Aim: In recent years, FDG-PET examinations have become more important for problems in oncology, especially in staging of bronchogenic carcinoma. In the retrospective study presented here, the influence of PET on the planning of radiotherapy for patients with non-small-cell lung cancer (NSCLC) was investigated. Methods: The study involved 39 patients with NSCLC who had been examined by PET for staging. They received radiotherapy on the basis of the anterior/posterior portals including the primary tumour and the mediastinum planned according to CT- and bronchoscopic findings. The results of the PET examination were not considered in initial radiotherapy planning. The portals were retrospectively redefined on the basis of FDG uptake considering the size and localization of the primary tumour; and FDG activities outside the mediastinal part of the portals. Results: In 15 out of 39 patients, the CT/PET-planned portals differed from the CT-planned ones. In most cases (n = 12) the CT/PET field was smaller than the CT field. The median geometric field size of the portals was 179 cm{sup 2}, after redefinition using PET 166 cm{sup 2}. In 20 patients with disturbed ventilation caused by the tumour (atelectosis, dystelectosis), a correction of the portal was suggested significantly more frequently than in the other patients (p = 0.03). Conclusions: Our results demonstrate the synergism of topographical (CT) and metabolic (FDG-PET) information, which could be helpful in planning radiotherapy of bronchial carcinoma, especially for patients with disturbed ventilation. (orig.) [German] Ziel: Die FDG-PET-Untersuchung hat in den vergangenen Jahren bei onkologischen Fragestellungen insbesondere beim Staging des Bronchialkarzinoms wachsende Bedeutung erlangt. In der vorliegenden retrospektiven Untersuchung wurde der Einfluss der PET auf die Strahlentherapieplanung bei Patienten mit non-small-cell lung cancer (NSCLC) untersucht. Methoden: Die Untersuchung umfasste 39 Patienten mit

Bone scintigraphy for horses; Die Skelettszintigrafie beim Pferd

Energy Technology Data Exchange (ETDEWEB)

Jahn, Werner [Pferdeklinik Bargteheide (Germany)

2010-03-15

Scintigraphy (bone scan) is being used approximately since 1980 in the horse under general anaesthesia. With the construction of custom-made overhead gantries for gamma-cameras scintigraphy found widespread entry in big equine referral hospitals for bone-scanning of the standing horse. Indications for the use of a bone scan in the horse are inflammatory alterations in the locomotor apparatus. It is primarily used for diagnosis of lameness of unknown origin, suspect of stress fracture or hairline fracture and for horses with bad riding comfort with suspected painful lesions in the spine. (orig.)

Effects of overhead power lines on the bird population of the Radenhaeuser Lache area in the Marburg-Biedenkopf district, Hessen; Auswirkungen von Freileitungen auf die Voegel der Radenhaeuser Lache, Landkreis Marburg-Biedenkopf/Hessen

Energy Technology Data Exchange (ETDEWEB)

Kliebe, K.

1997-12-01

In the Radenhaeuser Lache area in the county of Marburg-Biedenkopf 122 birds belonging to at least 18 species were found dead (85.2%) or injured (14.8%) in the period from 1991 to the end of July 1997. In four cases collisions with the high voltage overhead power lines (OHL) running above the flat expanse of water (42 lines of 110 kV and 380 kV) were actually seen. Collisions with the conductors seem to occur with equal frequency when birds come in to land and when they take off in flocks (particularly ducks and lapwings) whether or not this is owing to some disturbance or other (birds of prey, human beings, helicopters or hot-air balloons). (orig.) [Deutsch] Im Bereich der Radenhaeuser Lache (Kreis Marburg-Biedenkopf) wurden seit 1991 bis Ende Juli 1997 122 Voegel in mindestens 18 Arten tot (85,2%) oder verletzt (14,8%) registriert. Kollissionen mit den das Flachgewaesser ueberspannenden Hochspannungsleitungen (42 Seile mit 110 bzw. 380 kV) wurden in vier Faellen durch Sichtbeobachtungen nachgewiesen. Leitungsanfluege geschehen wohl gleichrangig beim Landeanflug und beim scharenweisen Abflug (vor allem Enten und Kiebitze) ohne oder auf Grund von Stoerungen (jagende Greifvoegel, Menschen, Hubschrauber und Heissluftballons). (orig.)

Wer sich den Göttern widersetzt, der stirbt jung : Untersuchung der Unvermeidbarkeit des Suizids in Die Leiden des jungen Werthers hinsichtlich der Strömung des „Sturm und Drang“

OpenAIRE

Andersson, Rasmus

2015-01-01

Der Ausgang des Romans Die Leiden des Jungen Werther (1774, von Johann Wolfgang von Goethe) wird beim ersten Anblick oft als tragische Folge einer unglücklichen und unerwiderten Liebe zu Lotte angesehen. In dieser vorliegenden Arbeit wird der weit erforschten Frage der Unvermeidbarkeit des Suizids im Werk eine alternative Deutung geliefert. Diese ist außerhalb des Romans angesiedelt, und zeigt, dass der Suizid schon in der Epoche angelegt ist.

Technische Feuchtgebiete zur Nachreinigung von Abwasser:Stickstoff, Abwasserdesinfektion, Spurenstoffe

OpenAIRE

Rühmland, Sabine

2015-01-01

Stickstoff, Spurenstoffe und Krankheitserreger können auch in geringen Mengen Schäden in Gewässern bzw. beim Menschen verursachen. In dieser Arbeit soll geklärt werden, inwieweit das naturnahe Abwasserreinigungsverfahren der technischen Feuchtgebiete zur Nachreinigung von Abwasser geeignet ist. Dafür wurden in Berlin sieben bewachsene Bodenfilter und Abwasserteiche im techni-schen Maßstab einer Kläranlage mit Nährstoffelimination nachgeschaltet. Ein Sandfilter, ein Sandfilter mit Lehm und...

Hüftgelenks-Endoprothesen

Science.gov (United States)

Widmer, Markus; von Felten-Rösler, Ursula; Wintermantel, Erich

Die Hüftgelenk-Endoprothese wird im vorliegenden Buch als herausragendes Beispiel eines lasttragenden orthopädischen Implantates aufgeführt. Lasttragende Implantate werden in dieser Monographie den metabolisch induktiven Implantaten gegenübergestellt, bei denen Kräfte eine untergeordnete Rolle sowohl in der Werkstoffentwicklung als auch beim späteren Einsatz im Empfängerorganismus darstellen. Zu den metabolisch induktiven Implantaten werden beispielsweise Zellträger und “drug-release”-Systeme gerechnet.

Umfassende molekulargenetische Diagnostik für angeborene Hörstörungen auf Basis neuer Sequenziertechniken

OpenAIRE

Bolz, HJ; Neuhaus, C; Bergmann, C; Eisenberger, T

2011-01-01

Hintergrund: Etwa 2/3 der angeborenen Hörstörungen (im Folgenden synonym "Taubheit") sind genetisch bedingt. Aufgrund der genetischen Heterogenität (>50 bekannte Gene) war eine umfassende molekulare Diagnostik bislang finanziell und zeitlich nicht leistbar. Diese ist aber wichtig, u.a. um zwischen isolierter und syndromaler Taubheit (mit z.T. schweren Komplikationen wie plötzlichem Herztod beim Jervell und Lange-Nielsen-Syndrom) zu unterscheiden. Durch neue Sequenziermethoden (next-generatio...

Isolation und Charakterisierung retroviraler Partikel und Proteine zur Untersuchung immunsuppressiver Effekte

OpenAIRE

Pietsch, Heiko

2016-01-01

Obgleich auf dem Gebiet der Transplantationsmedizin in jüngster Zeit beachtliche Fortschritte erzielt worden sind, ist der Mangel an Organspendern ein fortbestehendes Problem. Im Rahmen der Xenotransplantation können Schweine als Spender zur Transplantation von Zellen oder Organen beim Menschen dienen. Um die Sicherheit der Xenotransplantation zu gewährleisten, ist sowohl die Entwicklung sensitiver Nachweismethoden als auch die Einschätzung des Gefahrenpotentials durch eine Infektion für den ...

Modernisation of Leipzig main station. Reconstruction into ''Promenaden'' shopping mall; Sanierung Hauptbahnhof Leipzig. Umbau zum ''Promenaden''-Einkaufscenter

Energy Technology Data Exchange (ETDEWEB)

Schmid, W. [Pressebuero fuer Technische Gebaeudeausruestung, Muenchen (Germany)

1999-07-01

Leipzig main station was modernized, and a service center and shopping mall was installed. The main problem consisted in maintaining an efficient train service, so that project management was considered particularly important. [German] Mit der umfassenden Renovierung des Leipziger Hauptbahnhofs wurde ergaenzend zur Sanierung der Verkehrsdrehscheibe ein Dienstleistungszentrum geschaffen. Eine der zu bewaeltigenden Schwierigkeiten beim Umbau war die Gewaehrleistung des Bahnbetriebs, so dass besonderer Wert auf ein umfassendes Projektmanagement gelegt wurde. (orig.)

Irradiation inhibits the regeneration of aneurogenic limbs

International Nuclear Information System (INIS)

Wallace, H.; Maden, M.

1976-01-01

The developing arms of axolotl larvae from the 2-digit stage onward and the aneurogenic arms of surgically denervated larvae maintained in parabiosis are able to regenerate after amputation. Such regeneration is uniformly inhibited by local irradiation of the arm, whether innervated or not. This demonstration refutes a recent hypothesis that x-rays interfere with a special activity of nerves required for regeneration, and supports the earlier concept that x-rays act directly on those cells which must proliferate to form the regenerated tissues

Carbamoyl-phosphate synthase (ammonia) of rat and axolotl liver: determination of immunological cross-reactivity without purification of the axolotl enzyme

NARCIS (Netherlands)

Lamers, W. H.; de Graaf, A.; Mooren, P. G.; Moorman, A. F.; Charles, R.

1982-01-01

A method has been developed to establish the degree of cross-reactivity of an antiserum raised against purified carbamoyl-phosphate synthase (ammonia) from adult rat liver, toward a homologous enzyme from another species without purification of the latter enzyme. For that purpose the ratio between

Study of colored anodized aluminum with calcon in sulfuric acidic solution using cyclic voltammetry and impedance measurement methods

Energy Technology Data Exchange (ETDEWEB)

Norouzi, P.; Ganjali, M.R.; Golmohamaddi, M.; Mousavi, S. [Department of Chemistry, Faculty of Science, University of Tehran, Tehran (Iran); Vatankhah, G. [Iranian Organization for Science and Technology (IROST), Isfahan Center, A5 Ghezelbash Avenue, Tohid Street, Isfahan 8173954541 (Iran)

2003-04-01

The effect of coloring condition of Al with Calcon (sodium 2,2'-dihydroxy-azonaphthalene-4-sulfonate), on the corrosion resistance of Al in 0.1 M sulfuric acid solution was studied, using cyclic voltammetry and measurement of impedance noise methods. The changes in the corrosion resistance of colored aluminum electrodes were evaluated by measuring the magnitude of impedance and cyclic voltammetric responses of anodized and colored electrodes. An irreversible corrosion response was observed at the cyclic voltammogram of the colored aluminum electrode. The current and threshold potential of corrosion responses strongly depends on the applied conditions during anodizing, coloring and sealing stages. In addition, significant changes in impedance at the ac voltammogram and noise level at some ac frequencies were observed, when the electrodes were colored under various conditions. In this regard, the surface of the electrode was studied by Scanning Electron Microscopy (SEM). Comparison of SEM images of the colored and uncolored aluminum specimens showed that the colored surface contained a significant numbers of pits. The results indicated that coloring aluminum with Calcon could reduce corrosion resistance of aluminum and increase roughness of the oxide film. (Abstract Copyright [2003], Wiley Periodicals, Inc.) [German] Mit Hilfe zyklischer Voltammetrie und Messungen mit Impedanzrauschmethoden wurde der Einfluss der Faerbungsbedingungen von Aluminium mit Calcon (Natrium 2,2'-Dihydroxyazonaphthalen-4-Sulfonat) auf den Korrosionswiderstand von Aluminium in 0,1 M Schwefelsaeure untersucht. Die Veraenderungen des Korrosionswiderstandes von gefaerbten Aluminiumelektroden wurden durch Messungen der Hoehe der Impedanzreaktion bzw. der Reaktion bei der zyklischen Voltammetrie von anodisierten und gefaerbten Elektroden beurteilt. Eine irreversible Korrosionsreaktion wurde beim zyklischen Voltammogramm der gefaerbten Aluminiumelektrode beobachtet. Der Strom und das

Weiterentwicklung Gruppenleiter/innen-Kurs: Ein Projekt in der Freiwilligenarbeit des CVJM/CVJF Regionalverband Basels: Projektbericht

OpenAIRE

Fankhauser, Miriam

2016-01-01

Im folgenden Bericht geht es um das Projekt «Weiterentwicklung Gruppenleiter/innen-Kurs – Ein Pro- jekt in der Freiwilligenarbeit des CVJM/CVJF Regionalverband Basels». Dieses Projekt wurde von der Studentin Miriam Fankhauser im Rahmen der Praxisausbildung an der Hochschule Luzern für Soziale Arbeit durchgeführt. In Auftrag gegeben wurde das Projekt vom CVJM/CVJF Regionalverband Basel. Beim eben genannten Projekt ging es darum, den Gruppenleiter/innen-Kurs weiterzuentwickeln. Der Kurs rich...

Positive Effekte des Mindestlohns auf Arbeitsplatzqualität und Arbeitszufriedenheit

OpenAIRE

Pusch, Toralf; Rehm, Miriam

2017-01-01

Über den Zusammenhang zwischen Mindestlöhnen und Änderungen bei der Arbeitsplatzqualität ist bisher wenig bekannt. Nach der Mindestlohneinführung in Deutschland stieg die Arbeitsplatzzufriedenheit insgesamt. Neben höheren Stunden- und Bruttolöhnen und verringerten Arbeitszeiten gibt es als möglichen Grund auch eine arbeitsorganisatorische Aufwertung der Arbeitsplätze. Bei bestehenden Beschäftigungsverhältnissen konnten Hinweise auf Verbesserungen beim Betriebsklima und einer mehr auf Mitarbei...

Medien und Berufsvorstellungen von Kindern: eine experimentelle Studie zum Einfluss von Kinderbüchern auf das Berufsspektrum von Kindergartenkindern

OpenAIRE

Brüggemann, Tim; Gehrau, Volker; Handrup, Jutta

2015-01-01

"Der Beitrag thematisiert zunächst den Stand der beruflichen Orientierung von Jugendlichen sowie die pädagogischen Bemühungen beim Übergang Schule-Beruf, insbesondere im Hinblick auf eine Erweiterung des häufig engen Spektrums von Berufen, die bei der Berufswahl berücksichtig werden. Dabei richten sich die Bestrebungen, diesem Problem entgegenzuwirken, bislang vor allem auf Jugendliche. Anschließend wird anhand vorliegender Ergebnisse aus der Medienforschung diskutiert, in welcher Weise Masse...

Dynamische Programm-Code-Verwaltung und -Optimierung für eingebettete Systeme

OpenAIRE

Schell, Dominic

2009-01-01

Bei Desktop-PCs ist ein großer Hauptspeicherausbau im Bereich jenseits von 1 GB dank gesunkener Speicherpreise und auf Grund gestiegener Anforderungen keine Seltenheit mehr. Es existiert jedoch eine Unmenge Kleinstrechner, wie z.B. im Automobilbereich eingesetzte Steuergeräte, die sich einen großen Speicherausbau wegen des Platzbedarfs der Speicherchips, deren Energiekonsum und den zusätzlichen Kosten nicht leisten können. Ein wichtiges Ziel beim Erzeugen der Software für eingebettete Systeme...

Endometriose - eine epigenetische Erkrankung?

OpenAIRE

Imesch, P; Samartzis, E P; Fink, D

2011-01-01

Endometriose wird in ihrer Pathogenese bis heute nur unzureichend verstanden. Dies hat zur Folge, dass die Therapieoptionen, insbesondere die nicht-chirurgischen Behandlungen, nicht kausal ausgelegt sind und viele Fragen bei der betroffenen Patientin wie beim Arzt offen bleiben. Gerade das genaue Verständnis der frühen Phasen der Endometrioseentstehung und ihrer molekularen Vorgänge wären aber in der Entwicklung neuer nicht-chirurgischer Behandlungspläne sehr hilfreich und dringend nötig.

The vehicle dynamics control system of Bosch; Die Fahrdynamikregelung von Bosch

Energy Technology Data Exchange (ETDEWEB)

Zanten, A.T. van [Robert Bosch GmbH, Stuttgart (Germany); Erhardt, R. [Robert Bosch GmbH, Stuttgart (Germany); Pfaff, G. [Robert Bosch GmbH, Stuttgart (Germany)

1996-11-01

Vehicle handling at the physical limit of adhesion between the tires and the road is extremely difficult. In such situations the driver may be supported by controlling the longitudinal and the lateral forces on the tires. The Vehicle Dynamics Control System of Bosch (VDC) does that by controlled braking of individual wheels which makes the vehicle motion approach the nomial motion intended by the driver. It uses signals to derive the driver`s intent (steering wheel angle, brake pressure, engine torque) and signals to dervie the actual motion of the vehicle (yaw rate, lateral acceleration). The support of the driver is not limited to coasting conditions. Also during full braking (ABS), partial braking, engine drag, free rolling and acceleration (ASR) of the vehicle the system supports the driver in all safety critical situations. In this paper an overview of the VDC is given. The goal of the development of VDC, the physical background, the concept of the system, the control and the controller algorithm are described. The benefit of VDC is demonstrated by an experimental test. (orig.) [Deutsch] Fahrdynamikregelsysteme FDR sind Regelsysteme im Bremssystem und Antriebsstrang, die das seitliche Ausbrechen des Fahrzeugs verhindern. Waehrend ABS das Blockieren der Raeder beim Bremsen und ASR das Durchdrehen der Raeder beim Antrieb verhindert, verhindert FDR das Schleudern und das Schieben des Fahrzeugs. (orig.)

entre la pirámide y el axolotl

Directory of Open Access Journals (Sweden)

Paula Andrea Marín Colorado

2006-01-01

Full Text Available En este artículo se presenta un acercamiento a la novela Materia dispuesta, del escritor mexicano Juan Villoro. En esta aproximación analítica se pretende dilucidar la conexión entre la obra literaria y el medio en el que se gesta, así como con el momento histórico recreado en la anécdota de la novela (el terremoto ocurrido en Ciudad de México en 1985; lo anterior con el objetivo de establecer la propuesta estética del autor en esta obra y su relación con la visión que construye Materia dispuesta sobre los procesos de Modernidad y Postmodernidad en Latinoamérica. Para tal propósito se recurrirá a las investigaciones literarias y sociológicas de Mijail Bajtín, Zigmunt Bauman, Carlos Monsiváis y Octavio Paz, entre otros.

Experimentelle, analytische und numerische Untersuchungen des Rührreibschweißprozesses

OpenAIRE

Hoßfeld, Max

2016-01-01

Mit dem Rührreibschweißverfahren steht seit einigen Jahren eine Fügetechnologie zur Verfügung, mit der viele fügetechnische Problemstellungen speziell beim Fügen von Aluminiumlegierungen gelöst oder vermieden werden können. Mittels Rührreibschweißen können sämtliche Aluminiumlegierungen zuverlässig, hocheffizient und mit einem sehr hohen Verbindungswirkungsgrad gefügt werden. Dabei weisen rührreibgeschweißte Verbindungen bereits ohne Nachbehandlung sehr gute statische und zyklische Festigkeit...

Success in the protection of the ozone layer is at risk. An interview concerning the German view on CFC- and H-CFC-phaseout all over the world; Bisherige Erfolge zum Schutz der Ozonschicht sind gefaehrdet. Ein Fachgespraech ueber die deutsche Meinung zum FCKW- und H-FCKW-Phaseout ueberall in der Welt

Energy Technology Data Exchange (ETDEWEB)

Kraus, H.W.; Weissenborn, P.

1995-11-01

This article repeats an interview with the commissioner of international measures for the protection of the ozone layer of the Federal Ministry of the Environment which took place in the run-up to the 7th conference of the signatory states of the Montreal Protocol. (BWI) [Deutsch] Der vorliegende Beitrag gibt ein Interview wieder, das mit dem Beauftragten fuer internationale Massnahmen zum Schutz der Ozonschicht beim Bundesumweltministerium im Vorfeld der 7. Konferenz der Vertragsstaaten zum Montrealer Protokoll gefuehrt wurde. (BWI)

Erinnerungen. Aus dem Feldzuge der Franzosen in Russland unter Napoleon im Jahre 1812, von einem preußischen Bombardier, dem jetzigen Major Weinberger. Unveröffentlichtes Manuskript (1849), herausgegeben von Peter-Michael Berger

OpenAIRE

Weinberger, Friedrich Ludwig

2012-01-01

Friedrich Ludwig Weinberger (1794–1869) diente im Juni 1812 als Freiwilliger bei der Königsberger Garnisonsartillerie. Diese 400 Soldaten wurden von Napoleon in die Garde seiner Grande Armée zur Invasion Russlands zwangsweise eingegliedert. Als einer von nur 13 Überlebenden seiner Truppe kehrte Weinberger im März 1813 aus russischem Gewahrsam zurück. Über seine Erlebnisse beim Vormarsch, den Kämpfen, der Besetzung Moskaus, dem Rückzug und der Heimkehr verfasste er einen Bericht, den er m...

Einführung in die Konstruktionsmethodik

Science.gov (United States)

Linke, Petra; Weidermann, Frank

Für die Entwicklung eines konkurrenzfähigen Produktes ist eine sehr gute Idee von entscheidender Bedeutung. Eine mittelmäßige Idee, konstruktiv gut umgesetzt reicht beim heutigen Verdrängungswettbewerb nicht mehr, um am Markt bestehen zu können. Rund 80% der Kosten eines Produktes werden in der Konstruktion festgelegt. Deshalb steht am Anfang einer Produktentwicklung immer eine intensive Ideenfindung. Der konstruktive Entwicklungsprozess ist dann weiter gegliedert in Planen und Klären der Aufgabe, Konzipieren, Entwerfen und Ausarbeiten.

Freizeit beim Feind. US-amerikanische Soldaten in Ost-Berlin

Directory of Open Access Journals (Sweden)

Stefanie Eisenhuth

2018-04-01

Full Text Available This article focuses on an almost forgotten type of ›border crosser‹ in the divided city of Berlin: the members of the American military community. To them (as well as to the members of the French and British forces, the Berlin Wall marked the front line of the Cold War. At the same time, though, they were allowed to cross the border and spend their free time in East Berlin. Especially in the 1970s and 1980s, when the dollar was tumbling, American families took advantage of the favourable exchange rate and crossed the border for cheap shopping, dining and entertainment. Due to Berlin’s status, the GDR government had to tolerate this kind of tourism, but nevertheless tried to prevent any personal contact between Americans and East Germans. The regime could also benefit financially from the Western tourists. This demonstrates the ambivalence of the Honecker era, the concurrence of an increased openness and internal erosion. The study is based on documents from the GDR’s Ministry for State Security, the West Berlin Senate Chancellery and the US Berlin Brigade as well as on contemporary newspaper articles. * * * Der Aufsatz widmet sich einer ungewöhnlichen Gruppe von Berliner Grenzgängern: den vor Ort stationierten US-Soldaten. Für sie (wie auch für die Soldaten der britischen und französischen Armee markierte die Mauer einerseits die Front des Kalten Krieges, andererseits durften sie diese ohne große Kontrollen passieren und ihre Freizeit in Ost-Berlin verbringen – was sie besonders in den 1970er- und 1980er-Jahren auch intensiv taten, denn in Zeiten der Dollarkrise versprach die östliche Stadthälfte viel Vergnügen, Restaurantbesuche und Einkaufsmöglichkeiten für wenig Geld. Die DDR-Regierung war genötigt, die Grenzgänge zu tolerieren. Von dieser Form des Tourismus konnte sie finanziell profitieren, versuchte konkrete Kontaktaufnahmen aber zu vermeiden. Der Umgang mit den Grenzgängen amerikanischer Soldaten und ihrer Familien verdeutlicht somit auch die Ambivalenz von politischer Öffnung und zunehmender Überwachung, von internationaler Verflechtung und Binnenerosion in der Ära Honecker. Der Beitrag stützt sich vor allem auf Dokumente des Ministeriums für Staatssicherheit (MfS, der Berliner Senatskanzlei und der amerikanischen Berlin Brigade sowie auf zeitgenössische Presseartikel.

Finally clarity when energy saving; Endlich Klarheit beim Energiesparen

Energy Technology Data Exchange (ETDEWEB)

Anon.

2012-07-01

How much money do users in mechanical engineering and plant construction save in the implementation of energy efficiency measures? What actions bring which savings? Festo AG and Co. KG (Esslingen, Federal Republic of Germany) provides answers to these questions in terms of the pneumatic control system.

Radiotherapy for shoulder impingement; Bestrahlung beim Impingementsyndrom des Schultergelenks

Energy Technology Data Exchange (ETDEWEB)

Adamietz, B. [Universitaetsklinikum Erlangen (Germany). Inst. fuer Radiologie; Sauer, R.; Keilholz, L. [Universitaetsklinikum Erlangen (Germany). Strahlentherapeutische Klinik

2008-05-15

Background and Purpose: Up to now, degenerative shoulder diseases were summarized by the term 'periarthritis humeroscapularis'. Actual shoulder diseases can be differentiated etiopathologically according to a primary and secondary impingement syndrome. Narrowing of the subacromial space, which is caused by an osseous shape variant, leads to primary impingement. Secondary impingement develops, when the subacromial space is reduced by swelling tissue below the osseous shoulder roof. This study aimed for the exact diagnosis to indicate therapy and to classify the results according to the Constant score. Patients and Methods: From August 1999 to September 2002, 102 patients with 115 shoulder joint conditions underwent radiation therapy (RT). All joints received two RT series (6 x 0.5 Gy/series) applied in two to three weekly fractions, totaling a dosage of 6.0 Gy (250 kV, 15 mAs, 1-mm Cu filter). The second RT course started 6 weeks after the end of the first. 115 shoulders were examined before RT, 6 weeks after the second RT course and, finally, during the follow-up from January to May 2003. Results: Pain relief was achieved in 94/115 shoulder joints (82%) after 18-month follow-up (median). A significant difference existed between secondary impingement and primary/non-impingement according to response. Tendinosis calcarea, bursitis subdeltoidea, tendovaginitis of the long biceps tendon, and capsulitis adhaesiva responded well to therapy. Conclusion: Shoulder diseases of secondary impingement demonstrate a good response to RT. Less or no benefit was found in primary impingement syndrome or complete rotator cuff disruption and acute shoulder injuries, respectively. (orig.)

Trichinella britovi beim Rotfuchs (Vulpes vulpes) in Österreich

DEFF Research Database (Denmark)

Krois, E.; Nöckler, K.; Duscher, G.

2005-01-01

infections in foxes. Materials and methods: Masseter and tongue samples from 1,546 foxes with known origin (sample coordinates from the provinces of Carinthia [n=401], Salzburg [108], Styria [493], Tyrol [395] and Vorarlberg [149] were determined by Geographic Information System), sent to the State...... Veterinary Laboratory in Moedling for rabies testing, were examined for Trichinella with the compression technique. Positive samples were evaluated quantitatively by digestion and differentiated by PCR. Results: 24 foxes (1.55%) were positive (Carinthia: 1.52%, Salzburg: 2.77%, Styria: 1.62%, the Tyrols: 1.......26%, Vorarlberg: 1.44%). In addition to the formerly known distribution of vulpine trichinellosis, positive animals were also found close to the border to Slovenia. Highest numbers of larval per gram muscle tissue (lpg) were found in the tongues (1-257 lpg compared to 0-43 lpg in masseter muscle tissue...

Verletzungspotential für Kinder und Jugendliche beim Trampolinspringen

OpenAIRE

Kosev, I; Folz, B

2015-01-01

Hintergrund: 62% der Deutschen haben ein Trampolin in ihrem Garten. Die Sprunggeräte gehören inzwischen fast zur Standardspielausrüstung. Im Rahmen unserer Beobachtungen über Unfallverletzungen der Kopf-Hals-Region zeigte sich, dass das Trampolinspringen mit Verletzungen im Kopf/Hals-Bereich einhergehen kann. In der vorliegenden Arbeit handelt es sich um eine prospektive Analyse der in den letzten Jahren an unserer Klinik behandelten Patienten mit Trampolinverletzungen. Methode: In dieser Ü...

Interobserver variability in target volume delineation of hepatocellular carcinoma. An analysis of the working group ''Stereotactic Radiotherapy'' of the German Society for Radiation Oncology (DEGRO)

Energy Technology Data Exchange (ETDEWEB)

Gkika, E.; Kirste, S. [Medical Center - University of Freiburg, Department of Radiation Oncology, Freiburg im Breisgau (Germany); Tanadini-Lang, S.; Andratschke, N.; Guckenberger, M. [University Hospital Zuerich, Department of Radiation Oncology, Zurich (Switzerland); Holzner, P.A.; Neeff, H.P. [Medical Center - University of Freiburg, Department of Visceral Surgery, Freiburg (Germany); Rischke, H.C. [Medical Center - University of Freiburg, Department of Radiation Oncology, Freiburg im Breisgau (Germany); Medical Center - University of Freiburg, Department of Nuclear Medicine, Freiburg (Germany); Reese, T. [University Hospital Halle-Wittenberg, Department of Radiation Oncology, Halle-Wittenberg (Germany); Lohaus, F. [Technische Universitaet Dresden, Department of Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Dresden (Germany); German Cancer Research Center (DKFZ), Heidelberg (Germany); Technische Universitaet Dresden, OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Dresden (Germany); National Center for Tumor Diseases (NCT), Dresden (Germany); German Cancer Consortium (DKTK), Dresden (Germany); Duma, M.N. [Helmholtz Zentrum Munich, Institute of Innovative Radiotherapy, Department of Radiation Sciences, Munich (Germany); TU Munich, Department of Radiation Oncology, Klinikum Rechts der Isar, Munich (Germany); Dieckmann, K. [Medical University Vienna, Department of Radiation Oncology, General Hospital Vienna, Vienna (Austria); Semrau, R. [University Hospital of Cologne, Department of Radiation Oncology, Cologne (Germany); Stockinger, M. [University Hospital Mainz, Department of Radiation Oncology, Mainz (Germany); Imhoff, D. [University Hospital Frankfurt, Department of Radiation Oncology, Frankfurt (Germany); Saphir Radiosurgery Center, Frankfurt (Germany); Kremers, N. [Medical Center - University of Freiburg, Department of Radiology, Freiburg (Germany); Haefner, M.F. [University Hospital Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Nestle, U.; Grosu, A.L.; Brunner, T.B. [Medical Center - University of Freiburg, Department of Radiation Oncology, Freiburg im Breisgau (Germany); University of Freiburg, Faculty of Medicine, Freiburg (Germany); German Cancer Consortium (DKTK), Freiburg (Germany); German Cancer Research Center (DKFZ), Heidelberg (Germany)

2017-10-15

Panel zu evaluieren. Die Analyse wurde von der Arbeitsgruppe Stereotaxie der deutschen Gesellschaft fuer Radioonkologie (DEGRO) durchgefuehrt. Die GTVs von 3 anonymisierten HCC-Patienten wurden von 16 Aerzten aus 9 Zentren mit Expertise in der Leberstereotaxie anhand multiphasischer Computertomogramme (CT) beurteilt. Beim ersten Patienten war der Tumor sehr gut abgrenzbar. Der zweite Patient hatte ein multilokulaeres HCC (ein Konglomerat und ein peripherer Herd) und war zuvor mittels transarterieller Chemoembolisation (TACE) behandelt worden. Der periphere Herd lag direkt neben der TACE-Stelle. Der dritte Patient hatte einen schwer abzugrenzenden Tumor wegen ausgedehnten Leberinhomogenitaeten bei ausgepraegter Leberzirrhose und einer begleitenden Pfortaderthrombose (PVT). Die IOA wurde nach Landis und Koch evaluiert. Die IOA war beim ersten Patienten exzellent (Kappa: 0,85); im zweiten Fall moderat (Kappa: 0,48) fuer den peripheren Herd und substanziell (Kappa 0,73) fuer das Konglomerat. Beim peripheren Herd ist diese Inkonsistenz durch TACE kaudal des Tumors entstanden. Beim dritten Patienten war die IOA mit einem Kappa-Wert von 0,34 ausreichend aufgrund signifikanter Heterogenitaet hinsichtlich der genauen Tumorabgrenzung und dem PVT. Die IOA war bei den gut abgrenzbaren Tumoren sehr gut. In komplexeren Faellen mit Perfussionsinhomogenitaeten oder Lipiodolanreicherung durch Vortherapien war die IOA beeintraechtigt. (orig.)

Bishop Thomas Lewis O’Beirne and his church-building programme in the diocese of Meath 1798-1823

OpenAIRE

Gallagher, Mary Caroline

2009-01-01

The first quarter of the nineteenth century was a time of great change and uncertainty in Ireland. The rebellion of 1798 was followed in 1801 by the Act of Union, which brought about legislative and ecclesiastical union from Britain. If the Church of Ireland was ever to make a success of its mission in-Ireland, it was in these early years of the nineteenth century. On the eve of this opportunity Thomas Lewis O’Beime, an Irish convert and former Roman Catholic seminarian, was tr...

Retrotransposon long interspersed nucleotide element-1 (LINE-1) is activated during salamander limb regeneration

Science.gov (United States)

Zhu, Wei; Kuo, Dwight; Nathanson, Jason; Satoh, Akira; Pao, Gerald M.; Yeo, Gene W.; Bryant, Susan V.; Voss, S. Randal; Gardiner, David M.; Hunter, Tony

2012-01-01

Salamanders possess an extraordinary capacity for tissue and organ regeneration when compared to mammals. In our effort to characterize the unique transcriptional fingerprint emerging during the early phase of salamander limb regeneration, we identified transcriptional activation of some germline-specific genes within the Mexican axolotl (Ambystoma mexicanum) that is indicative of cellular reprogramming of differentiated cells into a germline-like state. In this work, we focus on one of these genes, the long interspersed nucleotide element-1 (LINE-1) retrotransposon, which is usually active in germ cells and silent in most of the somatic tissues in other organisms. LINE-1 was found to be dramatically upregulated during regeneration. In addition, higher genomic LINE-1 content was also detected in the limb regenerate when compared to that before amputation indicating that LINE-1 retrotransposition is indeed active during regeneration. Active LINE-1 retrotransposition has been suggested to have a potentially deleterious impact on genomic integrity. Silencing of activated LINE-1 by small RNAs has been reported to be part of the machinery aiming to maintain genomic integrity. Indeed, we were able to identify putative LINE-1-related piRNAs in the limb blastema. Transposable element-related piRNAs have been identified frequently in the germline in other organisms. Thus, we present here a scenario in which a unique germline-like state is established during axolotl limb regeneration, and the re-activation of LINE-1 may serve as a marker for cellular dedifferentiation in the early-stage of limb regeneration. PMID:22913491

Microarray and cDNA sequence analysis of transcription during nerve-dependent limb regeneration

Directory of Open Access Journals (Sweden)

Bryant Susan V

2009-01-01

Full Text Available Abstract Background Microarray analysis and 454 cDNA sequencing were used to investigate a centuries-old problem in regenerative biology: the basis of nerve-dependent limb regeneration in salamanders. Innervated (NR and denervated (DL forelimbs of Mexican axolotls were amputated and transcripts were sampled after 0, 5, and 14 days of regeneration. Results Considerable similarity was observed between NR and DL transcriptional programs at 5 and 14 days post amputation (dpa. Genes with extracellular functions that are critical to wound healing were upregulated while muscle-specific genes were downregulated. Thus, many processes that are regulated during early limb regeneration do not depend upon nerve-derived factors. The majority of the transcriptional differences between NR and DL limbs were correlated with blastema formation; cell numbers increased in NR limbs after 5 dpa and this yielded distinct transcriptional signatures of cell proliferation in NR limbs at 14 dpa. These transcriptional signatures were not observed in DL limbs. Instead, gene expression changes within DL limbs suggest more diverse and protracted wound-healing responses. 454 cDNA sequencing complemented the microarray analysis by providing deeper sampling of transcriptional programs and associated biological processes. Assembly of new 454 cDNA sequences with existing expressed sequence tag (EST contigs from the Ambystoma EST database more than doubled (3935 to 9411 the number of non-redundant human-A. mexicanum orthologous sequences. Conclusion Many new candidate gene sequences were discovered for the first time and these will greatly enable future studies of wound healing, epigenetics, genome stability, and nerve-dependent blastema formation and outgrowth using the axolotl model.

Precise control of miR-125b levels is required to create a regeneration-permissive environment after spinal cord injury: a cross-species comparison between salamander and rat

Directory of Open Access Journals (Sweden)

Juan Felipe Diaz Quiroz

2014-06-01

Full Text Available Most spinal cord injuries lead to permanent paralysis in mammals. By contrast, the remarkable regenerative abilities of salamanders enable full functional recovery even from complete spinal cord transections. The molecular differences underlying this evolutionary divergence between mammals and amphibians are poorly understood. We focused on upstream regulators of gene expression as primary entry points into this question. We identified a group of microRNAs (miRNAs that are conserved between the Mexican axolotl salamander (Ambystoma mexicanum and mammals but show marked cross-species differences in regulation patterns following spinal cord injury. We found that precise post-injury levels of one of these miRNAs (miR-125b is essential for functional recovery, and guides correct regeneration of axons through the lesion site in a process involving the direct downstream target Sema4D in axolotls. Translating these results to a mammalian model, we increased miR-125b levels in the rat through mimic treatments following spinal cord transection. These treatments downregulated Sema4D and other glial-scar-related genes, and enhanced the animal’s functional recovery. Our study identifies a key regulatory molecule conserved between salamander and mammal, and shows that the expression of miR-125b and Sema4D must be carefully controlled in the right cells at the correct level to promote regeneration. We also show that these molecular components of the salamander’s regeneration-permissive environment can be experimentally harnessed to improve treatment outcomes for mammalian spinal cord injuries.

Ectopic Fgf signaling induces the intercalary response in developing chicken limb buds.

Science.gov (United States)

Makanae, Aki; Satoh, Akira

2018-01-01

Intercalary pattern formation is an important regulatory step in amphibian limb regeneration. Amphibian limb regeneration is composed of multiple steps, including wounding, blastema formation, and intercalary pattern formation. Attempts have been made to transfer insights from regeneration-competent animals to regeneration-incompetent animalsat each step in the regeneration process. In the present study, we focused on the intercalary mechanism in chick limb buds. In amphibian limb regeneration, a proximodistal axis is organized as soon as a regenerating blastema is induced. Intermediate structures are subsequently induced (intercalated) between the established proximal and distal identities. Intercalary tissues are derived from proximal tissues. Fgf signaling mediates the intercalary response in amphibian limb regeneration. We attempted to transfer insights into intercalary regeneration from amphibian models to the chick limb bud. The zeugopodial part was dissected out, and the distal and proximal parts were conjunct at st. 24. Delivering ectopic Fgf2 + Fgf8 between the distal and proximal parts resulted in induction of zeugopodial elements. Examination of HoxA11 expression, apoptosis, and cell proliferation provides insights to compare with those in the intercalary mechanism of amphibian limb regeneration. Furthermore, the cellular contribution was investigated in both the chicken intercalary response and that of axolotl limb regeneration. We developed new insights into cellular contribution in amphibian intercalary regeneration, and found consistency between axolotl and chicken intercalary responses. Our findings demonstrate that the same principal of limb regeneration functions between regeneration-competent and -incompetent animals. In this context, we propose the feasibility of the induction of the regeneration response in amniotes.

