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Sample records for beim neotenen axolotl

  1. The Mexican Axolotl in Schools

    Science.gov (United States)

    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)

  2. Generation of axolotl hematopoietic chimeras

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    David Lopez

    2015-02-01

    Full Text Available Wound repair is an extremely complex process that requires precise coordination between various cell types including immune cells.  Unfortunately, in mammals this usually results in scar formation instead of restoration of the original fully functional tissue, otherwise known as regeneration.  Various animal models like frogs and salamanders are currently being studied to determine the intracellular and intercellular pathways, controlled by gene expression, that elicit cell proliferation, differentiation, and migration of cells during regenerative healing.  Now, the necessary genetic tools to map regenerative pathways are becoming available for the axolotl salamander, thus allowing comparative studies between scarring and regeneration.  Here, we describe in detail three methods to produce axolotl hematopoietic cell-tagged chimeras for the study of hematopoiesis and regeneration.

  3. Transgenesis in axolotl (Ambystoma mexicanum).

    Science.gov (United States)

    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.

  4. An introduction to the Mexican axolotl (Ambystoma mexicanum).

    Science.gov (United States)

    Gresens, Jill

    2004-10-01

    A number of unusual traits, including a remarkable capacity for wound healing and limb regeneration, make the axolotl an interesting animal model. The author provides an overview of axolotl care and use in biomedical research.

  5. Thyroxine-induced metamorphosis in the axolotl (Ambystoma mexicanum).

    Science.gov (United States)

    Coots, Peggy S; Seifert, Ashley W

    2015-01-01

    The axolotl (Ambystoma mexicanum) has remained an important model for regeneration and developmental biology for over a century. Although axolotls in captive-bred colonies usually exist in an aquatic form, they retain the ability to undergo metamorphosis following exposure to thyroid hormone. Here we present a robust method for inducing metamorphosis in adult axolotls that results in high survivability and produces terrestrial animals that can be maintained in long-term captivity.

  6. Limb Regeneration in Axolotl: Is It Superhealing?

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    Stéphane Roy

    2006-01-01

    Full Text Available The ability of axolotls to regenerate their limbs is almost legendary. In fact, urodeles such as the axolotl are the only vertebrates that can regenerate multiple structures like their limbs, jaws, tail, spinal cord, and skin (the list goes on throughout their lives. It is therefore surprising to realize, although we have known of their regenerative potential for over 200 years, how little we understand the mechanisms behind this achievement of adult tissue morphogenesis. Many observations can be drawn between regeneration and other disciplines such as development and wound healing. In this review, we present new developments in functional analysis that will help to address the role of specific genes during the process of regeneration. We also present an analysis of the resemblance between wound healing and regeneration, and discuss whether axolotls are superhealers. A better understanding of these animals' regenerative capacity could lead to major benefits by providing regenerative medicine with directions on how to develop therapeutic approaches leading to regeneration in humans.

  7. Transcriptional landscapes of Axolotl (Ambystoma mexicanum).

    Science.gov (United States)

    Caballero-Pérez, Juan; Espinal-Centeno, Annie; Falcon, Francisco; García-Ortega, Luis F; Curiel-Quesada, Everardo; Cruz-Hernández, Andrés; Bako, Laszlo; Chen, Xuemei; Martínez, Octavio; Alberto Arteaga-Vázquez, Mario; Herrera-Estrella, Luis; Cruz-Ramírez, Alfredo

    2018-01-15

    The axolotl (Ambystoma mexicanum) is the vertebrate model system with the highest regeneration capacity. Experimental tools established over the past 100 years have been fundamental to start unraveling the cellular and molecular basis of tissue and limb regeneration. In the absence of a reference genome for the Axolotl, transcriptomic analysis become fundamental to understand the genetic basis of regeneration. Here we present one of the most diverse transcriptomic data sets for Axolotl by profiling coding and non-coding RNAs from diverse tissues. We reconstructed a population of 115,906 putative protein coding mRNAs as full ORFs (including isoforms). We also identified 352 conserved miRNAs and 297 novel putative mature miRNAs. Systematic enrichment analysis of gene expression allowed us to identify tissue-specific protein-coding transcripts. We also found putative novel and conserved microRNAs which potentially target mRNAs which are reported as important disease candidates in heart and liver. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. 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.

  9. Housing and maintenance of Ambystoma mexicanum, the Mexican axolotl.

    Science.gov (United States)

    Farkas, Johanna E; Monaghan, James R

    2015-01-01

    The aim of this paper is to assemble a significant amount of information on Ambystoma mexicanum, the axolotl salamander, to assist in the basic knowledge needed to raise, breed, and study most aspects of axolotl biology. It is important to understand the basic biology of the axolotl in order to make informed decisions on their proper care and use in experiments. Therefore, we will provide necessary information to the non-herpetologist that will assist in their study of this unique and fascinating animal. We also aim to provide a resource on the general anatomy, behavior, and experimental tips specific to the Mexican axolotl that will be of use to most axolotl laboratories. Axolotls have been actively researched since the 1860s, giving testament to their relatively straightforward maintenance and their versatility as an animal model for development and regeneration. Interest in using the axolotl in laboratory research has grown tremendously over the past decade, so dedicated resources to support the study of this species are needed and encouraged.

  10. Lens regeneration in axolotl: new evidence of developmental plasticity

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    Suetsugu-Maki Rinako

    2012-12-01

    Full Text Available Abstract Background Among vertebrates lens regeneration is most pronounced in newts, which have the ability to regenerate the entire lens throughout their lives. Regeneration occurs from the dorsal iris by transdifferentiation of the pigment epithelial cells. Interestingly, the ventral iris never contributes to regeneration. Frogs have limited lens regeneration capacity elicited from the cornea during pre-metamorphic stages. The axolotl is another salamander which, like the newt, regenerates its limbs or its tail with the spinal cord, but up until now all reports have shown that it does not regenerate the lens. Results Here we present a detailed analysis during different stages of axolotl development, and we show that despite previous beliefs the axolotl does regenerate the lens, however, only during a limited time after hatching. We have found that starting at stage 44 (forelimb bud stage lens regeneration is possible for nearly two weeks. Regeneration occurs from the iris but, in contrast to the newt, regeneration can be elicited from either the dorsal or the ventral iris and, occasionally, even from both in the same eye. Similar studies in the zebra fish concluded that lens regeneration is not possible. Conclusions Regeneration of the lens is possible in the axolotl, but differs from both frogs and newts. Thus the axolotl iris provides a novel and more plastic strategy for lens regeneration.

  11. Novel axolotl cardiac function analysis method using magnetic resonance imaging.

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    Pedro Gomes Sanches

    Full Text Available 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 of axolotls. Three axolotls were imaged with magnetic resonance imaging using a retrospectively gated Fast Low Angle Shot cine sequence. Within one scanning session the axolotl heart was imaged three times in all planes, consecutively. Heart rate, ejection fraction, stroke volume and cardiac output were calculated using three techniques: (1 combined long-axis, (2 short-axis series, and (3 ultrasound (control for heart rate only. All values are presented as mean ± standard deviation. Heart rate (beats per minute among different animals was 32.2±6.0 (long axis, 30.4±5.5 (short axis and 32.7±4.9 (ultrasound and statistically similar regardless of the imaging method (p > 0.05. Ejection fraction (% was 59.6±10.8 (long axis and 48.1±11.3 (short axis and it differed significantly (p = 0.019. Stroke volume (μl/beat was 133.7±33.7 (long axis and 93.2±31.2 (short axis, also differed significantly (p = 0.015. Calculations were consistent among the animals and over three repeated measurements. The heart rate varied depending on depth of anaesthesia. We described a new method for defining and imaging the anatomical planes of the axolotl heart and propose one of our techniques (long axis analysis may prove useful in defining cardiac function in regenerating axolotl hearts.

  12. Early regulation of axolotl limb regeneration.

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    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.

  13. 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.

  14. Continuous growth of the motor system in the axolotl

    International Nuclear Information System (INIS)

    Holder, N.; Clarke, J.D.; Stephens, N.; Wilson, S.W.; Orsi, C.; Bloomer, T.; Tonge, D.A.

    1991-01-01

    During growth of the axolotl, motor neurons, and muscle fibres are added to the motor system. By double labelling neurons with tritiated thymidine and retrogradely transported HRP, we show that some motor neurons are born at postembryonic stages. Further analysis of motor neurons with the aid of HRP reveals this population of newly born cells relatively frequently in small (5-7 cm long) axolotls, but only rarely in large (7-13 cm long) axolotls. Evidence is presented that suggests that these immature cells are in the process of migrating from close to the ependyma out to the ventral horn. HRP transport also reveals growth cones of advancing axons within spinal nerves in animals up to 6 cm in length. Cell counts by light and electron microscopic methods show that muscle fibres are generated throughout larval life in the iliotibialis, a typical limb muscle. This analysis provides data consistent with the notion that new muscle fibres are added from a localised growth zone situated at the superficial edge of the muscle. These results are discussed in terms of the correlation between continuous growth of the motor system and the ability of the axolotl to functionally repair lesions to the peripheral nervous system

  15. 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

  16. 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

  17. ISOLATION AND CHARACTERIZATION OF AXOLOTL NPDC-1 AND ITS EFFECTS ON RETINOIC ACID RECEPTOR SIGNALING

    Science.gov (United States)

    Theodosiou, Maria; Monaghan, James R; Spencer, Michael L; Voss, S Randal; Noonan, Daniel J

    2009-01-01

    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 retinoic acid receptor (RAR)-mediated transcription. To obtain comparative and developmental insights about NPDC-1 function, we cloned the axolotl (Ambystoma mexicanum) orthologue and measured transcript abundances among tissues sampled during the embryonic and juvenile phases of development, and also during spinal cord regeneration. Structurally, the axolotl orthologue of NPDC-1 retained sequence identity to mammalian sequences in all functional domains. Functionally, we observed that axolotl NPDC-1 mRNA expression peaked late in embryogenesis, with highest levels of expression occurring during the time of limb development, a process regulated by retinoic acid signaling. Also similar to what has been observed in mammals, axolotl NPDC-1 directly interacts with axolotl RAR, modulates axolotl RAR DNA binding, and represses cell proliferation and axolotl RAR-mediated gene transcription. These data justify axolotl as a model to further investigate NPDC-1 and its role in regulating retinoic acid signaling. PMID:17331771

  18. Identification of reference genes and validation for gene expression studies in diverse axolotl (Ambystoma mexicanum) tissues.

    Science.gov (United States)

    Guelke, Eileen; Bucan, Vesna; Liebsch, Christina; Lazaridis, Andrea; Radtke, Christine; Vogt, Peter M; Reimers, Kerstin

    2015-04-10

    For the precise quantitative RT-PCR normalization a set of valid reference genes is obligatory. Moreover have to be taken into concern the experimental conditions as they bias the regulation of reference genes. Up till now, no reference targets have been described for the axolotl (Ambystoma mexicanum). In a search in the public database SalSite for genetic information of the axolotl we identified fourteen presumptive reference genes, eleven of which were further tested for their gene expression stability. This study characterizes the expressional patterns of 11 putative endogenous control genes during axolotl limb regeneration and in an axolotl tissue panel. All 11 reference genes showed variable expression. Strikingly, ACTB was to be found most stable expressed in all comparative tissue groups, so we reason it to be suitable for all different kinds of axolotl tissue-type investigations. Moreover do we suggest GAPDH and RPLP0 as suitable for certain axolotl tissue analysis. When it comes to axolotl limb regeneration, a validated pair of reference genes is ODC and RPLP0. With these findings, new insights into axolotl gene expression profiling might be gained. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. 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...

  20. 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.

  1. Experimentally induced metamorphosis in axolotls reduces regenerative rate and fidelity

    Science.gov (United States)

    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

  2. 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.

  3. The axolotl (Ambystoma mexicanum), a neotenic amphibian, expresses functional thyroid hormone receptors.

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    Safi, Rachid; Bertrand, Stéphanie; Marchand, Oriane; Duffraisse, Marilyne; de Luze, Amaury; Vanacker, Jean-Marc; Maraninchi, Marie; Margotat, Alain; Demeneix, Barbara; Laudet, Vincent

    2004-02-01

    Neotenic amphibians such as the axolotl (Ambystoma mexicanum) are often unable to undergo metamorphosis under natural conditions. It is thought that neoteny represents a deviation from the standard course of amphibian ontogeny, affecting the thyroid axis at different levels from the central nervous system to peripheral organs. Thyroid hormone receptors (TRs) that bind the thyroid hormone (TH) T(3) have been described in axolotl. However, the full sequences of TR were needed to better characterize the TH response and to be able to assess their functional capacity at the molecular level. We report that each of the alpha and beta axolotl TRs bind both DNA and TH, and they activate transcription in response to TH in a mammalian cell-based transient transfection assay. Moreover, both TRs are expressed in axolotl tissues. Interestingly, each TR gene generates alternatively spliced isoforms, harboring partial or total deletions of the ligand-binding domain, which are expressed in vivo. Further, we found that in the axolotl, TH regulates the expression of stromelysin 3 and collagenase 3, which are TH target genes in Xenopus. Taken together, these results suggest that axolotl TRs are functional and that the molecular basis of neoteny in the axolotl is not linked to a major defect in TH response in peripheral tissues.

  4. Detailed tail proteomic analysis of axolotl (Ambystoma mexicanum) using an mRNA-seq reference database.

    Science.gov (United States)

    Demircan, Turan; Keskin, Ilknur; Dumlu, Seda Nilgün; Aytürk, Nilüfer; Avşaroğlu, Mahmut Erhan; Akgün, Emel; Öztürk, Gürkan; Baykal, Ahmet Tarık

    2017-01-01

    Salamander axolotl has been emerging as an important model for stem cell research due to its powerful regenerative capacity. Several advantages, such as the high capability of advanced tissue, organ, and appendages regeneration, promote axolotl as an ideal model system to extend our current understanding on the mechanisms of regeneration. Acknowledging the common molecular pathways between amphibians and mammals, there is a great potential to translate the messages from axolotl research to mammalian studies. However, the utilization of axolotl is hindered due to the lack of reference databases of genomic, transcriptomic, and proteomic data. Here, we introduce the proteome analysis of the axolotl tail section searched against an mRNA-seq database. We translated axolotl mRNA sequences to protein sequences and annotated these to process the LC-MS/MS data and identified 1001 nonredundant proteins. Functional classification of identified proteins was performed by gene ontology searches. The presence of some of the identified proteins was validated by in situ antibody labeling. Furthermore, we have analyzed the proteome expressional changes postamputation at three time points to evaluate the underlying mechanisms of the regeneration process. Taken together, this work expands the proteomics data of axolotl to contribute to its establishment as a fully utilized model. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Forever young: Endocrinology of paedomorphosis in the Mexican axolotl (Ambystoma mexicanum).

    Science.gov (United States)

    De Groef, Bert; Grommen, Sylvia V H; Darras, Veerle M

    2018-05-16

    The Mexican axolotl (Ambystoma mexicanum) is a salamander species that does not undergo metamorphosis, resulting in the retention of juvenile characteristics in the mature breeding stage (paedomorphosis). Here we review the endocrinological studies investigating the proximate cause of axolotl paedomorphosis with a focus on the hypothalamo-pituitary-thyroid (HPT) axis. It is well established that axolotl paedomorphosis is a consequence of low activity of the HPT axis. The pituitary hormone thyrotropin (TSH) is capable of inducing metamorphosis in the axolotl, which indicates that all processes and interactions in the HPT axis below the pituitary level are functional, but that TSH release is impaired. In metamorphosing species, TSH secretion is largely controlled by the hypothalamic neuropeptide corticotropin-releasing hormone (CRH), which seems to have lost its thyrotropic activity in the axolotl. However, preliminary experiments have not yet confirmed a role for faulty CRH signalling in axolotl paedomorphosis. Other hypothalamic factors and potential pituitary inhibitors need to be investigated to identify their roles in amphibian metamorphosis and axolotl paedomorphosis. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. 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.)

  7. 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...

  8. 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 ...

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Misexpression experiment of Tbx5 in axolotl (Ambystoma mexicanum) hindlimb blastema.

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    Shimokawa, Takashi; Kominami, Rieko; Yasutaka, Satoru; Shinohara, Harumichi

    2013-01-01

    Axolotls (Ambystoma mexicanum) have the ability to regenerate amputated limbs throughout their life span. In the present study, we attempted to elucidate how axolotls can specify limb type correctly during the regeneration process. We misexpressed Tbx5 in regenerating hindlimb blastema, and consequently a forelimb-like hindlimb regenerated from the hindlimb blastema. On the other hand, no change was observed in Tbx5-overexpressing forelimb blastema, and thus we considered that Tbx5 plays a key role in the specification of forelimb during the regeneration process of axolotl limbs. However, axolotls' fore- and hindlimbs have very similar structures except for the number of fingers, and it was very difficult to judge whether the forelimb-like regenerate was a true forelimb or merely a forelimb-like hindlimb. Therefore, in order to confirm our conclusion, we have to investigate other genes that are expressed differentially between fore- and hindlimbs in future experiments.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Comparison of tissue processing methods for microvascular visualization in axolotls.

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    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.

  16. A histological atlas of the tissues and organs of neotenic and metamorphosed axolotl.

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    Demircan, Turan; İlhan, Ayşe Elif; Aytürk, Nilüfer; Yıldırım, Berna; Öztürk, Gürkan; Keskin, İlknur

    2016-09-01

    Axolotl (Ambystoma Mexicanum) has been emerging as a promising model in stem cell and regeneration researches due to its exceptional regenerative capacity. Although it represents lifelong lasting neoteny, induction to metamorphosis with thyroid hormones (THs) treatment advances the utilization of Axolotl in various studies. It has been reported that amphibians undergo anatomical and histological remodeling during metamorphosis and this transformation is crucial for adaptation to terrestrial conditions. However, there is no comprehensive histological investigation regarding the morphological alterations of Axolotl organs and tissues throughout the metamorphosis. Here, we reveal the histological differences or resemblances between the neotenic and metamorphic axolotl tissues. In order to examine structural features and cellular organization of Axolotl organs, we performed Hematoxylin & Eosin, Luxol-Fast blue, Masson's trichrome, Alcian blue, Orcein and Weigart's staining. Stained samples from brain, gallbladder, heart, intestine, liver, lung, muscle, skin, spleen, stomach, tail, tongue and vessel were analyzed under the light microscope. Our findings contribute to the validation of the link between newly acquired functions and structural changes of tissues and organs as observed in tail, skin, gallbladder and spleen. We believe that this descriptive work provides new insights for a better histological understanding of both neotenic and metamorphic Axolotl tissues. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. 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

  18. Transforming growth factor: beta signaling is essential for limb regeneration in axolotls.

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    Mathieu Lévesque

    2007-11-01

    Full Text Available Axolotls (urodele amphibians have the unique ability, among vertebrates, to perfectly regenerate many parts of their body including limbs, tail, jaw and spinal cord following injury or amputation. The axolotl limb is the most widely used structure as an experimental model to study tissue regeneration. The process is well characterized, requiring multiple cellular and molecular mechanisms. The preparation phase represents the first part of the regeneration process which includes wound healing, cellular migration, dedifferentiation and proliferation. The redevelopment phase represents the second part when dedifferentiated cells stop proliferating and redifferentiate to give rise to all missing structures. In the axolotl, when a limb is amputated, the missing or wounded part is regenerated perfectly without scar formation between the stump and the regenerated structure. Multiple authors have recently highlighted the similarities between the early phases of mammalian wound healing and urodele limb regeneration. In mammals, one very important family of growth factors implicated in the control of almost all aspects of wound healing is the transforming growth factor-beta family (TGF-beta. In the present study, the full length sequence of the axolotl TGF-beta1 cDNA was isolated. The spatio-temporal expression pattern of TGF-beta1 in regenerating limbs shows that this gene is up-regulated during the preparation phase of regeneration. Our results also demonstrate the presence of multiple components of the TGF-beta signaling machinery in axolotl cells. By using a specific pharmacological inhibitor of TGF-beta type I receptor, SB-431542, we show that TGF-beta signaling is required for axolotl limb regeneration. Treatment of regenerating limbs with SB-431542 reveals that cellular proliferation during limb regeneration as well as the expression of genes directly dependent on TGF-beta signaling are down-regulated. These data directly implicate TGF

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

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    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.

  20. 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.

  1. Optimized axolotl (Ambystoma mexicanum) husbandry, breeding, metamorphosis, transgenesis and tamoxifen-mediated recombination.

    Science.gov (United States)

    Khattak, Shahryar; Murawala, Prayag; Andreas, Heino; Kappert, Verena; Schuez, Maritta; Sandoval-Guzmán, Tatiana; Crawford, Karen; Tanaka, Elly M

    2014-03-01

    The axolotl (Mexican salamander, Ambystoma mexicanum) has become a very useful model organism for studying limb and spinal cord regeneration because of its high regenerative capacity. Here we present a protocol for successfully mating and breeding axolotls in the laboratory throughout the year, for metamorphosing axolotls by a single i.p. injection and for axolotl transgenesis using I-SceI meganuclease and the mini Tol2 transposon system. Tol2-mediated transgenesis provides different features and advantages compared with I-SceI-mediated transgenesis, and it can result in more than 30% of animals expressing the transgene throughout their bodies so that they can be directly used for experimentation. By using Tol2-mediated transgenesis, experiments can be performed within weeks (e.g., 5-6 weeks for obtaining 2-3-cm-long larvae) without the need to establish germline transgenic lines (which take 12-18 months). In addition, we describe here tamoxifen-induced Cre-mediated recombination in transgenic axolotls.