Die Internen Und Externen Interferenzfehler Beim Lernprozess Des Deutschen Als Zweitfremdsprache Für Türkische Muttersprachler Und Vorschläge Zur Fehlertherapie Internal And External Interference Errors In The Process Of Learning German As A Second Foreign Language And Methods To Prevent Mistakes

Directory of Open Access Journals (Sweden)

Adnan OFLAZ

2013-09-01

Full Text Available Das Ziel dieser Untersuchung liegt darin, die verschiedenen Arten von Interferenzen, die beim Lernprozess der deutschen Sprache auftreten, zuerst theoretisch aufzuklären, dann systematisch mit der kontrastiven Methode durch eine Fehleranalyse zu bestimmen und danach auszuwerten. Die Beeinflussung der Sprache von einer anderen Sprache verursacht Überschneidungen. Interferenzfehler können wir in den Bereichen “Phonologie, Orthographie, Morphologie, Syntax, Semantik, Pragmatik oder auch Textlinguistik erkennen. Anschließend werden Vorschläge zur Fehlerkorrektur auf den grammatikalischen, ortographischen und lexikalischen Ebenen vorgenommen. Betrachtet man dies aus dem kognitiven Blickwinkel, kann jeder unschwer erkennen, dass die Vorkenntnisse retroaktive und proaktive Effekte haben. Das heißt, diese Kenntnisse können den Lernprozess entweder positiv oder negativ beeinträchtigen. Von diesem Ausgangspunkt aus werden in dieser Arbeit die Wechselwirkungen, die sowohl von der erstgelernten Fremdsprache als auch von der Muttersprache abhängig sind, der Reihe nach identifiziert, klassifiziert und abschliessend analysiert. Auf den Ergebnissen dieser Fehleranalyse basierend, machen Studenten unter dem Einfluss der interlingualen Interferenzen meist Fehler bei der Wortstellung, der Zeitform „Perfekt“, Pluralbildung, der Deklination der Adjektive, der Groß- bzw Kleinschreibung und bei dem Gebrauch der Konjunktionen sowie auf den lexikalischen Ebenen. Unter dem Einfluss der intralingualen Interferenzen machen sie Fehler bei der Bildung der Zeitformen „Perfekt und Präteritum“ und bei der Konjugation des Verbs. The primary aim of this study is to analyze the different types ofinterferences that may occur in the process of learning the Germanlanguage both theoretically and systematically by making use of thecontrastive method in order to detect and evaluate common errors. In asecond step, methods to correct these errors on a grammatical

Ein schlankes Datenmodell für E-Books: die providerneutrale Aufnahme

Directory of Open Access Journals (Sweden)

Manfred Müller

2015-12-01

Full Text Available Der Artikel zeigt verschiedene Lösungsansätze, wie je nach Prinzipien der Verbund-Datenhaltung eine providerneutrale E-Book-Beschreibung modelliert sein kann. Die skizzierten Datenmodelle bieten einen Ausblick, welche Chancen in der frühzeitigen Adaption des providerneutralen Datenmodells beim Übergang zu den Datenstrukturen in den Cloud-basierten Erschließungsumgebungen bestehen. The article demonstrates current approaches to provider-neutral ebook records in German unioncatalogs and gives a perspective on how to transfer the outlined data models into cloud-based catalog systems.

RANK/RANK-Ligand/OPG: Ein neuer Therapieansatz in der Osteoporosebehandlung

Directory of Open Access Journals (Sweden)

Preisinger E

2007-01-01

Full Text Available Die Erforschung der Kopplungsmechanismen zur Osteoklastogenese, Knochenresorption und Remodellierung eröffnete neue mögliche Therapieansätze in der Behandlung der Osteoporose. Eine Schlüsselrolle beim Knochenabbau spielt der RANK- ("receptor activator of nuclear factor (NF- κB"- Ligand (RANKL. Durch die Bindung von RANKL an den Rezeptor RANK wird die Knochenresorption eingeleitet. OPG (Osteoprotegerin sowie der für den klinischen Gebrauch entwickelte humane monoklonale Antikörper (IgG2 Denosumab blockieren die Bindung von RANK-Ligand an RANK und verhindern den Knochenabbau.

Buoyancy disorders in pet axolotls Ambystoma mexicanum: three cases.

Science.gov (United States)

Takami, Yoshinori; Une, Yumi

2018-01-31

As far as we are aware, there are no previous reports on the pathologic conditions of buoyancy disorders in Ambystoma mexicanum. Herein, we describe various clinical test results, clinical outcomes, and the pathological findings of an experimental pneumonectomy procedure in 3 A. mexicanum exhibiting abnormal buoyancy. The 3 pet A. mexicanum were adults, and their respective ages and body weights were 1, 5, and 6 yr and 48, 55, and 56 g. Two of these cases were confirmed via radiographic examination to have free air within the body cavity, and all 3 cases were found via ultrasonography to have an acoustic shadow within the body cavity and were diagnosed with pneumocoelom. Lung perforations were detected macroscopically in 2 of the cases, and all 3 cases had fibrosis in the caudal ends of the lungs. Removal of the lung lesions eliminated the abnormal buoyancy in all 3 cases. We concluded that air had leaked into the body cavity from the lungs, and we propose that lung lesions are an important cause of buoyancy disorders in A. mexicanum.

Homology of the cranial vault in birds: new insights based on embryonic fate-mapping and character analysis

Science.gov (United States)

Maddin, Hillary C.; Piekarski, Nadine; Sefton, Elizabeth M.; Hanken, James

2016-08-01

Bones of the cranial vault appear to be highly conserved among tetrapod vertebrates. Moreover, bones identified with the same name are assumed to be evolutionarily homologous. However, recent developmental studies reveal a key difference in the embryonic origin of cranial vault bones between representatives of two amniote lineages, mammals and birds, thereby challenging this view. In the mouse, the frontal is derived from cranial neural crest (CNC) but the parietal is derived from mesoderm, placing the CNC-mesoderm boundary at the suture between these bones. In the chicken, this boundary is located within the frontal. This difference and related data have led several recent authors to suggest that bones of the avian cranial vault are misidentified and should be renamed. To elucidate this apparent conflict, we fate-mapped CNC and mesoderm in axolotl to reveal the contributions of these two embryonic cell populations to the cranial vault in a urodele amphibian. The CNC-mesoderm boundary in axolotl is located between the frontal and parietal bones, as in the mouse but unlike the chicken. If, however, the avian frontal is regarded instead as a fused frontal and parietal (i.e. frontoparietal) and the parietal as a postparietal, then the cranial vault of birds becomes developmentally and topologically congruent with those of urodeles and mammals. This alternative hypothesis of cranial vault homology is also phylogenetically consistent with data from the tetrapod fossil record, where frontal, parietal and postparietal bones are present in stem lineages of all extant taxa, including birds. It further implies that a postparietal may be present in most non-avian archosaurs, but fused to the parietal or supraoccipital as in many extant mammals.

Regulation of Injury-Induced Ovarian Regeneration by Activation of Oogonial Stem Cells.

Science.gov (United States)

Erler, Piril; Sweeney, Alexandra; Monaghan, James R

2017-01-01

Some animals have the ability to generate large numbers of oocytes throughout life. This raises the question whether persistent adult germline stem cell populations drive continuous oogenesis and whether they are capable of mounting a regenerative response after injury. Here we demonstrate the presence of adult oogonial stem cells (OSCs) in the adult axolotl salamander ovary and show that ovarian injury induces OSC activation and functional regeneration of the ovaries to reproductive capability. Cells that have morphological similarities to germ cells were identified in the developing and adult ovaries via histological analysis. Genes involved in germ cell maintenance including Vasa, Oct4, Sox2, Nanog, Bmp15, Piwil1, Piwil2, Dazl, and Lhx8 were expressed in the presumptive OSCs. Colocalization of Vasa protein with H3 mitotic marker showed that both oogonial and spermatogonial adult stem cells were mitotically active. Providing evidence of stemness and viability of adult OSCs, enhanced green fluorescent protein (EGFP) adult OSCs grafted into white juvenile host gonads gave rise to EGFP OSCs, and oocytes. Last, the axolotl ovaries completely regenerated after partial ovariectomy injury. During regeneration, OSC activation resulted in rapid differentiation into new oocytes, which was demonstrated by Vasa + /BrdU + coexpression. Furthermore, follicle cell proliferation promoted follicle maturation during ovarian regeneration. Overall, these results show that adult oogenesis occurs via proliferation of endogenous OSCs in a tetrapod and mediates ovarian regeneration. This study lays the foundations to elucidate mechanisms of ovarian regeneration that will assist regenerative medicine in treating premature ovarian failure and reduced fertility. Stem Cells 2017;35:236-247. © 2016 AlphaMed Press.

Beginn und Dosisanpassung einer intensivierten konventionellen Insulintherapie (ICT beim Erwachsenen

Directory of Open Access Journals (Sweden)

Lohr R

2012-01-01

Full Text Available Eine intensivierte Insulintherapie (ICT ist die Behandlung der Wahl bei Diabetes mellitus Typ 1 und auch bei vielen Menschen mit insulinpflichtigem Typ-2-Diabetes. Bei Therapiebeginn müssen individuell Insuline ausgewählt und die richtige Dosierung festgelegt werden. Im weiteren Verlauf ist dann die Anpassung der Insulintherapie an besondere Alltagssituationen wie Sport oder akute Erkrankungen vorrangig. Eine gute Patientenschulung und eine gute Zusammenarbeit zwischen Betroffenem und Behandlerteam sind entscheidend, um diese komplizierte Therapie erfolgreich umzusetzen.

Infektion mit Epstein-Barr-Virus und Tumor-Entstehung beim Menschen

Science.gov (United States)

Kirchner, H.

1981-08-01

The Epstein-Barr Virus (EBV) is the only infectious agent for which a close association with human malignant tumors has been clearly demonstrated. These tumors are one type of nasopharyngeal carcinoma which is frequent in parts of East Asia and the Burkitt lymphoma which predominantly occurs in parts of Africa and New Guinea. Nonetheless, the EBV is the causative agent of infectious mononucleosis (IM), a benign, self-limiting lymphoproliferative disease of adolescents. The major difference between the countries in which the EBV-induced tumors occur and those in which IM occurs is the late primary EBV infection in the latter, whereas primary infection with EBV occurs in the first year of life in the former. All theories of viral carcinogenesis have to explain the long latency period between primary infection and tumor growth and how an ubiquitous virus may be oncogenic. Thus, invariably, one has to assume a role of cofactors, which may be of cytogenetic nature or may be represented by additional infections or by chemical agents. Since most modern theories of carcinogenesis consider a multi-step development of tumors, the theory that infection with an ubiquitous virus at the right time of life represents one step to carcinogenesis seems to be tenable.

Postoperative Verlaufskontrollen beim Ulcus cruris nach Shave-Operation und Hauttransplantation

OpenAIRE

Pantelaki, Ioanna

2016-01-01

\\(\\bf Hintergrund:\\) Die Arbeit hat das Ziel die Shave-Operation mit Meshgraft-Deckung hinsichtlich der Einheilungsrate und der Schmerzreduktion zu untersuchen. \\(\\bf Methoden:\\) 56 Patienten mit einem Ulcus cruris unterzogen sich dem genannten Eingriff. Vor und 6 Monate nach der Operation wurden die Ulkusgröße, die bakterielle Besiedlung und die Schmerzintensität analysiert. \\(\\bf Ergebnis:\\) Bei 42,86% der Patienten konnte eine Abheilung erreicht werden, wobei die Ergebnisse hoch sign...

Epidemiologische Studie zur Verbreitung porziner Circoviren beim Wildschwein in Deutschland

OpenAIRE

Knell, Sebastian Christoph

2007-01-01

PMWS, weltweit die wirtschaftlich bedeutendste Erkrankung in der Schweineinproduktion, wird mit PCV 2 assoziiert. Weitere Erkrankungen wie Reproduktionsstörungen und der „porcine respiratory disease Complex (PRDC)“ werden mit dem Virus assoziiert und das Virus gilt als ein Faktor für das „Porzine Dermatitis und Nephropathie Syndrom“ (PDNS). Porzine Circoviren vom Typ I, die als Zellkulturkontaminante entdeckt wurden, gelten als nicht pathogen. Der Erreger beider Typen ist in den Hausschweine...

Einfluss freier Fettsäuren auf die Insulinsekretion beim Menschen

OpenAIRE

Steigenberger, Mirjam Elisabeth

2008-01-01

Zu den pathophysiologischen Grundlagen des Diabetes mellitus Typ 2 gehören die Insulinresistenz und die gestörte Insulinsekretion. Ziel dieser Arbeit war es, zu untersuchen, ob der Spiegel der freien Fettsäuren im Nüchternplasma bei Risikopersonen für Diabetes mellitus Typ 2 die Insulinsekretion beeinträchtigt. Hierfür untersuchten wir in einer Querschnittsuntersuchung 1055 Probanden mit positiver Familienanamnese für Typ 2 Diabetes mellitus. Unabhängig von Alter, Geschlecht, Insulinsensitivi...

Der Strafgrund beim untauglichen und baim tauglichen Versuch / Claus Roxin

Index Scriptorium Estoniae

Roxin, Claus

2017-01-01

Kuritegelikust kavatsusest kuriteokatse toimepanekul Saksa ja Hispaania karistusõiguses. Ajakirjanumber sisaldab erinevaid artikleid Hispaania ja Saksa karistusõigusest ning on pühendatud hispaania õigusteadlase Santiago Mir Puig'i 70. sünnipäevale

Imaging of appendicitis in adults; Bildgebung der Appendizitis beim Erwachsenen

Energy Technology Data Exchange (ETDEWEB)

Karul, M.; Berliner, C.; Keller, S.; Yamamura, J. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Diagnostic and Interventional Radiology; Tsui, T.Y. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of General, Visceral- and Thoracic Surgery

2014-06-15

Three imaging modalities are available for the diagnosis of acute appendicitis: ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). Transabdominal ultrasound should be the first-line imaging test. Abdominal CT is superior to US and is required immediately in patients with atypical clinical presentation of appendicitis and suspected perforation. However, low-dose unenhanced CT is equal to standard-dose CT with intravenous contrast agents in the detection of five signs of acute appendicitis (thickened appendiceal wall more than 2 mm, cross-sectional diameter greater than 6 mm, periappendicitis, abscess, and appendicolith). MRI is necessary in pregnant women and young adults. This review illustrates the principles of state-of-the-art imaging techniques and their clinical relevance. (orig.)

Advanced thermal management of diesel engines; Neues Thermomanagement beim Dieselmotor

Energy Technology Data Exchange (ETDEWEB)

Wenzel, Wolfgang; Becker, Michael [BorgWarner, Ludwigsburg (Germany). Konzernvorentwicklung fuer Pkw-Antriebssysteme; Shutty, John [BorgWarner, Auburn Hills (United States). Regelung und Simulation in der Konzernvorentwicklung

2013-05-01

The potential of thermal management with respect to CO{sub 2} reduction is given by faster warm-up of engine and drivetrain, reduced losses from water pump and fan and finally the operation of the engine in an optimal temperature range. In a new approach, BorgWarner applies a variable coolant pump and a controlled coolant valve to a conventional cooling system. Both components, as well as the viscous fan clutch, are controlled by a newly developed controls approach.

Transkriptionelle Regulation des Wachstumsfaktors Gastrin beim kleinzelligen- und nichtkleinzelligen Bronchialkarzinom

OpenAIRE

Zippert, Renate

2000-01-01

Die transkriptionelle Regulation der Expression von Gastrin in SCLC- und NSCLC-Zellen war bisher nicht untersucht worden. Die Klonierung der 5´-flankierenden Sequenzen des Gastringens und die Herstellung von Gastrinpromotor-Reportergenkonstrukten ermöglichte eine vergleichende funktionelle Untersuchung der Gastrinpromotor-Aktivität in der SCLC-Zellinie H69, der NSCLC-Zellinie 32M1 und der Mesotheliom-Zellinie MSTO-211H. Die vorliegenden Untersuchungen konnten so eine zelltypspezifisc...

Error in objecto - warum E-Books keine Bücher sind

Directory of Open Access Journals (Sweden)

Ruth Katzenberger

2014-12-01

Full Text Available Elektronische Medien gewinnen für Bibliotheken zunehmend an Bedeutung. Trotz dieser Entwicklung bestehen in der bibliothekarischen Praxis erhebliche Unsicherheiten beim Umgang mit elektronischen Medien. Das liegt vor allem daran, dass ein gedrucktes Buch und seine elektronische Version den gleichen Inhalt haben. So liegt der Schluss nahe, dass es sich beim Print-Buch und seinem elektronischen Pendant um ein Zwillingspaar handelt, das in der bibliothekarischen Arbeit gleich behandelt werden kann. Dieser Eindruck wird verstärkt, wenn bei der elektronischen Ausleihe der E-Books von Ausleihe, Vormerkung und Widerruf gesprochen wird. Nachfolgend soll verdeutlich werden, dass der digitale Zwilling des Printbuches aus rechtlicher Sicht gerade kein „echter Zwilling“ ist. Dieser Beitrag umreißt die rechtliche Problematik, die sich ergibt, sobald Bibliotheken ihren Nutzern E-Books zur Verfügung stellen. Although electronic media are becoming more and more important for libraries, there is still considerable uncertainty about how to deal with these materials. Electronic media and print media have the same content. Therefore, librarians tend to think that a printed book and its electronic counterpart are, as it were, a pair of twins which can be treated alike. This assumption is reinforced by the  use of traditional terminology like “borrowing” and “reservation” in the contect of e-books, e-papers etc. However, from a legal point of view, the digital twin is not a twin at all.  The paper describes the legal problems connected to e-lending in libraries.

Non-granulomatous prostatitis: MR appearance with an endorectal surface coil; Nichtgranulomatoese Prostatitis: Erscheinungsbild im MRT mit endorektaler Oberflaechenspule (``Endo-MRT``)

Energy Technology Data Exchange (ETDEWEB)

Szolar, D.H.M. [Magnetresonanztomographie-Zentrum, Univ. Graz (Austria); Ranner, G. [Magnetresonanztomographie-Zentrum, Univ. Graz (Austria); Preidler, K.W. [Magnetresonanztomographie-Zentrum, Univ. Graz (Austria); Lax, S. [Inst. fuer Pathologische Anatomie, Univ. Graz (Austria)

1995-01-01

Inflammatory conditions of the prostate are often idfficult to distinguish from early stages of prostate cancer with imaging techniques. The use of an endorectal surface coil in MRI of the prostate gland has been reported to provide superior resolution and better imaging of details than MRI with a body coil in the diagnosis of early prostate cancer. We report a 34-year-old patient with nonspecific non-granlomatous prostatitis in whom T{sub 2}-weighted endorectal surface coil magnetic resonance imaging (ESCMRI) showed a region of markedly decreased signal intensity in the periphery of the gland. The low signal intensity of the lesion, its sharp demarcation from the normal part of the peripheral zone of the prostate and the marked bulge of the surface contour without capsular breach of the organ were interpreted as evidence of a bioptically proven benign inflammatory condition. (orig.) [Deutsch] Die Unterscheidung entzuendlicher Prozesse von Fruehstadien maligner Neoplasien der Prostata mittels Magnetresonanztomographie bereitet immer wieder Schwierigkeiten. Die Anwendung einer Oberflaechenspule erlaubt durch hoehere Aufloesung eine exaktere Beurteilung der Prostatakapsel, was eine hoehere Treffsicherheit beim Nachweis moeglicher organueberschreitender Infiltrationen bedeutet. Wir praesentieren den Fall eines 34jaehrigen Mannes mit unspezifischer, nichtgranulomatoeser Prostatitis, bei dem das MR-Tomogramm mit endorektal plazierter Oberflaechenspule (Endo-MRT) in der Peripherzone ein Areal deutlich herabgesetzter Signalintensitaet auf T{sub 2}-gewichteten Aufnahmen zeigte. Die scharfe Begrenzung der ausgedehnten signalarmen Laesion gegenueber dem nichtbefallenen Anteil der Peripherzone beim im Endo-MRT identifizierbarer intakter Kapsel liess ein organueberschreitendes Malignom ausschliessen und bestaetigte durch histologische Aufarbeitung der Bioptate den Endo-MRT-Verdachtsbefund einer Prostatitis. (orig.)

[Helsinki declaration on patient safety in anaesthesiology -part 10: infection control/hygiene].

Science.gov (United States)

Kerwat, Klaus; Wulf, Hinnerk

2013-11-01

There is a plethora of laws, regulations, guidelines and recommendations relating to infection control and hygiene. Major issues are the prevention of nosocomial infections, staff protection and environmental protection. Of the highest relevance are the infection control law [Infektionsschutzgesetz (IfSG)], the hygiene regulations of the German federal states [Hygieneverordnungen der Bundesländer], the German technical rules for biological materials [Technische Regel Biologische Arbeitsstoffe 250 (TRBA 250)] - biological materials in health-care and welfare work [Biologische Arbeitsstoffe im Gesundheitswesen und in der Wohlfahrtspflege], the guidelines for hospital hygiene and prevention of infection of the commission for hospital hygiene and prevention of infection of the Robert-Koch Institute [Richtlinie für Krankenhaushygiene und Infektionsprävention von der Kommission für Krankenhaushygiene und Infektionsprävention (KRINKO) beim Robert Koch-Institut], the recommendations of the commission on anti-infectives, resistance and therapy of the Robert-Koch Institute [Empfehlungen der Kommission Antiinfektiva, Resistenz und Therapie (ART) beim Robert Koch-Institut]. Of subordinate importance are, e.g., the recommendations of the German Society for Anesthesiology and Intensive Medicine (DGAI). It is practically impossible for an anesthesiologist working in a hospital to have knowledge of all laws, regulations, guidelines and recommendations. And this is also not reasonable. Thus it is necessary to distinguish the relevant from the irrelevant. Checklists can be useful here. The most important and effective individual action in hospital hygiene is and remains hand hygiene as is propagated in the action "clean hands", irrespective of all laws, regulations, guidelines and recommendations. © Georg Thieme Verlag Stuttgart · New York.

Schaltungsunterlagen

Science.gov (United States)

Döring, Peter

Beim Zeichnen von Schaltplänen werden alle zugehörigen Maschinen, Geräte, Schaltteile und Leitungen nicht maßstabsgetreu und der tatsächlichen Ausführung ähnlich gezeichnet, sondern durch genormte graphische Symbole dargestellt. Die Ausführungen in diesem Kapitel sollen dazu eine Hilfestellung geben. Behandelt werden folgende Themen: Wichtige VDE-Bestimmungen; Diagrammdarstellungen; Schaltzeichen nach DIN; Kennzeichnung von elektrischen Betriebsmitteln; Schaltungsunterlagen der Energietechnik; Schaltungsunterlagen der Elektronik; Schaltzeichen für Binäre Elemente; Entwurf von Schaltungen: Einzelplatinen, Gedruckte Schaltungen; Projektierung. Zahlreiche Tabellen und Abbildungen dienen zur Erläuterung.

Mit Expertenwissen zu Aussagen über künftige Entwicklungen — der Horizon Report Higher Education

Directory of Open Access Journals (Sweden)

Rudolf Mumenthaler

2014-03-01

Full Text Available Der Horizon Report Higher Education dient auch für Hochschulbibliotheken als wichtige Referenz zur Bewertung aktueller Trends und künftiger Entwicklungen. Der Autor stellt die dem Report zugrunde liegende Methode vor, beleuchtet diese kritisch und reflektiert die Aussagekraft der Prognosen. Die Stärken des Horizon Report liegen in der breiten Abstützung, der Offenheit des Verfahrens und der Publikation sowie der Ausarbeitung der von Expertinnen und Experten ausgewählten Themen. Gewisse Schwächen sieht der Autor in der Abhängigkeit von anderen Trendstudien sowie beim Auswahlverfahren der Trendthemen.

Multimedia und Lernstiltyp. Unterstützt Online-Distance-Learning unterschiedliche Lernstiltypen und führt zu mehr Lernerfolg?

Directory of Open Access Journals (Sweden)

Petra Lindemann-Matthies

2006-09-01

Full Text Available In der vorliegenden Studie haben wir uns mit der Frage beschäftigt, ob Lernerfolg, Multimedianutzung und der Lernstiltyp nach Kolb (1984 im Distance- Learning-Kurs VIRT.UM, der online angeboten wird, zusammenhängen. Dabei stellte sich heraus, dass Studierende beim Arbeiten mit VIRT.UM zwar selektiv unter den ihnen angebotenen Multimediatypen auswählten, die Auswahl aber nicht von ihrem jeweiligen Lernstiltyp abhing. Der Lernerfolg der Studierenden wurde durch die Nutzung bestimmter Multimediatypen gefördert, hing aber ebenfalls nicht vom Lernstiltyp ab. Hierfür gibt es verschiedene, sich nicht ausschliessende Erklärungen.

Bluetooth in the car: chances and limits; Bluetooth im Auto: Moeglichkeiten und Grenzen

Energy Technology Data Exchange (ETDEWEB)

Hascher, W.

2000-06-01

Car manufacturers, electronic suppliers and research institutions such as the MIT in the U.S. everywhere work on complementing or replaced the wiring harness by radio links. One way of doing this is ''Bluetooth'', a short-distance-radio technology on the 2.4GHz-band.(orig.). [German] Weltweit wird in den Automobilkonzernen, bei den Elektronik-Zulieferfirmen und in Forschungseinrichtungen (z.B. beim MIT in den USA) daran gearbeitet, den 'Kabelbaum' im Kfz durch Funkverbindungen zu ergaenzen bzw. Teile davon zu ersetzen. Eine Loesung hierfuer ist 'Bluetooth', eine Kurzstrecken-Funktechnologie im 2,4-GHz-Band. (orig.)

Integrated project: Microbiological and physiological studies on the presence of residual concentrations in mineral-oil-contaminated soils after rehabilitation. Final report. Pt. 2; Mikrobiologische und physiologische Untersuchungen zur Frage der Restkonzentration bei der Sanierung mineraloelkontaminierter Boeden. Abschlussbericht. T. 2

Energy Technology Data Exchange (ETDEWEB)

Miethe, D.; Riis, V.; Stimming, M.

1996-01-04

It has been known for a long time that microorganisms are able to utilise mineral oils. Today various methods are practised which exploit autochthonous microorganisms` ability to utilise mineral oils. The main problem of microbial decomposition of hydrocarbons is that mineral oil residues remain. The aim of the present research project was therefore to determine the limits of the metabolisability of the substrate and find out why residues remain. Mineral oils and residual fractions differ markedly in their decomposability. Intermediate distillates are easily decomposed to a degree of 95-97% by well-adapted consorts. For high-boiling mineral oils (bp>400 C) the degree of decomposition is approx. 60%. Extracts from contaminated sites range from 40 to 60% in their degree of decomposability. The incomplete microbial decomposition of mineral oils is mainly due to their structure. There remain chemically and thermally extremely, inert hydrocarbons (mainly aliphatic and aromatic fused-ring systems) which are either hardly metabolisable or not at all. An important factor in soils or at other contaminated sites is that some of the substrate is not available because it is bound to the matrix thus increasing the proportion of residue. The next task after examining and presenting the causes of incomplete decomposition is to minimise residual mineral oil concentrations remaining after microbial decomposition. Here the use of special surfactants or of auxiliary substrates could point a way. Project applications to this end have already been submitted to the Federal Ministry for Education and Research. (orig.) [Deutsch] Dass Mikroorganismen in der Lage sind, Mineraloele zu verwerten, ist seit langem bekannt. Verfahren, die das Potential autochthoner Mikroorganismen zur Verwertung von Mineraloelen nutzen sind Praxis. Hauptproblem beim mikrobiellen Abbau der Kohlenwasserstoffe ist das Verbleiben von Mineraloelresten. Das Ziel des Forschungsvorhabens war die Ermittlung der Grenzen

Distinct and conserved prominin-1/CD133-positive retinal cell populations identified across species.

Directory of Open Access Journals (Sweden)

József Jászai

2011-03-01

Full Text Available Besides being a marker of various somatic stem cells in mammals, prominin-1 (CD133 plays a role in maintaining the photoreceptor integrity since mutations in the PROM1 gene are linked with retinal degeneration. In spite of that, little information is available regarding its distribution in eyes of non-mammalian vertebrates endowed with high regenerative abilities. To address this subject, prominin-1 cognates were isolated from axolotl, zebrafish and chicken, and their retinal compartmentalization was investigated and compared to that of their mammalian orthologue. Interestingly, prominin-1 transcripts--except for the axolotl--were not strictly restricted to the outer nuclear layer (i.e., photoreceptor cells, but they also marked distinct subdivisions of the inner nuclear layer (INL. In zebrafish, where the prominin-1 gene is duplicated (i.e., prominin-1a and prominin-1b, a differential expression was noted for both paralogues within the INL being localized either to its vitreal or scleral subdivision, respectively. Interestingly, expression of prominin-1a within the former domain coincided with Pax-6-positive cells that are known to act as progenitors upon injury-induced retino-neurogenesis. A similar, but minute population of prominin-1-positive cells located at the vitreal side of the INL was also detected in developing and adult mice. In chicken, however, prominin-1-positive cells appeared to be aligned along the scleral side of the INL reminiscent of zebrafish prominin-1b. Taken together our data indicate that in addition to conserved expression of prominin-1 in photoreceptors, significant prominin-1-expressing non-photoreceptor retinal cell populations are present in the vertebrate eye that might represent potential sources of stem/progenitor cells for regenerative therapies.

Notochord-derived hedgehog is essential for tail regeneration in Xenopus tadpole.

Science.gov (United States)

Taniguchi, Yuka; Watanabe, Kenji; Mochii, Makoto

2014-06-18

Appendage regeneration in amphibians is regulated by the combinatorial actions of signaling molecules. The requirement of molecules secreted from specific tissues is reflected by the observation that the whole process of regeneration can be inhibited if a certain tissue is removed from the amputated stump. Interestingly, urodeles and anurans show different tissue dependencies during tail regeneration. The spinal cord is essential for tail regeneration in urodele but not in anuran larva, whereas the notochord but not the spinal cord is essential for tail regeneration in anuran tadpoles. Sonic hedgehog is one of the signaling molecules responsible for such phenomenon in axolotl, as hedgehog signaling is essential for overall tail regeneration and sonic hedgehog is exclusively expressed in the spinal cord. In order to know whether hedgehog signaling is involved in the molecular mechanism underlying the inconsistent tissue dependency for tail regeneration between anurans and urodeles, we investigated expression of hedgehog signal-related genes in the regenerating tail of Xenopus tadpole and examined the effect of the hedgehog signal inhibitor, cyclopamine, on the tail regeneration. In Xenopus, sonic hedgehog is expressed exclusively in the notochord but not in the spinal cord of the regenerate. Overall regeneration was severely impaired in cyclopamine-treated tadpoles. Notochord maturation in the regenerate, including cell alignment and vacuolation, and myofiber formation were inhibited. Proliferation of spinal cord cells in the neural ampulla and of mesenchymal cells was also impaired. As in the axolotl, hedgehog signaling is required for multiple steps in tail regeneration in the Xenopus tadpole, although the location of the Shh source is quite different between the two species. This difference in Shh localization is the likely basis for the differing tissue requirement for tail regeneration between urodeles and anurans.

The urodelean Mauthner cell. Morphology of the afferent synapses to the M-cell of larval Salamandra salamandra

Energy Technology Data Exchange (ETDEWEB)

Cioni, C.; De Palma, F.; De Vito, L.; Stefanelli, A. [Rome, Univ. (Italy). Dipt. di Biologia Animale e dell`Uomo

1997-12-31

In the present work the fine morphology and the distribution of the afferent synapses to the Mauthner cell of larval Salamandra salamandra are described. The aim of the study is to characterize the synaptic bed in the larvae of this terrestrial salamander in order to compare it with that of larval axolotl and larval anurans. Four main types of afferent endings have been identified: myelinated club endings, round-vesicle end bulbs, flattened-vesicle end bulbs and spiral fibers endings. The M-cell afferent synaptology of larval stages of terrestrial amphibians is quite similar to that previously observed in larval stages of aquatic species. This fact can be related to the fundamental similarities between the larval lifestyles.

The urodelean Mauthner cell. Morphology of the afferent synapses to the M-cell of larval Salamandra salamandra

Energy Technology Data Exchange (ETDEWEB)

Cioni, C; De Palma, F; De Vito, L; Stefanelli, A [Rome, Univ. (Italy). Dipt. di Biologia Animale e dell` Uomo

1998-12-31

In the present work the fine morphology and the distribution of the afferent synapses to the Mauthner cell of larval Salamandra salamandra are described. The aim of the study is to characterize the synaptic bed in the larvae of this terrestrial salamander in order to compare it with that of larval axolotl and larval anurans. Four main types of afferent endings have been identified: myelinated club endings, round-vesicle end bulbs, flattened-vesicle end bulbs and spiral fibers endings. The M-cell afferent synaptology of larval stages of terrestrial amphibians is quite similar to that previously observed in larval stages of aquatic species. This fact can be related to the fundamental similarities between the larval lifestyles.

Die emotionale Dimension während der Sprechproduktion im Fremdsprachenlernprozess

Directory of Open Access Journals (Sweden)

Bahar İŞİGÜZEL

2017-12-01

Full Text Available Die Gefühle bzw. Emotionen der Lernenden beim Fremdsprachenlehr- und Lernprozess spielen eine wichtige Rolle. Mit der Verknüpfung der Emotion und Kognition beim Lernprozess, haben die positiven Gefühle eine große Bedeutung für den Lernerfolg. Als eine produktive Fertigkeit hat das Sprechen eine wesentlich intensive Beziehung mit den Emotionen, weil es in der realen Zeit fließend laufen muss. Der Lernende soll bei der Sprechproduktion spontan die richtigen Wörter auf die richtige Art und Weise anwenden und sie auch noch verständlich aussprechen. Leider erreicht die Sprechfertigkeit meistens eine niedrigere Niveaustufe als die anderen drei (Schreiben, Lesen und Hören Fertigkeiten im Fremdsprachenunterrichtprozess. Diese qualitative Untersuchung konzentriert sich auf die Daten (Tonaufnahme, die anhand eines Interviews während einer Sprechproduktionsübung im universitären Fremdsprachenunterricht gesammelt wurden. Um die emotionale Dimension der Lernenden während der Sprechproduktion zu identifizieren, wurden im Einzelinterview die Frage „Wie fühlst du dich während du eine Fremdsprache (Englisch sprichst?“ gestellt. Die Teilnehmer dieser Untersuchung waren 29 Studenten, die im WS 2016 - 2017 an Universität Nevşehir Hacı Bektaş Veli (Türkei immatrikuliert waren. Die Auswertung des Interviews folgte mit einer Transkription und einer Interpretation der Tonaufnahmen. Die Meinungen zu der emotionalen Dimension während der Sprechproduktion der Studenten wurden kategorisiert. Die Resultate dieser qualitativen Untersuchung zeigen, dass die emotionale Dimension der Lernenden im universitären Kontext sich in drei Kategorien (positiv, negativ und frühere Ausbildung verteilen.

Webbasierte linguistische Forschung: Möglichkeiten und Begrenzungen beim Umgang mit Massendaten

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Juska-Bacher, Britta

2013-12-01

Full Text Available Over the past ten to fifteen years, web-based methods of sociological research have emerged alongside classical methods such as interviews, observations and experiments, and linguistic research is increasingly relying upon them as well. This paper provides an overview of three web-based approaches, i.e. online surveys, crowd-sourcing and web-based corpus analyses. Examples from specific projects serve to reflect upon these methods, address their potential and limitations, and make a critical appraisal. Internet-based empirical research produces vast and highly diverse quantities of (speaker-based or textual data, presenting linguistic research with new opportunities and challenges. New procedures are required to make effective use of these resources.

Who has priority during the regulation?; Wer hat Vorrang beim Abregeln?

Energy Technology Data Exchange (ETDEWEB)

Janzing, Bernward

2013-04-15

The remote control of wind power plants by direct marketers raises questions - not only on the technology, but also on the hierarchy of actors. From the technical perspective, the current practice of feed-in is not particularly well developed. So far, the regulation of wind turbines via radio ripple control is carried out in stages to 60, 30 and 0 %. The traditional ripple control technology does not send a message back to the sender if the wind turbine has received the signal and reacts to it. Smart meter and digital control technology can provide assistance in this case. Consequences for the plant safety result from this regulation: The performance of a wind turbine shall be reduced only with a gradient of ten percent of the initial output per minute. If the data transfer is interrupted, the reduction of the power will be closed automatically after 30 minutes.

Lean-burn stratified combustion at gasoline engines; Magere Schichtverbrennung beim Ottomotor

Energy Technology Data Exchange (ETDEWEB)

Breitbach, Hermann [Daimler AG, Stuttgart (Germany). Entwicklung Einspritzung und Betriebsstoffe; Waltner, Anton [Daimler AG, Stuttgart (Germany). Verbrennungsentwicklung Pkw-Ottomotoren; Landenfeld, Tilo [Robert Bosch GmbH, Schwieberdingen (Germany). Hochdruckeinspritzung Piezo; Porten, Guido [Robert Bosch GmbH, Schwieberdingen (Germany). Systementwicklung Benzindirekteinspritzung

2013-05-01

Spray-guided lean-burn combustion is an integral part of the Mercedes-Benz technology strategy for highly efficient and clean gasoline engines. With regard to the excellent fuel efficiency combined with outstanding specific power, a good combustion system robustness and the low particulate emissions, the concept offers a very good cost/benefit ratio especially for the Euro 6 emission legislation. Thus, Mercedes-Benz believes, that the sprayguided lean-burn combustion offers the by far highest future viability of gasoline engine combustion systems.

Spiral CT for evaluation of chest trauma; Spiral-CT beim Thoraxtrauma

Energy Technology Data Exchange (ETDEWEB)

Roehnert, W. [Universitaetsklinikum Dresden (Germany). Inst. und Poliklinik fuer Radiologische Diagnostik; Weise, R. [Universitaetsklinikum Dresden (Germany). Inst. und Poliklinik fuer Radiologische Diagnostik

1997-07-01

After implementation of spiral CT in our department, we carried out an analysis for determining anew the value of CT as a modality of chest trauma diagnosis in the emergency department. The retrospective study covers a period of 10 months and all emergency patients with chest trauma exmined by spiral CT. The major lesions of varying seriousness covered by this study are: pneumothorax, hematothorax, pulmonary contusion or laceration, mediastinal hematoma, rupture of a vessel, injury of the heart and pericardium. The various fractures are not included in this study. In many cases, spiral CT within relatively short time yields significant diagnostic findings, frequently saving additional angiography. A rigid diagnostic procedure cannot be formulated. Plain-film chest radiography still remains a diagnostic modality of high value. (Orig.) [Deutsch] Nach Einfuehrung der Spiral-CT in unserer Einrichtung versuchten wir, den Stellenwert der Computertomographie in der Notfalldiagnostik des Thoraxtraumas neu zu bestimmen. Dazu wurden retrospektiv ueber einen Zeitraum von 10 Monaten alle mittels Spiral-CT untersuchten Notfallpatienten mit Thoraxverletzungen ausgewertet. Im Vordergrund standen folgende Befunde unterschiedlichen Schweregrades: Pneumothorax, Haematothorax, Lungenkontusion/-lazeration, Mediastinalhaematom, Gefaessruptur, Herz- und Herzbeutelverletzung. Auf die unterschiedlichen Frakturen wird bewusst nicht naeher eingegangen. In vielen Faellen liefert die Spiral-CT mit relativ geringem Zeitaufwand wesentliche diagnostische Aussagen. Haeufig kann auf eine Angiographie verzichtet werden. Ein starres diagnostisches Stufenschema laesst sich nicht definieren. Die Thoraxuebersichtsaufnahme besitzt einen unveraendert hohen Stellenwert. (orig.)