  2. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  5. Musashi and Plasticity of Xenopus and Axolotl Spinal Cord Ependymal Cells

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    Ellen A. G. Chernoff

    2018-02-01

    Full Text Available The differentiated state of spinal cord ependymal cells in regeneration-competent amphibians varies between a constitutively active state in what is essentially a developing organism, the tadpole of the frog Xenopus laevis, and a quiescent, activatable state in a slowly growing adult salamander Ambystoma mexicanum, the Axolotl. Ependymal cells are epithelial in intact spinal cord of all vertebrates. After transection, body region ependymal epithelium in both Xenopus and the Axolotl disorganizes for regenerative outgrowth (gap replacement. Injury-reactive ependymal cells serve as a stem/progenitor cell population in regeneration and reconstruct the central canal. Expression patterns of mRNA and protein for the stem/progenitor cell-maintenance Notch signaling pathway mRNA-binding protein Musashi (msi change with life stage and regeneration competence. Msi-1 is missing (immunohistochemistry, or at very low levels (polymerase chain reaction, PCR, in both intact regeneration-competent adult Axolotl cord and intact non-regeneration-competent Xenopus tadpole (Nieuwkoop and Faber stage 62+, NF 62+. The critical correlation for successful regeneration is msi-1 expression/upregulation after injury in the ependymal outgrowth and stump-region ependymal cells. msi-1 and msi-2 isoforms were cloned for the Axolotl as well as previously unknown isoforms of Xenopus msi-2. Intact Xenopus spinal cord ependymal cells show a loss of msi-1 expression between regeneration-competent (NF 50–53 and non-regenerating stages (NF 62+ and in post-metamorphosis froglets, while msi-2 displays a lower molecular weight isoform in non-regenerating cord. In the Axolotl, embryos and juveniles maintain Msi-1 expression in the intact cord. In the adult Axolotl, Msi-1 is absent, but upregulates after injury. Msi-2 levels are more variable among Axolotl life stages: rising between late tailbud embryos and juveniles and decreasing in adult cord. Cultures of regeneration

  6. Musashi and Plasticity of Xenopus and Axolotl Spinal Cord Ependymal Cells

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    Chernoff, Ellen A. G.; Sato, Kazuna; Salfity, Hai V. N.; Sarria, Deborah A.; Belecky-Adams, Teri

    2018-01-01

    The differentiated state of spinal cord ependymal cells in regeneration-competent amphibians varies between a constitutively active state in what is essentially a developing organism, the tadpole of the frog Xenopus laevis, and a quiescent, activatable state in a slowly growing adult salamander Ambystoma mexicanum, the Axolotl. Ependymal cells are epithelial in intact spinal cord of all vertebrates. After transection, body region ependymal epithelium in both Xenopus and the Axolotl disorganizes for regenerative outgrowth (gap replacement). Injury-reactive ependymal cells serve as a stem/progenitor cell population in regeneration and reconstruct the central canal. Expression patterns of mRNA and protein for the stem/progenitor cell-maintenance Notch signaling pathway mRNA-binding protein Musashi (msi) change with life stage and regeneration competence. Msi-1 is missing (immunohistochemistry), or at very low levels (polymerase chain reaction, PCR), in both intact regeneration-competent adult Axolotl cord and intact non-regeneration-competent Xenopus tadpole (Nieuwkoop and Faber stage 62+, NF 62+). The critical correlation for successful regeneration is msi-1 expression/upregulation after injury in the ependymal outgrowth and stump-region ependymal cells. msi-1 and msi-2 isoforms were cloned for the Axolotl as well as previously unknown isoforms of Xenopus msi-2. Intact Xenopus spinal cord ependymal cells show a loss of msi-1 expression between regeneration-competent (NF 50–53) and non-regenerating stages (NF 62+) and in post-metamorphosis froglets, while msi-2 displays a lower molecular weight isoform in non-regenerating cord. In the Axolotl, embryos and juveniles maintain Msi-1 expression in the intact cord. In the adult Axolotl, Msi-1 is absent, but upregulates after injury. Msi-2 levels are more variable among Axolotl life stages: rising between late tailbud embryos and juveniles and decreasing in adult cord. Cultures of regeneration-competent Xenopus tadpole

  7. 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

  8. 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.

  9. 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.

  10. 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...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  14. 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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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...

  19. Proteomic analysis of blastema formation in regenerating axolotl limbs

    Directory of Open Access Journals (Sweden)

    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

  20. 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 ...

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Regulation of antibody synthesis in the X-irradiated Mexican axolotl

    International Nuclear Information System (INIS)

    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

  5. Regulation of antibody synthesis in the X-irradiated Mexican axolotl

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. 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

  7. 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...

  8. 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...

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. 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...

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  16. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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...

  1. Zu einigen entwicklungstendenzen beim ausdruck der gewissheits modalität

    Directory of Open Access Journals (Sweden)

    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.

  2. 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...

  3. 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...

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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

  7. Microarray Analysis of microRNA Expression during Axolotl Limb Regeneration

    Science.gov (United States)

    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

  8. 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.

  9. Microarray analysis of microRNA expression during axolotl limb regeneration.

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  13. 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...

  14. [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.

  15. 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

  16. 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...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  19. 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.

  20. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.

  8. 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

  9. 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...

  10. 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.

  11. 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.

  12. 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.

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

    Science.gov (United States)

    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.

  14. Proliferation zones in the axolotl brain and regeneration of the telencephalon

    Directory of Open Access Journals (Sweden)

    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

  15. 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.

  16. 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

  17. 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.

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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.

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

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

    Directory of Open Access Journals (Sweden)

    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.

  4. 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

  5. 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.

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

    Science.gov (United States)

    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

  7. 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.

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

    Science.gov (United States)

    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.

  9. 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.

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

    Science.gov (United States)

    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.

  11. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  14. 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.)

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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.)

  2. 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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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...

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

    Directory of Open Access Journals (Sweden)

    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

  12. 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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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.

  17. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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.)

  10. 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.

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

    Science.gov (United States)

    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.

  12. 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

  13. 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)

  14. 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.)

  15. 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.)

  16. 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.)

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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)

  2. 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.

  3. 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

    Directory of Open Access Journals (Sweden)

    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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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 ...

  10. 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.)

  11. 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.

  12. 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

  13. 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...

  14. 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.)

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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...

  2. 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.)

  3. 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.)

  4. 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

  5. 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...

  6. 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...

  7. 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...

  8. 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.

  9. 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.)

  10. 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.

  11. 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.

  12. 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

  13. 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.)

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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...

  19. 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.)

  20. 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.)

  1. 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.

  2. 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.)

  3. 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...

  4. 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...

  5. 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.)

  6. 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.)

  7. 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.

  8. Webbasierte linguistische Forschung: Möglichkeiten und Begrenzungen beim Umgang mit Massendaten

    Directory of Open Access Journals (Sweden)

    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.

  9. 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.)

  10. 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....

  11. 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.).

  12. 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.).

  13. 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.

  14. 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.

  15. 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...

  16. 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.)

  17. 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.)

  18. 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.

  19. 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)

  20. 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.

  1. 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.)

  2. 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.

  3. 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.)

  4. 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.

  5. 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.)

  6. 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.)

  7. 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.

  8. 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.

  9. 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...

  10. 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.)

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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 ...

  18. 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.

  19. 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.

  20. Fracture of an industrial steam turbine horizontal joint nut upon tightening; Bruch der Mutter einer Horizontalteilfugenverschraubung einer Industriedampfturbine beim Anziehen

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Boromir; Giller, Madeleine; Neidel, Andreas; Riesenbeck, Susanne [Siemens AG - Gasturbinenwerk Berlin (Germany). Energy Sector Werkstoffprueflabor

    2017-11-01

    The nut of a horizontal joint fastener cracked upon tightening during assembly in an industrial steam turbine factory. It was previously used in an over-pressure test, but was otherwise not yet used in service. Nut and bolt were made of the nickel-based superalloy Nimonic 80A, a precipitation-hardenable wrought high-strength alloy with excellent creep and corrosion properties. Such alloys usually get a complex heat treatment after hot-rolling, comprising homogenizing and multiple ageing cycles. The subject nut failed due to an extreme case of mixed grain size which detrimentally affected mechanical properties and was attributed to an insufficient degree of deformation during hot rolling.

  1. Ecological aspects to the use of pretreated waste in thermal plants; Oekologische Aspekte beim Einsatz aufbereiteter Abfaelle in thermischen Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Friedel, M.; Urban, A.I. [Kassel Univ. (Gesamthochschule) (Germany). Fachgebiet Abfalltechnik

    1998-09-01

    The present contribution focuses on the input side of individual process techniques. It shows on the basis of example calculations how two parameters describing the incinerable (residual) waste that are of particular importance for unconventional thermal treatment methods, namely ``pollutant load`` and ``calorific value``, can be influenced by a recycling stage and then further by mechanical-biological pretreatment. [Deutsch] Im folgenden soll das Hauptaugenmerk auf die Inputseite zu den einzelnen thermischen Verfahren gelegt werden und anhand einer Beispielrechnung aufgezeigt werden, wie sich die fuer einen Einsatz in nichtkonventionellen thermischen Verfahren besonders wichtigen Parameter des aufbereiteten (Rest)Abfalls `Schadstoffbelastung` und `Heizwert` zunaechst durch eine Verwertung und weiter durch eine mechanisch-biologische Vorbehandlung veraendern. (orig./SR)

  2. 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.)

  3. Bestimmung der fehlenden transversalen Energie auf der ersten Triggerstufe beim ATLAS-Experiment und Optimierung der Triggerselektion von supersymmetrischen Ereignissen

    CERN Document Server

    Rieke, Stefan

    2009-01-01

    The standard model (SM) of particle physics is a theory, describing three out of four fundamental forces. The prediction of the standard model are in good agreement with the results of measurement of the experiments at the CERN, the Fermi lab and other research establishments. Still, not all open questions of the particle physics could be answered with this model. For example, it is not possible to implement the fourth fundamental force, the gravity, into the SM. Another example are candidates for the dark matter, which couldn’t described by the standard model, but cosmological experiments show that the contribution of the dark matter is about 25% of the universe. The supersymmetry, which introduce a symmetry between fermions and bosons, is regarded as one of the most promising solution for these open questions. In this theory, each new particle so-called supersymmetric particles is related to one particle in the standard model. If supersymmetry is realized in nature, one possible model of this symmetry is ...

  4. 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.)

  5. Ecological improvements in conjunction with the new RADAG hydro power plant; Oekologische Aufwertungsmassnahmen beim Neubau des Wehrkraftwerks der RADAG

    Energy Technology Data Exchange (ETDEWEB)

    Ruess, Beatrice [RUS AG, Baden (Switzerland)

    2010-07-01

    Together the weir power plant and the upgrading measures will create salient ecological improvements of the actual conditions of the residual water route. Of special importance are the increased runoff into the Old Rhine and the additional structuring measures. The natural evasion waters combined with the Collection Gallery and the Vertical Slot fish ladder together with the new fish ladder at the Main Power Station will on one hand greatly improve the longitudinal continuum and on the other hand create habitats for species relying on strong-flowing waters. (orig.)

  6. 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.)

  7. 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.)

  8. Vaporization of materials in the operation of high temperature fuel cells (SOFCs); Verdampfung von Werkstoffen beim Betrieb von Hochtemperaturbrennstoffzellen (SOFCs)

    Energy Technology Data Exchange (ETDEWEB)

    Stanislowski, M.

    2006-07-01

    One of the main problems concerning the development of state of the art planar SOFCs are the occurrence of ageing effects in long term application. To a great deal these effects are caused by the release of volatile Cr-species from metallic interconnects which leads to an inhibition of the electrochemical processes at the cathode resulting in a rapid degradation of the cell performance. A goal in further development of SOFC-systems is the reduction of the operation temperature of the cell from currently 800 C to 700 C and below. For this purpose alternative electrolyte materials with higher oxygen ion conductivities have to be developed. Doped lanthanum gallates have been identified as promising materials. However for these materials a depletion of Ga by vaporization has been observed under anodic conditions which may lead to a destruction of their electrolyte properties. The aim of this work is the study of the vaporization processes leading to the mentioned degradation effects. For this purpose an experimental setup according to the transpiration method has been developed. Concerning the vaporization of chromium the Cr release rates of the main ferritic interconnect alloys, namely Crofer 22 APU, ZMG 232, E-Brite, IT-10, IT-11, IT-14 and Ducrolloy as well as a variety of Ni- and Co-base superalloys and stainless steels with different contents of Al, Si, Ti, Mn, W, Ni and Co were measured at 800 C in air and compared to each other. The alloys that form an upper layer of Cr-Mn-spinel on top of the grown chromia scale showed a reduction of the Cr release by 61-75 % compared to pure chromia scales whereas alloys with an outer Co3O4(s) scale had a by more than 90 % reduced Cr release. For the former alloys a significant vaporization of Mn under anodic conditions could be detected. Concerning the vaporization of doped lanthanum gallates the vaporization rates of the elements Ga, Mg, Sr and La were measured as function time, temperature, gas flow rate and stoichiometry for compositions of the type La(1-x)SrxMgy(Fez)Ga(1-y-z)O(3-delta)(s) with x=0,1-0,3, y=0,12-0,32 and z=0-0,08. As a consequence of the depletion of Ga the formation of the impurity phases LaSrGaO4(s) and LaSrGa3O7(s) was observed. Kinetic parameters were obtained by fitting the results to a vaporization model with imposed solid state diffusion. In order to elucidate the quality of thermodynamic calculations equilibrium measurements were performed with pure Cr2O3(s) and Ga2O3(s) in air or Ar/H2 respectively as function of temperature and humidity. For the vaporization of Ga2O3(s) it could be shown that GaOH(g) is the most abundant Ga species in the gas phase. The determined partial pressures for CrO2(OH)2(g) and CrO3(g) or GaOH(g) respectively and the derived enthalpies and entropies of reaction for CrO2(OH)2(g) and GaOH(g) showed significant differences compared to the thermodynamical data in the literature. (orig.)

  9. On the use of hydrate inhibitors for operating natural gas caverns; Zum Einsatz von Hydratinhibitoren beim Betrieb von Erdgasspeichern

    Energy Technology Data Exchange (ETDEWEB)

    Kleinitz, W.; Lissanon, S.J.; Luehn, H.G. [Preussag Energie GmbH, Lingen/Ems (Germany)

    1997-12-31

    One way to prevent gas hydrates in natural gas caverns is to use thermodynamic or kinetic inhibitors in a defined temperature / pressure range. The present contribution describes the temperature conditions prevailing in the tubing string. It also discusses bacterial processes around wells arising in association with methanol digesting bacteria, diethylene glycol digesting bacteria, and kinetic inhibitors. Further topics include inhibitor dosage and absorption drying. (MSK) [Deutsch] Zur Vermeidung von Gashydraten im Erdgasspeicherbereich werden thermodynamische oder kinetische Inhibitoren in einem definierten Temperatur/Druckbereich eingesetzt. Im Folgenden werden die Temperaturbedingungen im Steigrohrsystem erlaeutert. Ebenso werden die bakteriellen Vorgaenge im Bohrlochsbereich in folgenden Einzelheiten: Methanol-verwertenden Bakterien, Diethylenglykol-verwertende Bakterien sowie kinetische Inhibitoren diskutiert. Weitere Themenpunkte sind die Inhibitordosierung und die Adsorptionstrocknung.

  10. 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.).

  11. 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...

  12. 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...

  13. 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.)

  14. Procedure guidelines for radioiodine therapy of differentiated thyroid cancer (version 3); Verfahrensanweisung zur Radioiodtherapie (RIT) beim differenzierten Schilddruesenkarzinom (Version 3)

    Energy Technology Data Exchange (ETDEWEB)

    Dietlein, M.; Schicha, H. [Deutsche Gesellschaft fuer Nuklearmedizin (DGN) (Germany); Koeln Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Dressler, J. [Deutsche Gesellschaft fuer Nuklearmedizin (DGN) (Germany); Nuklearmedizinsiche Klinik der Henriettenstiftung, Hannover (Germany); Eschner, W. [Deutsche Gesellschaft fuer Nuklearmedizin (DGN) (Germany); Deutsche Gesellschaft fuer Medizinische Physik (DGMP) (Germany); Koeln Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Gruenwald, F. [Deutsche Gesellschaft fuer Nuklearmedizin (DGN) (Germany); Frankfurt Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Lassmann, M. [Deutsche Gesellschaft fuer Nuklearmedizin (DGN) (Germany); Deutsche Gesellschaft fuer Medizinische Physik (DGMP) (Germany); Wuerzburg Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Leisner, B. [Deutsche Gesellschaft fuer Nuklearmedizin (DGN) (Germany); Allgemeines Krankenhaus St. Georg, Hamburg (Germany); Luster, M.; Reiners, C. [Deutsche Gesellschaft fuer Nuklearmedizin (DGN) (Germany); Wuerzburg Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Moser, E. [Deutsche Gesellschaft fuer Nuklearmedizin (DGN) (Germany); Radiologische Universitaetsklinik Freiburg (Germany); Schober, O. [Deutsche Gesellschaft fuer Nuklearmedizin (DGN) (Germany); Muenster Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    2007-07-01

    The procedure guideline for radioiodine therapy (RIT) of differentiated thyroid cancer (version 3) is the counterpart to the procedure guideline for {sup 131}I whole-body scintigraphy (version 3) and specify the interdisciplinary guideline for thyroid cancer of the Deutsche Krebsgesellschaft concerning the nuclear medicine part. Recommendation for ablative {sup 131}I therapy is given for all differentiated thyroid carcinoma (DTC) >1 cm. Regarding DTC {<=}1 cm {sup 131}I ablation may be helpful in an individual constellation. Preparation for {sup 131}I ablation requires low iodine diet for two weeks and TSH stimulation by withdrawal of thyroid hormone medication or by use of recombinant human TSH (rhTSH). The advantages of rhTSH (no symptoms of hypothyroidism, lowerblood activity) and the advantages of endogenous TSH stimulation (necessary for {sup 131}I-therapy in patients with metastases, higher sensitivity of {sup 131}I whole-body scan) are discussed. In most centers standard activities are used for {sup 131}I ablation. If pretherapeutic dosimetry is planned, the diagnostic administration of {sup 131}I should not exceed 1-10MBq, alternative tracers are {sup 123}I or {sup 124}I. The recommendations for contraception and family planning are harmonized with the recommendation of ATA and ETA. Regarding the best possible protection of salivary glands the evidence is insufficient to recommend a specific setting. To minimize the risk of dental caries due to xerostomia patients should use preventive strategies for dental hygiene. (orig.)

  15. 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.).

  16. 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.)

  17. Influence of thyroid metabolism on radioiodine therapy in Graves` disease; Einfluss der Stoffwechsellage auf die Radioiodtherapie beim Morbus Basedow

    Energy Technology Data Exchange (ETDEWEB)

    Boerner, A.R. [Forschungszentrum Juelich (Germany). Inst. fuer Medizin; Weckesser, M.; Boy, C.; Schmidt, D.; Langen, K.J.; Mueller-Gaertner, H.W. [Duesseldorf Univ. (Germany). Nuklearmedizinische Klinik]|[Forschungszentrum Juelich (Germany). Inst. fuer Medizin

    1997-12-01

    Radioiodine therapy is one of two definitive methods of treatment in Graves` disease beside near-total thyreoidectomy. Simple strategies like optimization of thyroid metabolism help to improve efficacy in radioiodine therapy thus lowering applied radioiodine doses, radiation exposure to the patient and to the environment and avoiding multiple vain therapeutic efforts. These strategies are likely to reduce costs at the same time. (orig.) [Deutsch] Die Radioiodtherapie ist eine der beiden definitiven Therapiemethoden bei Morbus Basedow neben der nahezu totalen Thyreoidektomie. Ziel ist es, mit einfachen Methoden wie der optimalen Einstellung der Stoffwechsellage die Effizienz der Radioiodtherapie zu optimieren im Hinblick auf eine Reduktion der einzusetzenden Aktivitaet, der Gesamtstrahlenexposition fuer Patient und Umwelt und durch Vermeidung mehrfacher, vergeblicher therapeutischer Ansaetze. Diese Optimierung traegt auch zur Reduktion der Gesamtkrankheitskosten bei. (orig.)

  18. Herausforderungen beim Aufbau und bei der Pflege einer Bilddatenbank – ein Anwendungsbeispiel aus dem Digitalen Forschungsarchiv Byzanz (DiFAB

    Directory of Open Access Journals (Sweden)

    Nina Rannharter

    2017-09-01

    Full Text Available Mit Metadaten versehene, digital archivierte Bilder sind aufgrund ihrer hohen Komplexität eine ständige Herausforderung für den Aufbau von Metadatenstrukturen und für das Beibehalten von adäquaten Metadatenstandards in Bilddatenbanken. Besonders bei Bildern über eine materielle Kultur zeichnet sich diese Komplexität in den diversen Ebenen ab. Zur Verdeutlichung dieser Problematik dient ein einzelnes Monument mit seiner fotographischen Dokumentation als geisteswissenschaftliches Anwendungsbeispiel aus dem Digitalen Forschungsarchiv Byzanz (DiFAB der Universität Wien. Unter der grundsätzlichen Berücksichtigung der künftigen Anforderungen und der einfachen Navigation von Metadaten beinhaltet dieser Beitrag u. a. die Herausforderungen mit den diversen analogen und digitalen Formen der Dokumentation, der historischen Geographie, der kulturspezifischen Terminologie sowie mit der kunsthistorischen Bedeutung einer exakten und unscharfen Datierung für Forschungsarchive.