Videobasierte Systeme

Science.gov (United States)

Knoll, Peter

Videosensoren spielen für Fahrerassistenz systeme eine zentrale Rolle, da sie die Interpretation visueller Informationen (Objektklassifikation) gezielt unterstützen. Im Heckbereich kann die Video sensorik in der einfachsten Variante die ultraschallbasierte Einparkhilfe bei Einpark- und Rangiervorgängen unterstützen. Beim Nachtsichtsystem NightVision wird das mit Infrarotlicht angestrahlte Umfeld vor dem Fahrzeug mit einer Frontkamera aufgenommen und im Fahrzeugcockpit auf einem Display dem Fahrer angezeigt (s. Nachtsichtsysteme). Andere Fahrerassistenzsysteme verarbeiten die Videosignale und generieren daraus gezielt Informationen, die für eigenständige Funktionen (z. B. Spurverlassenswarner) oder aber als Zusatzinformation für andere Funktionen ausgewertet werden (Sensordatenfusion).

Results of VGB research work with respect to operation of BWR pipes made of austenitic SS; Ergebnisse des VGB-Forschungsvorhabens zur Absicherung des Betriebsverhaltens austenitischer Staehle in SWR-Rohrleitungen

Energy Technology Data Exchange (ETDEWEB)

Kilian, R [Siemens AG Energieerzeugung KWU, Erlangen (Germany); Bruemmer, G [Hamburgische Electricitaets-Werke AG, Hamburg (Germany)

1998-11-01

von Formfehlern beim Schweissen (z.B. Kantenversatz, Quetschfalten); 4. Reduzierung der Zugeigenspannungen beim Schweissen; 5. Einhaltung der neuen VGB-Wasserchemie-Richtlinien. (orig./MM)

Vorschrift oder Thunfisch? – Zur Langzeitverfügbarkeit von Forschungsdaten

Directory of Open Access Journals (Sweden)

Tim Hasler

2013-10-01

Full Text Available Ich mache ihm ein Angebot, das er nicht ablehnen kann.” Diese Aussage aus einem gänzlich anderen Kontext lässt sich recht treffend übertragen als Wunsch von Dienstleistern und Zweck von Dienstleistungen für Datenproduzenten im Forschungsdatenmanagement. Zwar wirkt Druck zur Datenübergabe nicht förderlich, die Eröffnung einer Option aber sehr wohl. Im vorliegenden Artikel geht es um das Verständnis der Nachhaltigkeit von Forschung und ihren Daten anhand der Erkenntnisse und Erfahrungen aus der ersten Phase des DFG-Projekts EWIG. [Fn 01] Eine Auswahl von Fallstricken beim Forschungsdatenmanagement wird anhand der Erkenntnisse aus Expertengesprächen und eigenen Erfahrungen beim Aufbau von LZA-Workflows vorgestellt. Erste Konzepte in EWIG zur Datenübertragung aus unterschiedlich strukturierten Datenquellen in die „Langfristige Domäne” werden beschrieben. "I'm gonna make him an offer he can't refuse". This quote from a completely different context can be aptly rendered as a statement of service providers as well as the purpose of services for data producers in the field of research data management. Although pressure is not the leverage of choice if you want researchers to deposit their research data in some kind of repository, offering an option does the trick quite well. In this article we present some of the concepts for sustainability of research and its data from the first phase the of the project EWIG, funded by the Deutsche Forschungsgemeinschaft. A selection of pitfalls in research data management is presented based on the findings from expert interviews and our own experiences in the construction of LTP workflows. First concepts in EWIG to transfer data from differently structured data sources into the "Permanent Domain" are described.

Gebändigtes Knallgas: Brennstoffzellen im mobilen und stationären Einsatz

Science.gov (United States)

Waidhas, Manfred; Landes, Harald

2001-07-01

Die Brennstoffzelle hat aus technischer Sicht einen hohen Stand erreicht. Die PEMFC konnte ihre Zuverlässigkeit in einer Reihe von Nischenanwendungen, aber auch in Form erster mobiler und dezentraler Prototypen beweisen. Die SOFC und die MCFC konnten bereits in Anlagen von 100 kW und mehr in Erprobung gehen. Um jedoch wirtschaftlich konkur-renzfähig zu den etablierten Technologien der mobilen und dezentralen Energiewandlung zu werden, muss noch eine drastische Kostenreduktion sowohl beim Brennstoffzellen-Stack als auch bei den zu seinem Betrieb notwendigen Hilfsaggregaten erreicht werden. Für Fahrzeugantriebe muss außerdem eine Antwort auf die noch offene Treibstofffrage (Infrastruktur, H2-Erzeugung und H2-Speicherung) gefunden werden.

Seismic methods for the characterisation of reservoirs in developing old natural gas fields in Germany; 3D Seismische Verfahren zur Reservoircharakterisierung bei der Entwicklung alter Erdoelfelder in Deutschland

Energy Technology Data Exchange (ETDEWEB)

Krajewski, P.; Stahl, E.; Bischoff, R. [Preussag Energie GmbH, Lingen (Germany); Guderian, K.; Hasse, G.; Schmiermann, I. [BEB Erdoel und Erdgas GmbH, Hannover (Germany); Groot, P. de [De Groot-Bril Earth Sciences BV, Enschede (Netherlands)

1998-12-31

Two examples are chosen to describe the possiblities and limitations of using 3D seismic data for the interpretation of structures and the seismic characterisation of reservoirs. New techniques of seismic classification offer a great deal of possibilities, especially if - as in the case of Ruehme - there is a sufficiency of data from many borehole locations which enables the training of algorithms.(orig.) [Deutsch] Anhand zweier Beispiele wurden die Moeglichkeiten aber auch die Grenzen des Einsatzes 3D seismischer Daten bei der strukturellen Interpretation und der seismischen Reservoircharakterisierung aufgezeigt. Neuartige Techniken der seismischen Klassifizierung erweitern die Moeglichkeiten dabei betraechtlich, insbesondere, wenn - wie beim Beispiel Ruehme - durch die vielen Bohrlokationen ausreichend Daten zum Trainieren der Algorithmen zur Verfuegung stehen. (orig.)

Una vez más: sobre el tratamiento jurídico-penal del hecho de conciencia

Directory of Open Access Journals (Sweden)

Claus Roxin

2014-06-01

Full Text Available El presente escrito hace referencia a la discusión sobre las consecuencias del derecho fundamental a la libertad de conciencia en el derecho penal. En especial se analizan las diferentes posturas que existen en la doctrina sobre el tratamiento jurídico-penal de los hechos de conciencia: las posibilidades de justificación, de exculpación y de atenuación. Asimismo se presentan nuevos argumentos a favor de una posible exculpación por ausencia de necesidad preventiva de punición (Entschuldigung beim Fehlen einer präventiven Bestrafungsnotwendigkeit y se contrasta esta postura con las sustentadas por Jorge Figueiredo Dias y Wolfgang Frisch.

Rezension zu: Beate Hochholdinger-Reiterer: Kostümierung der Geschlechter. Schauspielkunst als Erfindung der Aufklärung. Göttingen: Wallstein Verlag 2014.

Directory of Open Access Journals (Sweden)

Claudia Daiber

2016-07-01

Full Text Available Von geschlechtlichen Einlagerungen in Sprache und deren Funktionen beim Schreiben der Theatergeschichte der deutschsprachigen Aufklärung handelt die von Beate Hochholdinger-Reiterer vorgelegte Habilitationsschrift. Die von ihr aufgedeckten sprachlichen Codes, die als ‚heimliche Archive‘ fungieren, werden auf die durch sie vermittelte symbolische Ordnung der Geschlechter hin analysiert. Prozesse der Literarisierung, Institutionalisierung und Subventionierung führten in dieser Epoche zur Etablierung des ‚einen‘ Theaters. Diese Prozesse verhandelten jedoch gleichermaßen Fragen des Nationalstaates und der Geschlechterordnung mit und konstruierten hinsichtlich letzterer eine ‚patrilineare Genealogie‘, die ‚andere‘ Diskurse mit ‚anderen‘ Ordnungen, die es in den Umbrüchen nachweislich auch gab, stimmlos gelassen haben.

Superiority of the practical method to theory: Diagnose of service life of ropes in overhead transmission grids; Praktische Methode der Theorie ueberlegen: Diagnose der Lebensdauer von Freileitungsseilen

Energy Technology Data Exchange (ETDEWEB)

Brueckner, W.F.

2005-02-07

In designing overhead transmission lines, cable tension is of prior importance. High tension means shorter life unless vibration dampers are installed. On the other hand, higher tension will reduce the overall cost to an optimum level. The author presents experience and measured vibration sensitivities. (orig.) [German] Beim Entwurf von Freileitungen ist die Zugspannung der Seile von besonderer Bedeutung. Erhoehte Seilzugspannungen verringern die Lebensdauer der Seile, soweit die Schwingungsgefahr nicht durch geeignete Schwingungsdaempfer vermieden wird. Mit erhoehter Seilzugspannung verringern sich auch die Kosten der gesamten Freileitung bis zur optimalen Grenze, die von den Kosten je km fuer verschiedene Spannweiten zu bestimmen ist. Der Verfasser beschreibt Erfahrungen ueber die gemessene Schwingungsgefaehrdung der Seile. (orig.)

Quantitative information literacy: Designing an online course at the interface between information literacy and statistical literacy

Directory of Open Access Journals (Sweden)

Christina Kläre

2017-04-01

Während sich die Informationskompetenzunterstützung in unterschiedlichen Dienstleistungsausprägungen in Bibliotheken etabliert hat, spielt das Komplement Statistikkompetenz dort höchstens eine untergeordnete Rolle. Der Aufsatz erläutert die Erstellung des Online-Selbstlernkurses „Daten und Statistiken recherchieren und nutzen“ an der Universitätsbibliothek Duisburg-Essen und zeigt, wie ein solcher Onlinekurs eine Brücke zwischen den beiden Kompetenzen und insbesondere den Auskunftsdiensten der Bibliothek und der statistischen Methodenlehre schlagen kann. Der Aufsatz berücksichtigt vor allem die Anwendersicht unter Bezug auf die didaktischen Analysen und Entscheidungen beim Design des an Subject Guides/Forschungsführern orientierten Moodle-Kurses für die Zielgruppe Studierende der Wirtschafts-, Sozial- und Politikwissenschaften.

Focal lesions in whole-body MRI in multiple myeloma. Quantification of tumor mass and correlation with disease-related parameters and prognosis; Fokale Laesionen in der Ganzkoerper-MRT beim multiplen Myelom. Quantifizierung der Tumorlast und Korrelation mit krankheitstypischen Parametern und Prognose

Energy Technology Data Exchange (ETDEWEB)

Brandelik, S.C.; Kauczor, H.U. [Universitaetsklinikum Heidelberg, Diagnostische und Interventionelle Radiologie, Heidelberg (Germany); Krzykalla, J.; Hielscher, T. [Deutsches Krebsforschungszentrum (dkfz), Biostatistik, Heidelberg (Germany); Hillengass, J. [Universitaetsklinikum Heidelberg, Haematologie und Onkologie, Heidelberg (Germany); Kloth, J.K. [Radiologie Loebau, Loebau (Germany); Weber, M.A. [Universitaetsklinikum Heidelberg, Diagnostische und Interventionelle Radiologie, Heidelberg (Germany); Universitaetsmedizin Rostock, Diagnostische und Interventionelle Radiologie, Rostock (Germany)

2018-01-15

In this study, we evaluated methods of quantification of tumor mass in whole-body MRI (wb-MRI) in multiple myeloma and correlated these with disease-related parameters in serum and bone marrow. We retrospectively evaluated wb-MRIs of 52 patients with focal infiltration pattern and a total of 700 focal lesions (subsequently called lesions). We determined the longest diameter (LD), the segmented volume (SV), and the morphology (spherical or non-spherical). We correlated total number/volume of the lesions with clinical parameters and prognosis and furthermore LD with SV. After that we analyzed the agreement of SV and estimated volume (EV) using the volume formula of a sphere based on LD. Results showed no significant correlations of total number/volume with prognosis or clinical parameters. The latter were situated predominantly in the normal range. Furthermore, 10% of lesions were spherical. SV and LD correlated significantly in single lesions and on patient level. SV was in lesions <6 cm{sup 3} systematically larger and in lesions ≥6 cm{sup 3} smaller than EV. In 95%, we found in small lesions a deviation of EV versus SV from +0.9 cm{sup 3} to -4.6 cm{sup 3} and in large lesions from +160 cm{sup 3} to -111 cm{sup 3} (EV-SV). Quantification of tumor mass in the focal infiltration pattern is performed more accurately by volumetry than LD due to the predominant existence of non-spherical lesions. The patient cohort with clinical parameters predominantly in the normal range is distributed to ISS stage I and partly pretreated, a fact that makes interpretation of absent correlations more difficult. Consider also a variation in activity of lesions and a diffuse infiltration not detectable by MRI. (orig.) [German] In dieser Studie wurden Methoden der Tumorlastquantifizierung in der Ganzkoerper-Magnetresonanztomographie (GK-MRT) beim Multiplen Myelom untersucht und mit krankheitstypischen Parametern in Serum und Knochenmark korreliert. Die GK-MRT von 52 Patienten mit

Die kognitiv-metaphorische Motiviertheit beim Erlernen von Idiomen am Beispiel eines Aufgabenblattes

Directory of Open Access Journals (Sweden)

Kispál, Tamás

2011-01-01

Full Text Available The cognitive metaphorical motivation of idioms is one of the most treated subjects in English-language articles about teaching of idioms. In German-language phraseodidactic literature it is a rather rare phenomenon. The metaphorical motivation of several idiomatic expressions is undoubted. In this article we argue for their cognitive metaphorical motivation. It is hypothesized that the joint representation of several typical context examples, with idioms of the same conceptual metaphor, not only promotes the recognition and understanding of idioms but also the detection of cognitive metaphorical motivation of idioms. Context-sensitive tasks make a significant contribution to uncovering and learning the metaphorical idioms for learners of German as a foreign language. The learning-enhancing role of this method for the acquisition of idioms and their meanings are to be illustrated with the example of the conceptual metaphor life is a journey, the metaphorical idioms based on this conceptual metaphor, and an example worksheet.

Knee and ankle injuries from playing football; Knie- und Sprunggelenkverletzungen beim Fussballspiel

Energy Technology Data Exchange (ETDEWEB)

Kramer, J.; Scheurecker, G. [Roentgeninstitut am Schillerpark, Linz (Austria)

2010-05-15

Soccer is the most common sport activity worldwide. Over the last two decades the increase in soccer players has mainly been due to increased interest by females. In general, soccer is a relatively safe sport activity, especially if minor injuries resulting in short periods of absence from playing or training are neglected. However, due to the high number of soccer players severe injuries are also frequent. These are a problem not only for the injured player and the team but may also become problematic for the socio-economic system. In up to 80-90% structures of the lower extremities are injured. For sufficient radiological diagnosis knowledge of the biomechanics of the soccer game and some details about the history of the injury may be of help. To prevent soccer injuries or keep the degree of injury low, special programs had been developed. (orig.) [German] Fussball ist die weltweit am meisten verbreitete Sportart. Der Zuwachs an Fussballspieler(innen) in den letzten beiden Jahrzehnten wird jedoch hauptsaechlich auf das verstaerkte Interesse an weiblichen Spielern zurueckgefuehrt. Das Fussballspiel gilt grundsaetzlich, insbesondere wenn man geringfuegige Verletzungen, die keine therapeutischen Massnahmen notwendig machen, sondern lediglich eine kurzfristige Trainings- oder Spielpause bedingen, als eine relativ sichere Sportart. Auf Grund der Vielzahl an SpielerInnen kommt es allerdings doch zu einer betraechtlichen Anzahl durchaus sehr schwerer Verletzungen. Diese Tatsache stellt ein Problem fuer Spieler und Team dar und mag moeglicherweise auch fuer das soziooekonomische System problematisch werden. Von Verletzungen sind v. a. auf Grund der Natur des Spieles die unteren Extremitaeten betroffen. Zur Durchfuehrung einer suffizienten radiologischen Diagnostik sind Kenntnisse der moeglichen Verletzungsmechanismen und eine Anamneseerhebung von nicht zu unterschaetzendem Wert. Um jedoch derartige Laesionen zu vermeiden bzw. gering zu halten, wurde ueber die Jahre hinweg immer mehr Wert auf Praevention gelegt. (orig.)

Einsatzverhalten genuteter CBN-Schleifscheiben mit keramischer Bindung beim Außenrund-Einstechschleifen

OpenAIRE

Kirchgatter, Mathias

2010-01-01

Industrielle Schleifprozesse für Bauteile aus gehärteten Stahlwerkstoffen werden vermehrt mit keramisch gebundenen CBN-Schleifscheiben durchgeführt, die sich bei vielen Anwendungen aufgrund ihres Eigenschaftsprofils und der erweiterten Einstellbarkeit der Bindungsspezifikationen gegenüber anderen Schleifwerkzeugtypen durchsetzen. Der Optimierungsdruck der Großserien- und Massenfertigungsprozesse hat bereits zu einer beachtlichen Entwicklung hinsichtlich der Leistungsfähigkeit dieses Werkzeugt...

Safety relief valve instabilities; Instabiles Verhalten beim Betrieb von direkt belasteten Sicherheitsventilen

Energy Technology Data Exchange (ETDEWEB)

Neuhaus, Thorsten; Bloemeling, Frank; Jung, Andreas; Schaffrath, Andreas [TUeV NORD SysTec GmbH und Co. KG, Hamburg (Germany)

2012-11-01

The opening and closing of safety relief valves induce pressure vibrations and respective loads on the piping system. The quantification of the internal pressure load and the pipe segment forces for the proof of the structural integrity of the piping system and the supports is performed using the code DYVRO. It is not clear whether the calculated result of high-frequent opening and closing shows a realistic behavior or is caused by a simplified modeling. The contribution offers strategic recommendations to avoid unrealistic calculations.

Radiation exposure on flights; Strahlenexposition beim Fliegen. Ein Fall fuer den Strahlenschutz

Energy Technology Data Exchange (ETDEWEB)

Blettner, Maria [Mainz Univ. (Germany). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik (IMBEI); Boehm, Theresia; Eberbach, Frieder [Vereinigung Cockpit e.V. Main Airport Center (MAC), Frankfurt (Germany). AG Strahlenschutz; Bottollier-Depois, Jean-Francois [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France); Clairand, Isabelle; Huet, Christelle [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France). Ionizing Radiation Dosimetry Lab.; Frasch, Gerhard [Bundesamt fuer Strahlenschutz, Oberschleissheim/Neuherberg (Germany). Beruflicher Strahlenschutz und Strahlenschutzregister; Hammer, Ga el P. [Laboratoire National de Sante E.P., Dudelange (Luxembourg). Registre Morphologique des Tumeurs; Mares, Vladimir; Ruehm, Werner [Helmholtz Zentrum Muenchen Deutsches Forschungszentrum fuer Gesundheit und Umwelt GmbH, Neuherberg (Germany); Voelkle, Hansruedi [Fribourg Univ. (Switzerland). Physikdept.

2014-09-01

Extend and effects of radiation doses occuring during flights are treated under various aspects. Part of them are, in the first line, radiation exposure of the flying staff and the results of epidemiologic studies regarding the health consequences, as well as aspects of practical radiation protection for the flying staff. Computer programs for dose calculation on flights round off the theme. (orig.)

Schweißbereichsdiagramme Instrumente zur Qualitätssicherung beim Widerstandspunktschweißen

DEFF Research Database (Denmark)

Weber, G.; Widmer, R.; Rasmussen, Mogens Hørslev

2001-01-01

and electrode force, the influence of the sheet material, of the welding current form and of the electrode cape shape is examined. By the example of a medium frequency inverter welding gun, an optimization of the welding parameters of welding current, welding time and electrode force with three...

Multi-parametric MR imaging for prostate carcinoma; Multiparametrische MR-Bildgebung beim Prostatakarzinom

Energy Technology Data Exchange (ETDEWEB)

Schlemmer, Heinz-Peter [Deutsches Krebsforschungszentrum, Heidelberg (Germany). Abt. Radiologie

2017-03-15

Multi-parametric NMR imaging in case of prostate carcinoma can improve diagnostics, allows reliable prognostic estimations and helps to find the optimum individual therapy. The contribution is focused to deliver the needed methodological tools and background knowledge for the daily routine.

How x rays inhibit amphibian limb regeneration

International Nuclear Information System (INIS)

Maden, M.; Wallace, H.

1976-01-01

The effects of an inhibiting dose of 2,000 rad of x-rays on the regenerating limbs of axolotl larvae have been examined in a histological and cytological study. Particular attention was paid to the mitotic indices of normal and irradiated epidermal and blastemal cells. Both the characteristic pattern of epidermal mitotic stimulation which normally follows amputation and the later increase in blastemal mitoses are suppressed by irradiation. In most cells the effects are permanent, but in a small proportion a mitotic delay is induced and upon subsequent division chromosome damage in the form of micronuclei is revealed. Thus irradiated cells which do divide almost certainly die. These results are discussed in relation to other theories of x-ray inhibition of regeneration with particular reference to the view that irradiated cells can be reactivated

Collagen reconstitution is inversely correlated with induction of limb regeneration in Ambystoma mexicanum.

Science.gov (United States)

Satoh, Akira; Hirata, Ayako; Makanae, Aki

2012-03-01

Amphibians can regenerate missing body parts, including limbs. The regulation of collagen has been considered to be important in limb regeneration. Collagen deposition is suppressed during limb regeneration, so we investigated collagen deposition and apical epithelial cap (AEC) formation during axolotl limb regeneration. The accessory limb model (ALM) has been developed as an alternative model for studying limb regeneration. Using this model, we investigated the relationship between nerves, epidermis, and collagen deposition. We found that Sp-9, an AEC marker gene, was upregulated by direct interaction between nerves and epidermis. However, collagen deposition hindered this interaction, and resulted in the failure of limb regeneration. During wound healing, an increase in deposition of collagen caused a decrease in the blastema induction rate in ALM. Wound healing and limb regeneration are alternate processes.

Development and regulation of response properties in spinal cord motoneurons

DEFF Research Database (Denmark)

Perrier, J F; Hounsgaard, J

2000-01-01

The intrinsic response properties of spinal motoneurons determine how converging premotor neuronal input is translated into the final motor command transmitted to muscles. From the patchy data available it seems that these properties and their underlying currents are highly conserved in terrestrial...... vertebrates in terms of both phylogeny and ontogeny. Spinal motoneurons in adults are remarkably similar in many respects ranging from the resting membrane potential to pacemaker properties. Apart from the axolotls, spinal motoneurons from all species investigated have latent intrinsic response properties...... mediated by L-type Ca2+ channels. This mature phenotype is reached gradually during development through phases in which A-type potassium channels and T-type calcium channels are transiently expressed. The intrinsic response properties of mature spinal motoneurons are subject to short-term adjustments via...

New opportunities to measure pressures inside combustion engine without having separate drilling for the pressure-sensors; Neue Moeglichkeiten der Druckindizierung in Verbrennungsmotoren ohne separate Messbohrung

Energy Technology Data Exchange (ETDEWEB)

Brechbuehl, S.; Schnepf, M.; Sonntag, R.; Wolfer, P. [Kistler Instrumente AG, Winterthur (Switzerland)

2000-07-01

beim Ottomotor, bzw. Gluehbirne beim Dieselmotor installiert werden koennen, hat in den letzten Jahren an Bedeutung zugenommen. Wegen des geringen Platzangebotes zur Unterbringung des Drucksensors in Messzuendkerzen und Gluehkerzenadaptern stellen heutige Ausfuehrungen immer einen Kompromiss dar zwischen Signalguete, Montagefreundlichkeit, sowie der Aufrechterhaltung der Originalfunktionalitaet. So musste bei der Druckmessung mit Gluehkerzenadaptern in Dieselmotoren bisher auf die Gluehfunktion gaenzlich verzichtet werden. In der vorliegenden Arbeit wurde ein neu entwickelter Gluehkerzenadapter vorgestellt, in welchem neben einem piezoelektrischen Drucksensor auch eine Gluehwendel mit voller Heizleistung integriert ist. Mit dieser Messgluehkerze sind jetzt Druckmessungen beim Kaltstart und waehrend des Nachgluehbetriebs unter realen Betriebsbedingungen moeglich. Bei der Druckmessung mit Messzuendkerzen in Ottomotoren musste bisher zur Erzielung einer guten Signalqualitaet eine exzentrische Lage der Mittelelektrode in Kauf genommen werden. In der vorliegenden Arbeit wurde ein neu entwickelter Zuendkerzenadapter mit zentrischer Mittelelektrode vorgestellt. Diese Betriebs-Messzuendkerze ermoeglicht eine Zylinderdruckmessung mit guter Signalqualitaet bei unveraenderter Funkenlage. Durch die zentrische Keramik wird das Aufsetzen des Originalzuendrails wesentlich erleichtert. Das Herz beider Neuentwicklungen ist eine Miniatur-Sensorik, welche mit neuen Kristallen eine hoehere Empfindlichkeit und Temperaturstabilitaet aufweist. (orig.)

Surveillance of anal carcinoma after radiochemotherapy. A retrospective analysis of 80 patients

Energy Technology Data Exchange (ETDEWEB)

Sauter, Matthias; Vavricka, Stephan R. [Triemli Hospital, Department of Medicine, Division of Gastroenterology, Zurich (Switzerland); University Hospital Zurich, Division of Gastroenterology and Hepatology, Zurich (Switzerland); Keilholz, Georg; Kranzbuehler, Helmut; Lombriser, Norbert [Triemli Hospital, Division of Radiation-Oncology, Zurich (Switzerland); Heinrich, Henriette; Misselwitz, Benjamin [University Hospital Zurich, Division of Gastroenterology and Hepatology, Zurich (Switzerland); Winder, Thomas [University Hospital Zurich, Department of Oncology, Zurich (Switzerland)

2017-08-15

Surveillance after radiochemotherapy of anal carcinoma (ACa) with curative intent is recommended in guidelines, but data regarding the effectiveness of follow-up are lacking. We aimed to assess the performance of an ACa surveillance program in a real-life setting. We retrospectively summarized clinical history, physical findings, and follow-up investigations (endoanal ultrasound, endoscopy, CT scan) obtained during 42 months (±27 months) from 80 patients after radiochemotherapy of ACa. In 7/80 cases (8.8%) an incomplete response to therapy was identified at or before the 6-month time point after the end of treatment; 4 of the 7 cases were identified during scheduled follow-up. In 6 cases (7.5%), recurrent disease was found after the 6-month time point. Recurrence was systemic in 5 cases and local/inguinal in 1 case. In 3 of the 6 cases (50%), recurrence was identified during scheduled follow-up. In one asymptomatic patient, a single liver metastasis was detected during scheduled follow-up and the patient remains free of disease 19 months after surgery. Surveillance resulted in a high rate of false-positive findings (70 findings in 604 investigations), of which only 14 could be confirmed. Scheduled follow-up after treatment of ACa detected recurrent disease at systemic sites, enabling potentially curative treatment in a single case. Effectiveness of abdominal imaging during follow-up after ACa treatment should be tested in a prospective trial. (orig.) [German] Nach kurativ intendierter kombinierter Radiochemotherapie beim Analkarzinom (ACa) wird von den Guidelines eine Nachsorge empfohlen, die Datenlage hierzu ist jedoch mangelhaft. Ziel unserer Studie war es, die Wertigkeit der Nachsorge beim ACa in einem ''Real-life''-Setting zu evaluieren. Es erfolgte die retrospektive Aufarbeitung der Nachsorge inklusive Anamnese, klinischer Untersuchung und Nachsorgeuntersuchungen (untere Endosonographie, Endoskopie, Computertomographie Abdomen

Seed loss in prostate brachytherapy. Operator dependency and impact on dosimetry

Energy Technology Data Exchange (ETDEWEB)

El-Bared, Nancy; Sebbag, Natanel; Beliveau-Nadeau, Dominic; Hervieux, Yannick; Larouche, Renee; Taussky, Daniel; Delouya, Guila [Centre hospitalier de l' Universite de Montreal - Hopital Notre-Dame, Departement de Radio-Oncologie, Montreal, QC (Canada)

2016-05-15

Seed verloren: 20% der Implantate beim erfahrenen Arzt und 17,2 % beim weniger erfahrenen Arzt (p = 0,4). Eine Migration zum Thorax wurde in 5,9% nachgewiesen (6,9 vs. 2,2 %; p = 0,004). Die durchschnittliche Seed-Verlustrate war 0,57% [Standardabweichung (SD) 1,39] und der Prozentsatz an abgegangenen Seeds pro implantierten Seeds 0,14% (SD 0,65). Der erfahrenere Arzt hatte im Vergleich zum weniger erfahrenen Arzt einen hoeheren Prozentsatz abgegangener Seeds (0,36% vs. 0,25%; p = 0,055) sowie von Seeds im Thorax (0,1% vs. 0,02%; p < 0,001). Beim Verlust von mindestens einem Seed wurde eine Reduktion der D90 um 4,2 Gy (p < 0,001) und der V150 um 3,5% (p = 0,002) festgestellt. Ein Seed-Abgang senkt V150 und D90 signifikant. Ob ein Seed-Abgang nachgewiesen werden kann, haengt vom behandelnden Arzt ab. (orig.)

Metallurgical phenomena in laser finishing: Interdependences between solidification morphologies and hot cracking in laser welding of mostly austenitic materials. Final reportc; Metallkundliche Phaenomene der Laserstrahlmaterialbearbeitung. Teilvorhaben: Zusammenhaenge zwischen Erstarrungsmorphologien und Heissrissentstehung beim Laserschweissen von vornehmlich austenitischen Werkstoffen. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Schobbert, H.

2000-06-01

be performed by using measuring results of this newly developed test assembly. For the first time, different types of hot cracks in correlation to the change of primary solidification mode could be detected. The primary austenitic weld metals of the materials 1.4828 and 1.4306, which formed due to the change of solidification mode, showed a susceptibility to DDC. The results of this research project are a contribution to quantify the change of solidification mode and thus, the restriction of hot cracking resistance of the tested materials. (orig.) [German] Als ein spezifisches Problem des Laserschweissens stellt sich bei den wirtschaftliche wuenschenswerten hohen Schweissgeschwindigkeiten jedoch heraus, dass besonders austenitische Staehle mit einer Zusammensetzung in der Naehe der eutektischen Rinne ihren Erstarrungsmodus aendern und damit die Heissrisssicherheit eingeschraenkt sein kann. Vor diesem Hintergrund sind in der Forschungsarbeit die beim Laserschweissen entstehenden Erstarrungsmorphologien dieser Staehle in der Naehe der eutektischen Rinne besonders unter dem Aspekt kurzeitmetallurgisch bedingter kinetischer Effekte unter den Bedingungen einer schneller Erstarrung untersucht worden. Fuer drei im praktischen Einsatz weit verbreitete nichtrostende Staehle (1.4828, 1.4306 und 1.4404) wird ein von der Erstarrungsgeschwindigkeit abhaengiger Wechsel des primaeren Erstarrungsmodus von primaer ferritsch zu primaer austenitisch nachgewiesen. Die kritische Erstarrungsgeschwindigkeit kann in guter Naeherung mit einem neu entwickelten Modell durch eine geometrische Analyse der Erstarrungsstrukturen ermittelt werden. Die von der Zusammensetzung der Werkstoffe abhaengige kritische Erstarrungsgeschwindigkeit fuer den Wechsel der Primaererstarrung betraegt fuer diese Werkstoffe groessenordnungsmaessig etwa 1 m/min. Als ein wesentliches Ergebnis wird fuer die zu primaer austenitisch gewechselten Erstarrungsmorphologien die zunaechst vermutete Beeintraechtigung der

Efficient turbine control. Advantages through controlling internal turbine power in place of turbo generator output; Effektive Turbinenregelung. Vorteile durch die Regelung der inneren Turbinenleistung anstelle der Turbogeneratorleistung

Energy Technology Data Exchange (ETDEWEB)

Sindelar, R.

1999-07-01

Hitherto, the electrical output of turbo generators has generally been controlled by means of power output controllers. Load changes caused, for example, by changeovers to isolated unit operation where the load requirements are unknown at first, often resulted in `wrong way control` effects that sometimes even caused entire turbine generator sets to fail. Controlling the internal turbine power makes it possible to avoid such consequences. (orig.) [Deutsch] Die elektrische Leistung eines Turbogenerators wurde bislang durch Leistungsregler geregelt. Im Falle einer Lastaenderung, wie sie beispielsweise beim Uebergang in den Betrieb auf ein Teilnetz (Insel-) mit vorher unbekannter Last vorkommt, trat ein Falschregeleffekt auf. Auf diesen wurden bereits Turbosatzausfaelle zurueckgefuehrt. Wird anstelle der elektrischen Leistung allerdings die innere Turbinenleistung geregelt, so tritt der Falschregeleffekt nicht ein. (orig.)

Extraprostatische Expansion des Prostatakarzinoms und seine Beziehung zu den Resektionsrändern bei der radikalen Prostatektomie aus Sicht des Pathologen

Directory of Open Access Journals (Sweden)

Noll P

2008-01-01

Full Text Available Das Prostatakarzinom stellt heute in der westlichen Welt das am häufigsten diagnostizierte Karzinom beim Mann dar. Entsprechend dieser Häufigkeit werden zunehmend radikale Prostatektomien durchgeführt. Die histologische Aufarbeitung des Operationspräparates liefert dem Urologen die wichtigsten Prognosefaktoren des Prostatakarzinoms. Hierbei besteht ein enger Zusammenhang zwischen der extraprostatischen Ausdehnung des Tumors und seiner Beziehung zu den Resektionsrändern. Anhand einer eigenen Untersuchung an 200 radikal operierten Prostatakarzinomen konnte gezeigt werden, dass hierbei die Lokalisation, der Malignitätsgrad und die Größe des Tumors entscheidende Bedeutung haben. Die Ermittlung dieser Parameter ist abhängig von einer standardisierten Untersuchungstechnik auf der Grundlage einer vollständigen histologischen Aufarbeitung der Prostata.

Measurements of the beam background in ALEPH

CERN Document Server

Lutters, Gerd Rudolf

2001-01-01

Die vorliegende Arbeit fa t die in den Jahren gewonnenen Erkenntnisse uber strahl induzierten Untergrund in dem ALEPHExperimentdetektor des LEPSpeicherringes GeV Strahlenergie zusammen Die selbstentwickelte AnkunftszeitAnalysetechnik erlaubt aufgrund der Daten des eigens entwickelten SAMBA Untergrundmonitors eine Prognose der Strahluntergrund raten beim Betrieb des LEPIISpeicherringes GeV Strahlenergie mit verdoppelter Schwer punktsenergie Am LEPISpeicherring ist die maximale Luminositat nicht durch die Parameter der Lumino sitatsbeziehung sondern durch die maximal vertraglichen Dunkelstrome in den Spurdetektoren und damit durch die Strahluntergrundraten begrenzt Die Strahluntergrundrate deren dominie render Beitrag Synchrotronstrahlung in den Quadrupolen der Experimentzone ist erhoht sich linear mit dem Strahlstrom Die Synchrotronstrahlung wird in LEP durch Kollimatoren abgeblen det so da neben direkten Photonen an den Kollimatoren oder strahlabwarts liegenden Elemen ten der Vakuumkammer comptongestreute Pho...

Ecological construction methods are energy saving construction methods - experiences with the low-energy standard; Oekologisches Bauen ist energiesparendes Bauen - Erfahrungen mit dem Niedrigenergiestandard

Energy Technology Data Exchange (ETDEWEB)

Feist, W. [Inst. Wohnen und Umwelt, Darmstadt (Germany)

1995-09-01

Efficient energy utilisation (intelligent energy saving techniques) is characterised by the following features. When realised in new buildings using currently available techniques it can help save up to 90% of what has hitherto been considered normal energy consumption. It becomes economically efficient for reductions in energy consumption of 50% or more. In terms of cost it outcompetes all non-fossil energy carriers (i.e., excluding oil, natural gas, and coal) of the future. (orig./HW) [Deutsch] Die rationelle Energienutzung (`intelligente Einspartechnik`) - kann mit heute verfuegbarer Technik beim Neubau bis ca. 90% der bisher verwendeten Energie einsparen helfen; - ist bei Energieeinsparungen von ueber 50% bereits heute wirtschaftlich vertretbar; - ist gegenueber allen Zukunftsenergietraegern, die nicht auf fossilen Brennstoffen (also Oel, Erdgas und Kohle) basieren, konkurrenzlos kostenguenstig. (orig./HW)

Zur didaktischen Konzeption von «Sozialen Lernplattformen» für das Lernen in Gemeinschaften

Directory of Open Access Journals (Sweden)

Michael Kerres

2011-12-01

Full Text Available Mit der aktuellen Diskussion über Web 2.0 stellt sich die Frage nach der Zukunft von traditionellen Lernplattformen. Der Beitrag stellt verschiedene Entwicklungsoptionen vor und beschreibt die Perspektiven «sozialer Lernplattformen». Bei diesen stehen die Aktivitäten der Akteure und ihre Interaktion im Vordergrund und nicht Dokumente und Lernmaterialien. Sie sind durchlässig für Informationen aus dem und in das Internet, woraus sich unterschiedliche Optionen für die Privatheit von Informationen ergeben. Schliesslich unterstützen sie die Zusammenarbeit, die Entwicklung von Bekanntschaften und den Aufbau sozialer Gruppen. Dabei stellt sich die Frage, wie diese sozialen Strukturen auf einer Plattform zu konzipieren sind, um Gemeinschaftsbildung beim Lernen zu fördern.

Optimal matching of energy supply and demand; Optimale Anpassung der Energiebereitstellung an den Bedarf

Energy Technology Data Exchange (ETDEWEB)

Baumgarth, S. [Competence Center for Building Networks in Wolfenbuettel (Germany); Boggasch, E.; Heiser, M.; Schernus, G.P. [Fachhochschule Braunschweig/Wolfenbuettel (Germany)

2004-06-01

New strategies are presented for matching heat supply and demand on the basis of a bus technology. Investment costs are at a minimum as the automation stations are activated by introducing new programs. (orig.) [German] Seit einiger Zeit wird ueber verschiedene Regelungsstrategien versucht, die Energiebereitstellung so an den Bedarf (Verbraucher) anzupassen, dass die Waermeverluste beim Transport auf den Zuleitungen sowie in der Energiezentrale minimiert werden. Fuer mehrere Anwendungen aus dem Bereich der Heizungs-, Lueftungs- und Klimatechnik sollen hier neue Strategien vorgestellt werden, die erst mit dem Einsatz der Bus-Technologien in der Gebaeudeautomation moeglich sind. Fuer die Betrachtungen ist es auch von Wichtigkeit, dass zu deren Umsetzung moeglichst keine zusaetzlichen Investitionskosten erforderlich sind, sondern dass die in den Automationsstationen durch Einfuegen neuer Programme zu aktivieren sind. (orig.)

Mobility narratives that move me

DEFF Research Database (Denmark)

Lysgaard, Jonas Andreasen; Kronlid, David

and fiction. By opposing the classic anthropocentric ontological split between human (discourse) and object, fiction and Reality, OOO opens up for a new understanding of the role of narratives as independent objects on the same scale as grains of sand, universities, axolotls and planets. In short...... of speed, acceleration, the rhythm of technogenic moving and mooring, which can be translated into an understanding of our own movements and moorings through life and how we engage with new things, such as mediating new information through a certain pace, rhythm, movement, acceleration, slowing down....... This fictive/Real example of a narrative object illustrates that regardless of the metaphysical status of what/who we encounter in education and throughout life, if this experience becomes meaningful to us, we are navigating around them, towards them, and enmesh with them in the same principle ways...