  19. Thermal management for GDI engine. Ways to reduce warm up; Thermomanagement beim DI Ottomotor. Wege zur Verkuerzung des Warmlaufs

    Energy Technology Data Exchange (ETDEWEB)

    Koch, F.; Haubner, F.; Schwaderlapp, M. [FEV Motorentechnik GmbH und Co KG, Aachen (Germany)

    2001-07-01

    The cooling system of modern engines has to fulfill demands which are for the engine fuel consumption, increase of efficiency, decrease of emissions and for the vehicle warm up characteristic and cabin heater power. Most of the potential to optimize the cooling system is found at low engine loads and during the warm up. For future systems a precise control of the cooling power is required. Parameters are the engine load and the control of coolant and component temperatures. This parameters are necessary to define the strategy of a thermal management system of the engine. Simulation models were developed to describe the thermal behavior and the interactions between cooling system and thermodynamic, thermal load of the components and Tribology. Based on this a concept was worked out which lead to a fuel consumption reduction of 3,8% in NEFZ. (orig.) [German] Das Kuehlsystem heutiger Motoren muss Anforderungen erfuellen, die sich motorseitig aus Verbrauchsreduzierung, Wirkungsgradoptimierung und gleichzeitiger Verschaerfung der Abgasnormen sowie fahrzeugseitig aus der Warmlaufdynamik insbesondere der fuer die Fahrzeugheizung benoetigten Leistung ergeben. Die Potenziale zur Optimierung des Kuehlsystems finden sich vorwiegend fuer den Motorbetrieb bei niedrigen Motorlasten und im Warmlauf. Fuer zukuenftige Systeme erfordert dies eine exaktere Regelung der Kuehlleistung, die sich am tatsaechlichen Bedarf des Motors orientiert. Als wesentliche Parameter sind die staerkere Beruecksichtigung der Motorlast und die gezielte Regelung der Kuehlmittel- sowie der Bauteiltemperaturen zu nennen. Besondere Bedeutung bekommt die Definition der Betriebsweise eines Thermomanagementsystems. Zur Auslegung wurden Simulationsmodelle entwickelt, die das thermische Verhalten und die wesentlichen Interaktionen des Kuehlsystems mit der Thermodynamik, der thermischen Bauteilbelastung und der Tribologie detailliert beschreiben und ein Konzept erarbeitet, das fuer ein Mittelklassefahrzeug 3,8% Verbrauchsverbesserung im NEFZ bringt. (orig.)

  20. 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.

  1. 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...

  2. Multiplicity of Buc copies in Atlantic salmon contrasts with loss of the germ cell determinant in primates, rodents and axolotl

    OpenAIRE

    Skugor, Adrijana; Tveiten, Helge; Johnsen, Hanne; Andersen, Øivind

    2016-01-01

    Background The primordial germ cells (PGCs) giving rise to gametes are determined by two different mechanisms in vertebrates. While the germ cell fate in mammals and salamanders is induced by zygotic signals, maternally delivered germ cell determinants specify the PGCs in birds, frogs and teleost fish. Assembly of the germ plasm in the oocyte is organized by the single Buc in zebrafish, named Velo1 in Xenopus, and by Oskar in Drosophila. Secondary loss of oskar in several insect lineages coin...

  3. 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.

  4. Gain-of-function assays in the axolotl (Ambystoma mexicanum) to identify signaling pathways that induce and regulate limb regeneration.

    Science.gov (United States)

    Lee, Jangwoo; Aguilar, Cristian; Gardiner, David

    2013-01-01

    The adult salamander has been studied as a model for regeneration of complex tissues for many decades. Only recently with the development of gain-of-function assays for regeneration, has it been possible to screen for and assay the function of the multitude of signaling factors that have been identified in studies of embryonic development and tumorigenesis. Given the conservation of function of these regulatory pathways controlling growth and pattern formation, it is now possible to use the functional assays in the salamander to test the ability of endogenous as well as small-molecule signaling factors to induce a regenerative response.

  5. 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

  6. 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

  7. Lung volume reduction in pulmonary emphysema from the radiologist's perspective; Lungenvolumenreduktion beim Lungenemphysem aus der Sicht des Radiologen

    Energy Technology Data Exchange (ETDEWEB)

    Doellinger, F.; Poellinger, A. [Charite Universitaetsmedizin Berlin (Germany). Dept. of Radiology; Huebner, R.H. [Charite Universitaetsmedizin Berlin (Germany). Dept. of Internal Medicine/Infectious and Respiratory Diseases; Kuhnigk, J.M. [Fraunhofer MEVIS, Bremen (Germany). Inst. for Medical Image Computing

    2015-08-15

    Pulmonary emphysema causes decrease in lung function due to irreversible dilatation of intrapulmonary air spaces, which is linked to high morbidity and mortality. Lung volume reduction (LVR) is an invasive therapeutical option for pulmonary emphysema in order to improve ventilation mechanics. LVR can be carried out by lung resection surgery or different minimally invasive endoscopical procedures. All LVR-options require mandatory preinterventional evaluation to detect hyperinflated dysfunctional lung areas as target structures for treatment. Quantitative computed tomography can determine the volume percentage of emphysematous lung and its topographical distribution based on the lung's radiodensity. Modern techniques allow for lobebased quantification that facilitates treatment planning. Clinical tests still play the most important role in post-interventional therapy monitoring, but CT is crucial in the detection of postoperative complications and foreshadows the method's high potential in sophisticated experimental studies. Within the last ten years, LVR with endobronchial valves has become an extensively researched minimally-invasive treatment option. However, this therapy is considerably complicated by the frequent occurrence of functional interlobar shunts. The presence of ''collateral ventilation'' has to be ruled out prior to valve implantations, as the presence of these extraanatomical connections between different lobes may jeopardize the success of therapy. Recent experimental studies evaluated the automatic detection of incomplete lobar fissures from CT scans, because they are considered to be a predictor for the existence of shunts. To date, these methods are yet to show acceptable results.

  8. Initial experience in the underground use of laser scanners in the monitoring of bulk materials; Erste Erfahrungen beim untertaegigen Einsatz von Laserscannern in der Massengutueberwachung

    Energy Technology Data Exchange (ETDEWEB)

    Voss, H.W. [RAG Aktiengesellschaft, Bottrop (Germany). Bergwerk Prosper-Haniel

    2008-04-17

    The profitability of coal mines is significantly affected by the structural and organisational conditions in the area of bulk material transport. The introduction and implementation of measures to improve logistics constitutes a permanent challenge in the mines. The continuous increase in face outputs in the mines of RAG by the use of increasingly efficient coal-winning equipment also imposes higher demands on the conveyor belts. The capacity of the infrastructure is not high enough in many cases to cope with these quantities. In addition to organisational solutions investigation of the conveyor system to determine optimum or maximum utilisation of capacity is necessary. This has been done at the Prosper-Haniel mine with offline and online simulation systems for several years. The contribution includes further development of mass flow measurement, the newly used volumetric flow measuring system and thus the possibility of direct determination of the dirt content in the material conveyed from the workings. In conjunction with the face data direct determination of the quantity of dirt cut with the coal is possible. (orig.)

  9. Advantages for nitrocarburizing processes with post oxidation in continuous furnaces; Anlagen und verfahrenstechnische Vorteile beim Nitrocarburieren mit Nachoxydieren in kontinuierlichen Ofenanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Irretier, Olaf [Industrieberatung fuer Waermebehandlungstechnik IBW Dr. Irretier, Kleve (Germany); Salerno, David [Safed Suisse, Delemont (Switzerland)

    2011-06-15

    The present contribution shows the possibilities and test results of the new developed nitrocarburizing process called Oxycad NT {sup registered}. It could be shown, that this process is very suitable for bulk materials which have to be heat treated in conveyor belt furnaces for an optimum wear and corrosion resistance. (orig.)

  10. Heat transfer and pressure drop during flow boiling of R407C; Waermeuebergang und Druckverlust beim Stroemungssieden von R407C

    Energy Technology Data Exchange (ETDEWEB)

    Rollmann, Philipp; Spindler, Klaus [Stuttgart Univ. (DE). Inst. fuer Thermodynamik und Waermetechnik (ITW)

    2011-10-15

    The heat transfer and pressure drop during flow boiling of R407C in a horizontal microfin tube have been investigated. The measured heat transfer coefficient is compared with the correlations of Liu and Winterton as well as Cavallini et al. The measured pressure drop is compared with the correlations of Kuo and Wang as well as Mueller-Steinhagen and Heck. (orig.)

  11. On the heat transfer in the pool boiling at tightly finned steel tubes; Zum Waermeuebergang beim Behaeltersieden an eng berippten Stahlrohren

    Energy Technology Data Exchange (ETDEWEB)

    Bujok, Patrick; Wang, Yabai; Luke, Andrea [Kassel Univ. (Germany). Lehrstuhl fuer Technische Thermodynamik

    2012-07-01

    Process-integrated energy efficiency in power plants and process plants can only be achieved with new innovative apparatus concepts. There exist no sufficient reference applications, no data to assist in interpretation a well as no certificates of operational safety for these apparatus concepts. Thus, these concepts are not applied despite of the significant energetic advantages. Under this aspect, industrial companies (plant fabricators, plant operators and engineering offices) and five universities have affiliated to a multi-institutional project in order to explore unused opportunities on the integration of heat. The Department of Technical Thermodynamics at the University of Kassel (Federal Republic of Germany) regards to apparatuses which effectively and securely transfer a heat flow at especially low differences of temperatures between the heat dissipating and heat absorbing side of an evaporator with structured ducts. It has been known for many decades that ribbed structures are one of the most efficient methods to transfer heat. Ribbed ducts in heat exchangers are used in the refrigeration technology as well as in the technology of air conditioning. Nevertheless, plain tubes still are the technical standard in the chemical and process industry. The objective of this research project consists of a presentation of macrostructures and microstructures which can be produced efficiently with regard to the heat transfer, at a relatively low cost as well as in large quantities with a consistent structure. Furthermore, a substantial database for the design of evaporators with such surface textures is set up. Thus, evaporators being produced by the project partner Wieland-Werke AG (Ulm, Federal Republic of Germany) were investigated on a laboratory scale as well as in small tube bundles. Subsequently, selected structures were applied in the technical centre of the project partner Linde AG (Pullach, Federal Republic of Germany) in order to validate the transferability from the laboratory scale (single tube, mini-bundle) to the technical scales. On this occasion, the authors investigate the impact of tightly finned steel tubes with trapezoidal cross-sectional ribs on the heat transfer during the boiling in case of free convection over a wide range of pressures from the beginning up to the fully developed nucleate boiling. Hydrocarbons such as n-pentane and i-octane as a natural refrigerant in the process industry are used as a boiling fluid. The results of the investigations at an electrically heated and horizontally placed test tube consisting of structural steel are compared with correlations from the literature. First results from a mixture of both hydrocarbons show that the heat transfer deteriorates if only a little amount of the heavier boiling component is added.

  12. The effect of bonus/malus systems on the sales of new vehicles; Wirkung von Bonus-Malus-Systemen beim Neuwagenkauf

    Energy Technology Data Exchange (ETDEWEB)

    Haan, P. de

    2008-07-01

    This presentation made at the Swiss 2008 research conference on traffic by Peter de Haan from the Institute for Environmental Decisions at the Swiss Federal Institute of Technology ETH in Zurich takes a look at the effects of bonus/malus systems on the sales of new vehicles. The author notes that in spite of technological progress made, increasing car size, weight and mileage along with increased motor power has eaten up two-thirds of energy-efficiency progress made. The effect of the long lifetime of modern vehicles is commented on. The results of a survey made are presented and discussed, as are the results of simulations. Further aspects discussed include effects on the motor trade and road safety and the indirect effects of bonuses. Finally, trends in the area are noted.