Bone graft substitutes for the treatment of traumatic fractures of the extremities [Knochenersatzmaterialien zur Behandlung von traumatischen Frakturen der Extremitäten

Directory of Open Access Journals (Sweden)

Hagen, Anja

2012-06-01

Knochenersatzmaterialien eingesetzt.Es stellt sich die Frage nach der Wirksamkeit, Kostenwirksamkeit sowie nach ethischen, sozialen und juristischen Implikationen beim Einsatz von Knochenersatzmaterialien bei traumatischen Frakturen.Eine systematische Literaturrecherche wird in den medizinischen elektronischen Datenbanken MEDLINE, EMBASE etc. im Dezember 2009 durchgeführt. In die Bewertung werden randomisierte kontrollierte Studien (RCT ggf. mit gesundheitsökonomischen Analysen sowie Publikationen zu ethischen, sozialen sowie juristischen Aspekten einbezogen. Die medizinische Informationssynthese erfolgt nach Bewertung der Studienqualität u.a. in Form von Metaanalysen, die gesundheitsökonomische Informationssynthese deskriptiv.14 RCT werden in die medizinische und zwei Analysen in die gesundheitsökonomische Bewertung einbezogen, zu ethischen, sozialen und juristischen Aspekten werden keine Publikationen identifiziert. Beim Vergleich Bone morphogenetic protein (BMP-2 gegenüber Standardtherapie ohne Knochentransplantat bei Frakturen ergeben sich in einem RCT (mit erhöhtem Verzerrungspotenzial signifikante Unterschiede zugunsten BMP-2 bezüglich mehrerer Endpunkte. Bei Calciumphosphat (CaP-Zementen und knochenmarkhaltigen Kompositmaterialien zeigen sich beim Vergleich gegenüber Knochentransplantaten in den RCT (alle mit hohem Verzerrungspotenzial signifikante Unterschiede zugunsten der Knochenersatzmaterialien bezüglich einzelner Endpunkte. Bei allen anderen Materialien finden sich in fast allen Vergleichen keine signifikanten Unterschiede.Die BMP-2-Anwendung zusätzlich zur Standardbehandlung ohne Knochentransplantation führt bei Betrachtung aller Patienten mit traumatischen offenen Frakturen zur Kostenerhöhung. Einsparungen durch zusätzlichen BMP-2-Einsatz lassen sich allerdings bei der Patientensubgruppe mit hochgradig offenen Frakturen (Gustilo-Anderson-Grad-IIIB errechnen. Die Kostenwirksamkeit beim BMP-2-Einsatz vs. Standardbehandlung mit Knochentransplantation sowie beim

Gene expression patterns specific to the regenerating limb of the Mexican axolotl

Directory of Open Access Journals (Sweden)

James R. Monaghan

2012-07-01

Salamander limb regeneration is dependent upon tissue interactions that are local to the amputation site. Communication among limb epidermis, peripheral nerves, and mesenchyme coordinate cell migration, cell proliferation, and tissue patterning to generate a blastema, which will form missing limb structures. An outstanding question is how cross-talk between these tissues gives rise to the regeneration blastema. To identify genes associated with epidermis-nerve-mesenchymal interactions during limb regeneration, we examined histological and transcriptional changes during the first week following injury in the wound epidermis and subjacent cells between three injury types; 1 a flank wound on the side of the animal that will not regenerate a limb, 2 a denervated limb that will not regenerate a limb, and 3 an innervated limb that will regenerate a limb. Early, histological and transcriptional changes were similar between the injury types, presumably because a common wound-healing program is employed across anatomical locations. However, some transcripts were enriched in limbs compared to the flank and are associated with vertebrate limb development. Many of these genes were activated before blastema outgrowth and expressed in specific tissue types including the epidermis, peripheral nerve, and mesenchyme. We also identified a relatively small group of transcripts that were more highly expressed in innervated limbs versus denervated limbs. These transcripts encode for proteins involved in myelination of peripheral nerves, epidermal cell function, and proliferation of mesenchymal cells. Overall, our study identifies limb-specific and nerve-dependent genes that are upstream of regenerative growth, and thus promising candidates for the regulation of blastema formation.

Die trinitarische Spekulation und göttliche Freiheit beim späten Schelling

Czech Academy of Sciences Publication Activity Database

Landa, Ivan

-, č. 3 (2011), s. 74-86 ISSN 0010-3713 R&D Projects: GA AV ČR(CZ) KJB900090902 Institutional research plan: CEZ:AV0Z90090514 Keywords : trinity * freedom * God * Schelling * Hegel Subject RIV: AA - Philosophy ; Religion

Neues Punktionsinstrumentarium: Provox-Vega®-Punktionsset: Anwendung beim Einbringen einer Stimmprothese nach Laryngektomie

NARCIS (Netherlands)

Lorenz, K.J.; Hilgers, F.M.; Maier, H.

2013-01-01

Background The use of voice prostheses has been considered the gold standard in voice rehabilitation following laryngectomy for the last 20 years. Insertion is generally performed as a primary procedure during laryngectomy or as a secondary procedure with a re-usable trocar or rigid esophagoscope, a

Structured diagnostic imaging in patients with multiple trauma; Strukturierte radiologische Diagnostik beim Polytrauma

Energy Technology Data Exchange (ETDEWEB)

Linsenmaier, U.; Rieger, J.; Rock, C.; Pfeifer, K.J.; Reiser, M. [Institut fuer Klinische Radiologie, Klinikum der Universitaet Muenchen, Innenstadt (Germany); Kanz, K.G. [Chirurgische Klinik, Klinikum der Universitaet Muenchen, Innenstadt (Germany)

2002-07-01

Purpose. Development of a concept for structured diagnostic imaging in patients with multiple trauma.Material and methods. Evaluation of data from a prospective trial with over 2400 documented patients with multiple trauma. All diagnostic and therapeutic steps, primary and secondary death and the 90 days lethality were documented.Structured diagnostic imaging of multiple injured patients requires the integration of an experienced radiologist in an interdisciplinary trauma team consisting of anesthesia, radiology and trauma surgery. Radiology itself deserves standardized concepts for equipment, personnel and logistics to perform diagnostic imaging for a 24-h-coverage with constant quality.Results. This paper describes criteria for initiation of a shock room or emergency room treatment, strategies for documentation and interdisciplinary algorithms for the early clinical care coordinating diagnostic imaging and therapeutic procedures following standardized guidelines. Diagnostic imaging consists of basic diagnosis, radiological ABC-rule, radiological follow-up and structured organ diagnosis using CT. Radiological trauma scoring allows improved quality control of diagnosis and therapy of multiple injured patients.Conclusion. Structured diagnostic imaging of multiple injured patients leads to a standardization of diagnosis and therapy and ensures constant process quality. (orig.) [German] Fragestellung. Entwicklung eines strukturierten Konzeptes zur radiologischen Diagnostik polytraumatisierter Patienten.Methodik. Die Datenevaluation erfolgte auf Basis einer prospektiven interdisziplinaere Polytraumastudie mit ueber 2400 Patienten. Alle diagnostischen und therapeutischen Schritte werden jeweils unter Angabe von Zeitpunkt und auftretenden Komplikationen erfasst, ein primaeres oder sekundaeres Versterben und die 90-Tage-Letalitaet werden dokumentiert.Die strukturierte radiologische Diagnostik von Mehrfachverletzen verlangt die Integration eines erfahrenen Radiologen in ein interdisziplinaeres Behandlungsteam, bestehend aus Anaesthesie, Radiologie und Unfallchirurgie. Die Radiologie ihrerseits bedarf eines standardisierten apparativen, personellen, und logistischen Konzeptes zur Durchfuehrung der bildgebenden Diagnostik polytraumatisierter Patienten bei gleichbeliebender Qualitaet im 24-h-Betrieb.Ergebnisse. Die vorliegende Arbeit beschreibt anerkannte Kriterien fuer die Einleitung einer Schockraumbehandlung, Methoden der Traumadokumentation und interdisziplinaere Algorithmen, die die Diagnostik und Therapie in der fruehen klinischen Behandlungsphase nach standardisierten Bedingungen koordinieren.Die Radiologische Diagnostik umfasste die Basisdiagnostik mit radiologischer ABC-Regel, radiologischem Follow-up und die Organdiagnostik mittels Computertomographie (CT). Die Einfuehrung eines Schemas zum radiologischen Traumascoring ermoeglicht eine Qualitaetskontrolle von Diagnostik und Therapie.Schlussfolgerungen. Strukturierte radiologische Diagnostik fuehrt zu einer Standardisierung des Vorgehens bei gleichbleibender Qualitaet. (orig.)

Safety requirements to the operation of hydropower plants; Sicherheit beim Betrieb von Wasserkraftwerken

Energy Technology Data Exchange (ETDEWEB)

Lux, Reinhard [Berufsgenossenschaft Energie Textil Elektro Medienerzeugnisse (BG ETEM), Koeln (Germany)

2011-07-01

Employers have to take into account various safety and health requirements relating to the design, construction, operation and maintenance of hydropower plants. Especially the diversity of the hydropower plant components requires the consideration of different safety and health aspects. In 2011 the ''Fachausschuss Elektrotechnik'' (expert committee electro-technics) of the institution for statutory accident insurance and prevention presented a new ''BG-Information'' dealing with ''Safe methods operating hydropower plants''. The following article gives an introduction into the conception and the essential requirements of this new BG-Information. (orig.)

Radiological interventional procedures for the acute abdomen; Radiologisch-interventionelle Massnahmen beim akuten Abdomen

Energy Technology Data Exchange (ETDEWEB)

Trumm, C.; Hoffmann, R.T.; Reiser, M.F. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany)

2010-03-15

In patients with acute thrombo-embolic occlusion of the superior mesenteric artery, catheter-assisted thrombolytic therapy represents a procedure of increasing importance in addition to surgery and intensive care treatment. The thrombolytic drugs utilized for this purpose are urokinase, streptokinase and recombinant tissue plasminogen activator (rtPA). Therapeutic embolization is predominantly used in the treatment of arterial bleeding from the gastro-intestinal tract, the liver, the intestines (due to an aneurysm or vascular malformation) and in bleeding from intestinal anastomoses. Polyvinyl alcohol particles, embospheres, gelfoam and microcoils can be utilized as embolic agents. Percutaneous transhepatic cholangiodrainage and stent implantation are applied in patients with biliary obstructions caused by inoperable tumors of the gall bladder or bile ducts, of the pancreatic head or duodenum and by metastases located in the liver parenchyma or hepatic hilum. Image-guided percutaneous drainage is a valuable option in the management of abscesses in the peritoneal cavity; less common indications are lymphoceles, biliomas, urinomas, hematomas, necrosis and pseudocysts. (orig.) [German] Die kathetergestuetzte thrombolytische Therapie stellt im Kontext einer chirurgischen und intensivmedizinischen Versorgung von Patienten mit thrombembolisch bedingter mesenterialer Ischaemie ein unterstuetzendes Behandlungsverfahren von zunehmender Bedeutung dar. Als thrombolytische Agenzien werden Urokinase, Streptokinase und der rekombinante Gewebeplasminogenaktivator (rtPA) verwendet. Die therapeutische Embolisation kommt neben der endoskopischen und chirurgischen Blutungsstillung bei arteriellen Blutungen im Gastrointestinaltrakt, aus der Leber, im Darm (als Folge eines Aneurysmas oder einer vaskulaeren Malformation) sowie bei blutenden intestinalen Anastomosen zum Einsatz. Zur Embolisation koennen Polyvinylalkoholpartikel, Embosphaeren, Gelfoam oder Mikrocoils verwendet werden. Die perkutane transhepatische Cholangiodrainage und die biliaere Stentimplantation bei malignem Ikterus kommen bei inoperablen Tumoren der Gallenblase oder Gallenwege, Tumoren des Pankreaskopfs oder Duodenums sowie Metastasen im Bereich von Leber oder Leberpforte zum Einsatz. Indikationen fuer die bildgesteuerte perkutane Drainage sind abdominelle Abszesse, weniger haeufig Lymphozelen, Biliome, Urinome, Haematome, Nekrosen sowie Pseudozysten. (orig.)

Modern imaging techniques in patients with multiple myeloma; Moderne Bildgebungsverfahren beim Multiplen Myelom

Energy Technology Data Exchange (ETDEWEB)

Bannas, Peter; Adam, G.; Derlin, T. [Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie; Kroeger, N. [Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany). Klinik und Poliklinik fuer Stammzelltransplantation

2013-01-15

Imaging studies are essential for both diagnosis and initial staging of multiple myeloma, as well as for differentiation from other monoclonal plasma cell diseases. Apart from conventional radiography, a variety of newer imaging modalities including whole-body low-dose-CT, whole-body MRI and 18F-FDG PET/CT may be used for detection of osseous and extraosseous myeloma manifestations. Despite of known limitations such as limited sensitivity and specificity and the inability to detect extraosseous lesions, conventional radiography still remains the gold standard for staging newly diagnosed myeloma, partly due to its wide availability and low costs. Whole-body low-dose CT is increasingly used due to its higher sensitivity for the detection of osseous lesions and its ability to diagnose extraosseous lesions, and is replacing conventional radiography at selected centres. The highest sensitivity for both detection of bone marrow disease and extraosseous lesions can be achieved with whole-body MRI or 18F-FDG PET/CT. Diffuse bone marrow infiltration may be visualized by whole-body MRI with high sensitivity. Whole-body MRI is at least recommended in all patients with normal conventional radiography and in all patients with an apparently solitary plasmacytoma of bone. To obtain the most precise readings, optimized examination protocols and dedicated radiologists and nuclear medicine physicians familiar with the complex and variable morphologies of myeloma lesions are required. (orig.)

Lebensdauer von Stahlseilen beim kombinierten Lauf über Treib- und Ablenkscheiben unterschiedlicher Rillenform

OpenAIRE

Berner, Oliver Roger

2011-01-01

Die Lebensdauer von Stahldrahtseilen in Treibscheibenaufzügen wird von unterschiedlichen Faktoren beeinflusst. Bei allen Anwendungen, bei denen Seile über Rollen laufen, erfahren die Seile eine Zug- und Biegebeanspruchung, die zu einer Materialermüdung und zu einem Verschleiß der Drähte an der Seiloberfläche und im Inneren der Seile führt. Darüber hinaus findet man bei Treibscheibenaufzügen systembedingt weitere anwendungsspezifische Beanspruchungen, die zu einer zusätzlichen Lebensdauerminde...

Status reports on the development and application of acoustic emission analysis. Proceedings; Statusberichte zur Entwicklung und Anwendung der Schallemissionsanalyse. Beitraege

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

. Schallemissionsanalyse beim Gesamtermuedungstest eines Windkraftrotorblattes; 6. Methoden zur Ueberpruefung der Messempfindlichkeit von Schallemissionssensoren im Labor; 7. Schallemissionsanalyse beim Berstversuch an Aluminiumgussgehaeusen; 8. Visualisierung von Schallemissionslokalisierungen; 9. Schwellenunabhaengige und lueckenlose Aufzeichnung von Merkmalen und Wellenformen transienter und kontinuierlicher Schallemission; 10. Charakterisierung von breitbandigen Schallemissionsaufnehmern; 11. Handling grosser Datenmengen in der Schallemissionsanalyse - ein Beitrag zur Algorithmenentwicklung; 12. Akustische Emission und Ultraschall zur Charakterisierung von Rissgeflechten im Salzgestein. Ein Vortrag wurde separat fuer diese Datenbank aufgenommen.

Acute injury of the ankle joint; Akutes Trauma des Sprunggelenks

Energy Technology Data Exchange (ETDEWEB)

Breitenseher, M.J. [Univ. Klinik fuer Radiodiagnostik, Abt. fuer Osteologie und Besondere Klinische Einrichtung Magnet Resonanz, AKH, Wien (Austria)]|[Ludwig-Boltzmann-Institut fuer Radiologisch-Physikalische Tumordiagnostik, Vienna (Austria)

1999-01-01

The diagnosis of lateral collateral ankle ligament trauma is based on patient history, clinical examination, and clinical stress tests. If the clinical stress test is positive, stress radiography could be performed. There is no consensus about the usefulness of stress radiography in acute ankle sprain, particularly about the cut-off talar tilt angle beyond which a two-ligament rupture would be certain, ranging from 5 to 30 . Today MRI is not used for this indication, although it allows, with controlled positioning of the foot and with defined sections, visualization of injured lateral collateral ankle ligaments. In ankle injuries, plain radiographs form the established basis of diagnostic imaging and can provide definitive answers in most cases. CT is used in complex fractures for complete visualization. MRI is the method of choice for several diagnostic problem cases, including occult fractures and post-traumatic avascular necrosis. In tendon injuries, MRI is important if ultrasound is not diagnostic. Generally, for the evaluation of acute ankle injuries, MRI is the most important second-step procedure when radiographs are nondiagnostic. (orig.) [Deutsch] Die Diagnose einer lateralen Bandverletzung beim frischen Sprunggelenkstrauma fusst auf der Anamnese, der klinischen Untersuchung und klinischen Stresstests. Bei positiven klinischen Stresstests kann eine Stressradiographie durchgefuehrt werden. Es gibt keine Uebereinstimmung fuer den Wert der Stressradiographie beim frischen Supinationstrauma des Sprunggelenks, insbesonders fuer den Winkel der Aufklappbarkeit bei einer Zweibandverletzung, der von 5 -30 reicht. Die MRT wird zur Zeit bei dieser Indikation nur in Einzelfaellen benutzt, obwohl sie mit definierter Fusspositionierung und Ausrichtung der Untersuchungsebene eine ausgezeichnete Beurteilung der Sprunggelenksbaende erlaubt. Bei knoecherner Sprunggelenksverletzungen ist die Verwendung des konventionellen Roentgen die etablierte Methode und meist

Reduction of energy consumption and reduction of galvanisation fluid loss by means of innovative galvanisation drums made of novel materials and with novel geomentries. Final report; Senkung des Energieverbrauches und Verringerung der Galvanisierbadverschleppung durch die Entwicklung von innovativen Galvanisiertrommeln aus neuen Werkstoffen mit neuer Geometrie. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Tscherwitschke, R.

2003-09-01

The project intended to develop a galvanizing drum with higher efficiency (30 percent) without inducing limitations, either by reducing the exposure time at identical energy consumption or by permitting a higher coating rate at higher energy consumption. Developments during the last 50 years have been unsatisfactory in this field. (orig.) [German] Ziel des Projektes war, eine Galvanisiertrommel zu entwickeln, die ohne sonstige Einschraenkung eine signifikante Leistungssteigerung erbringt, konkret bei gleichem Energie-Einsatz (V x A) die Expositionszeit beim Galvanisierprozess reduziert oder bei gleichem Energie-Einsatz ein groesseres Warenvolumen mit der gleichen Schichtdicke, galvanisch beschichtet. Angestrebte Effizienzsteierung war 30%. In der gleichen Groessenordnung sollte eine Energieeinsparung einhergehen. In den letzten 50 Jahren gab es nur eine Entwicklung in diese Richtung, die sich aus einer Reihe von Gruenden nicht dauerhaft durchgesetzt hat. (orig.)

La nécropole mérovingienne d’Erstein (Bas-Rhin) : étude des textiles minéralisés au contact des fibules

OpenAIRE

Médard, Fabienne; Rohmer, Pascal; Moulherat, Christophe; Guillaume, Jacques

2008-01-01

Au cours des années 1999 et 2000, des fouilles de sauvetage ont été menées au lieu dit « Beim Limersheimerweg », non loin de la ville d’Erstein (France, Bas-Rhin). Une importante nécropole datée entre le début du VIe et la fin du VIIe siècle après J.-C. a été mise au jour. 239 sépultures au mobilier funéraire très riche ont été découvertes. Alors que les matières organiques d’origine végétale et animale ont été peu préservées, les nombreuses pièces d’armement (épées longues, scramasaxes, cout...

Was ein Wort bedeutet, kann ein Satz nicht sagen: Zur Bedeutung der Terminologiearbeit für die Technische Kommunikation und das Fachtextübersetzen

Directory of Open Access Journals (Sweden)

Klaus-Dirk Schmitz

2010-05-01

Full Text Available Einleitung: Dieser Beitrag geht von einem Zitat des österreichisch-britischen Philosophen Ludwig Wittgenstein aus und bezeiht sich auf seine Aussagen über Wörter und Sätze. Zielsetzung: Analyse und Diskussion der Relevanz von WittgensteinsAussage für die Terminologiearbeit in der Technischen Kommunikation und beim Fachübersetzen. Methode: Kritische Analyse und Betrachtung. Ergebnis: Neben den terminologischen Grundbegriffen Begriff, Benennung und Gegenstand werden vor allem die Definition als Begriffsbeschreibung sowie die Kriterien zur Bildung von Benennungen untersucht. Schlussfolgerung: Das Zitat von Wittgenstein lässt viele Interpretationen zu. Für die Technische Kommunikation und das Fachübersetzen muss aber die Definition (Satz den Begriff hinter der Benennung (Wort erklären. Idealerweise ist aber die Benennung so transparent, dass dadurch schon die Begriffsklärung erfolgt.

The Neustadt-Glewe geothermal project - problems and experience during operation; Das Geothermieprojekt Neustadt-Glewe - Probleme und Erfahrungen mit einer laufenden Anlage

Energy Technology Data Exchange (ETDEWEB)

Menzel, H [Erdwaerme Neustadt-Glewe GmbH (Germany)

1997-12-01

The scope and goals of the project and the principle of the Neustadt-Glewe geothermal system are presented. The system was commissioned in February 1995, so that sufficient performance data and availability information are now available. Problems that occurred are described and analyzed. Preliminary analyses of the consumption-dependent cost and cost distribution provide a basis for statements on the economic efficiency of geothermal projects. (orig.) [Deutsch] Es werden Inhalt und Ziel des Projektes, sowie das Prinzip der Geothermienutzung in Neustadt-Glewe kurz dargestellt. Nachdem die Anlage im Februar 1995 in Betrieb ging, koennen erste Betriebsergebnisse und Zuverlaessigkeitsaussagen gegeben werden. Es werden Probleme beim Betrieb der Anlagen geschildert und analysiert. Erste Analysen fuer die verbrauchsabhaengigen Kosten und die Kostenverteilung bilden die Grundlage fuer Aussagen zur Wirtschaftlichkeit derartiger Projekte. (orig.)

Aspects of numerical modelling in expert practice; Aspekte der numerischen Modellierung in der gutachterlichen Praxis

Energy Technology Data Exchange (ETDEWEB)

Schaedler, G.

1998-01-01

Referring to a relatively restricted field, namely the preparation of expertises in small-scale climatology and air hygiene, the paper wants to give insight into the methods of, and the problems associated with, the numerical modellings used. Frequently occurring tasks are described, the numerical models used are briefly outlined, and some of the problems are discussed which are encountered when using these models. (orig./KW) [Deutsch] Der vorliegende Aufsatz soll am Beispiel eines relativ eng umgrenzten Themenkreises, naemlich der gutachterlichen Taetigkeit im Bereich der kleinraeumigen Klimatologie und Lufthygiene, einen Einblick in die Methoden und Probleme der dabei eingesetzten numerischen Modellierung geben. Zunaechst werden haeufig auftretende Aufgabenstellungen dargestellt, dann die verwendeten numerischen Modelle kurz vorgestellt und schliesslich einige der Probleme angesprochen, die sich beim praktischen Einsatz dieser Modelle stellen. (orig./KW)

Basics of acute stroke treatment; Grundzuege der akuten Schlaganfalltherapie

Energy Technology Data Exchange (ETDEWEB)

Haass, A. [Neurologische Universitaetsklinik Homburg/Saar (Germany)

2005-05-01

Therapie auf einer Normalstation, selbst wenn dort ein spezialisiertes Team taetig ist. In der Akutphase sollen der haeufig angestiegene Blutdruck bis zu systolischen Werten von 200-220 mmHg toleriert und auf keinen Fall zu rasch gesenkt werden. Weitere evidenzbasierte Richtlinien fuer die Basistherapie sind optimale O{sub 2}-Versorgung, Blutzucker nicht hoeher als 100-150 mg% und Koerpertemperaturen ueber 37,5 C mit physikalischen Massnahmen oder medikamentoes senken. Die Therapie des erhoehten intrakraniellen Druckes besteht in der Hochlagerung des Oberkoerpers, der Gabe von Glyzerin, Mannit und/oder Sorbit, mechanischer Beatmung und unter entsprechender Ueberwachung von Trispuffer. Die dekompressive Kraniektomie kommt beim malignen Mediainfarkt und stark raumfordernden Kleinhirninfarkt in Frage. Die Fibrinolyse ist die effektivste Therapie des Hirninfarkts und doppelt so wirksam wie beim Myokardinfarkt. Sie ist im vorderen Kreislauf im 3-h-Zeitfenster zugelassen. Solange noch eine Penumbra durch ein PWI-DWI-Mismatch im MRT nachweisbar ist, kann in spezialisierten Zentren die intraarterielle Lyse bis zu 6 h nach Symptombeginn durchgefuehrt werden. Beim Hirninfarkt im Basilarisstromgebiet ist das Lysezeitfenster deutlich laenger. Die intraarterielle Lyse erfolgt in ueberregionalen Stroke Units mit rtPA oder Urokinase. Die Behandlung der Post-Stroke-Depression und neuropsychologischer Defizite gehoert genauso zur Weiterbehandlung wie die Bekaempfung der Risikofaktoren und Begleiterkrankungen wie Hypertonus, Diabetes mellitus und Herzrythmusstoerungen. (orig.)

Radiological diagnostics of multiple myeloma; Radiologische Diagnostik des multiplen Myeloms

Energy Technology Data Exchange (ETDEWEB)

D' Anastasi, M.; Grandl, S.; Reiser, M.F.; Baur-Melnyk, A. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany)

2014-06-15

Robust and reliable imaging methods are required to estimate the skeletal tumor load in multiple myeloma, as well as for the diagnosis of extraskeletal manifestations. Imaging also plays an essential role in the assessment of fracture risk and of vertebral fractures. The conventional skeletal survey has been the gold standard in the imaging of multiple myeloma for many years. Other modalities which have been investigated and are in use are whole-body computed tomography (WBCT), 18F-fluorodeoxyglucose positron emission tomography computed tomography (FDG PET-CT) and whole-body magnetic resonance imaging (WBMRI). These techniques are able to depict both mineralized bone and the bone marrow with a high sensitivity for myeloma lesions. Several studies have shown that cross-sectional imaging is superior to the skeletal survey in the detection of myeloma lesions and WBMRI has been shown to be significantly more sensitive than WBCT for the detection of focal myeloma lesions as well as for diffuse infiltration. The FDG PET-CT technique has a sensitivity comparable to WBMRI. Due to the higher sensitivity in the detection of myeloma lesions WBCT and WBMRI should replace the skeletal survey. A WBCT should be performed if there is suspicion of multiple myeloma. If no focal lesions are found WBMRI or at least MRI of the spine and pelvis should be additionally performed if available. If WBMRI has been initially performed and focal lesions are present, an additional WBCT may be performed to assess the extent of bone destruction and fracture risk. In cases of monoclonal gammopathy of undetermined significance (MGUS), solitary and smoldering myeloma, a WBMRI, if available, should be performed in addition to WBCT. (orig.) [German] Die Aufgabe der bildgebenden Diagnostik beim multiplen Myelom (MM) ist die zuverlaessige Erfassung der Tumorlast im Skelett sowie auch der extraskelettalen Manifestationen und der assoziierten Komplikationen (z. B. Wirbelkoerperfrakturen, Frakturgefahr

Radiation-induced liver injury mimicking liver metastases on FDG-PET-CT after chemoradiotherapy for esophageal cancer. A retrospective study and literature review

Energy Technology Data Exchange (ETDEWEB)

Voncken, Francine E.M.; Aleman, Berthe M.P. [The Netherlands Cancer Institute - Antoni van Leeuwenhoek, Department of Radiation Oncology, Amsterdam (Netherlands); Dieren, Jolanda M. van [The Netherlands Cancer Institute - Antoni van Leeuwenhoek, Department of Gastroenterology, Amsterdam (Netherlands); Grootscholten, Cecile [The Netherlands Cancer Institute - Antoni van Leeuwenhoek, Department of Internal Medicine, Amsterdam (Netherlands); Lalezari, Ferry [The Netherlands Cancer Institute - Antoni van Leeuwenhoek, Department of Radiology, Amsterdam (Netherlands); Sandick, Johanna W. van [The Netherlands Cancer Institute - Antoni van Leeuwenhoek, Department of Surgery, Amsterdam (Netherlands); Steinberg, Jeffrey D.; Vegt, Erik [The Netherlands Cancer Institute - Antoni van Leeuwenhoek, Department of Nuclear Medicine, Amsterdam (Netherlands)

2018-02-15

For esophageal cancer patients treated with neoadjuvant chemoradiotherapy (nCRT), restaging using F-18-fluorodeoxyglucose (FDG) positron emission tomography computed tomography (PET-CT) following nCRT can detect interval metastases, including liver metastases, in almost 10% of patients. However, in clinical practice, focal FDG liver uptake, unrelated to liver metastases, is observed after chemoradiotherapy. This radiation-induced liver injury (RILI) can potentially lead to overstaging. A systematic search for potential cases of RILI after (chemo)radiotherapy for esophageal cancer was performed in the electronic reports from all PET-CT scans made between 2006 and 2015 in our hospital. Additional data about potential cases were obtained from the electronic medical records. A literature review of RILI was also performed. Of 205 patients undergoing nCRT, 6 cases with localized increased FDG uptake in the caudate or left liver lobe following nCRT for esophageal cancer were identified. None of these patients had signs of liver metastases with additional imaging, during surgery, on biopsy, or during follow-up (range 11-46 months). At our institute, the incidence of RILI after neoadjuvant chemoradiotherapy for esophageal cancer was 3%. In the literature, RILI is described in about 8% of patients at the time of restaging. FDG-avid lesions occur in the high radiation dose area, usually corresponding to the caudate or left liver lobe. FDG accumulation in the caudate or left liver lobe after CRT in the area that received a high radiation dose may be caused by metastases or RILI. Awareness of the pitfall of high FDG uptake in RILI is crucial to avoid misinterpretation and overstaging. (orig.) [German] Nach neoadjuvanter Radiochemotherapie (nCRT) findet man bei ungefaehr 10 % der Patienten mit Oesophaguskarzinom beim Restaging in der F-18-Fluorodeoxyglukose-Positronenemissionscomputertomographie (FDG-PET-CT) Intervallmetastasen, einschliesslich Lebermetastasen. In der klinischen

Hydrogel injection reduces rectal toxicity after radiotherapy for localized prostate cancer

Energy Technology Data Exchange (ETDEWEB)

Pinkawa, Michael; Berneking, Vanessa; Koenig, Liane; Frank, Dilini; Bretgeld, Marilou; Eble, Michael J. [RWTH Aachen University, Department of Radiation Oncology, Aachen (Germany)

2017-01-15

) erhalten hatten, wurde eingeschlossen. Die Anzahl der wegen Beschwerden beim Stuhlgang resultierenden Interventionen in den ersten 2 Jahren nach RT wurde verglichen. Die Patienten wurden prospektiv vor RT, am letzten Tag der RT sowie im Median 2 Monate und 17 Monate nach RT mit einem validierten Fragebogen befragt (Expanded Prostate Cancer Index Composite). Die Basischarakteristika waren in beiden Gruppen vergleichbar. Die Behandlung von Beschwerden beim Stuhlgang (0 vs. 11 %; p < 0,01) und endoskopische Untersuchungen (3 vs. 19 %; p < 0,01) wurden bei Patienten mit Abstandhalter seltener durchgefuehrt. Ueber ein Jahr nach RT aenderten sich die durchschnittlichen Punktwerte fuer die Darmfunktion bei Patienten mit Abstandhalter verglichen mit den Ausgangswerten nicht, im Gegensatz dazu fand sich bei Patienten ohne Abstandhalter ein durchschnittlicher Abfall von 5 Punkten. Bei 0 vs. 12 % trat ein maessiges/grosses Problem durch Beschwerden beim Stuhlgang neu auf (p < 0,01). Statistisch signifikante Unterschiede fanden sich bei den Items ''weicher Stuhlgang'', ''blutiger Stuhlgang'', ''schmerzhafter Stuhlgang'' und ''Haeufigkeit des Stuhlgangs''. Die Injektion eines Abstandhalters ist mit einem signifikanten Vorteil fuer Patienten nach RT des Prostatakarzinoms assoziiert. (orig.)

Swept source optical coherence tomography of objects with arbitrary reflectivity profiles

Science.gov (United States)

Mezgebo, Biniyam; Nagib, Karim; Fernando, Namal; Kordi, Behzad; Sherif, Sherif

2018-03-01

Swept Source optical coherence tomography (SS-OCT) has become a well established imaging modality for both medical and industrial diagnostic applications. A cross-sectional SS-OCT image is obtained by applying an inverse discrete Fourier transform (DFT) to axial interferogram measured in the frequency domain (k-space). Fourier inversion of the obtained interferogram typically produces a potentially overlapping conjugate mirror image, whose overlap could be avoided by restricting the object to have its highest reflectivity at its surface. However, this restriction may not be fulfilled when imaging a very thin object that is placed on a highly reflective surface, or imaging an object containing a contrast agent with high reflectivity. In this paper, we show that oversampling of the SS-OCT signal in k-space would overcome the need for such restriction on the object. Our result is demonstrated using SS-OCT images of Axolotl salamander eggs.

Analytische Betrachtung des Quantisierungsfehlers bei grundlegenden Rechenoperationen der digitalen Signalverarbeitung

Directory of Open Access Journals (Sweden)

W. Schlecker

2005-01-01

Full Text Available Bei der Realisierung digitaler Schaltungen mit einem ASIC oder FPGA kann die Wortbreite der Berechnungen frei gewählt werden. Um die Fläche bzw. die benötigte Hardware zu minimieren, wird versucht, die Berechnungen mit minimaler Wortbreite zu implementieren. Dabei muss jedoch das Quantisierungsrauschen, das durch das Beschränken der Wortbreite entsteht, berücksichtigt werden. Häufig wird hierzu eine worst-case Abschätzung des Fehlers gemacht oder mit Simulationen die benötigte Wortbreite bestimmt. Der vorliegende Beitrag betrachtet die Auswirkungen der Quantisierung analytisch. Dabei wird von gleichverteilten Eingangssignalen ausgegangen. Es wird das Quantisierungsrauschen in Abhängigkeit von der Eingangs- und Ausgangswortbreite bei der Multiplikation und beim Skalarprodukt betrachtet. Die Untersuchungen wurden für Runden und für Abschneiden analytisch durchgeführt und durch Simulation bestätigt.

Monitoring `Renewable resources`. Vegetable oils and other fuels from plants. Third status report; Monitoring `Nachwachsende Rohstoffe`. Pflanzliche Oele und andere Kraftstoffe aus Pflanzen. Dritter Sachstandsbericht

Energy Technology Data Exchange (ETDEWEB)

Roesch, C.

1997-11-01

The present status report `vegetable oils and other fuels from plants` deals with important developments on the utilization of biofuels in spark ignition engines and diesel engines since presentation of the report `growing raw materials` of the Enquete comission `Technikfolgenabschaetzung und -bewertung`. The report deals mainly with rapeseed oil and rape seed oil fatty acid methyl ester produced from this (mentioned short of biodiesel) as well as with bioethanol made from sugar beet and grain. (orig./SR) [Deutsch] Der vorliegende Sachstandsbericht `Pflanzliche Oele und andere Kraftstoffe aus Pflanzen` beschaeftigt sich mit den wichtigsten Entwicklungen beim Einsatz von Biokraftstoffen in Otto- und Dieselmotoren seit Vorlage des Berichts `Nachwachsende Rohstoffe` der Enquete-Kommission `Technikfolgenabschaetzung und -bewertung`. Der Bericht befasst sich schwerpunktmaessig mit Rapsoel und daraus hergestelltem Rapsoelfettsaeuremethylester (kurz Biodiesel genannt) sowie mit aus Zuckerrueben und Getreide erzeugtem Bioethanol. (orig./SR)

Review: Gerald Beck (2013. Sichtbare Soziologie. Visualisierung und soziologische Wissenschaftskommunikation in der Zweiten Moderne

Directory of Open Access Journals (Sweden)

Axel Philipps

2014-01-01

Full Text Available Visualisierungen von Wissen hatten und haben im Kern des Faches Soziologie einen schweren Stand. Gerald BECK nimmt sich daher in seinem Buch "Sichtbare Soziologie" der Thematik an, um die Stellung von Visualisierungen in der Soziologie zu verstehen, damit verbundene Problemfelder zu identifizieren und für visuelle Umsetzungen zu sensibilisieren. Er setzt dazu beim Übergang zur Zweiten Moderne an und betrachtet anhand von neun Fallbeispielen gelungene und weniger gelungene Visualisierungen. Durch die verkürzte Aufarbeitung des Verhältnisses der Soziologie zum Bild bleiben jedoch wichtige Einsichten unberücksichtigt, sodass BECKs Empfehlungen, die Zahl der Visualisierungen und die visuelle Kompetenz zu erhöhen, kaum geeignet sind, die Skepsis in der Soziologie gegenüber Visualisierungen zu überwinden. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1401228

Mykotische Infektionen des Penis

Directory of Open Access Journals (Sweden)

Mayser P

1999-01-01

Full Text Available Die häufigste mykotische Infektion des Penis stellt die Balanitis/Balonoposthitis durch Candida albicans dar. Sie weist eine steigende Inzidenz auf und scheint vornehmlich durch Genitalverkehr übertragen zu werden. Penile Infektionen durch Dermatophyten sind sehr selten, obwohl die Tinea inguinalis zu den häufigeren Erkrankungen zählt. Eine Mitbeteiligung des Penis im Rahmen von Systemmykosen kennzeichnet zumeist ein schwer verlaufende Erkrankung. Ursächlich kann beim immunoinkompetenten Patienten nahezu jeder Erreger in Frage kommen. Biopsie sowie Gewebekultur aus den meist ulzerativen Veränderungen können die Diagnose sichern. Die meisten superfiziellen Infektionen sprechen zufriedenstellend auf eine topische antimykotische Behandlung an, insbesondere wenn Provokationsfaktoren und die Möglichkeit der sexuellen Transmission berücksichtigt werden. Ausgedehnte Infektionen durch Dermatophyten, Hefen und natürlich systemische Infektionen erfordern eine systemische antimykotische Therapie.

Waiting for the Barbarians: Conrad, Kafka, Coetzee

Directory of Open Access Journals (Sweden)

Simona Micali

2017-12-01

Full Text Available The threat of the “Barbarians at the gates”, who bring chaos and death upon civilization, has gradually become one of the thematic obsessions of contemporary imagination. Along the course of the 20th century, the Enemy became less and less the bearer of another culture, and more and more the carrier of a Nonculture or an Anticulture. Such evolution is particularly evident in popular imagination, in all the comics and blockbuster films which stage the final battle between the heros of (white, Western civilization against a dreadful army of barbarian enemies. The article focus on three works – Heart of Darkness by Joseph Conrad, Beim Bau der chinesischen Mauer by Franz Kafka, Waiting for the Barbarians by J.M. Coetzee – which investigate on this mechanism from within, highlighting its ideological implications and its tragic potential.

The Ecology of Urban Tectonics

DEFF Research Database (Denmark)

Beim, Anne; Hvejsel, Marie Frier

2016-01-01

This paper is related to previous research by the authors that examine the phenomenon of tectonics as architectural design theory and method. These studies have shown that the notion of tectonics at large is associated with exclusive architecture, and that, as a profession architects have...... to develop methods for applying tectonic knowledge extracted from significant existing examples for developing future practical methods (Frampton 2002: 81). The specific intention of this paper is to push the understanding of tectonics further, into the scale of the urban context and thereby to discuss...... using Hansen’s work as a case study. (Beim & Madsen (ed.) 2014) Methodologically this has been done by applying the notion of ‘urban tectonics’ inspired by the work of Eduard F. Sekler, as a critical lens. (Sekler 1964, Sekler 1965) Through this lens we study how Hansen was able to treat culture...

Defecography - analysis of qualitative findings; Evakuationsproktographie - Analyse qualitativer Befunde

Energy Technology Data Exchange (ETDEWEB)

Schott, U. [Tuebingen Univ. (Germany). Abt. Radiologische Diagnostik; Braunschweig, R. [Tuebingen Univ. (Germany). Abt. Radiologische Diagnostik; Claussen, C.D. [Tuebingen Univ. (Germany). Abt. Radiologische Diagnostik

1994-12-31

The defectography is an examination of the anorectal function in defecatory disorder. The defecography has a diagnostic impact on disease, which only emerge during defecation as intussusception, enterocele, prolapse or sphincter dysfunction. Other findings as rectocele or descending pelvic floor are ambiguous concerning clinical relevance. The interpretation of defecography should include patient`s history and clinical findings and - if available - endoscopic and manometric findings. (orig.) [Deutsch] Die Evakuationsproktographie ist eine Funktionsuntersuchung des Anorektums beim Symptomenkreis der Defaekationsbeschwerden. Die Domaene der Evakuationsproktographie sind Erkrankungen, die sich nur unter den Provokationsbedingungen der Defaekation manifestieren, wie die Intussuzeption, Enterocele, temporaerer Wandprolaps oder Anismus. Andere Befunde wie eine Rektocele oder Beckenbodenschwaeche sind in ihrer klinischen Relevanz umstritten. Die Bewertung der Evakuationsproktographie im Rahmen des Beschwerdebildes des Patienten sollte in Zusammenschau von vollstaendiger anamnestischer und klinischer Information und - sofern vorhanden - Befunden von Rektoskopie und Rektummanometrie erfolgen. (orig.)

Methods for safe and economical design of components of ABS/ABR braking systems in terms of operating stability; Methodik zur sicheren und wirtschaftlichen betriebsfesten Auslegung von Komponenten in ABS/ASR-Bremssystemen

Energy Technology Data Exchange (ETDEWEB)

Bacher-Hoechst, M. [Robert Bosch GmbH, Technisches Zentrum Schwieberdingen (Germany); Sonsino, C.M. [Fraunhofer-Institut fuer Betriebsfestigkeit (LBF), Darmstadt (Germany)

1997-05-01

The combination of hardware-in-the-loop simulators with stress calculation in terms of operating stability at Robert Bosch GmbH, as well as experience gathered at LBF Darmstadt with component in terms of operating stability, result in optimized design of hydraulic units for antilock systems (ABS) and acceleration skid control systems (ASC). Thus, both safety demands and economic demands are met. (orig./AKF) [Deutsch] Die kombinierte Anwendung von Hardware-In-The-Loop-Simulatoren mit betriebsfestigkeitsgerechter Belastungserfassung bei der Robert Bosch GmbH und die beim LBF Darmstadt vorliegenden Erfahrungen bei der betriebsfesten Bauteilauslegung fuehren zu einer optimierten Auslegung und Absicherung von Hydraulikaggregaten fuer Antiblockier- und Antriebsschlupfregelungssyteme (ABS,ASR). Die wesentlichen Schritte dieses Vorgehens wurden gezeigt. Auf diese Weise ist es moeglich, den Sicherheitsanforderungen derartiger Bauteile einerseits und den wirtschaftlich-technischen Rahmenbedingungen andererseits zu entsprechen. (orig./AKF)

Regulation of proximal-distal intercalation during limb regeneration in the axolotl (Ambystoma mexicanum).

Science.gov (United States)

Satoh, Akira; Cummings, Gillian M C; Bryant, Susan V; Gardiner, David M

2010-12-01

Intercalation is the process whereby cells located at the boundary of a wound interact to stimulate proliferation and the restoration of the structures between the boundaries that were lost during wounding. Thus, intercalation is widely considered to be the mechanism of regeneration. When a salamander limb is amputated, the entire cascade of regeneration events is activated, and the missing limb segments and their boundaries (joints) as well as the structures within each segment are regenerated. Therefore, in an amputated limb it is not possible to distinguish between intersegmental regeneration (formation of new segments/joints) and intrasegmental regeneration (formation of structures within a given segment), and it is not possible to study the differential regulation of these two processes. We have used two models for regeneration that allow us to study these two processes independently, and report that inter- and intrasegmental regeneration are different processes regulated by different signaling pathways. New limb segments/joints can be regenerated from cells that dedifferentiate to form blastema cells in response to signaling that is mediated in part by fibroblast growth factor. © 2010 The Authors. Journal compilation © 2010 Japanese Society of Developmental Biologists.

Characterization of glycosaminoglycans during tooth development and mineralization in the axolotl, Ambystoma mexicanum.

Science.gov (United States)

Wistuba, J; Völker, W; Ehmcke, J; Clemen, G

2003-10-01

Glycosaminoglycans (GAGs) involved in the formation of the teeth of Ambystoma mexicanum were located and characterized with the cuprolinic blue (CB) staining method and transmission electron microscopy (TEM). Glycosaminoglycan-cuprolinic blue precipitates (GAGCB) were found in different compartments of the mineralizing tissue. Various populations of elongated GAGCB could be discriminated both according to their size and their preferential distribution in the extracellular matrix (ECM). GAGCB populations that differ in their composition could be attributed not only to the compartments of the ECM but also to different zones and to different tooth types (early-larval and transformed). Larger precipitates were only observed within the dentine matrix of the shaft of the early-larval tooth. The composition of the populations differed significantly between the regions of the transformed tooth: pedicel, shaft and dividing zone. In later stages of tooth formation, small-sized GAGCBs were seen as intracellular deposits in the ameloblasts. It is concluded that the composition of GAGCB populations seems to play a role in the mineralization processes during tooth development in A. mexicanum and influence qualitative characteristics of the mineral in different tooth types and zones, and it is suggested that GAGs might be resorbed by the enamel epithelium during the late phase of enamel formation.

MRI for troubleshooting detection of prostate cancer; MRT zur Problemloesung beim Nachweis des Prostatakarzinoms

Energy Technology Data Exchange (ETDEWEB)

Beyersdorff, D.; Hamm, B. [Universitaetsmedizin Berlin, Charite Mitte (Germany)

2005-06-01

Prostate cancer is the most common malignancy in males. Men aged 50 and older are recommended to undergo an annual digital rectal examination (DRE) and determination of prostate-specific antigen (PSA) in serum for early detection. However, prostate biopsies guided by transrectal ultrasound (TRUS) come up negative for cancer in many patients despite having PSA levels above 4 ng/ml. T2-weighted Magnetic Resonance Imaging (MRI) is able to represent the prostate including the surrounding anatomy and depict suspicious areas of low intensity within a high-intensity peripheral zone. MRI has a higher sensitivity for detecting prostate carcinomas than DRE and TRUS in patients having an elevated PSA value and a negative core biopsy. However, its specificity is poor since other abnormalities such as prostatic intraepithelial neoplasia (PIN), prostatitis, scars, or haemmorrhage have a similar MRI appearance. The use of additional techniques such as MR spectroscopy and contrast-enhanced dynamic MRI improves sensitivity, but in particular it improves the specificity of tumor detection. Newly developed biopsy devices enable the performance of targeted biopsies in areas that appear suspicious in the MRI. (orig.)

Neuro-MRI-findings in patients with primary panhypopituitarism; Neuro-MR-Befunde beim primaeren Panhypopituitarismus

Energy Technology Data Exchange (ETDEWEB)

Fellner, F. [Erlangen-Nuernberg Univ., Erlangen (Germany). Inst. fuer Diagnostische Radiologie]|[Oberoesterreichische Landesnervenklinik Wagner Jauregg, Linz (Austria). Inst. fuer Neuroradiologie; Triebe, S.; Baum, U.; Schmitt, R.; Flottemesch, J.; Bautz, W. [Erlangen-Nuernberg Univ., Erlangen (Germany). Inst. fuer Diagnostische Radiologie; Hensen, J. [Erlangen-Nuernberg Univ., Erlangen (Germany). Abt. fuer Endokrinologie und Stoffwechsel

1998-12-31

We report a case of congenital panhypopituitarism. MR imaging of the brain revealed a hypoplastic adenohypophysis and a hypoplastic pituitary stalk which was interrupted in its superior segment. An ectopic neurohypophysis was found located in the area of the hypothalamus (``hypothalamic hot spot``). The ectopic neurohypophysis showed strong enhancement after intravenous application of Gd-DTPA. MR imaging of the hypothalamic-hypophyseal axis is well suited for the differentiation between congenital and acquired forms of panhypopituitarism in clinically uncertain cases. (orig.) [Deutsch] Wir berichten ueber einen Patienten mit kongenitalem Panhypopituitarismus. Die MRT des Zerebrums zeigte eine hypoplastische Adenohypophyse sowie ein hypoplastisches Infundibulum hypophysis. Es fand sich eine ektope Neurohypophyse im Areal des Hypothalamus (`hypothalamic hot spot`). Die ektope Neurohypophyse zeigte nach Gadoliniumgabe eine kraeftige Kontrastmittelanreicherung. Die MRT der hypothalamisch-hypophysaeren Achse eignet sich somit in klinisch unklaren Faellen fuer die Differentialdiagnostik zwischen angeborenen und erworbenen Formen des Panhypopituitarismus. (orig.)

The clinical use of mammography in the male; Klinische Relevanz der Mammographie beim Mann

Energy Technology Data Exchange (ETDEWEB)

Merkle, E [Ulm Univ. (Germany). Abt. Radiologie; Mueller, M [Ulm Univ. (Germany). Abt. Radiologie; Vogel, J [Ulm Univ. (Germany). Abt. Radiologie; Klatt, S [Ulm Univ. (Germany). Abt. Innere Medizin I; Goerich, J [Ulm Univ. (Germany). Abt. Radiologie; Berger, H G [Ulm Univ. (Germany). Allgemeinchirurgische Abt.; Brambs, H J [Ulm Univ. (Germany). Abt. Radiologie

1996-01-01

During a period of four years 104 mammograms were performed in 89 men. Mastectomies were carried out on 23 men (group 1). 66 patients (group 2) were followed up clinically and in 15 patients serial mammograms were obtained. In group 1 there were 5 patients with bilateral gynaecomastia, 9 with unilateral gynaecomastia and two with pseudogynaecomastia and there were 7 patients with malignancies. In group 2 there were 46 patients with bilateral gynaecomastia and 10 patients with unilateral gynaecomastia. Pseudogynaecomastia was found in 25 patients. There were 7 malignancies, of which 5 had been suspected clinically and one had been diagnosed as gynaecomastia by mammography. Two carcinomas in situ were missed clinically and also by mammography. When malignancy is not suspected on clinical grounds the first examination should be sonography. Where, however, malignancy is suspected, and for follow-up, mammography retains its primary position. (orig./MG) [Deutsch] In einem 4-Jahres-Zeitraum wurden bei 89 Maennern insgesamt 104 Mammogramme angefertigt. 23 Maenner (=Gruppe 1) wurden mastektomiert. 66 Patienten (=Gruppe 2) wurden klinisch und zum Teil mammographisch kontrolliert. Alle Mammogramme wurden in Unkenntnis des klinischen Befundes retrospektiv ausgewertet und, wenn moeglich, dem histologischen Ergebnis gegenuebergestellt. In der Gruppe 1 fand sich eine beidseitige Gynaekomastie in 5/23 Faellen, eine einseitige Form in 9/23 Faellen, eine Pseudogynaekomastie in 2/23 Faellen und ein Malignom in 7/23 Faellen. In Gruppe 2 ergab sich eine beidseitige Gynaekomastie in 46/81 Faellen gegenueber einer einseitigen Form in 10/81 Faellen. Eine Pseudogynaekomastie fand sich in 25/81 Faellen. Von 7 Malignomen waren 5 klinisch suspekt, wobei eines mammographisch als Gynaekomastie imponierte. Zwei In-situ-Karzinome waren sowohl mammographisch als auch klinisch okkult. Klinisch nicht malignomsuspekte Befunde sollten primaer der Mammasonographie zugefuehrt werden. Bei Malignomverdacht und in der Tumornachsorge hingegen hat die Mammographie auch weiterhin ihren festen Platz. (orig./MG)

Rekonstruktion mit Netz beim komplexen Prolaps der Frau: Was hilft es der Patientin wirklich?

Directory of Open Access Journals (Sweden)

Hierl J

2010-01-01

Full Text Available Einleitung: Der komplexe Genitaldeszensus der Frau geht oftmals mit einer deutlichen Einschränkung der Lebensqualität (LQ einher. Dennoch ist der Endpunkt der meisten klinischen Analysen rein anatomischer und funktioneller Natur. In der vorliegenden Untersuchung wurden die Einflüsse der operativen Rekonstruktion mit einem Netz prospektiv auf die LQ evaluiert. Patienten und Methoden: Bei insgesamt 111 Patientinnen mit Deszensus erfolgte zwischen 08/2005 und 12/2007 eine operative Versorgung mittels vaginaler Netzeinlage (anteriorer bzw. kompletter Mesh-Repair. Die LQ wurde prospektiv prä- und postoperativ anhand standardisierter LQ-Fragebögen erfasst. Ergebnisse: Präoperativ zeigte sich bei den Patientinnen eine signifikant reduzierte LQ gegenüber einem Normalkollektiv (p 0,01. Bei 7 % der Patientinnen mit anteriorem, und bei 11 % mit komplettem Mesh-Repair lag postoperativ kein adäquates klinisches Ergebnis vor. In diesem Kollektiv zeigte sich kein signifikanter Unterschied in den LQ-Tests prä- und postoperativ. Bei gutem postoperativem Ergebnis zeigte sich in der Gruppe mit anteriorer Netzeinlage lediglich bei 45 % (p = 0,021, bei kompletter Netzeinlage nur bei 31 % (p = 0,041 eine signifikant verbesserte LQ. Bei kleiner Fallzahl und kurzem Nachbeobachtungszeitraum kann eine gültige Aussage bezüglich der LQ nach Deszensuschirurgie mit Netzeinlage jedoch noch nicht getroffen werden.

Procedure and accuracy in the Eurotunnel breakthrough. Vorgehensweise und Genauigkeit beim Durchschlag des Eurotunnels

Energy Technology Data Exchange (ETDEWEB)

Korittke, N. (DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany, F.R.). Inst. fuer Lagerstaette und Vermessung (ILV))

1991-02-14

After a construction time of about 2.5 years the first link was made in the Eurotunnel between France and England, viz. the service tunnel, on 1 December 1990. Thanks to the accurate Gyromat measurements of the Institute for Mineral Deposits and Surveying of the Deutsche Montan Technologie (DMT) a transverse deviation of only 361 mm, a longitudinal deviation of 69 mm and a vertical deviation of 58 mm were determined in the breakthrough of the 22.3 and 15.6 km long tunnel sections. (orig.).

Cardiac computed tomography in patients with acute coronary syndrome; Kardiale CT beim akuten Koronarsyndrom

Energy Technology Data Exchange (ETDEWEB)

Schlett, C.L. [Universitaetsklinikum, Heidelberg (Germany). Abt. fuer Diagnostische und Interventionelle Radiologie; Alkadhi, H. [Universitaetsspital, Zuerich (Switzerland); Bamberg, F. [Universitaetsklinikum, Tuebingen (Germany). Diagnostische und Interventionelle Radiologie

2014-09-15

Currently, cardiac computed tomography (CT) is increasingly being implemented into clinical algorithms, primarily due to substantial technical advances over the last decade. Its use in the setting of suspected acute coronary syndrome is of particular relevance, given the high degree of accumulating scientific evidence of improving patient outcomes. Performing cardiac CT requires specific knowledge on the available scan acquisitions and patient preparation. Also, expertise is required in order to interpret the coronary and extra-coronary findings adequately. The present article provides an overview of the different aspects on the use of cardiac CT in the setting of acute coronary syndrome.

Gefuge und Eigenschaften - Modellierung der Keimbildungs- und Wachstumskinetik der Verbindungsschicht beim Nitrieren von Reineisen

DEFF Research Database (Denmark)

Somers, Marcel A.J.; Friehling, Peter B.

2002-01-01

to explain the accellerating effect of an oxidizing pretreatment on the nucleation on iron nitrides. A model was developed for describing growth of a double layer, which consists of epsilon-Fe2N1-z at the surface und gamma’-Fe4N1-x at the substrate. The model takes the dynamic state at the surface...... into account, and was fitted to experimental data for double layer growth....

Neoadjuvant chemoradiation therapy with gemcitabine/cisplatin and surgery versus immediate surgery in resectable pancreatic cancer. Results of the first prospective randomized phase II trial

Energy Technology Data Exchange (ETDEWEB)

Golcher, Henriette; Merkel, Susanne; Hohenberger, Werner [University Hospital Erlangen, Department of Surgery, Erlangen (Germany); Brunner, Thomas B. [University Hospital Erlangen, Department of Radiation Oncology, Erlangen (Germany); University Hospital Freiburg, Department of Radiation Oncology, Freiburg (Germany); Witzigmann, Helmut [University Hospital Leipzig, Department of Surgery, Leipzig (Germany); Hospital Dresden-Friedrichstadt, General Surgery, Dresden (Germany); Marti, Lukas [Hospital of Kanton St. Gallen, General Surgery, St. Gallen (Switzerland); Bechstein, Wolf-Otto [University Hospital Frankfurt, Department of Surgery, Frankfurt/Main (Germany); Bruns, Christiane [University Hospital Munich, Department of Surgery - Hospital Campus Grosshadern, Munich (Germany); University Hospital Magdeburg, Department of Surgery, Magdeburg (Germany); Jungnickel, Henry [Hospital Dresden-Friedrichstadt, General Surgery, Dresden (Germany); Schreiber, Stefan [University Hospital Leipzig, Department of Surgery, Leipzig (Germany); Grabenbauer, Gerhard G. [University Hospital Erlangen, Department of Radiation Oncology, Erlangen (Germany); Hospital Coburg, Department of Radiation Oncology, Coburg (Germany); Meyer, Thomas [University Hospital Erlangen, Department of Surgery, Erlangen (Germany); Hospital Ansbach, General Surgery, Ansbach (Germany); Fietkau, Rainer [University Hospital Erlangen, Department of Radiation Oncology, Erlangen (Germany)

2014-09-25

In nonrandomized trials, neoadjuvant treatment was reported to prolong survival in patients with pancreatic cancer. As neoadjuvant chemoradiation is established for the treatment of rectal cancer we examined the value of neoadjuvant chemoradiotherapy in pancreatic cancer in a randomized phase II trial. Radiological staging defining resectability was basic information prior to randomization in contrast to adjuvant therapy trials resting on pathological staging. Patients with resectable adenocarcinoma of the pancreatic head were randomized to primary surgery (Arm A) or neoadjuvant chemoradiotherapy followed by surgery (Arm B), which was followed by adjuvant chemotherapy in both arms. A total of 254 patients were required to detect a 4.33-month improvement in median overall survival (mOS). The trial was stopped after 73 patients; 66 patients were eligible for analysis. Twenty nine of 33 allocated patients received chemoradiotherapy. Radiotherapy was completed in all patients. Chemotherapy was changed in 3 patients due to toxicity. Tumor resection was performed in 23 vs. 19 patients (A vs. B). The R0 resection rate was 48 % (A) and 52 % (B, P = 0.81) and (y)pN0 was 30 % (A) vs. 39 % (B, P = 0.44), respectively. Postoperative complications were comparable in both groups. mOS was 14.4 vs. 17.4 months (A vs. B; intention-to-treat analysis; P = 0.96). After tumor resection, mOS was 18.9 vs. 25.0 months (A vs. B; P = 0.79). This worldwide first randomized trial for neoadjuvant chemoradiotherapy in pancreatic cancer showed that neoadjuvant chemoradiation is safe with respect to toxicity, perioperative morbidity, and mortality. Nevertheless, the trial was terminated early due to slow recruiting and the results were not significant. ISRCTN78805636; NCT00335543. (orig.) [German] Mehrere nichtrandomisierte Studien zeigten, dass eine neoadjuvante Therapie das Ueberleben bei Patienten mit Pankreaskarzinom verlaengert. Beim lokal fortgeschrittenen Rektumkarzinom gehoert die

Expression of a novel cardiac-specific tropomyosin isoform in humans

International Nuclear Information System (INIS)

Denz, Christopher R.; Narshi, Aruna; Zajdel, Robert W.; Dube, Dipak K.

2004-01-01

Tropomyosins are a family of actin binding proteins encoded by a group of highly conserved genes. Humans have four tropomyosin-encoding genes: TPM1, TPM2, TPM3, and TPM4, each of which is known to generate multiple isoforms by alternative splicing, promoters, and 3 ' end processing. TPM1 is the most versatile and encodes a variety of tissue specific isoforms. The TPM1 isoform specific to striated muscle, designated TPM1α, consists of 10 exons: 1a, 2b, 3, 4, 5, 6b, 7, 8, and 9a/b. In this study, using RT-PCR with adult and fetal human RNAs, we present evidence for the expression of a novel isoform of the TPM1 gene that is specifically expressed in cardiac tissues. The new isoform is designated TPM1κ and contains exon 2a instead of 2b. Ectopic expression of human GFP.TPM1κ fusion protein can promote myofibrillogenesis in cardiac mutant axolotl hearts that are lacking in tropomyosin

The scarless heart and the MRL mouse.

Science.gov (United States)

Heber-Katz, Ellen; Leferovich, John; Bedelbaeva, Khamilia; Gourevitch, Dmitri; Clark, Lise

2004-05-29

The ability to regenerate tissues and limbs in its most robust form is seen in many non-mammalian species. The serendipitous discovery that the MRL mouse has a profound capacity for regeneration in some ways rivalling the classic newt and axolotl species raises the possibility that humans, too, may have an innate regenerative ability. The adult MRL mouse regrows cartilage, skin, hair follicles and myocardium with near perfect fidelity and without scarring. This is seen in the ability to close through-and-through ear holes, which are generally used for lifelong identification of mice, and the anatomic and functional recovery of myocardium after a severe cryo-injury. We present histological, biochemical and genetic data indicating that the enhanced breakdown of scar-like tissue may be an underlying factor in the MRL regenerative response. Studies as to the source of the cells in the regenerating MRL tissue are discussed. Such studies appear to support multiple mechanisms for cell replacement.

Functional-anatomic evaluation of dilated uropathies in children using combined MR-nephrography and MR-urography compared to renal scintigraphy; Funktionell-anatomische Diagnostik dilatierter Uropathien bei Kindern mit kombinierter MR-Nephrographie und MR-Urographie im Vergleich zur renalen Isotopennephrographie

Energy Technology Data Exchange (ETDEWEB)

Reither, M. [Abt. fuer bildgebende Diagnostik am Kinderkrankenhaus Park Schoenfeld, Kassel (Germany); Tuerkay, S. [GE Medical Systems Deutschland GmbH, Solingen (Germany)

2004-02-01

Purpose: to evaluate MR-tomographic assessment of split renal function and degree of obstruction compared to diuretic renal scintigraphy, and pathoanatomic imaging of the urinary tract as all in one exam. Patients and methods: in a prospective study 62 children, aged 1 month to 9.5 years, mean 2.8 years, underwent diuretic renal scintigraphy and dynamic MR-nephrography at the same day except for 7 patients with a time interval of 1 day. In all patients we did T2w (water-technique) MR-urography additionally. Results: comparing spilt renal function we found a very close correlation in 54 out of 62 patients (correlation coefficient = 0.95). Due to technical failures 8 cases couldn't be calculated. Comparing degrees of obstruction there was an agreement in 57 out of 62 patients, 3 studies were gradually over-, 2 underestimated. All but one morphologic diagnoses in advance obtained by ultrasound and completed by other imaging modalities later on were confirmed MR-urographically. Though correctly imaged the functionless upper moiety in a renal duplication with ureterocele was misinterpreted at a first glance. (orig.) [German] Ziel: Es sollte geprueft werden, ob die Berechnung der seitengetrennten Nierenfunktion, die Bestimmung des Obstruktionsgrades und die pathoanatomische Darstellung des Harntraktes im Vergleich zur Diurese-Szintigraphie in einem Untersuchungsgang MR-tomographisch zuverlaessig moeglich ist. Patienten und Methode: In einer prospektiven Studie wurden bei 62 Kindern im Alter von 1 Monat bis 9,5 Jahren, Mittelwert 2,8 Jahre, ein Diurese-Szintigramm und eine dynamische MR-Nephrographie am gleichen Tag durchgefuehrt; lediglich bei 7 Patienten lag 1 Tag zwischen beiden Untersuchungen. Alle Patienten erhielten zusaetzlich eine T2w-MR-Urographie in ''Wasserbild''-Technik. Ergebnisse: Beim Vergleich der seitengetrennten Nierenfunktion fand sich eine sehr enge Korrelation bei 54 von insgesamt 62 Patienten (Korrelationskoeffizient = 0

Microbial reactions in coal and coal relevant structures. Part project: fungal and enzymatic depolarisation of brown coal for the production of low-molecular compounds. Interim report; Mikrobielle Umsetzung an Kohle und kohlenrelevanten Strukturen. Teilvorhaben: Pilzliche und enzymatische Depolymerisation von Braunkohle zur Gewinnung niedermolekularer Verbindungen. Zwischenbericht (Berichtszeitraum 01.01.1998 - 31.12.1998)

Energy Technology Data Exchange (ETDEWEB)

Ziegenhagen, D.; Bublitz, F.; Sorge, S.; Ullrich, R.; Hofrichter, M.; Fritsche, W.

1999-04-29

optimiert, dass maximale Ausbeuten an niedermolekularen Produkten erzielt werden. Im Mittelpunkt der im Berichtzeitraum durchgefuehrten Versuche standen die Suche nach neuartigen, ligninolytisch wirkenden Organismen, die Gewinnung ligninolytischer Enzyme, deren Immobilisierung an natuerlichen Traegersubstanzen sowie die weitere Untersuchung des Wirkspektrums der MnP. Der Einsatz unterschiedlicher Modellsubstrate sollte Aufschluss ueber die durch MnP spaltbaren Bindungstypen und moegliche Reaktionsprodukte geben. Hierbei wurden sowohl freie als auch an Kieselgel als Traeger fixierte Substrate eingesetzt. Ausgangspunkt beim Einsatz traegerfixierter Modellsubstrate waren Ueberlegungen, beim Umsaetzungen mit dem Pilzmycel zwischen intra- und extrazellulaeren Reaktionen unterscheiden zu koennen. (orig.)

Possible emissions from electricity generation from geothermal energy; Moegliche Emissionen bei der Stromerzeugung aus Geothermie

Energy Technology Data Exchange (ETDEWEB)

Heberle, Florian; Bruggemann, Dieter [Bayreuth Univ. (Germany). Lehrstuhl fuer Technische Thermodynamik und Transportprozesse (LTTT)

2013-03-15

Electricity from geothermal energy in the low temperature range can be efficiently recovered if power plant processes are used with organic working fluids. It is inevitable that a small part of the sometimes harmful fluids leaking from the plant - a conflict in the development of climate-friendly renewable energy actually. A short report of the Centre for Energy Technology at the University of Bayreuth, on behalf of UBA quantifies the emissions of fluorinated hydrocarbons for different development scenarios and emission rates. [German] Strom aus Erdwaerme im Niedertemperaturbereich kann effizient gewonnen werden, wenn Kraftwerksprozesse mit organischen Arbeitsmedien einsetzt werden. Dabei ist es nicht zu vermeiden, dass ein kleiner Teil der mitunter klimaschaedlichen Fluide, aus den Anlagen entweicht - ein Zielkonflikt beim Ausbau der eigentlich klimaschonenden erneuerbaren Energie. Ein Kurzgutachten des Zentrums fuer Energietechnik der Universitaet Bayreuth im Auftrag des UBA quantifiziert die Emissionen fluorierter Kohlenwasserstoffe fuer verschiedene Ausbauszenarien und Emissionsraten.

Cooperative project for energy-oriented modernisation of industrial buildings - coordination results; Projektverbund zur energiegerechten Sanierung industriell errichteter Gebaeude - Ergebnisse der Koordination

Energy Technology Data Exchange (ETDEWEB)

Kerschberger, A. [Assmann Beraten und Planen GmbH, Stuttgart (Germany)

1997-12-31

The cooperative project concept of the federal ministry of science and technology is discussed. Coordination activities as well as pilot projects and comparative projects are described. Results obtained so far are reported in detail; heat energy conservation potentials as substantiated by means of measurements are shown in tabulated form. Further indicated in tabulated form are the redevelopment costs per residential unit, the payback period of the entire project, and a comparison of reduced heating costs with increased basic rent for apportioning the costs of modernization. (MSK) [Deutsch] Die Konzeption des Projektverbundes des BMBF wird naeher erlaeutert. Die Aktivitaeten der Koordination und die Versuchs-und Vergleichsbauvorhaben werden beschrieben. Die bisherigen Ergebnisse werden detailliert geschildert und die messbeim Heizenergieverbrauch sind tabellarisch aufgezeigt. Ebenfalls in Tabellen dargestellt sind die Sanierungskosten pro Wohnung, die Amortisationszeiten der Gesamtmass

Die Gralssuche als Sauftour: mittelalterliche Erzählstrukturen in Bernard Leonettis parodistischem Fantasy-Thriller "La Quête brestoise" (2007

Directory of Open Access Journals (Sweden)

Anna Isabell Wörsdörfer

2016-06-01

Full Text Available Der Artikel untersucht die narrativen Parallelen zwischen roman courtois und phantastischem Thriller anhand von Bernard Leonettis „polar arthurien“ La Quête brestoise. Dabei rückt das Hauptmotiv der (Grals-Queste in den Vordergrund, das im mittelalterlichen Roman als ritterliche aventure und im Kriminalroman als actiongeladene Suche jeweils den strukturgebenden Handlungsrahmen darstellt und aufgrund des Kontrasts zwischen der früheren Lebenswelt des Protagonisten Chevalier und dem modernen Brest zahlreiche parodistische Züge erhält. Eine wichtige Rolle in der Analyse spielt ferner die Raum-Zeit-Struktur, die mit Bachtin als wunderbare Welt, in der die Zeit des Abenteuers vorherrscht, beschrieben werden kann und demnach derjenigen des höfischen Romans ähnelt: Beim letzten Gefecht, welches auf einer Yacht ausgetragen wird, die im Inneren eine Steingrotte birgt, scheint die Zeit stillzustehen und eigenen – phantastischen – Gesetzen zu unterliegen.

Threshold limit values, test values and sanitation values for soil sanitation; Richt-, Pruef- und Sanierungswerte fuer den Bodenschutz

Energy Technology Data Exchange (ETDEWEB)

Karlaganis, G.; Dettwiler, J. [Bundesamt fuer Umwelt, Wald und Landschaft (BUWAL), Bern (Switzerland). Abt. Stoffe, Boden, Biotechnologie

1998-09-01

Soils, the basis for human, plant and animal life, are exposed to quantitative and qualitative deterioration. Quantitative deterioration refers to paving of ground but also to erosion and soil destruction. There are new regulations for physical protection of soil which refer to soil erosion, compacting and handling of soil during building construction. (orig.) [Deutsch] Boden als natuerliche Lebensgrundlage fuer Mensch, Tiere und Pflanzen ist quantitativen und qualitativen Beeintraechtigungen ausgesetzt. Als quantitative Beeintraechtigung gilt jede Art von Verminderungen der Boeden durch Bauten und Anlagen, aber auch durch Erosion oder Bodenschwund. Erlassen worden sind nun neue Bestimmungen fuer drei Bereiche des physikalischen Bodenschutzes, naemlich fuer die Bodenerosion, die Bodenverdichtung und fuer den Umgang mit dem Boden vor allem beim Bauen. Die Verordnung vom 1. Juli 1998 ueber Belastungen des Bodens (VBBo`98) erhaelt neu drei Arten von Beurteilungs- bzw. Massnahmewerten, naemlich Richtwerte, Sanierungswerte und Pruefwerte. (orig./ABI)

Die Bedeutung der aktuellen Nierentumorklassifikation für Diagnostik und Therapie

Directory of Open Access Journals (Sweden)

Moch H

2008-01-01

Full Text Available In den letzten Jahren erweiterte sich das Verständnis zur Histogenese von Nierentumoren durch neue molekulare Erkenntnisse erheblich. Damit wurde es möglich, eine Klassifikation der Nierentumoren auf der Basis von molekularen Veränderungen vorzunehmen. Daneben wurden neue Tumortypen identifiziert, deren Kenntnis erheblichen Einfluss auf die Auswahl der Behandlungsstrategien haben kann. Bei zystischen Nierentumoren gibt es zum Beispiel neben Tumoren mit sehr guter Prognose auch hochmaligne Tumoren. Die charakteristischen molekularen Veränderungen sind einerseits für die Klassifikation der verschiedenen Nierentumoren relevant, andererseits können sie auch innerhalb der klarzelligen Nierenzellkarzinome ein potenzielles Ansprechen auf neue Medikamente vorhersagen. Die Kenntnis der molekularen Zielstrukturen bei Nierenkarzinomen ist die Grundlage für neue Therapien, die gegen spezifische Strukturen gerichtet sind. HIF- α-responsive Gene, z. B. VEGF, PDGF, TGFα, EGFR und Ca IX spielen dabei eine zentrale Rolle beim klarzelligen Nierenkarzinom.

Small water courses for electric power generation; Mit wenig Wasser zum Fliessen bringen

Energy Technology Data Exchange (ETDEWEB)

Ossberger, K.F.; Wirth, D. [Ossberger Turbinenfabrik GmbH und Co, Weissenburg (Germany)

1997-12-31

In principle, no one nowadays doubts the usefulness of small hydroelectric installations. Hydro power is a renewable energy source. Contrary to oil, gas or coal, the energy source is not consumed. Hydroelectric power generation neither gives rise to atmospheric pollution nor does it cause residual products; it is environment-friendly. Moreover, the energy used is a native one. These arguments no doubt advocate the broadest possible use of hydro power, especially also in the form of small hydroelectric installations. (orig.) [Deutsch] Grundsaetzlich gibt es heutzutage keinen Zweifel am Nutzen von Kleinkraftwerken. Die Wasserkraft ist eine regenerierbare Energiequelle. Im Gegensatz etwa zu Oel, Gas oder Kohle wird der Energietraeger Wasser beim Nutzungsvorgang nicht aufgebraucht. Die Stromerzeugung aus Wasserkraft belastet die Umwelt weder durch Luftschadstoffe noch Rueckstaende, sie ist umweltfreundlich. Und man nutzt damit einheimische Energie. Gewichtige Argumente zweifellos, die fuer eine moeglichst weitgehende Wasserkraftnutzung, gerade auch in Kleinkraftwerken, sprechen. (orig.)

Pollutants from road traffic and breathing problems in children; Schadstoffe aus dem Strassenverkehr und Atemwegsbeschwerden bei Kindern

Energy Technology Data Exchange (ETDEWEB)

Mutius, E. von [Muenchen Univ. (Germany). Dr. von Haunersche Kinderklinik

1996-06-01

So far, there ave been few studies on measurable health effects of emissions from road traffic. An analysis of the available studies yields no clear indication of a relationship between road traffic emissions and the incidence of asthma and allergies in infants. On the other hand, there are no valid data on individual pollutant exposure of infants in the framework of epidemiological studies which take account of other influencing factors.(orig./MG) [Deutsch] Der Frag, ob eine Schadstoffbelastung durch den Strassenverkehr einen messbaren schaedigenden Effekt auf die menschliche Gesundheit hat, ist bislang in wenigen Studien nachgegangen worden. Analysiert man die vorliegenden Studien, ergibt sich derzeit kein eindeutiger Hinweis auf einen starken Zusammenhang zwischen der Strassenverkehrsbelastung und dem Auftreten von Asthma und Allergien beim Kind. Allerdings fehlt es an validen Daten zur individuellen Schadstoffexposition bei Kindern im Rahmen epidemiologischer Studien, ie eine Beruecksichtigung anderer Einfluss- und Stoervariablen erlauben. (orig/MG)

Deregulation of the electric power market and chances of ecopolicy-based regulatory action. Report on the symposium organised by Forschungsstelle Umweltrecht at Hamburg University on June 2, 1994; Liberalisierung des Strommarktes und die Chancen fuer umweltpolitische Steuerungen. Bericht ueber das Symposium der Forschungsstelle Umweltrecht an der Universitaet Hamburg am 2. Juni 1994

Energy Technology Data Exchange (ETDEWEB)

Krebs, A [Freiherr-vom-Stein-Institut, Muenster (Germany)

1994-08-01

The report briefly discusses each paper presented at the symposium. Eleven experts from academia, administration and the power industry have been ventilating the various models of reform for deregulation of the electric power market currently under debate at national and international level, and the possibilities available under these models for ecopolicy-based regulatory activities for avoiding adverse effects on the environment. Other topics discussed addressed framework conditions to be defined for the reform models on the basis of constitutional laws, and rules of competition. (orig.) [Deutsch] Elf Experten aus Wissenschaft, Verwaltung und Energiewirtschaft eroertern die zur Zeit auf nationaler und internationaler Ebene diskutierten Reformmodelle fuer eine Liberalisierung des Strommarktes sowie die mit diesen jeweils verbundenen Moeglichkeiten der umweltpolitischen Steuerung von oekologischen Folgewirkungen. Weitere Themen des Symposions waren die wettbewerbs- und verfassungsrechtlichen Rahmenbedingungen einer Deregulierung des Strommarktes. Der Bericht behandelt in kurzer Form alle beim Symposion gehaltenen Referate. (orig.)

Symposium Ecological construction - from half-timbered- to passive house: living yesterday - today - tomorrow; Symposium Oekologische Bauweisen - vom Umgebinde- zum Passivhaus: Wohnen Gestern - Heute - Morgen

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

While the first part of the symposium was dedicated to half-timbered buildings in the traditional style of Lausitz, Bohemia and Silesia, the second part discussed passive buildings. [German] Das Umgebindehaus ist ein weltweit einmaliger Haustyp und zum anderen ist es ein traditionelles Haus unserer Region der Oberlausitz und angrenzender Teile von Boehmen und Schlesien. Das Symposium behandelt das Umgebindehaus in Vergangenheit und Gegenwart und will Motivation und Ansaetze geben, dieses wunderschoene Baukulturgut zu erhalten und unter modernen Wohn-, Arbeits- und Lebensbedingungen zu nutzen. Der zweite Teil der Tagung ist nicht minder wichtig. Beim Passivhaus geht es im wesentlichen darum, Heizwaermeverluste im Winter so klein zu halten, dass sie von den Gewinnen (Sonnenenergie, inneres Waermeaufkommen u.a.) gedeckt werden koennen. Damit wird der Waermeschutz des Gebaeudes vielleicht bis an die Grenzen getrieben und es entstehen neue Anforderungen an das Energiemanagement und die Qualitaet der technischen Gebaeudeausruestung. (orig.)

Complete freedom; Voellig losgeloest

Energy Technology Data Exchange (ETDEWEB)

Baun, R.

2000-10-01

The first two places in the list of technology trends went to engine technology - while the bronze medal was won by X-by-wire systems. The possibility of accelerating, braking, steering and gear shifting without mechanical links or connections creates new degrees of packaging freedom and allows for more comfort and safety. Some systems - for example the electronic accelerator - are already state-of-the-art technology. Steering and braking systems, however, still have a number of bureaucratic - and other - hurdles to overcome. (orig.) [German] Die beiden ersten Plaetze bei den Techniktrends gingen an die Motorentechnik - die Bronze-Medaille konnten sich die X-by-Wire-Systeme erobern. Beschleunigen, bremsen, lenken und schalten ohne mechanische Gestaenge oder Verbindungen schaffen neue Freiheitsgrade beim Package und ermoeglichen mehr Komfort und Sicherheit. Einige Systeme - etwa E-Gas - sind schon Stand der Technik. Bei den Lenk- und Bremssystemen stehen - unter anderem - noch buerokratische Sicherheitshuerden im Weg. (orig.)