  13. Specifications for refrigerating transport. More rigid temperature specifications for cooling transport; Anforderungen im Transportkaeltebereich. Erhoehte Anforderungen beim Kuehltransport wegen verschaerfter Temperaturvorschriften

    Energy Technology Data Exchange (ETDEWEB)

    Grosskopf, P [Frigoblock Grosskopf GmbH, Essen (Germany)

    2002-09-01

    The recommendations of the Federal Institute of Consumer Health Protection and Veterinary Medicine (Bundesinstitut fuer gesundheitlichen Verbraucherschutz und Veterinaermedizin, BgVV), which sums up all German and European temperature specifications for fresh and refrigerated products, as well as the new Ordinance on Refrigerated food (Verordnung ueber tiefgefrorene Lebensmittel, TLMV) and the new German Ordinance on Food Hygiene (Lebensmittelhygieneverordnjung,LMHV) including temperature monitoring specifications according to HACCP, induced these associations to draw up practical recommendations and guidelines for their members. [German] Die Temperaturempfehlungen des Bundesinstituts fuer gesundheitlichen Verbraucherschutz und Veterinaermedizin (BgVV), die alle deutschen und europaeischen Temperaturvorschriften fuer Frisch- und Tiefkuehlprodukte zusammenfassen sowie die Neufassung der Verordnung ueber tiefgefrorene Lebensmittel (TLMV) und die neue bundeseinheitliche Lebensmittelhygiene-Verordnung (LMHV) inkl. der Temperaturueberwachungsvorschriften gemaess HACCP, haben die betroffenen Verbaende veranlasst, entsprechende Praxisempfehlungen und Leitlinien fuer ihre Mitglieder zu erarbeiten. (orig.)

  14. Transformation behaviour and residual stresses in welding of new LTT filler materials; Umwandlungsverhalten und Eigenspannungen beim Schweissen neuartiger LTT-Zusatzwerkstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Kromm, Arne

    2011-07-06

    It has long been recognized that phase transformation plays a prominent part in the evolution of welding residual stresses in high-strength steel. But thus far, no approaches have been available to practically utilize this effect for welding residual stress control. Innovative Low Transformation Temperature (LTT) alloys featuring a characteristic chemical composition open up the possibility for joining high strength steels on their own strength level. Furthermore, martensitic phase transformation is supposed to permit deliberate adjustment of the welding residual stresses. Even though numerous investigations can be found in the literature on this issue, they provide only little insight into the interaction between phase transformation and resulting welding residual stresses. In order to clarify the problem presented, a matrix of LTT alloys was defined based on evaluated literature. The alloys were characterized with respect to their microstructure, mechanical properties and transformation temperature. Furthermore, it was possible within the scope of this study to realize in-situ experiments during welding using energy-dispersive diffraction methods. The new design and implementation of a welding setup specifically for use at synchrotron beamlines enabled the in-situ diffraction analysis of transformation processes. In the course of these experiments it could be managed to determine the transformation temperatures prevailing in the LTT weld metal. In addition the transformation kinetics of these alloys could be analyzed. The effects of the transformation behavior were analyzed based on the residual stress distributions at the surface of varying specimen geometries. The results illustrate on the one hand that the desired residual stress control by using LTT alloys is actually feasible. This is particularly found in cases with largely free shrinkage of the weld. With increasing shrinkage restraint, however, a shift of the residual stress level into the area of tension is seen to occur. This is observed for the considered alloys to be particularly pronounced in transverse direction of the weld. By contrast, the residual stress level in longitudinal weld direction is nearly independent of the shrinkage conditions. With the help of residual stress depth gradients it could be established that the additional shrinkage restraint manifests itself in a parallel shift of the residual stress level in the weld metal. Application of energy-dispersive diffraction methods additionally allowed it for the first time to determine residual stresses in the austenitic phase of the LTT alloy which is present parallel to martensite. Results gained under laboratory conditions mostly need to be verified under real fabrication conditions. For this purpose, a component weld test was performed in a special large-scale testing facility. Under structural shrinkage restraint, the load relieving effect of a specific LTT welding filler material could be proven by means of a pronounced stress reduction duringwelding. Overall, evidence was furnished that the concept of Low Transformation Temperature (LTT)alloys is successful and that the proven austenite-martensite transformation exerts a significanteffect on the residual stress level. [German] Die Erkenntnis, dass die Phasenumwandlung bei der Schweisseigenspannungsentstehung hochfester Staehle eine bedeutende Rolle spielt, gibt es bereits seit langer Zeit. Bisher existierten jedoch keine Ansaetze, diesen Effekt praktisch zur Schweisseigenspannungskontrolle zu nutzen. Neuartige Low Transformation Temperature (LTT) Legierungen bieten aufgrund ihrer charakteristischen chemischen Zusammensetzung die Moeglichkeit, hochfeste Staehle auf deren Festigkeitsniveau zu fuegen. Die martensitische Phasenumwandlung soll zudem eine gezielte Einstellung der Schweisseigenspannungen erlauben. Die im Schrifttum vorliegenden Untersuchungen zu diesem Thema sind zwar zahlreich, bieten jedoch nur wenige Erkenntnisse zur Wechselwirkung zwischen der Phasenumwandlung und den resultierenden Schweisseigenspannungen. Zur Klaerung dieser Fragestellung wurde basierend auf Literaturauswertungen eine Matrix von LTT-Legierungen verwirklicht, welche hinsichtlich des Gefueges, der mechanischen Eigenschaften und der Umwandlungstemperaturen charakterisiert wurden. Weiterhin konnten im Rahmen dieser Arbeit erstmals In-situ-Beugungsexperimente waehrend des Schweissens unter Anwendung energiedispersiver Methoden realisiert werden. Die Neukonzeption und Verwirklichung einer Schweissvorrichtung speziell fuer den Einsatz an Synchrotronstrahllinien ermoeglichte die bislang einzigartige In-situ-Analyse der Umwandlungsvorgaenge waehrend des Schweissens mit LTT-Legierungen. Im Zuge dieser Experimente konnte neben den im Schweissgut vorherrschenden Umwandlungstemperaturen zusaetzlich die Umwandlungskinetik dieser Legierungen ermittelt werden. Die Auswirkungen des Umwandlungsverhaltens wurden anhand der Eigenspannungsverteilungen in der Oberflaeche variierender Probengeometrien analysiert. Die Ergebnisse verdeutlichen einerseits, dass die mittels der LTT-Legierungen angestrebte Eigenspannungskontrolle tatsaechlich moeglich ist. Dies zeigt sich insbesondere dann, wenn eine weitgehend freie Schrumpfung der Naht vorliegt. Mit zunehmender Schrumpfbehinderung ergibt sich jedoch eine Verschiebung des Eigenspannungsniveaus in den Zugbereich. Dies ist bei den hier betrachteten Legierungen vornehmlich in Nahtquerrichtung ausgepraegt. Dagegen ist das Eigenspannungsniveau in Nahtlaengsrichtung nahezu unabhaengig von den Schrumpfbedingungen. Anhand von Eigenspannungstiefengradienten liess sich feststellen, dass sich die zusaetzliche Schrumpfbehinderung in einer Parallelverschiebung des Eigenspannungsniveaus im Schweissgut aeussert. Die Anwendung energiedispersiver Beugungsmethoden erlaubte zudem erstmals die Eigenspannungsermittlung in der parallel zum Martensit vorliegenden austenitischen Phase der LTT- Legierungen. Ergebnisse, die unter Laborbedingungen gewonnen werden, beduerfen zumeist der Ueberpruefung unter realen Fertigungsbedingungen. Zu diesem Zweck wurde ein Bauteilschweissversuch in einer speziellen Grosspruefanalage durchgefuehrt. Unter konstruktiver Schrumpfbehinderung gelang es, die lastabbauende Wirkung eines spezifischen LTT-Schweisszusatzes anhand einer ausgepraegten Spannungsreduktion waehrend des Schweissens zu belegen. Insgesamt wurde der Nachweis erbracht, dass das Konzept der Low Transformation Temperature (LTT) Legierungen zielfuehrend ist und die nachgewiesene Austenit-Martensitumwandlung einen signifikanten Effekt auf das Eigenspannungsniveau ausuebt.

  15. Ressourceneffizienz durch Digitalisierung: Vortrag gehalten beim Runden Tisch "Nachhaltige Digitalisierung", Digitalisierung als Motor der Nachhaltigkeit, 15. März 2017, Stuttgart

    OpenAIRE

    Sauer, Alexander

    2017-01-01

    Der Vortrag "Ressourceneffizienz durch Digitalisierung" behandelt folgende Themenkomplexe: - DigitalisierungalsInnovationstreiber - Geschäftsmodell-Innovation - Ressourceneffiziente Produktion - Expertensicht auf Unternehmenspotenziale durch Industrie 4.0

  16. [Kombinierte Anwendung von Strahlentherapie und adjuvanter Therapie mit einem Mistelextrakt (Viscum album L.) zur Behandlung des oralen malignen Melanoms beim Hund: Eine retrospektive Studie].

    Science.gov (United States)

    von Bodungen, Uta; Ruess, Katja; Reif, Marcus; Biegel, Ulrike

    2017-01-01

    Hintergrund: Orale maligne Melanome (OMM) des Hundes zeichnen sich durch schnelles Wachstum, lokale Invasion und hohe Metastasierungsraten aus. Extrakte auf Basis von Viscum album L. (VAE) werden zunehmend in der Krebstherapie sowohl in der Human- als auch in der Veterinärmedizin eingesetzt. Ziel unserer Studie war es zu untersuchen, inwieweit die adjuvante Therapie mit VAE eine therapeutische Option zur Behandlung von OMM ist. Besonderes Augenmerk galt dabei der Überlebenszeit und möglichen Nebenwirkungen. Tiere und Methoden: 26 Hunde mit OMM, die in einem der größten veterinäronkologischen Zentren der Schweiz allesamt eine Strahlentherapie erhielten (teilweise nach operativer Tumorresektion) wurden in die retrospektive Studie eingeschlossen: 18 Hunde wurden mit VAE behandelt (1 ml VAE (Iscador®) in ansteigenden Konzentrationen von 0,1 bis 20 mg/ml subkutan 3-mal pro Woche (VAE-Gruppe), 8 erhielten keine adjuvante Behandlung (Vergleichsgruppe). Wir verglichen die Größenentwicklung der OMM sowie die Überlebenszeit. Ergebnisse: Patienten mit Bestrahlung und adjuvanter VAE-Therapie zeigten mit 236 Tagen eine signifikant längere mediane Überlebenszeit im Vergleich zu Patienten mit Bestrahlung, aber ohne adjuvante VAE-Therapie (49 Tage; Log-Rank-Test: p = 0,0047). Die VAE-Therapie verlängerte die Überlebenszeit um mehr als zwei Drittel (Hazard Ratio (HR) = 0,30, 95%-Konfidenzintervall (KI) 0,11-0,86; p = 0,024), während ein höheres Tumorstadium gemäß UICC (Union internationale contre le cancer) einen statistischen Trend zur Verdopplung des Sterberisikos zeigte (UICC-Stadium III/IV vs. I/II: HR = 2,12, 95%-KI 0,88-5,12; p = 0,095). Zwei Patienten zeigten milde Nebenwirkungen während der VAE-Behandlung. Einer der beiden zeigte 1 Tag lang ein selbstlimitiertes Fieber, bei dem anderen Patienten reduzierten wir die Dosis von einem konzentrierteren zu einem weniger konzentrierten VAE (Serie 0) aufgrund von Müdigkeit, die daraufhin verschwand. Schlussfolgerungen: VAE ist eine sichere, nebenwirkungsarme Behandlung und scheint sich positiv auf die Überlebenszeit von Hunden mit OMM auszuwirken. Somit ist dieser therapeutische Ansatz es wert, vermehrt bei der adjuvant zur Strahlentherapie eingesetzten Behandlung des OMM in Betracht gezogen zu werden. Die verglichenen Gruppen waren jedoch klein, divers und nicht konsistent hinsichtlich aller prognostischen Parameter. Eine prospektive Studie mit einer größeren Studienpopulation wäre daher von Interesse. © 2017 S. Karger GmbH, Freiburg.