Les particules illocutoires, variable d’ajustement de la traduction sous-titrante au cinéma

Directory of Open Access Journals (Sweden)

Ève Vayssière

2010-12-01

Full Text Available Die illokutiven Partikel fungieren als Anpassungsvariable, die beim Übersetzungsakt zur Untertitelung von Filmen entweder weggelassen werden oder erscheinen. Wenn sie einfach gelöscht werden, ergeben sich weder grammatikalische Störungen noch Informationsverlust. Das Auftauchen dieser Partikel in den deutschen Untertiteln zeigt jedoch, wie wichtig sie sind: Als Partikel der Oralität tragen sie zur Idiomatizität bei.Les particules illocutoires sont des variables d’ajustement lors de l’acte de traduction sous-titrante au cinéma, elles peuvent être supprimées sans que cela occasionne de dysfonctionnement grammatical et elles disparaissent lors de la traduction en français sans que cela occasionne une perte d’informations. Leur apparition dans les sous-titres allemands montre néanmoins leur importance : particules de l’oralité, elles sont vecteur d’« idiomaticité ».

Effects of the preparation process on the quality of refuse-derived fuels: The example of chlorine; Einfluss der Aufbereitung auf die Qualitaet der Ersatzbrennstoffe am Beispiel von Chlor

Energy Technology Data Exchange (ETDEWEB)

Kost, T.; Roetter, S.; Bilitewski, B. [Technische Univ. Dresden (Germany)

2000-07-01

The different interest groups (environmental authorities, licensing authorities, producers and users of refuse-derived fuels) have different guidelines, proposals and product specifications for quality assurance. While the limiting values for heavy metals reflect the controversial positions of the parties concerned, limiting values for chlorine are generally set at less than 1 percent by weight. This is not an ecological consideration but derives from the technical aspects of safe operation in the industries concerned. [German] Fuer die Guetesicherung von Ersatzbrennstoffen liegen von den beteiligten Interessengruppen (Umweltaemter, Genehmigungsbehoerden, Hersteller und Anwender von Ersatzbrennstoffen) verschiedene Grenzwerte als Richtlinien, Vorschlaege und Produktspezifikationen vor. Waehrend die Werte fuer Schwermetalle die teilweise kontraere Positionen der Beteiligten widerspiegeln, besteht fuer den Parameter Chlor dagegen eine einheitliche Spezifikation von <1 Gew.-% (wf). Dieser Wert ergibt sich nicht in erster Linie aus oekologischen Anforderungen, sondern ist vielmehr an technischen Aspekten der Betriebssicherheit beim Einsatz in den Anwenderindustrien orientiert. (orig.)

Absorbers for combined heating and cooling permit new concepts; Absorber zum Kuehlen und Heizen gestatten neue Konzepte

Energy Technology Data Exchange (ETDEWEB)

Stadelmann, M. [Verband der Schweizerischen Gasindustrie, Zurich (Switzerland)

1998-05-01

Direct-fuelled absorption-type refrigerators are recently being used not only for cold generation but also for heat generation with a flow temperature of 80 C. They can cool, heat, or cool and heat simultaneously, eah with a 50% share. This opens up new fields of application, either as a stand-alone system or combined with a gas engine cogeneration unit and absorber for cold generation. Two examples are presented, i.e. a hotel and a shopping mall. (orig.) [Deutsch] Direktbefeuerte Absorptionskaeltemaschinen erzeugen neuerdings nicht nur Kaelte, sondern auch Heizungswaerme mit 80 C Vorlauftemperatur. Sie koennen kuehlen, heizen oder - bis je 50% der Leistung - beides gleichzeitig. Der Teillastwirkungsgrad beim Kuehlbetrieb ist hoeher als bekannt. Das eroeffnet neue Moeglichkeiten des Einsatzes solcher Geraete, sei es allein oder zusammen mit Gasmotor-BHKW und Absorber zur Kaelteerzeugung. Zwei Beispiele - ein Hotel und ein Einkaufszentrum - werden vorgestellt. (orig.)

Functional and structural regeneration in the axolotl heart (Ambystoma mexicanum) after partial ventricular amputation.

Science.gov (United States)

Cano-Martínez, Agustina; Vargas-González, Alvaro; Guarner-Lans, Verónica; Prado-Zayago, Esteban; León-Oleda, Martha; Nieto-Lima, Betzabé

2010-01-01

"In the present study we evaluated the effect of partial ventricular amputation (PVA) in the heart of the adult urodele amphibian (Ambystoma mexicanum) in vivo on spontaneous heart contractile activity recorded in vitro in association to the structural recovery at one, five, 30 and 90 days after injury. One day after PVA, ventricular-tension (VT) (16 ± 3%), atrium-tension (AT) (46 ± 4%) and heart rate (HR) (58+10%) resulted lower in comparison to control hearts. On days five, 30 and 90 after damage, values achieved a 61 ± 5, 93 ± 3, and 98 ± 5% (VT), 60 ± 4, 96 ± 3 and 99 ± 5% (AT) and 74 ± 5, 84 ± 10 and 95 ± 10% (HR) of the control values, respectively. Associated to contractile activity recovery we corroborated a gradual tissue restoration by cardiomyocyte proliferation. Our results represent the first quantitative evidence about the recovery of heart of A. mexicanum restores its functional capacity concomitantly to the structural recovery of the myocardium by proliferation of cardiomyocytes after PVA. These properties make the heart of A. mexicanum a potential model to study the mechanisms underlying heart regeneration in adult vertebrates in vivo.

Whole-body MSCT of patients after polytrauma: abdominal injuries; Ganzkoerper-MSCT beim Polytrauma: Abdominelle Verletzungen

Energy Technology Data Exchange (ETDEWEB)

Roehrl, B.; Sadick, M.; Diehl, S.; Dueber, C. [Universitaetsklinikum Mannheim, Inst. fuer Klinische Radiologie (Germany); Obertacke, U. [Universitaetsklinikum Mannheim, Zentrum fuer Orthopaedie und Traumatologie (Germany)

2005-12-15

Purpose: The goal of this retrospective study was to evaluate the spectrum of abdominal injuries and the reliability of computed tomography-based diagnosis in patients after polytrauma. Material and methods: CT findings and clinical reports for 177 patients after polytrauma were evaluated with regard to abdominal injuries. Clinical patient reports at the time of discharge from the hospital were utilized as the standard of reference. Abdominal injuries resulting from an accident, frequent additional traumas and following therapeutic procedures were recorded. In the case of discrepancies in the reports, the CT scans were viewed retrospectively. Results: In 30 out of 177 patients, 42 abdominal injuries were detected. 69% of the injuries were caused by traffic accidents while 31% resulted from falls. Liver and spleen injuries were the most common. 50% of the cases were treated surgically, and the other half of the cases underwent non-surgical conservative therapy. Massive chest traumas, pelvic injuries, cerebral traumas and injuries to extremities were commonly associated with abdominal injuries. Evaluation of the discrepancies in the clinical reports showed that injury to the pancreas and the small intestine were not successfully detected on CT, thus resulting in a false negative diagnosis. Early stages of organ parenchyma laceration were also initially misdiagnosed on CT. (orig.)

Nuclear radiation in warfare. A SIPRI publication. Strahlungswirkungen beim Einsatz von Kernwaffen. Eine SIPRI-Publikation

Energy Technology Data Exchange (ETDEWEB)

Rotblat, J.

1986-01-01

The subject is covered in chapters, entitled: introduction; digest of nuclear weaponry (characteristics of nuclear weapons; effects of nuclear weapons other than ionizing radiation (fire-ball, fall-out, thermal radiation, blast wave, electromagnetic pulse); the nuclear arms race; war scenarios; biological effects of radiations on man (radiation doses; natural sources of radiation; acute effects of radiation; long-term somatic effects; genetic effects; factors affecting the biological response to radiation; internal exposure; synergistic effects; protection against radiation effects); radiations from nuclear explosions (initial radiation; fall-out; effects of fall-out on animal and plant life; contamination of water and food supplies by fall-out); radiation casualties in a nuclear war; effectiveness of civil defence; other warlike uses of radiation (attacks on civilian nuclear power installations; radiological warfare; terrorist activities); conclusion.

System for reducing emissions during coke oven charging; System zur Emissionsverringerung beim Fuellen von Koksoefen

Energy Technology Data Exchange (ETDEWEB)

Schuecker, Franz-Josef [ThyssenKrupp Industrial Solutions AG, Dortmund (Germany). Head of Oven Machine Dept., Coke Plant Technologies

2014-10-01

This article describes a process which reduces emissions from coke production in coke plants. The focus is on the charging process, which can be partly responsible for the fact that statutory emissions limits, which were originally met, are exceeded as coke plants get older. This article presents a solution in the form of a newly developed system that allows the oven charging system - the charging car - to respond to age-related changes in the geometry of a coke oven and thereby reduce the level of emissions.

Diagnosis and differential diagnosis of hydrocephalus in adults; Diagnostik und Differenzialdiagnostik des Hydrozephalus beim Erwachsenen

Energy Technology Data Exchange (ETDEWEB)

Langner, Soenke; Mensel, Birger; Kuehn, Jens Peter; Kirsch, Michael [Univ. Medicine Greifswald (Germany). Inst. for Diagnostic Radiology and Neuroradiology; Fleck, Steffen; Baldauf, Joerg [Univ. Medicine Greifswald (Germany). Dept. of Neurosurgery

2017-08-15

Hydrocephalus is caused by an imbalance of production and absorption of cerebrospinal fluid (CSF) or obstruction of its pathways, resulting in ventricular dilatation and increased intracranial pressure. Imaging plays a crucial role in the diagnosis, differential diagnosis and planning of treatment. This review article presents the different types of hydrocephalus und their typical imaging appearance, describes imaging techniques, and discusses differential diagnoses of the different forms of hydrocephalus. Imaging plays a central role in the diagnosis of hydrocephalus. While magnetic resonance (MR) imaging is the first-line imaging modality, computed tomography (CT) is often the first-line imaging test in emergency patients.

Potentials and limits of downsizing a diesel engine; Potenziale und Grenzen des Downsizings beim Dieselmotor

Energy Technology Data Exchange (ETDEWEB)

Mauch, Andreas; Tophoven, Jens; Trzebiatowski, Tobias; Raatz, Thorsten [Robert Bosch GmbH, Stuttgart (Germany). Bereich Forschung und Vorausentwicklung

2011-07-15

In order to reach lowest CO{sub 2} emissions, Bosch modified a three-cylinder diesel engine regarding its turbo-charging and fuel injection system and integrated it into a mid-size luxury car. So it is possible to determine both, the potentials concerning fuel consumption and emissions of this downsizing approach as well as its limits. (orig.)

MRI of experimental focal cerebral ischemia in sheep; MR-Bildgebung eines experimentellen Schlaganfallmodells beim Schaf

Energy Technology Data Exchange (ETDEWEB)

Foerschler, A. [Universitaetsklinikum Leipzig (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Abt. fuer Neuroradiologie; Boltze, J. [Universitaetsklinikum Leipzig (Germany). Inst. fuer Klinische Immunologie und Transfusionsmedizin; Fraunhofer-Inst. fuer Zelltherapie und Immunologie (Germany); Waldmin, D. [Leipzig Univ. (Germany). Veterinaer-Anatomisches Inst.; Gille, U. [Fraunhofer-Inst. fuer Zelltherapie und Immunologie (Germany); Leipzig Univ. (Germany). Veterinaer-Anatomisches Inst.; Zimmer, C. [Technische Univ. Muenchen (Germany). Klinikum rechts der Isar, Abt. fuer Neuroradiologie

2007-05-15

Purpose: With respect to the specific characteristic of rete mirabile epidurale rostrale in sheep, the aim of this study was to investigate the use of time of flight (TOF) magnetic resonance angiography (MRA) to observe vascular anatomy and to validate MCA occlusion in a new model of experimental focal cerebral ischemia by permanent middle cerebral artery (MCA) occlusion in sheep (designed to study stroke therapy using autologous stem cells from umbilical cord blood). Furthermore, we wanted to assess the extent and natural time course of ischemic focal brain injury in sheep using functional and morphological magnetic resonance imaging (MRI). Materials and Method: 13 Merino sheep were examined. In 4 of the animals all, in 5 sheep 1 or 2 MCA branches were occluded and in 1 one case touched (sham operation). 4 controls did not undergo a surgical procedure. 23 MRI sessions were performed in 10 sheep. These sessions included T1, T2, T2{sup *} sequences, diffusion-weighted imaging (DWI) and TOF MRA before and 2 - 46 days after the onset of stroke using a 1.5T clinical MR scanner. Corrosion casts of the cerebral arteries of 3 sheep were prepared and compared to MRA. Results: The MRA visualized the vessel anatomy or occlusion distal to the rete mirabile. Anatomical variants concerning the variant origin of the MCA and inconstant arteria choroidea rostralis and communicans rostralis were revealed. Sheep with occluded left MCA showed space occupying lesions with a drop in ADC values. Depending on the number of preserved MCA branches (0; 1; 2), highly significant (p < 0.001) differences in lesion size (21 {+-} 5.7; 13; 1.7 {+-} 1.3 ml) could be found. No indication of ischemia but minimal contusion damage was observed in the sham operated animal. (orig.)

Imaging techniques and investigation protocols in pediatric emergency imaging; Aufnahmetechnik und Untersuchungsprotokolle beim paediatrischen Notfall

Energy Technology Data Exchange (ETDEWEB)

Scharitzer, M.; Hoermann, M.; Puig, S.; Prokop, M. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

2002-03-01

Paediatric emergencies demand a quick and efficient radiological investigation with special attention to specific adjustments related to patient age and radiation protection. Imaging modalities are improving rapidly and enable to diagnose childhood diseases and injuries more quickly, accurately and safely. This article provides an overview of imaging techniques adjusted to the age of the child and an overview of imaging strategies of common paediatric emergencies. Optimising the imaging parameters (digital radiography, different screen-film systems, exposure specifications) allows for substantial reduction of radiation dose. Spiral- and multislice-CT reduce scan time and enable a considerable reduction of radiation exposure if scanning parameters (pitch setting, tube current) are properly adjusted. MRI is still mainly used for neurological or spinal emergencies despite the advent of fast imaging sequences. The radiologist's task is to select an appropriate imaging strategy according to expected differential diagnosis and to adjust the imaging techniques to the individual patient. (orig.) [German] Das akut erkrankte Kind erfordert eine rasche radiologische Abklaerung mit besonderer Beruecksichtung der geaenderten Untersuchungsparameter bei gleichzeitig hohem Anspruch an den Strahlenschutz. Hochaufloesende Schallkoepfe, Multislice-CT und schnelle MR-Sequenzen erlauben eine bessere Anpassung der Untersuchungsmethoden an die Beduerfnisse in der Kinderradiologie. Ziel dieses Artikels ist eine Uebersicht ueber die verschiedenen radiologischen Untersuchungstechniken sowie deren Anpassung an kindliche Anforderungen und die Angabe von Untersuchungsalgorithmen der haeufigsten paediatrischen Notfaelle. In der Projektionsradiographie erlaubt die Optimierung der Aufnahmetechnik (digitale Radiographie, unterschiedliche Klassen von Film-Folien-Systemen, Belichtungsparameter) eine deutliche Reduktion der Strahlendosis bei diagnostisch ausreichender Qualitaet. Spiral- oder Multislice-CT ermoeglichen eine Verkuerzung der Untersuchungsdauer und eine exaktere Anpassung der Expositionsparameter (Pitchfaktor, mAs-Produkt) mit deutlicher Senkung der Strahlenbelastung. Die MRT wird trotz schneller Sequenzen vorwiegend bei neurologischen und spinalen Notfaellen eingesetzt. Die Aufgabe des Radiologen liegt darin, in Abhaengigkeit von den erwarteten paediatrischen Differenzialdiagnosen die korrekte Untersuchungsmodalitaet zu waehlen und die Untersuchungstechnik individuell anzupassen. (orig.)

Incorporation monitoring during handling of medically used radionuclides; Inkorporationsueberwachung beim Umgang mit medizinisch genutzten Radionukliden

Energy Technology Data Exchange (ETDEWEB)

Buchholz, Werner; Gerstmann, Udo [Bundesamt fuer Strahlenschutz, Oberschleissheim (Germany). FB Strahlenschutz und Gesundheit; Scholl, Clemens [Landesinstitut fuer Arbeitsgestaltung NRW, Duesseldorf (Germany). Inkorporationsmessstelle; Wanke, Carsten [Medizinische Hochschule Hannover (Germany). Strahlenschutz und Medizinische Physik

2017-08-01

The necessity of incorporation monitoring in nuclear medicine is dependent of the incorporation factor. For important applications, such as Tc-99m diagnostics and the radioiodine therapy specific measuring programs allow the determination of the incorporation factor. These factors are usually marginal so that a periodic monitoring is either not necessary or replaced by simple threshold measurements. Experiences of incorporation measuring stations show that incorporation might occur but does not induce significant doses.

Speed regulation of water turbines by status feedback; Drehzahlregelung von Wasserturbinen mit Zustandsreglern

Energy Technology Data Exchange (ETDEWEB)

Maurer, W

1991-12-31

The development of a speed controller by state freedback for water turbines will be presented. The possible improvement of the dynamic behaviour of the whole hydro power plant will be shown. The interaction of automatic control with the system and the influence of real working conditions will be described in detail. The procedure of controller design and the development of the description of the system in state equations will be explained. In addition to this the development of a digital program for the nonlinear simulation of hydro power plants will be presented. (orig.) [Deutsch] Die Entwicklung eines Zustandsreglers fuer die Drehzahlregelung von Wasserturbinen wird vorgestellt. Anhand nichtlinerer Simulationen wird die damit erzielbare Verbesserung des dynamischen Verhaltens der gesamten Wasserkraftanlage dokumentiert, sowie das Zusammenwirken mit regelungsnahen Steuerungen und der Einfluss praktischer Randbedingungen detailliert untersucht. Die Vorgehensweise beim Reglerentwurf und bei der Erstellung der dazu notwendigen linearen Beschreibung des dynamischen Verhaltens wird erlaeutert. Darueber hinaus wird die Entwicklung eines Programmsystems zur nichtlinearen Simulation von Wasserkraftanlagen beschrieben. (orig.)

Intercomparison tests and internal control samples as substantial elements of the quality control system: practical insights; Ringversuche und interne Kontrollproben als Elemente der Qualitaetssicherung: Erfahrungen aus der Praxis

Energy Technology Data Exchange (ETDEWEB)

Beyer, D.; Hartmann, M. [Bundesamt fuer Strahlenschutz, Berlin (Germany). Inst. fuer Angewandten Strahlenschutz

2002-07-01

The contribution highlights the practical experience accumulated in implementing the statutory ordinance on the monitoring of incorporated ionizing radiation by official monitoring stations, effective in Germany since 1996, focusing on the quality assurance system to be maintained by those stations. The examples used to illustrate practical aspects are: participation in intercomparison tests, sampling for internal control purposes, and the monitoring by way of excretion analyses of individuals handling alpha and beta emitters (nuclides) at their place of work. (orig./CB) [German] Im Jahre 1996 trat in Deutschland die 'Richtlinie ueber Anforderungen an Inkorporationsmessstellen' (Anforderungsrichtlinie) in Kraft. Danach werden fuer die Durchfuehrung der Inkorporationsueberwachung nur noch Messstellen amtlich anekannt, die unter anderem den dort gegebenen Anforderungen an Qualitaetssicherungsmassnahmen genuegen. Im Einzelnen betrifft dies die Teilnahme an Ringversuchen sowie die vorgeschriebenen internen Eigenkontrollen. Am Beispiel der Inkorporationsueberwachung durch Ausscheidungsanalyse, die bevorzugt beim Umgang mit alpha- und betastrahlenden Nukliden durchgefuehrt wird, werden die bisherigen Erfahrungen bei Anwendung der Anforderungsrichtlinie vorgestellt. (orig.)

Determination of the mass and width of the W-boson using the semileptonic decay channel with the OPAL detector at LEP

CERN Document Server

Vollmer, Cornelius Fritz

2004-01-01

Diese Arbeit ist eine Weiterentwicklung der beim OPAL-Experiment verwendeten Faltungsmethode zur Bestimmung der Masse des geladenen Eichbosons der schwachen Wechselwirkung. Die Methode wurde ausgeweitet auf eine gleichzeitige Bestimmung der Masse Mw und der Zerfallsbreite Gw des W-Boson genannten Eichbosons. Analysiert wurden dazu Daten, die mit dem OPAL-Experiment in den Jahren 1997 bis 2000 aufgezeichnet wurden. Von den möglichen Zerfällen der erzeugten W-Bosonpaare werden nur semileptonische betrachtet, bei denen ein W-Boson hadronisch in ein Quark-Antiquark-Paar zerfällt und das andere in ein geladenes Lepton und ein Neutrino. In der Faltungsmethode werden die aus der Detektorauflösung resultierenden Fehler der einzelnen Ereignisse berücksichtigt. Dazu wird eine Funktion P(m) für jedes Ereignis ermittelt, welche die Wahrscheinlichkeit angibt, daß die produzierten W-Bosonen eine mittlere Masse m haben. Diese sogenannte Ereigniswahrscheinlichkeitsdichte wird mit einer Physikfunktion PF(m;Mw,Gw) gefal...

The production of wear protection coatings reinforced with tungsten carbide by temperature-controlled welding with the CO{sub 2} laser; Herstellung wolframkarbidverstaerkter Verschleissschutzschichten durch temperaturgeregeltes Auftragschweissen mit dem CO{sub 2}-Laser

Energy Technology Data Exchange (ETDEWEB)

Nowotny, S.; Boddin, G.C.; Luft, A.; Techel, A. [Fraunhofer-Inst. fuer Werkstoffphysik und Schichttechnologie, Dresden (Germany); Uelze, A. [Hochschule fuer Technik und Wirtschaft Dresden (Germany)

1995-12-31

Protective coatings can be produced by laser coating with metal alloys reinforced by carbide, whose resistance to abrasive wear with a content of 40 to 50% by volume of hard material is comparable to sintered TC-Co hard metal. Due to the remaining ductile material behaviour and the metallurgical binding to the substrate, the coatings have high impact, fatigue and adhesion strengths. The use of process control leads to a stable coating process and to increased safety and reproduceability when working in narrow parameter areas. (orig./RHM) [Deutsch] Durch das Laserbeschichten mit karbidverstaerkten Metallegierungen koennen Schutzschichten erzeugt werden, deren Widerstand gegen Abrasivverschleiss bereits bei einem Hartstoff-Volumengehalt von 40 bis 50% gesintertem WC-Co-Hartmetall vergleichbar ist. Aufgrund des verbleibenden duktilen Werkstoffverhaltens und der metallurgischen Bindung zum Substrat verfuegen die Schichten ueber hohe Schlag-, Ermuedungs- und Haftfestigkeiten. Der Einsatz der Prozessregelung fuehrt zu einem stabilen Beschichtungsvorgang und zu einer erhoehten Sicherheit und Reproduzierbarkeit beim Arbeiten in eng begrenzten Parameterbereichen. (orig./RHM)

Hardwarearchitektur für einen universellen LDPC Decoder

Directory of Open Access Journals (Sweden)

C. Beuschel

2009-05-01

Full Text Available Im vorliegenden Beitrag wird eine universelle Decoderarchitektur für einen Low-Density Parity-Check (LDPC Code Decoder vorgestellt. Anders als bei den in der Literatur häufig beschriebenen Architekturen für strukturierte Codes ist die hier vorgestellte Architektur frei programmierbar, so dass jeder beliebige LDPC Code durch eine Änderung der Initialisierung des Speichers für die Prüfmatrix mit derselben Hardware decodiert werden kann. Die größte Herausforderung beim Entwurf von teilparallelen LDPC Decoder Architekturen liegt im konfliktfreien Datenaustausch zwischen mehreren parallelen Speichern und Berechnungseinheiten, wozu ein Mapping und Scheduling Algorithmus benötigt wird. Der hier vorgestellte Algorithmus stützt sich auf Graphentheorie und findet für jeden beliebigen LDPC Code eine für die Architektur optimale Lösung. Damit sind keine Wartezyklen notwendig und die Parallelität der Architektur wird zu jedem Zeitpunkt voll ausgenutzt.

Erkundungen im Spannungsfeld von Pädagogik, Spielspass und technischer Machbarkeit. Gedanken zur Konzeption und Entwicklung spielbasierter digitaler Lernumgebung

Directory of Open Access Journals (Sweden)

Florian Berger

2009-02-01

Full Text Available Computerspiele sind heute aus der digitalen Medienwelt nicht mehr wegzudenken. Ihre rasante technische Entwicklung sowie ihre hohe Akzeptanz in der Jugendkultur werfen Fragen nach pädagogischer Verwertbarkeit dieses Mediums auf. Auf diesem Gebiet besteht Forschungsbedarf: Für den Einsatz aktueller Spielkonzepte als Lehrmittel existieren keine fundierten Theorien oder Konzepte. Der schöpferische Umgang mit Spielen durch Anwender («Emergent Gameplay» bietet hier durch sein hohes Motivationspotential einen vielversprechenden Ansatz. Die oft wenig beachtete Rolle der digitalen Spielen zugrunde liegenden Softwaretechnik sollte stärkere Berücksichtigung finden: Es existiert einerseits ein für die Akzeptanz beim Anwender notwendiges Minimum, andererseits ist der Einsatz des aktuellen technischen «state of the art» für die Umsetzung pädagogischer und didaktischer Ambitionen durch seine enormen Anforderungen wenig zielführend. Im Ergebnis sind Idee und Spielspass das Mass auch für Anwendungen des Game Based Learn­ing.

The EPR (European Pressurized Water Reactor) containment - concept, testing of leakage behaviour, FRP liner

Energy Technology Data Exchange (ETDEWEB)

Touret, J.P. [EDF SEPTEN, Villeurbanne (France); Liersch, G. [Bayernwerk Kerenergie GmbH, Muenchen (Germany); Danisch, R. [Siemens AG, KWU NAD, Erlangen (Germany)

2001-07-01

The Basic Design of the EPR has now been completed. The containment plays a major safety-related role with respect to protection of the environment against radioactive releases. The EPR features a double (steel-reinforced concrete/prestressed concrete) containment design, with the inner containment coated additionally with a fibreglass-reinforced plastic (FRP) liner in certain areas. This means that containment leaktightness is provided mainly by the prestressed concrete and the FRP liner in the event of a postulated accident. The numerous findings of the tests carried out so far in both France and Germany are summarized. (orig.) [German] Das Basic Design fuer den EPR ist fertiggestellt. Entscheidend fuer eine Realisierung wird neben der politischen Akzeptanz vor allem die Wettbewerbsfaehigkeit mit anderen Energietraegern sein. Im EPR-Projekt wird der hohe Sicherheitsstandard der heutigen Kernkraftwerke in Deutschland und Frankreich ergaenzt, indem zusaetzlich technische Massnahmen ergriffen werden, um die Konsequenzen beim unterstellten Versagen aller sicherheitstechnischen Einrichtungen mit der Folge eines postulierten Niederschmelzen des Kerns technisch zu beherrschen. (orig.)

The Environmental Impact Assessment (EIA) for high-voltage overhead lines; Umweltvertraeglichkeitspruefung (UVP) fuer Hochspannungsfreileitungen

Energy Technology Data Exchange (ETDEWEB)

Klockow, S. [Landesentwicklungsgesellschaft Baden-Wuerttemberg, Stuttgart (Germany). Abt. Umwelt

1996-11-04

In some of the federal states of Germany the licensing of new or the laying or existing high-voltage overhead lines requires an environmental impact assessment. For many utility companies, however, environmental impact assessments for high-voltage lines are virgin territory. Experience shows that preparing the documentation is not a major problem. Questions usually arise over details such as the calculation of possible incidents or the comparison of different layouts. The authors describes general approaches and strategies and looks at specific problems. (orig.) [Deutsch] Bei der Genehmigung neuer oder der Verlegung vorhandener Hochspannungsfreileitungen ist in einigen Bundeslaendern eine Umweltvertraeglichkeitspruefung durchzufuehren. Fuer viele Energieversorgungsunternehmen ist die Erarbeitung von Umweltvertraeglichkeitsstudien fuer Hochspannungsleitungen aber noch Neuland. Praxiserfahrungen zeigen, dass die Erarbeitung der erforderlichen Unterlagen ohne groessere Schwierigkeiten moeglich ist. Fragen ergeben sich dabei aber bei speziellen Details, z.B. bei der Betrachtung von moeglichen Stoerfaellen oder beim Vergleich von Trassenvarianten. Der Verfasser skizziert das allgemeine Vorgehen und erlaeutert ausfuehrlich die Detailprobleme. (orig.)

GEC Alsthom put their hopes on fuel cells: A large potential for PEM fuel cells; GEC Alsthom setzt auf Brennstoffzellen: Grosses Potential fuer PEMFC

Energy Technology Data Exchange (ETDEWEB)

Anon,

1998-07-01

Fuel cells are regarded as one of the high-tech products of great promise for future energy supplies. High hopes are pinned on the PEM technology: This low-temperature fuel cell is applicable to both mobile applications as well as stationary systems, i.e. from small-scale heating systems through to CHP systems of medium output. GEC Alsthom, who entered into a strategic alliance with Ballard, the market leader in fuel cell technology, are the first power plant manufacturers to commit themselves in the fuel cell market sector. (orig./CB) [Deutsch] Brennstoffzellen gelten als einer der Hoffnungstraeger der zukuenftigen Energieversorgung. Grosse Erwartungen werden dabei in die PEM-Technologie gesetzt: Diese Niedertemperatur-Brennstoffzelle eignet sich sowohl fuer mobile Anwendungen als auch fuer den stationaeren Einsatz - von kleinen Hausheizungsanlagen bis hin zu BHKW mittlerer Leistungklasse. Mit GEC Alsthom und seinem Engagement beim Marktfuehrer Ballard steigt nun erstmals ein grosser Energieanlagenhersteller verstaerkt in dieses Marktsegment ein. (orig.)

Cryotherapy of the primary glaucoma; Kryotherapie des primaeren Glaukoms

Energy Technology Data Exchange (ETDEWEB)

Anders, M. [Abt. Augenheilkunde und Kryomedizin, Medizinische Akademie Dresden (Germany)

1994-12-31

Cryotherapy is an effective and conservative method of treatment for the primary glaucoma. The principal procedure of this one-time treatment consists in the application of 8-12 punctiform transconjunctival cold nuclei on circle approximately 2mm away from the cornea by means of a cryoapplicator (diameter approx. 2mm) cooled down to approx. -140 C. If all parameters involved in this treatment are accurately observed, the cryotherapy leads to compensation of the pathognomonic increased intraocular pressure in 90% of cases. (orig.) [Deutsch] Die Kryotherapie stellt beim primaeren Glaukom ein effektives und schonendes Behandlungsverfahren dar. Dieses besteht im Prinzip darin, dass mit einem auf ca. -140 C abgekuehlten Kryoapplikator (Durchmesser ca. 2 mm) einmalig 8-12 punktfoermige, transkonjunktivale Kaelteherde zirkulaer 2 mm von der Hornhaut entfernt gesetzt werden. Die so durchgefuehrte Kryotherapie fuehrt bei exakter Einhaltung aller borgegebenen Therapieparameter in 90% der Faelle zur Kompensation des bei dieser Krankeit erhoehten intraokularen Druckes. (orig.)

Cryotherapy of the primary glaucoma; Kryotheraphie des primaeren Glaukoms

Energy Technology Data Exchange (ETDEWEB)

Anders, M. [Medizinische Akademie, Dresden (Germany). Abt. Augenheilkunde und Kryomedizin

1994-12-31

Cryotherapy is an effective and conservative method of treatment for the primary glaucoma. The principal procedure of this one-time treatment consists in the application of 8-12 punctiform transconjunctional cold nuclei on a circle approximately 2 mm away from the cornea by means of a cryoapplicator (diameter approx. 2 mm) cooled down to approx. -140 C. If all parameters involved in this treatment are accurately observed, the cryotherapy leads to compensation of the pathognomonic increased intraocular pressure in 90% of cases. (orig.) [Deutsch] Die Kryotherapie stellt beim primaeren Glaukom ein effektives und schonendes Behandlungsverfahren dar. Dieses besteht im Prinzip darin, dass mit einem auf ca. -140 C abgekuehlten Kryoapplikator (Durchmesser ca. 2 mm) einmalig 8 - 12 punktfoermige transkonjunktivale Kaelteherde zirkulaer 2 mm von der Hornhaut entfernt gesetzt werden. Die so durchgefuehrte Kryotherapie fuehrt bei exakter Einhaltung aller vorgegebenen Therapieparameter in 90% der Faelle zur Kompensation des bei dieser Krankheit erhoehten intraokularen Druckes. (orig.)

Formation and functions of aerobic microbial granula; Entstehung und Funktionen aerober mikrobieller Granula

Energy Technology Data Exchange (ETDEWEB)

Etterer, T.; Wilderer, P.A. [Technische Univ. Muenchen, Garching (Germany). Lehrstuhl und Pruefamt fuer Wasserguete- und Abfallwirtschaft

1999-07-01

The present project investigates the phenomenon of the formation of aerobic microbial granula and their properties. To generate granula, sequencing batch reactors fed in batches were used. As shown by microbiological assays, fungi played an above-average role in granula formation and build-up. In first degradation experiments, furthermore, chemical oxygen demand (COD) could be reduced by over 90 %. The determination yielded comparable values to activated sludge, standing on average at 1.044g/ml. (orig.) [German] Im Rahmen des hier vorgestellten Projekts wurde das Phaenomen der Bildung aerober mikrobieller Granula sowie deren Eigenschaften untersucht. Zur Erzeugung von Granula wurden schubweise beschickte Reaktoren, sogenannte Sequencing-Batch-Reaktoren (SBR) verwendet. Wie mikrobiologische Untersuchungen zeigten spielen Pilze bei der Entstehung und beim Aufbau eine ueberdurchschnittliche Rolle. Des weiteren konnte in ersten Abbauversuchen der chemische Sauerstoff-Bedarf (CSB) um ueber 90% gesenkt werden. Die Dichtebestimmung ergab vergleichbare Werte zu Belebtschlamm und zwar im Durchschnitt 1,044 g/ml. (orig.)

Speed regulation of water turbines by status feedback; Drehzahlregelung von Wasserturbinen mit Zustandsreglern

Energy Technology Data Exchange (ETDEWEB)

Maurer, W.

1990-12-31

The development of a speed controller by state freedback for water turbines will be presented. The possible improvement of the dynamic behaviour of the whole hydro power plant will be shown. The interaction of automatic control with the system and the influence of real working conditions will be described in detail. The procedure of controller design and the development of the description of the system in state equations will be explained. In addition to this the development of a digital program for the nonlinear simulation of hydro power plants will be presented. (orig.) [Deutsch] Die Entwicklung eines Zustandsreglers fuer die Drehzahlregelung von Wasserturbinen wird vorgestellt. Anhand nichtlinerer Simulationen wird die damit erzielbare Verbesserung des dynamischen Verhaltens der gesamten Wasserkraftanlage dokumentiert, sowie das Zusammenwirken mit regelungsnahen Steuerungen und der Einfluss praktischer Randbedingungen detailliert untersucht. Die Vorgehensweise beim Reglerentwurf und bei der Erstellung der dazu notwendigen linearen Beschreibung des dynamischen Verhaltens wird erlaeutert. Darueber hinaus wird die Entwicklung eines Programmsystems zur nichtlinearen Simulation von Wasserkraftanlagen beschrieben. (orig.)

Silicon carbide, a ceramic material for the pump technology?; Siliciumcarbid - eine Keramik fuer die Pumpentechnologie

Energy Technology Data Exchange (ETDEWEB)

Vitzthum, E. [CeramTec AG, Lauf (Germany). Marketing und Customer Service

2000-12-01

Pumping of gases and liquids makes extreme demands on sliding bearings and their seals, especially if the material to be pumped is corrosive or contains abrasive constituents. Wear and corrosion are important economic factors. They shorten the life of machines and systems and cause standstill times and repair cost. All this decides the profitability of pumps and the competitive strength of products. In view of all this, it becomes clear why optimal materials selection is a crucial points in pumps and pumping systems. [German] Beim Foerdern von Gasen und Fluessigkeiten werden extrem hohe Anforderungen an Gleitlager und Gleitringdichtungen in Pumpen gestellt, die im direkten Kontakt mit dem zu foerdernden Medium sind, besonders dann, wenn das Medium korrosiv ist oder abrasive Bestandteile enthaelt. Verschleiss und Korrosion sind wesentliche Wirtschaftsfaktoren. Sie bestimmen die Standzeit von Maschinen und Anlagen, verursachen Betriebsstillstandszeiten und Reparaturkosten. Diese entscheiden ueber die Rentabilitaet von Prozessen und die Wettbewerbsfaehigkeit von Produkten, was eine optimale Auswahl des Werkstoffs auch in Pumpen und Pumpenanlagen unerlaesslich macht. (orig.)

Physical water treatment against calcification and rust; Physikalische Wasserbehandlung gegen Kalk und Rost

Energy Technology Data Exchange (ETDEWEB)

Burger, A [Hydrotec AG, Rehau (Germany). Forschung und Entwicklung

1995-03-01

In contrast to Germany, where the installation of small-sized, decentralised plants is still prefered, water supply companies in countries such as Denmark have already for some time successfully been using physical water treatment systems. Although the health and environmental benefits of this non-chemical method of water treatment are undisputed and its proper application is also economically beneficial, there is still a widerspread lack of information as to where such plants can be used. Consequently, older methods are often resorted to combatting calcification and rust. (orig.) [Deutsch] Waehrend in Laendern wie Daenemark physikalische Wasserbehandlungssysteme bereits seit laengerem erfolgreich von Wasserversorgungsunternehmen eingesetzt werden, ueberwiegt in Deutschland bislang der dezentrale Einbau meist kleinerer Geraete. Obwohl der Nutzen dieser Form chemiefreier Wasserbehandlung fuer Umwelt und Gesundheit ausser Frage steht, zudem bei richtiger Verwendung deutliche Kostenvorteile entstehen, besteht noch haeufig Unsicherheit ueber die Einsatzgebiete physikalischer Wasserbehandlungsgeraete. Dies fuehrt haefig dazu, beim Kampf gegen Kalk und Rost auf aeltere Verfahren zurueckzugreifen. (orig.)

Incident of inadvertent radiation exposure in a linac bunker

International Nuclear Information System (INIS)

Aerts, M.G.

2010-01-01

Full text: Implementation of a new Biomedical Equipment and service database poses special challenges. This paper describes the challenges and solutions during implementation of BEIMS (Mercury Computers) at RPAH and other sites within SSWAHS. During implementation we faced challenges of Code/Label design, workflow redesign, and data cleanup. Considerable time and effort went into the design of descriptive codes for breakdowns, tests, equipment types, meta-categories and the like. Some of the codes are explored and described to allow adoption by other entities if desired. Workflow redesign required us to include considerations of biomedical Technicians and Nurse Requestors. A simplified document was created for the self-education of Requestors and a full user manual (complete with screen shots) was created for Biomeds. More work remains, including simplification of standardised reports and ability to generate KPI's. The result is a system with improved utility compared to the old system and a flexible design enabling future improvements. (author)

A novel protein involved in heart development in Ambystoma mexicanum is localized in endoplasmic reticulum.

Science.gov (United States)

Jia, P; Zhang, C; Huang, X P; Poda, M; Akbas, F; Lemanski, S L; Erginel-Unaltuna, N; Lemanski, L F

2008-11-01

The discovery of the naturally occurring cardiac non-function (c) animal strain in Ambystoma mexicanum (axolotl) provides a valuable animal model to study cardiomyocyte differentiation. In homozygous mutant animals (c/c), rhythmic contractions of the embryonic heart are absent due to a lack of organized myofibrils. We have previously cloned a partial sequence of a peptide cDNA (N1) from an anterior-endoderm-conditioned-medium RNA library that had been shown to be able to rescue the mutant phenotype. In the current studies we have fully cloned the N1 full length cDNA sequence from the library. N1 protein has been detected in both adult heart and skeletal muscle but not in any other adult tissues. GFP-tagged expression of the N1 protein has revealed localization of the N1 protein in the endoplasmic reticulum (ER). Results from in situ hybridization experiments have confirmed the dramatic decrease of expression of N1 mRNA in mutant (c/c) embryos indicating that the N1 gene is involved in heart development.

Structure-property investigations on a laser beam welded dissimilar joint of aluminium AA6056 and titanium Ti6Al4V for aeronautical applications Part I: Local gradients in microstructure, hardness and strength

Energy Technology Data Exchange (ETDEWEB)

Horstmann, M.; Ventzke, V.; Petrovski, B.; Kocak, M. [GKSS Research Centre Geesthacht (Germany). Institute of Materials Research, Materials Mechanics; Kocik, R.; Tempus, G. [AIRBUS Deutschland GmbH, Metal Technology, Bremen (Germany); Vaidya, W.V.

2009-08-15

Sheets of AA6056 and Ti6Al4V were butt-joined by inserting the Ti-sheet into the profiled Al-sheet and by melting the Al-alloy alone using a split beam Nd:YAG laser. To study microstructural effects on properties, the Al-alloy was used in two tempers; T4 followed by post weld heat treatment T6, and in T6 followed by a defined duration of natural ageing at room temperature. As a basic step for fatigue and fracture investigations, local gradients in properties of this dissimilar joint are investigated using microscopy, hardness and tensile tests. Possible sites, from which fracture may initiate, have been then identified. All property changes are found to confine to the aluminium side. An intermetallic layer, although very thin, is found to form on the interface. The changeovers, firstly between the fusion zone and the heat affected zone and secondly between the heat affected zone and the base material, are found to be associated with changes in microstructure, hardness and strength. These are identified as the possible critical sites in addition to the interface. (Abstract Copyright [2009], Wiley Periodicals, Inc.) [German] Durch eine spezielle Stossvorbereitung wurden laserstrahlgeschweisster Mischverbindungen aus den Blechwerkstoffen AA6056 und Ti6Al4V hergestellt und zwar ohne die Verwendung von Zusatzwerkstoffen. Die grosse Differenz der Schmelztemperaturen erlaubt das selektive Erschmelzen des Aluminiumwerkstoffs, der wieder um den Titanwerkstoff benetzt, sodass es zur Ausbildung einer mechanisch-stabilen und tragfaehigen Verbindung kommt. Die Al-Legierung wurde in den Waermebehandlungszustaenden T4 und T6 verschweisst, um den mikrostrukturellen Einfluss auf die Eigenschaften der Verbindungen untersuchen zu koennen. Die Prozessfolgen sahen vor, dass beim Schweissen im Zustand T4 eine Warmauslagerung, beim Schweissen im Zustand T6 eine Kaltauslagerung definierter Dauer folgte. Die Charakterisierung lokaler Eigenschaftsgradienten hinsichtlich Gefuege, Mikrohaerte

Radiosensitization in esophageal squamous cell carcinoma. Effect of polo-like kinase 1 inhibition

Energy Technology Data Exchange (ETDEWEB)

Chen, Jenny Ling-Yu [National Taiwan University, Institute of Biomedical Engineering, College of Medicine and College of Engineering, Taipei (China); National Taiwan University Hospital Hsin-Chu Branch, Department of Radiation Oncology, Hsin-Chu (China); National Taiwan University Hospital and National Taiwan University Cancer Center, Department of Oncology, Taipei (China); Chen, Jo-Pai [National Taiwan University Hospital and National Taiwan University Cancer Center, Department of Oncology, Taipei (China); National Taiwan University Hospital Yun-Lin Branch, Department of Oncology, Yun-Lin (China); Huang, Yu-Sen [National Taiwan University, Institute of Biomedical Engineering, College of Medicine and College of Engineering, Taipei (China); National Taiwan University Hospital, Department of Medical Imaging, Taipei (China); National Taiwan University Hospital Yun-Lin Branch, Department of Medical Imaging, Yun-Lin (China); Tsai, Yuan-Chun; Tsai, Ming-Hsien; Jaw, Fu-Shan [National Taiwan University, Institute of Biomedical Engineering, College of Medicine and College of Engineering, Taipei (China); Cheng, Jason Chia-Hsien; Kuo, Sung-Hsin [National Taiwan University Hospital and National Taiwan University Cancer Center, Department of Oncology, Taipei (China); National Taiwan University, Graduate Institute of Oncology, Taipei (China); Shieh, Ming-Jium [National Taiwan University, Institute of Biomedical Engineering, College of Medicine and College of Engineering, Taipei (China); National Taiwan University Hospital and National Taiwan University Cancer Center, Department of Oncology, Taipei (China)

2016-04-15

This study examined the efficacy of polo-like kinase 1 (PLK1) inhibition on radiosensitivity in vitro and in vivo by a pharmacologic approach using the highly potent PLK1 inhibitor volasertib. Human esophageal squamous cell carcinoma (ESCC) cell lines KYSE 70 and KYSE 150 were used to evaluate the synergistic effect of volasertib and irradiation in vitro using cell viability assay, colony formation assay, cell cycle phase analysis, and western blot, and in vivo using ectopic tumor models. Volasertib decreased ESCC cell proliferation in a dose- and time-dependent manner. Combination of volasertib and radiation caused G2/M cell cycle arrest, increased cyclin B levels, and induced apoptosis. Volasertib significantly enhanced radiation-induced death in ESCC cells by a mechanism involving the enhancement of histone H3 phosphorylation and significant cell cycle interruption. The combination of volasertib plus irradiation delayed the growth of ESCC tumor xenografts markedly compared with either treatment modality alone. The in vitro results suggested that targeting PLK1 might be a viable approach to improve the effects of radiation in ESCC. In vivo studies showed that PLK1 inhibition with volasertib during irradiation significantly improved local tumor control when compared to irradiation or drug treatment alone. (orig.) [German] Diese Studie untersucht die Wirksamkeit der Polo-like -Kinase 1-(PLK1-)Inhibition auf die Strahlenempfindlichkeit in vitro und in vivo beim oesophagealen Plattenepithelkarzinom durch eine pharmakologische Herangehensweise mit dem hochwirksamen PLK1-Inhibitor Volasertib. Menschliche Zelllinien des oesophagealen Plattenepithelkarzinoms (ESCC), KYSE 70 und KYSE 150, wurden verwendet, um den synergistischen Effekt von Volasertib und Bestrahlung in vitro zu bewerten. Hierzu wurden Zellviabilitaets- und Koloniebildungsuntersuchungen sowie Zellwachstumsanalysen, Immunblots und ektopische In-vivo-Tumormodelle herangezogen. Volasertib verminderte die ESCC

HTGT-Turbotech II. Subproject 1.221: aerodynamic excitation of transonic turbine stages. Final report; HTGT-Turbotech II. Teilprojekt 1.221: Aerodynamische Anregung von transsonisch durchstroemten Turbinenstufen. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Stetter, H.; Urban, B.; Bauer, H.

1999-12-01

Flatterverhalten der Schaufeln von Dehnungsmessstreifen auf den Schaufeltraegern und die auftretenden Stossoszillationen mit Hilfe einer Hoch-Geschwindigkeits-Schlierenoptik, einer Laserschranke, applizierten Foliensensoren und instationaeren Drucksensoren erfasst wurde. Im transsonischen Bereich tritt beim ND-Spitzenschnittprofil ein hohes Anregungspotential durch Stossbewegungen auf. Beim Gasturbinengitter sind die Schwingungsamplituden auf Grund einer hohen Daempfung der elastischen Schaufelhalter geringer. Ein Rechenprogramm zur Simulation der transsonischen, reibungsbehafteten Stroemung durch axiale Turbomaschinen wurde auf die Behandlung bewegter Profile angepasst und fuer instationaere Stroemungssimulationen beschleunigt. Ein k-{epsilon}-Turbulenzmodell mit Wandfunktionen wurde implementiert und ein elliptisches 3D-Gittergenerierungsverfahren in den Stroemungsloeser integriert. An einem Doppelkreisbogenprofil wurden Stossoszillationen nachgerechnet. Die experimentell ermittelten Messdaten dienen als Validierungsgrundlage fuer die numerische Simulation der instationaeren Stroemung durch Schaufelreihen mit schwingenden Profilen. (orig.)

Actual approaches in diagnosis and therapy of malignant lymphoma; Staging und Therapiekontrolle bei Lymphomen

Energy Technology Data Exchange (ETDEWEB)

Moog, F. [LMU, Muenchen (Germany). Klinik fuer Nuklearmedizin; Roemer, W. [Technische Univ. Muenchen (Germany). Klinik fuer Nuklearmedizin

1998-07-01

Actual molecular strategies in therapy of lymphoma attempt to utilize the immune system to target and eliminate residual lymphoma cells after first line therapy. Therefore lymphoma-specific vaccines are used. Therapy was already successful in vitro, in vivo studies are planned for the near future. In the past two decades, prognosis of lymphoma patients has improved due to advances in staging as well as in therapy control. The introduction of duplex sonography allows the decision on dignity of suspicious lymph nodes not only by size criteria but also by different perfusion pattern. Similar advances have been made in cross sectional imaging like computed tomography and magnetic resonance imaging. The development of lymph node specific contrast agents present new tools for further investigation. In nuclear medicine, functional imaging using positron-emission tomography presents new perspectives especially in diagnosis and treatment control of malignant lymphoma. The visualization of the glucose metabolism using the radiolabeled glucose analogue fluorodeoxyglucose (FDG) allows the detection of involved lymph nodes independent of arbitrary criteria such as lesion diameter. First studies on the use of FDG-PET in staging and restaging of lymphoma patients show promising results. (orig.) [Deutsch] Das 2. Muenchner Nuklearmedizin-Symposium hatte unter anderem das Staging und die Therapiekontrolle bei malignen Lymphomen zum Thema. Neben molekular- und zellbiologischen Ansaetzen zur Lymphomvakzinierung wurde der aktuelle Stand der Moeglichkeiten beim Staging und der Therapiekontrolle aus der Sicht des Radiologen und des Nuklearmediziners vorgetragen. Moderne molekularbiologische Strategien basieren auf einer Modifikation der Immunantwort mit dem Ziel, minimale Tumorreste nach einer konventionellen Therapie zu eleminieren. Dabei kommt in erster Linie das Prinzip der `Tumorimpfung` zum Einsatz. Tumorzellen werden spezifisch ueber einen virusassoziierten Gentransfer oder einen

Bariumexaminations of the small intestine and the colon in inflammatory bowel disease; Konventionelle Duenn- und Dickdarmdiagnostik bei entzuendlichen Darmerkrankungen

Energy Technology Data Exchange (ETDEWEB)

Antes, G. [Abteilung fuer Radiologie, Klinikum Kempten-Oberallgaeu g, GmbH, Kempten (Germany)

2003-01-01

, jedoch stieg die Rate der Untersuchungen mit positivem Ergebnis von 46 auf 57%.Der Anteil der entzuendlichen Duenndarmerkrankungen (nicht nur Morbus Crohn) blieb mit 18% konstant. Bei den Kolonuntersuchungen konnte in 7 Faellen die Frage nach einer entzuendlichen Darmerkrankung positiv beantwortet werden. Die Strahlenexposition betraegt beim Enteroklysma von entzuendlichen Erkrankungen 7mSv, beim Kolonkontrasteinlauf 14 mSv.Schlussfolgerung Die Bariumuntersuchungen, insbesondere von Magen und Kolon, sind ruecklaeufig, sodass eine handwerkliche und interpretative Kunst verloren gehen kann.Das Enteroklysma wird immer noch als Referenzmethode fuer andere bildgebende Verfahren angesehen.Die ausgezeichnete Darstellung der Darmoberflaeche und die Beurteilung der Funktion sind ein Vorteil gegenueber den anderen bildgebenden Verfahren. (orig.)

PET in cerebrovascular disease; PET bei zerebrovaskulaeren Erkrankungen

Energy Technology Data Exchange (ETDEWEB)

Herholz, K. [Neurologische Universitaetsklinik der Univ. Koeln (Germany)]|[Max-Planck-Institut fuer Neurologische Forschung, Koeln (Germany)

1997-03-01

Tissue viability is of particular interest in acute cerebral ischemia because it may be preserved if reperfusion can be achieved rapidly, e.g. by acute thrombolysis. Measurements of regional cerebral blood flow (CBF) and oxygen consumption by PET can assess tissue viability, and they have substantially increased our knowledge of th pathophysiology of ischemic stroke and the associated penumbra. Widerspread clinical application in acute stroke, however, is unlikely because of the large logistic and personnel resources required. In chronic cerebrovascular disease, measurement of regional CBF and glucose metabolism, which is usually coupled, provide detailed insights in disturbance of cortical function, e.g. due to deafferentiation, and contribute to differentiation of dementia types. Chronic misery perfusion, i.e. reduced perfusion that does not match the metabolic demand of the tissue, can be demonstrated by PET. It may be found in some patients with high-grade arterial stenoses. Less severe impairment of brain perfusion can be demonstrated by measurement of the cerebrovascular reserve capacity. The most frequent clinical situations can be assessed by less demanding procedures, e.g. by SPECT. In conclusion, PET has its role in cerebrovascular disease primarily within scientific studies, where high resolution and absolute quantitation of physiological variables are essential. (orig.). 65 refs. [Deutsch] Beim akuten ischaemischen Insult ist die Vitalitaet des Gewebes von besonderem Interesse, da sie durch rasche Reperfusion, z.B. durch Thrombolyse, erhalten bleiben kann. Messungen der zerebralen Durchblutung und des Sauerstoffumsatzes mittels PET geben darueber wesentliche Aufschluesse, und sie sind wichtig fuer das Verstaendnis der Pathophysiologie ischaemischer Infarkte und der Penumbra mit kritischer Perfusion beim Menschen. Ihre breitere Anwendung in der klinischen Patientenversorgung kommt allerdings wegen des hohen Aufwandes derzeit kaum in Betracht. Bei

Drivage and surveying during construction of the Channel tunnel. Vortrieb und Vermessung beim Bau des Eurotunnels

Energy Technology Data Exchange (ETDEWEB)

Korittke, N. (DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany, F.R.). Inst. fuer Lagerstaette und Vermessung)

1990-07-26

The Institut fuer Lagerstaette und Vermessung (ILV) (Institute for Deposits and Surveying) of Deutsche Montan Technology (DMT) (German Mining Technology) is participating in many respects in the surveying work for construction of the Channel Tunnel. Three precision survey gyroscopes of the Gyromat type were supplied by the ILV to the Anglo-French tunnel construction consortium for indication of the direction during drivage of the Channel Tunnel from both ends. ILV inclinometers are integral parts of the control systems for two tunneling machines on the French side. ILV carries out main check measurements at regular intervals both on the French and British side. The position and height of a total of 62 km driven tunnel were checked in the course of five measuring series in 1989 and 1990. The DMT is one of the few German companies assisting in construction of the Eurotunnel on both sides of the Channel. Probably the most spectacular tunnel construction project this century together with the procedure, results and accuracies in the main check measurements are described. (orig.).

Signatures of dynamics in charge transport through organic molecules; Dynamisches Verhalten beim Ladungstransport durch organische Molekuele

Energy Technology Data Exchange (ETDEWEB)

Secker, Daniel

2008-06-03

The aim of the thesis at hand was to investigate dynamical behaviour in charge transport through organic molecules experimentally with the help of the mechanically controlled break junction (MCBJ) technique. the thesis concentrates on the complex interaction between the molecular contact configuration and the electronic structure. it is shown that by variation of the electrode distance and so by a manipulation of the molecule and contact configuration the electronic structure as well as the coupling between the molecule and the electrodes is affected. The latter statement is an additional hint how closely I-V-characteristics depend on the molecular contact configuration. Depending on the applied voltage and so the electric field there are two different configurations preferred by the molecular contact. A potential barrier between these two states is the origin of the hysteresis. A central part of the thesis is dealing with measurements of the current noise. Finally it can be concluded that the detailed discussion reveals the strong effect of dynamical interactions between the atomic configuration of the molecular contact and the electronic structure on the charge transport in single molecule junctions. (orig.)

Fundamentals of hydraulic piston pump applications in chemical engineering; Verfahrenstechnische Grundsaetze beim Einsatz von hydraulischen Kolbenpumpen

Energy Technology Data Exchange (ETDEWEB)

Haubold, H.J. [Putzmeister AG, Putzmeister Industrial Technology (PIT), Aichtal (Germany)

2007-07-01

This paper describes design features as well as criteria for the selection of the required piston pump under the circumstance of high viscose sludge. These kind of sludges are mostly contaminated with foreign bodies. Life cycle costs and professional service management are influencing factors of a successful pump operation. This paper will show in detail criteria's for the pipe transportation. For example the influence of the calculation for the pressure loss against the necessary pump pressure. In focus are all structural measures to reduce pressure peaks, as well as the reduction of pressure variation and their elimination in the delivery flow. This under the circumstance of a high pulsating pump delivery. This paper will be concluded with a reference of examples of applications and show new developments of piston pump design. (orig.)

ISOLATION AND CHARACTERIZATION OF AXOLOTL NPDC-1 AND ITS EFFECTS ON RETINOIC ACID RECEPTOR SIGNALING

OpenAIRE

Theodosiou, Maria; Monaghan, James R; Spencer, Michael L; Voss, S Randal; Noonan, Daniel J

2007-01-01

Retinoic acid, a key morphogen in early vertebrate development and tissue regeneration, mediates its effects through the binding of receptors that act as ligand-induced transcription factors. These binding events function to recruit an array of transcription co-regulatory proteins to specific gene promoters. One such co-regulatory protein, neuronal proliferation and differentiation control-1 (NPDC-1), is broadly expressed during mammalian development and functions as an in vitro repressor of ...

Benefits and drawbacks of TOFD and SAFT for crack depth measurement at thick-walled vessels; Vor- und Nachteile von TOFD und SAFT zur Risstiefenmessung an dickwandigen Behaeltern

Energy Technology Data Exchange (ETDEWEB)

Schmitz, V.; Mueller, W. [IZFP, Saarbruecken (Germany); Hecht, A. [BASF AG, Ludwigshafen (Germany)

1999-08-01

The results presented in the paper show that TOFD can be applied in many cases as a low-cost and reliable testing method, but is less suitable for some cases. These are: Description of cracks in welded joints which yield a multitude of data, as e.g. microstructural data, so that the method is less suitable for austenitic weld testing; detection of small cracks. (orig./CB) [Deutsch] Aus den gezeigten Beispielen ergibt sich, dass TOFD in einer Vielzahl von Anwendungsfaellen als preisguenstiges und zuverlaessiges Pruefverfahren eingesetzt werden kann, dass es aber fuer einige Anwendungsfaelle weniger geeignet ist: Diese Anwendungsfaelle sind: (1) Nachweis von Rissen in Schweissnaehten mit vielen Anzeigen, z.B. Gefuegeanzeigen, d.h. insbesondere bei austenitischen Schweissnaehten, und (2) Nachweis von kleinen Rissen. Der Nachweis auch von kleinen Rissen wird dahingegen beim Impuls-Echo Verfahren aufgrund des vorliegenden Winkelspiegeleffektes durchaus moeglich sein. Durch eine nachgeschaltete SAFT-Auswertung werden zum einen stoerendes Gefuegerauschen unterdrueckt und zum anderen Echos von Fehlstellen angehoben. Diese Verbesserung des Signal-Rausch-Abstandes fuehrt zu einer Verbesserung der Fehlererkennbarkeit und der Fehlerbewertung. (orig.)

Cross-disciplinary management of polytrauma patients: radiological screening and comparison; Interdisziplinaeres Management von polytraumatisierten Patienten: Beitrag der Radiologie

Energy Technology Data Exchange (ETDEWEB)

Messmer, P. [Universitaetskliniken Basel, Dept. Chirurgie, Allgemeinchirurgische Klinik, Abt. Traumatologie (Switzerland); Loew, R.; Jacob, A.L. [Universitaetskliniken Basel, Dept. Medizinische Radiologie, Abt. Diagnostische Radiologie (Switzerland)

2001-09-01

The comprehensive survey addresses the various modalities available today for trauma screening and presents a comparative assessment of their value in respect of type of trauma and evidence provided. (orig./CB) [German] Die Versorgung polytraumatischer Patienten stellt hoechste Anforderungen an das Koennen des Radiologen. Neben einer schnellen und schonenden Durchfuehrung der notwendigen Diagnostik darf keine potenziell lebensbedrohende Verletzung uebersehen werden. Die Kriterien fuer eine rationelle Diagnostik wurden im ATLS-Kurs (Advanced Trauma Life Support) zusammengefasst. Es gilt, die sog. 'golden hour' moeglichst effektiv fuer die Primaerdiagnostik und -therapie zu nutzen. Haeufige Verletzungsformen beim Polytrauma sind das Schaedel-Hirn-Trauma, Thoraxverletzungen, Milzverletzungen, Leberverletzungen und Frakturen von Becken, Wirbelsaeule und Extremitaeten. Die Primaere und Sekundaere Radiologische Diagnostik ist abhaengig von der Ausstattung der Klinik und besteht aus einer abdominellen Sonographie, Thorax ap, Beckenuebersicht ap, Halswirbelsaeule seitlich sowie falls vorhanden aus CT und Angiographie. Ein definitiver Schritt zur Verkuerzung der Zeit bis zur Behandlung waeren sterile OP-Einheiten mit integrierter Roentgendiagnostik (moeglichst nativ und CT), die ein staendiges Umlagern und Transportieren des Patienten verhindern koennten. (orig.)

Controlled deprotection and reorganization of uranyl oxo groups in a binuclear macrocyclic environment

Energy Technology Data Exchange (ETDEWEB)

Jones, Guy M.; Arnold, Polly L.; Love, Jason B. [Edinburgh Univ. (United Kingdom). EaStCHEM School of Chemistry

2012-12-07

The silylated uranium(V) dioxo complex [(Me{sub 3}SiOUO){sub 2}(L){sub 2}] is inert to oxidation, but after two-electron reduction to [(Me{sub 3}SiOUO){sub 2}(L)]{sup 2-}, it can be desilylated to form [OU(μ-O){sub 2}UO(L){sub 2}]{sup 2-} with reinstated uranyl character. Removal of the silyl group uncovers new redox and oxo rearrangement chemistry for uranium, thus reforming the uranyl motif and involving the U{sup VI/V} couple in dioxygen reduction. [German] Der silylierte Dioxouran(V)-Komplex [(Me{sub 3}SiOUO){sub 2}(L){sub 2}] (A) ist inert gegen Oxidation, kann aber nach Zweielektronenreduktion zu [(Me{sub 3}SiOUO){sub 2}(L)]{sup 2-} (1) zu [OU(μ-O){sub 2}UO(L){sub 2}]{sup 2-} (2) mit wiederhergestelltem Uranylcharakter desilyliert werden. Beim Entfernen der Silylgruppe zeigt sich eine neue Redox- und Oxoumlagerungschemie des Urans unter Rueckbildung des Uranylmotivs sowie der Beteiligung des U{sup VI/V}-Paars an einer Disauerstoffreduktion.

Poznaniu predchádza porozumenie (Der Erkenntnis geht das Verständnis voran

Directory of Open Access Journals (Sweden)

Jana Tomašovičová

2007-12-01

Full Text Available In diesem Beitrag deuten wir nach der Parmenides Inspiration zwei Wege der menschlichen Wanderung zur Wahrheit an. In Denkensgeschichte war ein Weg der begründeten Erkenntnis bevorzugt, auf dem wir gerade das aussuchen, was als haltbar im Änderungsprozess überdauert. Auf diesem Weg können wir ein souveränes denkendes Subjekt treffen, das wegen seiner Rationalität ein fester Grund beim Erkennen der Welt geworden ist. Am Anfang des 20. Jahrhunderts hat Martin Heidegger darauf hingewiesen, dass im altäglichen Leben unserer Erkenntnis das Verständnis dessen vorangeht, was wir besorgen. Heidegger hat also einen anderen Weg auserwählt, auf dem er bemerkt, dass für einen Mensch eher als seine Rationalität das Abfinden mit seiner faktischen Existenz charakteristisch ist. Heideggers Dasein ist nicht mehr ein Souverän, sondern eine Existenz, die sich um Seinsverständnis bemüht. Ungefähr ab 1930 finden wir eine Kehre im Heideggers Denken. Er sucht einen neuen Weg, auf dem er eine Ek-sistenz vorstellen will.

Electrical grid requirements to be met by superconducting components of energy supply systems; Elektrische Netzanforderungen an supraleitende Komponenten der Energieversorgung

Energy Technology Data Exchange (ETDEWEB)

Hoelter, D W; Radtke, U

1995-05-01

Suoerconducting components will reduce the effective losses of electrical equipment to practically zero. The new technology will bring about novel components with completely new or modified properties and capacities, and thus a number of economic advantages for grid operation. The novel components opened up by superconductivity technology are of particular interest to maximum and high-voltage applications. Components such as generators and transformers will be enhanced in their electrical performance, and effects of synergism are expected to be achieved in multi-functional applications of SMES and through specific combination of the components current limiter and cable, and transformer. (orig./MM) [Deutsch] Supraleitende Betriebsmittel reduzieren die Wirkverluste elektrischer Betriebsmittel praktisch auf null. Daraus resultieren Betriebsmittel mit neuen bzw. veraenderten elektrischen Eigenschaften, die fuer das Netz eine Reihe von Verbesserungen mit sich bringen koennen. Mit Supraleitung werden neuartige Betriebsmittel moeglich und fuer die Hoechst- und Hochspannungsebene wirtschaftlich attraktiv. Andere supraleitende Betriebsmittel wie Generator und Transformator erhalten verbesserte elektrische Eigenschaften. Synergieeffekte sind beim multi-funktionalen Einsatz des SMES und bei Kombination der Betriebsmittel Strombegrenzer und Kabel sowie Transformator zu erwarten. (orig./MM)

Powertrain definitions for Opel's brand sound considering the vehicle portfolio; Gestaltung des Powertrains fuer den Opel-Brand-Sound unter Beruecksichtigung der unterschiedlichen Positionierung der Fahrzeugpalette

Energy Technology Data Exchange (ETDEWEB)

Bernhard, U.; Herrmann, G.; Schmidt, G.O. [Adam Opel AG, Ruesselsheim (Germany)

2002-07-01

The change of value orientation in Western Europe lead to an increase of emotions buying a car. In addition to classic factors like design, today the carmakers use elements of emotion like brand sound to inspire the customers. On the one hand the job of the acoustic engineers is to meet the acoustic expectations depending on driving conditions. On the other hand there are to develop both combining elements over the whole portfolio and elements which allow a defined position of a carline-powertrain combination in the market. (orig.) [German] Im Zuge der Wandlung der westlichen Gesellschaften spielen Emotionen beim Kauf eines Automobils eine immer staerkere Rolle. Zur Unterstuetzung klassischer Mittel wie dem Design werden heute weitere emotionalisierende Elemente zur Begeisterung der Kunden eingesetzt, unter anderem auch das Klangbild eines Fahrzeugs. Dabei liegt die Aufgabe einerseits darin, der unterschiedlichen Erwartungshaltung in Abhaengigkeit vom Fahrzustand des Fahrzeugs gerecht zu werden. Andererseits die Gestaltung des Klangbildes so durchzufuehren, dass innerhalb des Portfolios sowohl verbindende Elemente als markentypisch zu finden sind als auch der Marktpositionierung gerecht werdende Elemente der einzelnen Fahrzeugtypen zu generieren. (orig.)

Interdisciplinary stratification of patients with myoma-related symptoms; Interdisziplinaere Stratifizierung von Patientinnen mit myombedingten Beschwerden

Energy Technology Data Exchange (ETDEWEB)

David, M. [Campus Virchow-Klinikum, Charite - Universitaetsmedizin Berlin, Klinik fuer Frauenheilkunde und Geburtshilfe, Berlin (Germany)

2008-07-15

With the establishment of uterine artery embolization (UAE), the individualization of treatment of the symptomatic myomatous uterus showed a general progression. The concrete therapy decision is made in an interactive process between doctor and patient. A series of factors influence the choice of a suitable, operative or non-operative, therapeutic procedure. In the weighting of therapeutic options between surgery or UAE, in addition to current results of studies which compare both techniques,recommendations made by expert committees and guidelines are helpful for a competent counseling of patients and additionally supportive in decision processes such as interdisciplinary stratification. (orig.) [German] Mit der Etablierung der Uterusarterienembolisation (UAE) wurde die Individualisierung der Behandlung beim symptomatischen Uterus myomatosus insgesamt weiter vorangetrieben. Die Therapieentscheidung wird individuell in einem interaktiven Prozess zwischen Arzt und Patientin getroffen. Eine Reihe von Faktoren beeinflusst die Auswahl eines geeigneten - operativen oder nichtoperativen - Therapieverfahrens. Bei der Abwaegung der Therapieoptionen Operation vs. UAE sind neben aktuellen Ergebnisse von Studien, die beide Verfahren vergleichen, fuer eine kompetente Beratung der Patientinnen Empfehlungen von Expertengremien bzw. Leitlinien hilfreich und in Entscheidungsprozessen wie der interdisziplinaeren Stratifizierung zusaetzlich unterstuetzend. (orig.)

Registration and visualisation of water management data on the basis of a geographic information system; Erfassung und Visualisierung wasserwirtschaftlicher Daten auf der Grundlage eines geographischen Informationssystems

Energy Technology Data Exchange (ETDEWEB)

Klein, F.J. [ENVIS GmbH, Ascheberg (Germany); Peterwitz, U. [Gelsenwasser AG, Gelsenkirchen (Germany)

2001-01-01

The GELSENWASSER water management system was renewed with regard to future request respectively the changing of millenium. Mobil, manual or long-distance transmission registrated water levels, outflows and precipitations from water catchment areas of several waterworks are administered with the aid of an ORACLE data bank system. Interfaces allow a many sided data in- and export with a third party as for example the federal ground water service. For making reports the wellknown OFFICE tool EXCEL is used. Informations related to areas like for instance water quality data are illustrated by a geographic information system. (orig.) [German] Das Wasserwirtschaftssystem der GELSENWASSER AG wurde im Hinblick auf die zukuenftigen Anforderungen bzw. den Jahrtausendwechsel erneuert. Mobil, manuell oder per Fernuebertragung erfasste Wasserstaende, Abfluesse und Niederschlaege aus den Einzugsgebieten mehrerer Wasserwerke werden mit Hilfe eines ORACLE-Datenbanksystems verwaltet. Schnittstellen erlauben einen vielseitigen Datenim- und -export mit Dritten wie z.B. dem Landesgrundwasserdienst. Beim Berichtswesen wird das vielseits gebraeuchliche OFFICE-Werkzueg EXCEL eingesetzt. Informationen mit Raumbezug wie z.B. Gewaesserguetedaten werden mit einem Geografischen Informationssystem dargestellt. (orig.)

Pediatric radiological diagnostics in suspected child abuse; Kinderradiologische Diagnostik bei Verdacht auf Kindesmisshandlung

Energy Technology Data Exchange (ETDEWEB)

Erfurt, C.; Schmidt, U. [Technische Universitaet Dresden, Institut fuer Rechtsmedizin, Medizinische Fakultaet, Dresden (Germany); Hahn, G. [Universitaetsklinikum Carl Gustav Carus, Dresden, Abteilung Kinderradiologie, Institut und Poliklinik fuer Radiologische Diagnostik, Dresden (Germany); Roesner, D. [Universitaetsklinikum Carl Gustav Carus, Dresden, Klinik und Poliklinik fuer Kinderchirurgie, Dresden (Germany)

2009-10-15

Advanced and specialized radiological diagnostics are essential in the case of clinical suspicion of pediatric injuries to the head, thorax, abdomen, and extremities when there is no case history or when ''battered child syndrome'' is assumed on the basis of inadequate trauma. In particular, the aim of this sophisticated diagnostic procedure is the detection of lesions of the central nervous system (CNS) in order to initiate prompt medical treatment. If diagnostic imaging shows typical findings of child abuse, accurate documented evidence of the diagnostic results is required to prevent further endangerment of the child's welfare. (orig.) [German] Klinisch diagnostizierte Verletzungen an Kopf, Thorax, Abdomen oder Extremitaeten eines Kindes bei scheinbar leerer Anamnese oder Angabe eines inadaequaten Traumas erfordern beim Verdacht auf ein Battered-Child-Syndrom eine erweiterte und spezialisierte radiologische Diagnostik. Diese soll insbesondere im Bereich des ZNS Verletzungsfolgen erfassen, um therapeutische Massnahmen einleiten zu koennen. Bei typischen, auf eine Misshandlung hinweisenden radiologischen Befunden ist eine praezise beweissichere Befunddokumentation erforderlich, um eine weitere Kindeswohlgefaehrdung zu vermeiden. (orig.)

Tried and tested automation system helps to reduce air pollution. Ausgereifte Automatisierung hilft beim Reduzieren schaedlicher Emissionen

Energy Technology Data Exchange (ETDEWEB)

Haack, R. (Still Otto GmbH, Bochum (Germany, F.R.)); Schreiter, K.D. (Siemens AG, Erlangen (Germany, F.R.). Bereich Anlagentechnik)

An important step in the coking process is the cooling of the red hot coke. This is mainly done by dowsing with water. The result is the emission of pollutant gases and the waste of heat energy. Disadvantages of this kind can be reduced by the use of a coke drying and cooling plant. This requires, however, because of its complex technology, a tried and tested automation system. A homogeneous solution to the problems faced by the automation system is found in the SIMATIC S5-150U automation unit which was delivered with the coke drying and cooling plant for Pohang (Korea) from the firm Still Otto GmbH in Bochum. This is the largest of its kind. (orig.).

Fair in the face: modern diagnostics of midfacial trauma; Mitten ins Gesicht: Moderne bildgebende Diagnostik beim Gesichtsschaedeltrauma

Energy Technology Data Exchange (ETDEWEB)

Zajaczek, J.E.W. [Abt. Neuroradiologie (OE 8210), Zentrum Radiologie, Medizinische Hochschule Hannover (Germany); Abt. Diagnostische Radiologie, Medizinische Hochschule Hannover (Germany); Rodt, T.; Keberle, M. [Abt. Diagnostische Radiologie, Medizinische Hochschule Hannover (Germany)

2007-07-15

Modern diagnostics of midfacial trauma are embedded in a diagnostic concept that is oriented to the therapeutic relevance for the individual. Critical analysis of the indicated and efficient radiological method in the acute phase shows that MSCT is currently the method of choice in the diagnosis of midfacial trauma. Besides extensive acquisition of data in the shortest time the possibilities of modern post-processing provide a three-dimensional picture of the often complex injuries in real time. Other perilous injuries are often more important especially for the polytrauma patient. With modern scan protocols intracranial injuries as well as injuries of bone and soft tissue of the head and neck region can be diagnosed during a single examination. Radiology plays a key role for the economically oriented strategy of patient care. (orig.)

Zur Bedeutung der Pharmakogenetik in der Veterinärmedizin am Beispiel des MDR1-Gendefektes beim Hund

OpenAIRE

Geyer, Joachim

2014-01-01

Die Pharmakogenetik untersucht, inwieweit Variationen in Genen, welche die pharmakokinetischen und pharmakodynamischen Prozesse eines Arzneistoffes kontrollieren für die interindividuellen Unterschiede in der Arzneistoffwirkung oder dem vermehrten Auftreten unerwünschter Arzneistoffwirkungen verantwortlich sind. Die pharmakogenetische Forschung hat in der Humanmedizin in den vergangenen 10-20 Jahren große Fortschritte erzielt, wobei die auf eine personalisierte Medizin ausgerichtete Berücksic...

Smart Metering: Learning from telecommunication providers. Innovative customized products; Beim Smart Metering von Telekommunikationsanbietern lernen. Innovative Buendelprodukte

Energy Technology Data Exchange (ETDEWEB)

Isbrecht, Volker; Sombrutzki, Ingo [Putz und Partner Unternehmensberatung AG, Hamburg (Germany). Strategie- und Projektmanagement - Energiewirtschaft; Hofer, Kristina [Putz und Partner Unternehmensberatung AG, Hamburg (Germany). CRM- und Telekommunikation

2010-04-06

Deregulation in the electricity and gas metering has raised interest in smart meters. Experts estimate that in a four-person household, smart meters may reduce electricity consumption by up to 10 percent, i.e. 50 - 90 Euros, and CO2 emissions by 8.5 million tonnes, which amounts to 4 percent of the total CO2 emissions in Germany. These are ideal conditions for utilities to develop innovative products for the mass market of private consumers and to improve their competitive standing in the market by a clearly communicated advantage to both the customers and the climate. By utilizing the experience gained in the telecommunications industry, they will be able to respond quickly to impending challenges. (orig.)

Positional information is reprogrammed in blastema cells of the regenerating limb of the axolotl (Ambystoma mexicanum).

Science.gov (United States)

McCusker, Catherine D; Gardiner, David M

2013-01-01

The regenerating region of an amputated salamander limb, known as the blastema, has the amazing capacity to replace exactly the missing structures. By grafting cells from different stages and regions of blastemas induced to form on donor animals expressing Green Fluorescent Protein (GFP), to non-GFP host animals, we have determined that the cells from early stage blastemas, as well as cells at the tip of late stage blastemas are developmentally labile such that their positional identity is reprogrammed by interactions with more proximal cells with stable positional information. In contrast, cells from the adjacent, more proximal stump tissues as well as the basal region of late bud blastemas are positionally stable, and thus form ectopic limb structures when grafted. Finally, we have found that a nerve is required to maintain the blastema cells in a positionally labile state, thus indicating a role for reprogramming cues in the blastema microenvironment.

Positional information is reprogrammed in blastema cells of the regenerating limb of the axolotl (Ambystoma mexicanum.

Directory of Open Access Journals (Sweden)

Catherine D McCusker

Full Text Available The regenerating region of an amputated salamander limb, known as the blastema, has the amazing capacity to replace exactly the missing structures. By grafting cells from different stages and regions of blastemas induced to form on donor animals expressing Green Fluorescent Protein (GFP, to non-GFP host animals, we have determined that the cells from early stage blastemas, as well as cells at the tip of late stage blastemas are developmentally labile such that their positional identity is reprogrammed by interactions with more proximal cells with stable positional information. In contrast, cells from the adjacent, more proximal stump tissues as well as the basal region of late bud blastemas are positionally stable, and thus form ectopic limb structures when grafted. Finally, we have found that a nerve is required to maintain the blastema cells in a positionally labile state, thus indicating a role for reprogramming cues in the blastema microenvironment.

Electrogenic glutamate uptake is a major current carrier in the membrane of axolotl retinal glial cells

Science.gov (United States)

Brew, Helen; Attwell, David

1987-06-01

Glutamate is taken up avidly by glial cells in the central nervous system1. Glutamate uptake may terminate the transmitter action of glutamate released from neurons1, and keep extracellular glutamate at concentrations below those which are neurotoxic. We report here that glutamate evokes a large inward current in retinal glial cells which have their membrane potential and intracellular ion concentrations controlled by the whole-cell patch-clamp technique2. This current seems to be due to an electrogenic glutamate uptake carrier, which transports at least two sodium ions with every glutamate anion carried into the cell. Glutamate uptake is strongly voltage-dependent, decreasing at depolarized potentials: when fully activated, it contributes almost half of the conductance in the part of the glial cell membrane facing the retinal neurons. The spatial localization, glutamate affinity and magnitude of the uptake are appropriate for terminating the synaptic action of glutamate released from photoreceptors and bipolar cells. These data challenge present explanations of how the b-wave of the electroretinogram is generated, and suggest a mechanism for non-vesicular voltage-dependent release of glutamate from neurons.