  17. Thermodynamic potential of the spray-guided combustion system for gasoline engines at Mercedes-Benz; Thermodynamisches Potenzial beim strahlgefuehrten Brennverfahren fuer Ottomotoren bei Mercedes-Benz

    Energy Technology Data Exchange (ETDEWEB)

    Schaupp, U.; Bertsch, D.; Schaub, R.; Schmolla, W.; Winter, H. [DaimlerChrysler AG (Germany)

    2007-07-01

    From the beginning of the nineteen's the development of DI engines for reducing fuel consumption was reinforced. The focus in studies by Mercedes-Benz was located in the development of a robust stratified operation mode (leaner than stoichiometric {lambda}>>1). To reach the targets the spray guided Mercedes-Benz combustion system with Piezo injection technology was developed and went into series production in the CLS 350 CGI in 2006. Main focus of the development was the control of the spray guided combustion system under mass production requirements by keeping-up the consumption- and emission-potentials. The advantage in fuel consumption in the NEDC of the CLS 350 CGI is 10% in comparison to the basic PFI technology. Besides the optimization of the injection system and the combustion chamber geometry a new ignition system offers an additional option for a further increase of the combustion efficiency. This article describes how this new ignition system can be used advantageously, how to get a bigger robustness window and how to open up additional reduction of fuel consumption and better untreated emissions. (orig.)

  18. Evaluation of multiple trauma victims with 16-row multidetector CT (MDCT): a time analysis; Anwendung der 16-Zeilen-Mehrdetektor-CT in der Initialdiagnostik beim Polytrauma: Eine Zeitanalyse

    Energy Technology Data Exchange (ETDEWEB)

    Heyer, C.M.; Nicolas, V. [Bochum Univ. (Germany). Inst. fuer Diagnostische Radiologie, Interventionelle Radiologie und Nuklearmedizin; Rduch, G.J. [Bochum Univ. (Germany). Klinik fuer Chirurgie; Wick, M.; Muhr, G. [Bochum Univ. (Germany). Medizinische Klinik III, Pneumologie, Allergologie und Schlafmedizin; Bauer, T.T. [Berufsgenossenschaftliche Kliniken Bergmannsheil, Ruhr-Univ. Bochum (Germany)

    2005-12-15

    Purpose: Description and time analysis of a 16-row MDCT protocol in the evaluation of multiple trauma patients considering transport, time of scanning, patient positioning, image reconstruction, and image interpretation. Materials and methods: Between May and December 2004, 60 multiple trauma patients underwent 16-row MDCT (Sensation, Siemens, Erlangen, Germany). The protocol included serial scanning of the head, spiral scanning of the cervical spine and contrast-enhanced spiral scanning of the thorax/abdomen with multiplanar reformations (MPR) of the thoracic/lumbar spine and the pelvis. All time intervals including transport, patient positioning, scanning, duration of MPR, total time in the examination room, and time to first and final image interpretation were prospectively evaluated. Furthermore, patient characteristics, trauma profiles, and mortality rates were recorded. Results: 46 male and 14 female patients (mean age 43.6 years) were enrolled in the study. Time analysis of 16-row MDCT revealed the following results (mean time standard deviation): Emergency room treatment and transport 19.2{+-}6.7 min, patient positioning 16.5{+-}6.5 min, scan duration 8.0{+-}3.3 min, total time in examination room 24.5{+-}7.2 min, image reconstruction including MPR 32.0{+-}16.4 min, and time of first (16.4{+-}4.7 min) and final image interpretation (82.5{+-}30.4 min). Trauma profiles revealed thoracic injuries in 35/60 patients (58.3%), head injuries in 23/60 patients (38.3%), abdominal injuries in 15/60 patients (25.0%), injuries of the cervical (9/60 patients, 15.0%), thoracic (12/60 patients, 20.0%), and lumbar spine (19/60 patients, 31.7%), pelvic injuries in 13/60 patients (21.7%), and injuries of extremities in 39/60 patients (65.0%). The mortality rate was 21.7%. (orig.)

  19. Multislice helical CT (MSCT) for mid-facial trauma: optimization of parameters for scanning and reconstruction; Mehrschicht-Spiral-CT (MSCT) beim Mittelgesichtstrauma: Optimierung der Aufnahme- und Rekonstruktionsparameter

    Energy Technology Data Exchange (ETDEWEB)

    Dammert, S.; Funke, M.; Obernauer, S.; Grabbe, E. [Abt. Roentgendiagnostik I, Georg-August-Univ. Goettingen (Germany); Merten, H.A. [Abt. fuer Mund-, Kiefer- und Gesichtschirurgie, Georg-August-Univ. Goettingen (Germany)

    2002-07-01

    Purpose: To determine the optimal scan parameters in multislice helical CT (MSCT) of the facial bone complex for both axial scanning and multiplanar reconstructions. Material and Methods: An anthropomorphic skull phantom was examined with a MSCT. Axial scans were performed with continuously increasing collimations (4 x 1.25 - 4 x 2.5 mm), tube current (20 - 200 mA) and table speeds (3.75 mm/rot. and 7.5 mm/rot.). Multiplanar reconstructions in coronal and parasagittal planes with different reconstruction increment and slice thickness were evaluated in terms of image noise, contour artifacts and visualisation of anatomical structures. Results: The best image quality was obtained with a collimation of 4 x 1.25 mm and a - table speed of 3.75 mm/rot. A reconstruction increment of 0.6 mm achieved the best time to image quality relation. With these parameters the bone structures were depicted in an optimal way without artifacts. The tube current could be reduced to 50 mA without significant loss of image quality. The optimized protocol was used for regular routine examinations in patients with facial trauma (n = 66). Conclusions: Low-dose MSCT using thin collimation, low table speed and small reconstruction increments provides excellent data for both axial images and multiplanar reconstructions in patients with facial trauma. An additional examination in coronal orientation is therefore no longer necessary. (orig.) [German] Zielsetzung: Verbesserung der Aufnahme- und Rekonstruktionsparameter in der Mehrschicht Spiral-CT (MSCT) zur Untersuchung des knoechernen Mittelgesichtes in verschiedenen Ebenen. Material und Methode: Ein anthropomorphes Schaedel-Phantom wurde in axialer Schichtfuehrung mit einem MSCT untersucht, wobei die Kollimation (1,25 - 2,5 mm), der Tischvorschubfaktor (Pitch 3 - 6) und der Roehrenstrom (20 - 200 mA) systematisch variiert wurden. Aus den Volumendatensaetzen wurden jeweils koronare und parasagittale Sekundaerreformationen mit unterschiedlichen Rekonstruktionsinkrementen und Schichtdicken erstellt. Anhand einer fuenfstufigen Bewertungsskala wurden die einzelnen Bildsaetze in Hinblick auf die Bildqualitaet und die diagnostische Aussagekraft beurteilt. Ergebnisse: Die beste Bildqualitaet in allen Orientierungen wurde mit einer Kollimation von 1,25 mm und einem Pitch von 3 erzielt. Dabei erwies sich ein Rekonstruktionsinkrement von 0,6 mm als guenstig. Alle knoechernen Strukturen konnten scharf und frei von Stufenartefakten dargestellt werden. Der Roehrenstrom liess sich ohne relevante Einschraenkung der Aussagekraft durch erhoehtes Bildrauschen auf 50 mA reduzieren. Mit diesen Parametern wurde ein Patientenkollektiv mit Mittelgesichtsverletzungen routinemaessig untersucht (n = 66). Schlussfolgerungen: Die MSCT mit multiplanaren Rekonstruktionen erlaubt unter Verwendung einer engen Kollimation, eines relativ niedrigen Pitch und eines drastisch reduzierten Roehrenstroms eine exzellente Darstellung aller knoechernen Mittelgesichtsstrukturen. Eine zweite Untersuchungsserie in koronarer Orientierung ist daher nicht mehr erforderlich. (orig.)

  20. Additive Fertigungsverfahren mit Praxisbeispielen: Vortrag gehalten beim Praxisforum 3D-Druck, 3D-Druck in Produktentwicklung und Fertigung - Anwendungen und Potenziale, 24.03.15, Landshut

    OpenAIRE

    Seidel, Christian

    2015-01-01

    Für die Additive Fertigung von Metallen und Kunststoffen gibt es verschiedenen Methoden und Funktionsprinzipien. Die Potenziale liegen unter anderem in der Formgebungsfreiheit, der Ressourceneffizienz und der Personalisierung. In den nächsten Jahren ist mit einem weiteren Rückgang der Kosten pro hergestelltem Volumen zu rechnen. Mit Hilfe der Bionik wird die Natur als Vorbild abstrahiert und findet Einsatz bei technischen Anwendungen. Als Beispiele für Additive Fertigungsverfahren sind der fu...

  1. Reduction of CO2 emissions during cement clinker burning : Part 2 = Ein Beitrag zur Reduzierung der CO2-Emissionen beim Zementklinkerbrand; Teil 2

    NARCIS (Netherlands)

    Vogel, S.; Kolditz, K.; Beilmann, F.; Finger, F.A.; Ott-Reinhardt, D.; Kralisch, D.

    2013-01-01

    The aim of the research project entitled "New technology in cement production for reducing CO2 emissions" sponsored by the German Federal Environmental Foundation was to lower the CO2 emissions during clinker burning. A possible reduction, relative to an industrial example, of up to 21 % in the

  2. Reduction of CO2 emissions during cement clinker burning; part 1 = Ein Beitrag zur Reduzierung der CO2-Emissionen beim Zementklinkerbrand; Teil 1

    NARCIS (Netherlands)

    Vogel, S.; Kolditz, K.; Bellmann, F.; Ott-Reinhardt, D.; Kralisch, D.

    2013-01-01

    The aim of the research project entitled "New technology in cement production for reducing CO2 emissions" sponsored by the German Federal Environmental Foundation was to lower the CO2 emissions during clinker burning. A possible reduction, relative to an industrial example, of up to 21 % in the

  3. 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.