Simultaneous integrated vs. sequential boost in VMAT radiotherapy of high-grade gliomas

Energy Technology Data Exchange (ETDEWEB)

Farzin, Mostafa [Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Radiation Oncology, Munich (Germany); Tehran University of Medical Science, Brain and Spinal Cord Injury Research Center, Neuroscience Institute, Tehran (Iran, Islamic Republic of); Molls, Michael; Astner, Sabrina; Oechsner, Markus [Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Radiation Oncology, Munich (Germany); Rondak, Ina-Christine [Klinikum rechts der Isar, Technische Universitaet Muenchen, Institut fuer Medizinische Statistik und Epidemiologie, Munich (Germany)

2015-12-15

beider Plaene wurde summiert, um die gesamte verabreichte Dosis zu ermitteln. Beim SIB-Konzept erhaelt das PTV 54 Gy in 30 Fraktionen (Einzeldosis 1,8 Gy), waehrend das Boostvolumen 60 Gy erhaelt (30 Fraktionen, Einzeldosis 2,0 Gy). Beim SEB erhielten die Risikoorgane hoehere Dosen (D{sub max} und D{sub mean}) als bei der SIB-Technik. Die Dosisunterschiede zwischen den beiden Techniken waren fuer nahezu alle Risikoorgane statistisch signifikant. Die Analyse der Dosisverteilungen in den Zielvolumina ergab vergleichbare Gesamtdosen und Dosishomogenitaeten. Unsere Analyse zeigt eine klare Tendenz, dass die SIB-Technik gegenueber der SEB-Technik einen Vorteil bezueglich der Schonung der Risikoorgane bietet. (orig.)

Functional MRI of the pelvic floor: postpartum changes of primiparous women after spontaneous vaginal delivery; Funktionelle Magnetresonanztomographie (MRT) des Beckenbodens: Postpartale Veraenderungen bei Erstgebaerenden nach vaginaler Spontangeburt

Energy Technology Data Exchange (ETDEWEB)

Lienemann, A.; Fischer, T.; Reiser, M. [Inst. fuer Klinische Radiologie, Klinikum der Univ. Muenchen (Germany); Anthuber, C. [Klinik und Poliklinik fuer Geburtshilfe und Frauenheilkunde, Klinikum der Univ. Muenchen/Grosshadern (Germany)

2003-08-01

Entbindung im Vergleich zu 41 Frauen, die noch nicht geboren hatten. Bestimmung morphometrischer Parameter (Muskeldicken, Beckenkonfiguration) und quantitative Erfassung der Lageveraenderungen der Beckenorgane beim Pressversuch anhand von Referenzlinien. Ergebnisse: Das Beckenskelett war bei beiden Gruppen gleich konfiguriert. Der M. puborectalis war in der Erstgebaerenden-Gruppe signifikant ausgeduennt. Im funktionellen Untersuchungsteil fanden sich in Ruhe keine wesentlichen Unterschiede zwischen beiden Kollektiven. Erst beim Pressversuch zeigte sich eine signifikant groessere Haeufigkeit von Zystozelen, Rektozelen und Rektumdeszensus bei den Erstgebaerenden. Schlussfolgerung: Um das Zusammenspiel der Beckenorgane hinsichtlich eines Organdeszensus zu beurteilen, ist eine dynamische Untersuchung erforderlich. Die funktionelle MRT des Beckenbodens ist ohne Strahlen- oder Kontrastmittelbelastung hervorragend geeignet, die signifikanten Veraenderungen am Beckenboden nach vaginaler Geburt aufzuzeigen. (orig.)

Cerebrospinal fluid leakage. Indications, technique and results of treatment with a blood patch; Liquorverlustsyndrom. Indikation, Technik und Ergebnisse der Behandlung mit ''blood patch''

Energy Technology Data Exchange (ETDEWEB)

Gottschalk, A. [Krankenhaus Nordwest, Abteilung Neuroradiologie, Frankfurt am Main (Germany)

2015-06-15

of several months, even though patients are already free of symptoms. In total, blood patch therapy is a safe and technically relative simple method with a high success rate. Therefore, it represents the therapy of choice in patients with spontaneous cerebrospinal fluid leakage as well as in cases of post-lumbar puncture syndrome refractory to conservative therapy. (orig.) [German] In den meisten Faellen ist ein Liquorverlustsyndrom iatrogen durch Lumbalpunktionen, Periduralanaesthesien oder operative Eingriffe an der Wirbelsaeule bedingt. Durch verbesserte diagnostische Moeglichkeiten werden jedoch auch spontane Liquorverlustsyndrome mit zunehmender Haeufigkeit diagnostiziert, deren Ursache oft nicht eindeutig zu klaeren ist. Zur radiologischen Diagnosesicherung und zur Lokalisierung des Liquorlecks stehen mit der Postmyelo-CT, der {sup 111}Indium-Radioisotopenzisternographie und der (Myelo-)MRT mehrere Verfahren mit unterschiedlichen Sensitivitaeten zur Verfuegung. Nach unserer eigenen Erfahrung ist eine primaer nativdiagnostische MRT mit fettsaturierten T2-Sequenzen in vielen Faellen bereits diagnostisch ausreichend, um das Liquorleck und seine Lokalisation zu sichern. In den uebrigen Faellen ist die Durchfuehrung einer ergaenzenden Postmyelo-CT oder alternativ einer Myelo-MRT empfehlenswert. Bei manchen Patienten mit spontanem Liquorverlustsyndrom finden sich dabei mehrere Liquorlecks auf unterschiedlichen Hoehen. Leitsymptom ist in den meisten Faellen ein lageabhaengiger orthostatischer Kopfschmerz. Waehrend das postpunktionelle Syndrom unter Bettruhe und medikamentoeser Therapie oft selbstlimitierend ist, bedarf es beim spontanen Liquorverlustsyndrom meist einer Blood-patch-Therapie. Der lumbale ''blood patch'' kann in der Regel problemlos unter Durchleuchtungskontrolle erfolgen. Bei einem ''blood patch'' an der HWS oder BWS wird aus Sicherheitsgruenden eine CT-gesteuerte Durchfuehrung empfohlen, um eine streng epidurale

System integration of CDC attenuation in the new Opel Astra; Systemintegration der CDC-Daempfung beim neuen Opel Astra

Energy Technology Data Exchange (ETDEWEB)

Balandat, W.; Kutsche, T. [ZF Sachs AG, Schweinfurt (Germany)

2004-08-01

The optional carriage system IDS Plus of the new Opel Astra was developed in close cooperation between opel, ZF Sachs and other suppliers. This networking approach resulted in a high degree of system integration with the electronic attenuation control system CDC as key element. (orig.) [German] Das optionale Fahrwerksystem IDS Plus im neuen Opel Astra entstand in enger Kooperation zwischen Opel, ZF Sachs und weiteren Zulieferern. Die Arbeit im Netzwerk fuehrte zu einer hohen Systemintegration, in deren Kern die elektronische Daempferregelung CDC steht. (orig.)

Crucible and coil monitoring during melting operation in induction crucible furnaces; Tiegel- und Spulenueberwachung beim Schmelzbetrieb von Induktionstiegeloefen

Energy Technology Data Exchange (ETDEWEB)

Doetsch, Erwin; Forsthoevel, Christoph; Rische, Marco [ABP Induction Systems GmbH, Dortmund (Germany)

2013-03-15

The immediate proximity of the metal melt, with a temperature of up to above, 1600 C, to the induction coil in inductive melting necessitates highly reliable monitoring systems, in order to prevent dangerous contact between the melt and the cooling-water-conducting copper section. Ground-fault monitoring, in which the electrical resistance between the melt and the coil is continuously measured, is a standard solution for this function. Everyday use of this long-established system has been made more dependable by automating a number of functions, and the system has also been adapted to modern plant technology, including synchronous tandem operation of two crucible furnaces from a common converter power supply, for example. Measurement of frequency and effective power, as a function of wall thickness, is a supplementary monitoring strategy. Processing of the measured data in the melt processor, in combination with visual assessment, permits appraisal of the integral crucible state and reliable estimation of the remaining service-life of the current crucible. (orig.)

Complications following surgery and adjuvant irradiation in rectal carcinoma. Komplikationen nach Operation und nach adjuvanter Bestrahlung beim Rektumkarzinom

Energy Technology Data Exchange (ETDEWEB)

Suhr, P.; Limmer, J. (Ulm Univ. (Germany, F.R.). Universitaetsklinikum)

1991-04-12

Colorectal cancer is one of the most common human malignancies. Adjuvant irradiation can decrease the risk of recurrence and subsequently the associated morbidity compared with surgery alone. The rate of radiation-induced complications amounts to approximately 10%, which is substantially lower than the frequency of observed local failure. (orig.).

ALS Ice Bucket Challenge: Warum die Kampagne über einen „Tsunami Effekt“ beim Spendenverhalten Eisberge versetzen kann

OpenAIRE

Decieux, Jean Philippe Pierre

2015-01-01

Im Sommer 2014 beherrschte eine Kampagne die sozialen Medien, welche auf originelle Art und Weise auf die Nervenkrankheit Amyotrophe Lateralsklerose (ALS) aufmerksam machen und dadurch Spendengelder für die Erforschung dieser Krankheit generieren wollte. Im Rahmen der sogenannten ALS-Ice-Bucket-Challenge-Kampagne gossen sich die Hauptdarsteller/innen von kleinen Internetclips eiskaltes Wasser über den Kopf und nominierten im Anschluss weitere Personen für die Challenge. Die Herausforderung bz...

Structural behaviour of pipe umbrellas in tunnel drives in granular soils; Tragverhalten von Rohrschirmdecken beim Tunnelbau im Lockergestein

Energy Technology Data Exchange (ETDEWEB)

Eckl, Michael

2012-11-01

An increase in the use of pipe umbrellas made of long piles or self drilling injection anchors can be seen in conventional tunnel drives. They are used as reinforcement ahead of the face. This paper consists of investigations concerning the structural and geotechnical behaviour of such umbrellas in granular soils. The research is based on finite element method calculations using a diverse range of essential influencing factors. From the evaluation of the calculations, conclusions can be drawn about the load bearing behaviour of the umbrellas and their interaction with the surrounding ground. A forecasting model is derived in order to predict the internal forces of the umbrella elements and a design methodology is presented. (orig.)

Technologische Zukünfte - Was kommt auf uns zu?: Vortrag gehalten beim 2. EUROPEAN INNOVATORS Jahresnetzwerktreffen, 2017, Hannover

OpenAIRE

Bantes, René

2017-01-01

Technological development is only surprising to the unprepared. The speed of technological development is heavily influenced by non-technological aspects. Societal norming lags profoundly behind the technological advances and turns into a roadblock for technological advances. For the foreseeable future technological disruption is more probable to emerge out of convergence of existing technologies then of revolutionary technological progress.

Environmental effects and potential hazards of chemical substances used in waste water purification; Umweltvertraeglichkeit und Gefaehrdungspotentiale von Abwasserbehandlungschemikalien

Energy Technology Data Exchange (ETDEWEB)

Schumann, H. [Umweltbundesamt, Berlin (Germany). Inst. fuer Wasser-, Boden- und Lufthygiene

1999-07-01

Waste water purification in sewage systems would be impossible without additions of chemical substances for coagulation, flocculation and neutralisation. However, these substances also pollute the purified waste water and the freshwater supplies. In addition, the non-reactive fraction of toxic substances originally contained in the waste water is discharged with the purified waste water and adds to the pollution of freshwater reservoirs. Detailed investigations are required for defining the state of the art in the use of chemical substances for waste water purification. [German] Um Schadstoffe aus dem Abwasser zu entfernen, werden in der Klaeranlage bestimmte Hilfsstoffe zugesetzt, ohne die eine Reinigung des Abwassers nicht in dieser Qualitaet moeglich waere und unverhaeltnismaessig teuer wuerde. Die Hilfsstoffe unterstuetzen den Reinigungsprozess durch Faellung, Flockung und Neutralisation. Durch den Einsatz dieser Chemikalien zur Behandlung von Abwaessern gelangen jedoch auch - Verunreinigungen durch die Nebenstoff-Matrix der eingesetzten Behandlungschemikalien in das behandelte Abwasser und in die Gewaesser und - durch ueberstoechiometrische Dosierung oder Additive tritt der nicht reagierende Teil toxischer Substanzen ebenfalls im behandelten Abwasserablauf und im Gewaesser auf. Detaillierte Untersuchungen erscheinen geboten, um auf dieser Grundlage den Stand der Technik beim Einsatz von Chemikalien zur Abwasserbehandlung zu formulieren. (orig./SR)

Effects of oxygen on the re-injection characteristics of thermal water with high salinity and a high iron content; Zum Einfluss von Sauerstoff auf das Reinjektionsverhalten hochsalinarer, eisenhaltiger Thermalwaesser

Energy Technology Data Exchange (ETDEWEB)

Martin, M.; Koeckritz, V. [TU BA Freiberg (Germany). Inst. fuer Bohrtechnnik und Fluidbergbau; Seibt, A. [GeoForschungsZentrum PB 4.4, Neubrandenburg (Germany)

1998-12-31

For reasons of environmental protection and in order to maintain a constant pressure level, hydrogeothermal water must be re-injected into the reservoir after use. However, human interception in the natural fluid/rock system will change the thermodynamic parameters and also the pH and redox potential. This may cause interactions between bedrock, underground water, and the re-injected fluid and have negatives effects on injectivity. Research is going on in this field on the basis of the experience gained in geothermal heating stations in north eastern Germany. (orig.) [Deutsch] Bei einer energetischen und/oder stofflichen Nutzung hydrogeothermaler Ressourcen muessen die Waesser aus Gruenden des Umweltschutzes und der Druckerhaltung im Speicher wieder in das Reservoir verbracht werden. Durch den Eingriff in das natuerliche System Fluid/Gestein werden nicht nur thermodynamische Zustandsgroessen veraendert, sondern es sind auch pH- und Redoxpotentialaenderungen z.B. durch Gasentloesungen zu erwarten. Dies kann beim Reinjizieren zu Wechselwirkungen zwischen dem Speichergestein, dem Schichtwasser und dem injizierten Fluid fuehren, was negative Auswirkungen auf die Injektivitaetsentwicklung haben kann. Eine geeignete Methode zur Aufklaerung von Einzeleffekten und zur Abschaetzung von chemischen Wechselwirkungen stellen Kerndurchstroemungsversuche dar. Ausgangspunkt der Untersuchungen sind die Erfahrungen aus dem Betrieb Geothermischer Heizzentralen Nordostdeutschlands. (orig.)

Steel, hard metal and diamonds. The history of drilling blast holes in mining and tunneling; Stahl, Hartmetall und Diamanten. Zur Geschichte des Sprenglochbohrens im Berg- und Tunnelbau

Energy Technology Data Exchange (ETDEWEB)

Feistkorn, E. [Inst. fuer Vortrieb und Gewinnung, DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany)

1997-12-31

Beginning of the blasting technique in mining and tunneling during the 17th century required drilling holes to take the explosive. Following the use of hammer and wedge, drilling was done over a long period of time by hand with mallet and drillsteel. Continuously, during the 19th century the handwork was replaced by drilling machines. Technically, the evolution of drilling equipment is marked by electrohydraulic control and automatization with the assistance of microelectronics. Regarding the material, the introduction of hard metal and - in addition for rotary drilling - the development of synthetic diamond material are the main features. (orig.) [Deutsch] Mit der Einfuehrung der Sprengtechnik im Bergbau und Tunnelbau im 17. Jahrhundert mussten verfahrensbedingt Bohrloecher zur Aufnahme des Sprengstoffes hergestellt werden. In Anlehnung an die Arbeit mit Schlaegel und Eisen erfolgte dies lange Zeit manuell mit dem Bohrfaeustel und Stahlbohrern. Die Handarbeit wurde waehrend der 2. Haelfte des 19. Jahrhunderts kontinuierlich durch Bohrmaschinen verdraengt. Maschinentechnisch ist die weitere Entwicklung durch elektrohydraulische Steuerungen und die Automatisierung der Bohrgeraete mit Hilfe der Mikroelektronik gekennzeichnet. Materialtechnisch stellen die Einfuehrung des Hartmetalls und beim drehenden Bohren zusaetzlich die Entwicklung synthetischer Diamantwerkstoffe die herausragenden Marksteine dar. (orig.)

Bundling for creating cross-selling potentials of energy supply companies; Cross-Selling-Potenziale bei Energieversorgungsunternehmen durch Bundling

Energy Technology Data Exchange (ETDEWEB)

Zinnbauer, M. [Ludwig-Maximilians-Universitaet Muenchen (Germany)

2001-07-01

As most of the electric utilities in Germany have decided by now to adopt the multi-utility strategy for sales promotion in the open electricity market, a questionnaire has been distributed to 1 000 households in order to find out whether product bundling or cross selling in combination with the low-interest product 'electricity' is a good strategy to enlarge the customer basis. EFOplan (Munic University) and the consulting firm Accenture have been in charge of the survey. The results show the current status of insight of household customers and their motives to change supplier, as well as the pattern of demand for product bundling. (orig./CB) [German] Da mittlerweile die meisten EVUs eine Multi-Utility-Strategie anstreben, wurde mittels einer schriftlichen Befragung von 1 000 deutschen Haushalten untersucht, ob die Vermarktung von Zusatz- bzw. Buendelprodukten in Kombination mit dem Low-Interest-Produkt Strom erfolgsversprechend ist. Die Befragung, die von EFOplan (Universitaet Muenchen) in Kooperation mit der Unternehmensberatung Accenture durchgefuehrt wurde, zeigt einerseits den aktuellen Status von Informationsstand und Wechselmotiven beim Stromkauf und andererseits die Bedarfsstruktur im Hinblick auf moegliche Buendelprodukte. (orig.)

Design and optimization of the low frequency eddy current technique for the volumetric inspection of austenitic small diameter tubes with a wall thickness up to 12 mm; Auslegung und Optimierung des Niederfrequenz-Wirbelstrom-Verfahrens fuer die volumetrische Pruefung von austenitischen Neben- und Kleinleitungen mit Wandstaerken bis 12 mm

Energy Technology Data Exchange (ETDEWEB)

Becker, R; Bessert, S; Disque, M; Weiss, R [Fraunhofer-Institut fuer Zerstoerungsfreie Pruefverfahren, Saarbruecken (Germany)

1998-11-01

The low-frequency eddy current technique discussed is a suitable external inspection technique detecting defects at the inner walls of small-diameter tubes and measuring their depths via the ligament. A testing system with optimized sensor lus software for image recording, evaluation, display and documentation is available. The current state of development of the system permits detection and measurement of defects up to 20 mm in size in austenitic inner walls 12.5 mm thick down to a depth of 3 mm. This applies both to the homogenous base metal and the weld with {delta} ferrite. (orig./CB) [Deutsch] Das vorgestellte Niederfrequenz-Wirbelstrom-Verfahren ist geeignet, bei Pruefung von aussen Fehler an der Innenseite von Klein- und Nebenleitungen nachzuweisen und ueber das Ligament deren Tiefe zu bestimmen. Ein entsprechendes Pruefsystem mit optimiertem Sensor und der Software zur Aufnahme, Auswertung, Darstellung und Dokumentation der Wirbelstrom-Urdaten steht zur Verfuegung. Beim jetzigen Entwicklungsstand liegt die Nachweisgrenze fuer einen 20 mm langen Innenfehler in einer 12.5 mm dicken austenitischen Wandung bei einer Fehlertiefe von 3 mm. Dies gilt sowohl fuer den homogenen Grundwerkstoff als auch fuer Schweissgefuege mit {delta}-Ferrit. (orig./MM)

Spreading amelanotic malignant melanoma: A rare differential diagnosis with tumors of the glandula submandibularis; Metastasiertes amelanotisches Melanom: Eine seltene Differentialdiagnose bei Tumoren der Glandula submandibularis

Energy Technology Data Exchange (ETDEWEB)

Ehrenberg, C.; Helmberger, H. [Technische Univ. Muenchen (Germany). Inst. fuer Roentgendiagnostik; Werner, M. [Institut fuer Allgemeine Pathologie und Pathologische Anatomie, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany)

1998-09-01

The case reported emphasizes the importance of immediate performance of imaging scans in case of the slightest suspicion that clinical symptoms might indicate malignancy of a detected lesion. Despite the superficially only marginal macroscopic findings, MR imaging as well as the CT scans revealed an advanced, malignant process that had been spreading. Particularly the soft tissue differential diagnosis obtained with MRI yields the information required for diagnostic characterization of the space occupying tumor mass. It will however be necessary in any case to verify the diagnosis by biopsy or extirpation and cytologic examination of tissue, as the imaging methods do not always unambigiously reveal the malignant dignity of the tumor. (orig./CB) [Deutsch] Der vorliegende Fall unterstreicht die Bedeutung einer umgehend durchgefuehrten Bildgebung beim geringsten Zweifel an der Benignitaet eines klinischen Symptoms. Trotz des aeusserlich nur marginalen makroskopischen Befundes zeigt die Kernspintomographie in Uebereinstimmung mit der Computertomographie einen fortgeschrittenen, bereits abgesiedelten Prozess. Insbesondere die MRT laesst aufgrund ihrer guten Weichteildifferenzierung einen Rueckschluss auf den Gewebstyp der Raumforderung zu. Einschraenkend bleibt jedoch festzuhalten, dass die maligne Dignitaet des Tumors in beiden bildgebenden Verfahren nicht ohne weiteres erkennbar ist, so dass die Biopsie bzw. Extirpation zur Histologiegewinnung unverzichtbar ist. (orig./MG)

Lectures held at the congress on ``Gas hydrates: problem substance / resource``, organised by the GDMK Division for ``Exploration and Extraction`` and the Institute for Mineral Oil and Natural Gas Research, in Clausthal-Zellerfeld (Harz) on 6/7 November 1997. Author`s manuscripts; Vortraege der Veranstaltung ``Gashydrate: Problemstoff/Resource`` des GDMK-Fachbereichs `Aufsuchung und Gewinnung` und dem Institut fuer Erdoel- und Erdgasforschung am 06. und 07. November 1997 in Clausthal-Zellerfeld (Harz). Autorenmanuskripte

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

The following topics are dealt with in detail: the chemical and physical properties of gas hydrates as derivable from their phase behaviour; the significance and occurrence of gas hydrates in offshore areas; gas hydrates and permafrost in continental northern West Siberia; information on HYACE, a research project of the European Union on test drilling for gas hydrates in offshore areas; sediment-mechanical criteria of gas hydrate formation in deep-sea sediments; gas hydrate formation in gas cavern storages; the use of hydrate inhibitors in operating natural gas storages; and the inhibition of gas hydrates with kinetic inhibitors. Eight abstracts were abstracted individually for the Energy Database. (MSK) [Deutsch] Folgende Themen werden detailliert behandelt: die chemischen und physikalischen Eigenschaften von Gashydraten,welche aus dem Phasenverhalten der Gashydrate herzuleiten sind; zur Bedeutung und Vorkommen von Gashydraten im Offshore-Bereich; Gashydrate und Permafrost im kontinentalen noerdlichen Westsibirien; Informationen zu HYACE, einem Forschungsprojekt der Europaeischen Union zu Probebohrungen nach Gashydraten im Offshore-Bereich; sedimentmechanische Kriterien bei der Gashydratbildung in Tiefseesedimenten; die Gashydratbildung in Gaskavernenspeichern; der Einsatz von Hydratinhibitoren beim Betrieb von Erdgasspeichern sowie die Inhibierung von Gashydraten mit kinetischen Inhibitoren. Fuer die Datenbank Energy wurden acht Beitraege einzeln aufgenommen.

Structure and characteristics of EB-PVD thermal insulation layers; Struktur und Eigenschaften von EB-PVD-Waermedaemmschichten

Energy Technology Data Exchange (ETDEWEB)

Schulz, U. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Koeln (Germany). Inst. fuer Werkstoff-Forschung

1996-12-31

Thermal insulation layers for guide blades and rotor blades in the first two stages of a high-pressure turbines are produced by electron-beam physical vapour deposition for maximum quality. The layers have a lifetime that is longer by a factor of 2 to 10 than for plasma-sprayed layers. The following characteristics of the ceramic layer have a decisive influence on the life of the composite system: Phase composition, distribution and stability, microstructure, density, thickness, crack distribution and cohesive strength. Some selected aspects of the interdependence between production parameters, microstructure of the thermal insulation layer and service life are gone into. [Deutsch] Zur Herstellung von Waermedaemmschichten (WDS) fuer Turbinenleit- und Laufschaufeln der ersten beiden Stufen in der Hochdruckturbine wird fuer hoechste Ansprueche an die Schichtqualitaet das EB-PDV-Verfahren (electron-beam physical vapour deposition) eingesetzt. Die Lebensdauer dieser Schichten ist um den Faktor 2 bis 10 besser als beim Plasmaspritzen. Bei der keramischen Waermedaemmschicht selbst beeinflussen folgende Eigenschaften die Lebensdauer des Gesamtschichtsystems nachhaltig: Phasenzusammensetzung, -verteilung und -stabilitaet, Mikrogefuege, Dichte, Dicke, Rissverteilung und kohaesive Festigkeit. Auf einige ausgewaehlt Aspekte des Zusammenhangs zwischen Herstellungsparametern, Mikrostruktur der Waermedaemmschicht und Lebensdauer wird kurz eingegangen. (orig.)

Development of the air actuated disk brakes for the MAN L2000; Die Druckluft-Scheibenbremsen-Entwicklung fuer den MAN L2000

Energy Technology Data Exchange (ETDEWEB)

Strauss, W.; Roehling, W.; Mueller, H.W.

1996-11-01

The latest MAN truck type L2000 (GVW 7.5 to 11 t) is the first vehicle in this range to be equipped with air actuated disc brakes on both axles. As this product group is subject to extreme price pressure and increased technical requirements, the existing braking system had to be replaced by a new one. The new wheel brake system demonstrates that objectives, especially with regard to vehicle handling and brake performance reserves, were met. At the same time the conditions for applying electronic braking systems were set up and cost targets reached. (orig.) [Deutsch] Beim neuen MAN L2000 mit einem zulaessigen Fahrzeuggewicht von 7,5 bis 11 t handelt es sich um das erste Automobil seiner Klasse, das auf beiden Achsen mit druckluftbetaetigten Scheibenbremsen ausgeruestet ist. Da diese Fahrzeugklasse unter einem hohen Kostendruck steht und die technischen Anforderungen erweitert wurden, musste die vorliegende Bremsenausruestung durch ein neues System ersetzt werden. Das neue Radbremsensystem zeigt, dass die gesteckten Ziele insbesondere in bezug auf Fahrverhalten und Reserven bei der Bremsleistung erreicht werden konnten. Gleichzeitig wurden die Voraussetzungen fuer den Einsatz elektronischer Bremssysteme geschaffen und die Kostenziele erreicht. (orig.)

Zeit im Wandel der Zeit.

Science.gov (United States)

Aichelburg, P. C.

Contents: Einleitung(P. C. Aichelburg). 1. Über Zeit, Bewegung und Veränderung (Aristoteles). 2. Ewigkeit und Zeit (Plotin). 3. Was ist die Zeit? (Augustinus). 4. Von der Zeit (Immanuel Kant). 5. Newtons Ansichten über Zeit, Raum und Bewegung (Ernst Mach). 6. Über die mechanische Erklärung irreversibler Vorgänge (Ludwig Boltzmann). 7. Das Maß der Zeit (Henri Poincaré). 8. Dauer und Intuition (Henri Bergson). 9. Die Geschichte des Unendlichkeitsproblems (Bertrand Russell). 10. Raum und Zeit (Hermann Minkowski). 11. Der Unterschied von Zeit und Raum (Hans Reichenbach). 12. Newtonscher und Bergsonscher Zeitbegriff (Norbert Wiener). 13. Die Bildung des Zeitbegriffs beim Kinde (JeanPiaget).14. Eine Bemerkung über die Beziehungen zwischen Relativitätstheorie und der idealistischen Philosophie (Kurt Gödel). 15. Der zweite Hauptsatz und der Unterschied von Vergangenheit und Zukunft (Carl Friedrich v. Weizsäcker). 16. Zeit als physikalischer Begriff (Friedrich Hund). 17. Zeitmessung und Zeitbegriff in der Astronomie (Otto Heckmann). 18. Kann die Zeit rückwärts gehen? (Martin Gardner). 19. Zeit und Zeiten (Ilya Prigogine, Isabelle Stengers). 20. Zeit als dynamische Größe in der Relativitätstheorie (P. C. Aichelburg).

Investigation for a chemical and physical description of different types of biomass; Untersuchung zur chemischen und physikalischen Beschreibung verschiedener Biomassen

Energy Technology Data Exchange (ETDEWEB)

Stuelpnagel, R [Kassel Univ. (Gesamthochschule), Witzenhausen (Germany). Inst. fuer Nutzpflanzenkunde

1998-09-01

If the same type of biomass is harvested at different times, preserved by different technques and then processed into fuel, the physical and chemical characteristics of the fuel will differ. After describing biomass fuel of the `wet line`, the author carried out investigations of lumpiness, bulk density and materials density of chopped materials in order to obtain a preliminary physical characterisation. Two samples of wood chips were characterized as well. The chemical description started with an analysis of nutrient content, acidity and concentrations of fermentation acids in the `wet line` biomass. (orig.) [Deutsch] Wird die gleiche Biomasse zu unterschiedlichen Zeitpunkten geerntet, auf verschiedenen Wegen konserviert und beim Feuchtgut mechanisch zu Brennstoff aufbereitet, so wird dies Einfluss auf die physikalischen und chemischen Charakteristika eines Brennstoffes nehmen. Nach einer ersten Beschreibung des Brennstoffes Biomasse aus der `Feuchtgutlinie` sollten durch Untersuchungen zur Stueckigkeit, Schuettdichte und Materialdichte von Haeckselgut aus beiden Verfahren eine erste physikalische Charakterisierung durchgefuehrt werden, in die auch zwei Proben von Holzhackschnitzeln einbezogen wurde. Mit der Analyse der Naehrstoffgehalte sowie der Aciditaet und der Gehalte an Gaersaeuren in den Biomassen aus der Feuchtgutlinie sollte die chemische Beschreibung begonnen werden. (orig.)

Terminal-Nerve-Derived Neuropeptide Y Modulates Physiological Responses in the Olfactory Epithelium of Hungry Axolotls (Ambystoma mexicanum)

OpenAIRE

Mousley, Angela; Polese, Gianluca; Marks, Nikki J.; Eisthen, Heather L.

2006-01-01

The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the o...

Nerve signaling regulates basal keratinocyte proliferation in the blastema apical epithelial cap in the axolotl (Ambystoma mexicanum).

Science.gov (United States)

Satoh, Akira; Bryant, Susan V; Gardiner, David M

2012-06-15

The ability of adult vertebrates to repair tissue damage is widespread and impressive; however, the ability to regenerate structurally complex organs such as the limb is limited largely to the salamanders. The fact that most of the tissues of the limb can regenerate has led investigators to question and identify the barriers to organ regeneration. From studies in the salamander, it is known that one of the earliest steps required for successful regeneration involves signaling between nerves and the wound epithelium/apical epithelial cap (AEC). In this study we confirm an earlier report that the keratinocytes of the AEC acquire their function coincident with exiting the cell cycle. We have discovered that this unique, coordinated behavior is regulated by nerve signaling and is associated with the presence of gap junctions between the basal keratinocytes of the AEC. Disruption of nerve signaling results in a loss of gap junction protein, the reentry of the cells into the cell cycle, and regenerative failure. Finally, coordinated exit from the cell cycle appears to be a conserved behavior of populations of cells that function as signaling centers during both development and regeneration. Copyright © 2012 Elsevier Inc. All rights reserved.

Inhibition of the Processes of Growth and Differentiation in the Embryonic Development of the Axolotl (Ambystma mexicanum)

NARCIS (Netherlands)

Stolk, Anth.

1954-01-01

The problem of the retardation of the processes of growth and differentiation is certainly as important as the processes of growth and differentiation themselves. It is striking, therefore, that whereas the analysis of growth has been carried out for a considerable period of time already, the

Calcium waves.

Science.gov (United States)

Jaffe, Lionel F

2008-04-12

Waves through living systems are best characterized by their speeds at 20 degrees C. These speeds vary from those of calcium action potentials to those of ultraslow ones which move at 1-10 and/or 10-20 nm s(-1). All such waves are known or inferred to be calcium waves. The two classes of calcium waves which include ones with important morphogenetic effects are slow waves that move at 0.2-2 microm s(-1) and ultraslow ones. Both may be propagated by cycles in which the entry of calcium through the plasma membrane induces subsurface contraction. This contraction opens nearby stretch-sensitive calcium channels. Calcium entry through these channels propagates the calcium wave. Many slow waves are seen as waves of indentation. Some are considered to act via cellular peristalsis; for example, those which seem to drive the germ plasm to the vegetal pole of the Xenopus egg. Other good examples of morphogenetic slow waves are ones through fertilizing maize eggs, through developing barnacle eggs and through axolotl embryos during neural induction. Good examples of ultraslow morphogenetic waves are ones during inversion in developing Volvox embryos and across developing Drosophila eye discs. Morphogenetic waves may be best pursued by imaging their calcium with aequorins.

Microarray analysis identifies keratin loci as sensitive biomarkers for thyroid hormone disruption in the salamander Ambystoma mexicanum.

Science.gov (United States)

Page, Robert B; Monaghan, James R; Samuels, Amy K; Smith, Jeramiah J; Beachy, Christopher K; Voss, S Randal

2007-02-01

Ambystomatid salamanders offer several advantages for endocrine disruption research, including genomic and bioinformatics resources, an accessible laboratory model (Ambystoma mexicanum), and natural lineages that are broadly distributed among North American habitats. We used microarray analysis to measure the relative abundance of transcripts isolated from A. mexicanum epidermis (skin) after exogenous application of thyroid hormone (TH). Only one gene had a >2-fold change in transcript abundance after 2 days of TH treatment. However, hundreds of genes showed significantly different transcript levels at days 12 and 28 in comparison to day 0. A list of 123 TH-responsive genes was identified using statistical, BLAST, and fold level criteria. Cluster analysis identified two groups of genes with similar transcription patterns: up-regulated versus down-regulated. Most notably, several keratins exhibited dramatic (1000 fold) increases or decreases in transcript abundance. Keratin gene expression changes coincided with morphological remodeling of epithelial tissues. This suggests that keratin loci can be developed as sensitive biomarkers to assay temporal disruptions of larval-to-adult gene expression programs. Our study has identified the first collection of loci that are regulated during TH-induced metamorphosis in a salamander, thus setting the stage for future investigations of TH disruption in the Mexican axolotl and other salamanders of the genus Ambystoma.

Initial characterization of the large genome of the salamander Ambystoma mexicanum using shotgun and laser capture chromosome sequencing.

Science.gov (United States)

Keinath, Melissa C; Timoshevskiy, Vladimir A; Timoshevskaya, Nataliya Y; Tsonis, Panagiotis A; Voss, S Randal; Smith, Jeramiah J

2015-11-10

Vertebrates exhibit substantial diversity in genome size, and some of the largest genomes exist in species that uniquely inform diverse areas of basic and biomedical research. For example, the salamander Ambystoma mexicanum (the Mexican axolotl) is a model organism for studies of regeneration, development and genome evolution, yet its genome is ~10× larger than the human genome. As part of a hierarchical approach toward improving genome resources for the species, we generated 600 Gb of shotgun sequence data and developed methods for sequencing individual laser-captured chromosomes. Based on these data, we estimate that the A. mexicanum genome is ~32 Gb. Notably, as much as 19 Gb of the A. mexicanum genome can potentially be considered single copy, which presumably reflects the evolutionary diversification of mobile elements that accumulated during an ancient episode of genome expansion. Chromosome-targeted sequencing permitted the development of assemblies within the constraints of modern computational platforms, allowed us to place 2062 genes on the two smallest A. mexicanum chromosomes and resolves key events in the history of vertebrate genome evolution. Our analyses show that the capture and sequencing of individual chromosomes is likely to provide valuable information for the systematic sequencing, assembly and scaffolding of large genomes.

Vesicular stomatitis virus enables gene transfer and transsynaptic tracing in a wide range of organisms.

Science.gov (United States)

Mundell, Nathan A; Beier, Kevin T; Pan, Y Albert; Lapan, Sylvain W; Göz Aytürk, Didem; Berezovskii, Vladimir K; Wark, Abigail R; Drokhlyansky, Eugene; Bielecki, Jan; Born, Richard T; Schier, Alexander F; Cepko, Constance L

2015-08-01

Current limitations in technology have prevented an extensive analysis of the connections among neurons, particularly within nonmammalian organisms. We developed a transsynaptic viral tracer originally for use in mice, and then tested its utility in a broader range of organisms. By engineering the vesicular stomatitis virus (VSV) to encode a fluorophore and either the rabies virus glycoprotein (RABV-G) or its own glycoprotein (VSV-G), we created viruses that can transsynaptically label neuronal circuits in either the retrograde or anterograde direction, respectively. The vectors were investigated for their utility as polysynaptic tracers of chicken and zebrafish visual pathways. They showed patterns of connectivity consistent with previously characterized visual system connections, and revealed several potentially novel connections. Further, these vectors were shown to infect neurons in several other vertebrates, including Old and New World monkeys, seahorses, axolotls, and Xenopus. They were also shown to infect two invertebrates, Drosophila melanogaster, and the box jellyfish, Tripedalia cystophora, a species previously intractable for gene transfer, although no clear evidence of transsynaptic spread was observed in these species. These vectors provide a starting point for transsynaptic tracing in most vertebrates, and are also excellent candidates for gene transfer in organisms that have been refractory to other methods. © 2015 Wiley Periodicals, Inc.

Wear resistant PVD-/CVD-dry lubricant coatings for the environmental and innovative production. Subproject 3: dry lubricant coatings - carbon coatings. Final report; Verschleissfeste PVD-/CVD-Trockenschmierstoffschichten fuer die umweltschonende und innovative Fertigung. Teilprojekt 3: Kohlenstoffbasierte Trockenschmierstoffschichten (TSS-C). Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Schattke, A.; Hockauf, W.

2002-09-05

wurden. Geeignete Schichten kamen in fertigungsnahe Feldtests bzw. in die Fertigung beim Endanwender Bosch und projektuebergreifend bei anderen Endanwendern des Gesamtprojektes. Es zeigte sich, dass die Kohlenstoffschichten bei Stanz- und Blechumformungsoperationen hervorragende Ergebnisse liefern. Auch beim Bohren und Gewindeformen in Gusswerkstoffen und niedrig legierten Staehlen konnten trocken fertigungsrelevante Ergebnisse erzielt werden. Bohren und Gewindeformen in Aluminiumlegierungen und hochlegierten Staehlen war trocken mit fertigungsrelevanten Schnittwerten nicht moeglich. Vergleichsversuche mit Minimalmengenschmierung haben jedoch aufgezeigt, dass trotz Reduzierung der Minimalmenge auf 6 ml/Std. deutlich hoehere Schnittwerte gefahren werden konnten, als mit bisher am Markt erhaeltlichen Beschichtungen. Auch die Standmenge und die Qualitaet der Bearbeitungen konnte verbessert werden. Der Versuch, besonders gute Beschichtungen auch in der Halbwarm-Massivumformung einzusetzen, ist leider gescheitert. Bei den hohen Temperaturen und Flaechenpressungen war ein Arbeiten ohne Schmiermittel grundsaetzlich nicht moeglich. Die Arbeiten wurden deshalb zur Mitte des Projektes abgebrochen. (orig.)

TAMR effect in the tunneling through monocrystalline GaAs barriers; TAMR-Effekt beim Tunneln durch einkristalline GaAs-Barrieren

Energy Technology Data Exchange (ETDEWEB)

Lobenhofer, Michael

2013-01-28

Within the scope of this thesis the TAMR-effect in magnetic tunnel junctions with a single-crystalline GaAs-barrier was investigated. As ferromagnetic electrodes Fe-, FeCo- and FePt-layers were used. The measured TAMR-effect was investigated with respect to its behaviour towards changes in external Parameters, like the applied voltage, the temperature and the external magnetic field. The physical origin of the effect was attributed to the interaction of Rashba- and Dresselhaus-Spin-Orbit-coupling inside the tunnelling barrier and at the metal/semiconductor-interfaces.