  4. A rare combination of findings revealed by MR imaging in the Marfan syndrome; Seltene Befundkonstellation beim Marfan-Syndrom im MR-Tomogramm

    Energy Technology Data Exchange (ETDEWEB)

    Kleimaker, G [Abt. fuer Nuklearmedizin und Spezielle Biophysik, Medizinische Hochschule Hannover (Germany); Ehrenheim, C [Abt. fuer Nuklearmedizin und Spezielle Biophysik, Medizinische Hochschule Hannover (Germany); Rittierodt, M [Abt. Neurochirurgie, Medizinische Hochschule Hannover (Germany); Jaster, S [Abt. Neurochirurgie, Medizinische Hochschule Hannover (Germany); Hundeshagen, H [Abt. fuer Nuklearmedizin und Spezielle Biophysik, Medizinische Hochschule Hannover (Germany)

    1996-08-01

    We report on the case of a 16-year-old boy known to have suffered form the Marfan syndrome for the past ten years. Even though he could not be regarded as a text-book perfect example, he showed some rare manifestations of the disease. Particular attention is given to the diagnostic possibilities offered by MR imaging. (orig./MG) [Deutsch] Wir berichten ueber den Fall eines 16jaehrigen Jungen mit einem seit etwa 10 Jahren bekannten Marfan-Syndrom, der zwar nicht das typisches Vollbild, jedoch einige seltene Auspraegungen dieses Krankheitsbildes aufweist. Die kernspintomographische Diagnostik findet besondere Beruecksichtung. (orig./MG)

  5. Bone scintigraphy compared to MRI and ultrasound in the early diagnosis of arthritis; Skelettszintigraphie im Vergleich mit MRT und Sonographie beim Fruehnachweis der Arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Sandrock, D. [Klinikum Chemnitz gGmbH, Klinik fuer Nuklearmedizin, Chemnitz (Germany)

    2006-12-15

    Chronic inflammatory arthritis is recognized specifically by bone erosions, caused by characteristic pannus tissue. In the finger joints dynamic low-Tesla MRI is nearly double but not completely sensitive in the detection of erosions than conventional radiography, sonography takes an intermediate position. Less specific signs of synovitis and tenosynovitis are shown with high sensitivity by both 3(2)-phase bone scintigraphy and ultrasound, MRI is less sensitive in this respect. However, standard situation of inflammation in bone scintigraphy - positive finding in early as well as late phase - is of surprisingly low sensitivity, any singular finding in the early or late phase has to be regarded as positive. Specificity of these singular findings is nevertheless sufficiently high, acute inflammatory joint changes and even erosions are also seen with MRI in obviously healthy persons. Only 2-phase bone scintigraphy is easily able to present a simultaneous survey of all joints of the body. For this reason 2-phase bone scintigraphy is most suitable for exclusion but also for primary diagnosis of disease, specification must be done afterwards by other imaging modalities or by laboratory findings. (orig.)

  6. Measures to comply with future particulate number standards with GDI engines; Massnahmen zum Erreichen zukuenftiger Grenzwerte fuer Partikelanzahl beim direkteinspritzenden Ottomotor

    Energy Technology Data Exchange (ETDEWEB)

    Dobes, Thomas; Fraidl, Guenter K.; Hollerer, Peter; Kapus, Paul E.; Ogris, Martin; Riener, Markus [AVL List GmbH, Graz (Austria)

    2011-07-01

    With the ongoing general discussion on fine particulates, also the particulates of Gasoline engines are now a focus of public interest. Compared to conventional Diesel engine, where due to the heterogeneous combustion, a certain amount of particles cannot be avoided; Gasoline engines a substantial reduction of particle number towards a level that does not compromise environmental aspects can be expected even without particle filter, however, with respective high development effort. Certainly the particle number emission is the most complex emission component with Gasoline engines both with regard to measurement technology, conditioning, reproducibility, tolerance sensitivity, long term stability, and OBD as well as development methodology. Thus a comprehensive development methodology - ranging from the detail optimization of individual injection parameters to mastering oil consumption and deposit formation over the whole vehicle lifetime, is most essential for an effective reduction of particle emission. Within this complex subject, the particulate counter itself proves to be uncritical whereas the sufficient conditioning of engine and vehicle and dilution tunnel, comprehensive base investigations have to be performed. All the established know how already generated for gaseous emission components is not sufficient to handle the particulate number issue properly. In spite of the fact, that very low particle numbers can be shown with single prototype vehicles, a reliable transfer into robust production solutions, comprehensive basic investigations especially with regard to tolerance sensitivity and robustness against fuel quality impacts and deposit formation have to be performed. Both for these open issues as well as for robust OBD solutions, actual field experience with a first generation of low particle engines is required. Thus, when introducing enhanced particle limits, the respective increased development durations and significantly enhanced efforts both for the development, calibration and validation have to be considered. (orig.)

  7. Survival advantage by neoadjuvant radiochemotherapy in locally advanced non-inflammatory breast cancer; Ueberlebensvorteil durch praeoperative Radiochemotherapie beim lokal fortgeschrittenen, nicht-inflammatorischen Brustkrebs

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Innokenti

    2011-07-01

    This study compares retrospectively, in terms of pathological complete response (pCR) and ten year survival rate, preoperative radiochemotherapy (RCT) with postoperative RCT for locally advanced or surgically in terms of breast conserving surgery or simple mastectomy unfavourable, non inflammatory breast cancers (LABC).

  8. Multiple utilization of energy in buildings. Utilization of waste heat at the Blood Transfusion Service; Energie im Gebaeude mehrfach nutzen. Abwaermenutzung beim Blutspendedienst Nord

    Energy Technology Data Exchange (ETDEWEB)

    Gaigalat, Jens

    2012-11-01

    For the Blood Transfusion Service North the German Red Cross (Berlin, Federal Republic of Germany) utilizes the waste heat from production facilities and laboratories for heating offices. By doing this, the VRV technology for the realization of this solution was used.

  9. Education and research when dismantling nuclear plants at the Technical University Dresden; Lehre und Forschung beim Rueckbau kerntechnischer Anlagen an der Technischen Universitaet Dresden

    Energy Technology Data Exchange (ETDEWEB)

    Hurtado, A.; Anthofer, A.; Cloppenborg, T.; Schreier, M. [Technische Univ. Dresden (Germany). Inst. fuer Energietechnik

    2013-08-15

    With the decision by the German government in 2011 to revoke the operating permission from 8 of the existing 17 German nuclear power plants, the responsibility of decommissioning and dismantling these plants has moved back into the focus of public awareness. Under the current legal conditions, the last nuclear plant will be disconnected from the grid on 31.12.2022 and this will create an enormous challenge for all the involved approving authorities, expert organisations, as well as companies involved in dismantling the plants. The development of new and efficient dismantling technologies and strategies is required to perform these highly responsible tasks. On the other hand, the nuclear competence and knowhow, as well as the promotion of young talents in the relevant scientific fields must be preserved. Technological and economic solutions are in demand for the various plants due to the different specifics of nuclear power plants. This will still require e.g. in the field of radiation protection highly qualified and well trained staff in future. The training of these skilled employees will require expanding the subject matter taught at universities, colleges and polytechnics to suit the changed parameters. The chair for hydrogen and nuclear energy technology at the TU Dresden will in future offer lectures as part of a new teaching discipline with the focus on dismantling and disposal. The course 'Dismantling nuclear power plants' took place for the first time in the summer semester 2013. It is organised as a three-day block seminar with an excursion to the company NIS Ingenieurgesellschaft mbH in Alzenau. The company NIS is a subsidiary of the Siempelkamp Nukleartechnik GmbH. This article intends to provide an overview of the contents of the courses and the impressions of the participants. In this way the TU Dresden is making a further contribution to preserving nuclear competence and inter-disciplinary dialogue. (orig.)

  10. Pharmacokinetic analysis of Gd-DTPA enhancement in dynamic MR of breast carcinoma. Pharmakokinetische Analyse der Gd-DTPA-Anreicherung in der MRT beim Mammakarzinom

    Energy Technology Data Exchange (ETDEWEB)

    Hess, T. (Deutsches Krebsforschungszentrum, Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie); Knopp, M.V. (Deutsches Krebsforschungszentrum, Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie); Hoffmann, U. (Deutsches Krebsforschungszentrum, Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie); Brix, G. (Deutsches Krebsforschungszentrum, Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie); Junkermann, H. (Heidelberg Univ. (Germany). Abteilung fuer Gynaekologische Radiologie); Zuna, I. (Deutsches Krebsforschungszentrum, Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie); Fournier, D. von (Heidelberg Univ. (Germany). Abteilung fuer Gynaekologische Radiologie); Kaick, G. van (Deutsches Krebsforschungszentrum, Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie)

    1994-06-01

    Dynamic Gd-DTPA enhanced MR of the breast was performed in one single slice in 27 patients with suspicious nodular lesions. The results could be histologically verified in all cases. A rapid spin-echo sequence with a time resolution of 8.75 s was used for the dynamic examination. The signal changes were analysed using a pharmacokinetic model which allowed parametrization of the contrast enhancement and transformation of the data into colour coded parameter images. The parameters allowed reliable distinction of 9 benign from 18 malignant lesions (p<0.05 for ''amplitude'', p<0.001 for ''k[sub 21]''). One fibroadenoma could not be distinguished from the carcinomas. Lymph node metastases and the pharmacokinetic parameter amplitude correlated significantly (p<0.05). (orig.)

  11. Queer worldings in the urban age. Die sub\\urban Journal Lecture beim Deutschen Kongress für Geographie im Oktober 2015 in Berlin

    Directory of Open Access Journals (Sweden)

    Natalie Oswin

    2015-11-01

    Full Text Available Der Beitrag stellt die Frage, in welchem Bezug die vieldiskutierte globale Urbanisierung, die sich in den vergangenen Jahrzehnten besonders im Globalen Süden weiter beschleunigt hat, mit einer ebenfalls zu beobachtenden verstärkten Thematisierung sexueller und geschlechtlicher Identitäten weltweit steht. Denn Kämpfe um Sichtbarkeit, Anerkennung und nicht-normative Lebensweisen artikulieren sich gerade in städtischen Kontexten mit besonderer Virulenz. Ein bislang weitgehend vernachlässigtes Potenzial wird dabei in Überschneidungen von Kritiken tradierter eurozentrischer Stadtkonzepte in den Urban Studies einerseits und der Infragestellung sexueller und geschlechtlicher – und ebenfalls oft an westlichen Standards orientierter – Normen in den Queer Studies andererseits gesehen. Sowohl Urban Studies als auch Queer Studies treiben ein worlding, eine Verweltlichung der untersuchten Probleme voran. Die Fragestellungen, die aus einer Zusammenführung von urban worlding und queer worlding entstehen, ermöglichen neue Blicke auf die Rolle, die gerade marginalisierte Subjekte in Prozessen von Urbanisierung und Globalisierung spielen.

  12. Dynamic MR-mammography in invasive lobular breast cancer; Dynamische MR-Mammographie beim invasiv lobulaeren Mammakarzinom bei 1,0 T

    Energy Technology Data Exchange (ETDEWEB)

    Sittek, H.; Perlet, C.; Kessler, M.; Reiser, M. [Institut fuer Radiologische Diagnostik, Klinikum Grossenhadern, Ludwig-Maximilians-Univ., Muenchen (Germany); Untch, M. [Klinik und Poliklinik fuer Frauenheilkunde und Geburtshilfe, Klinikum Grossenhadern, Ludwig-Maximilians-Univ., Muenchen (Germany)

    1998-12-31

    Material and Methods: We carried out 1505 MR mammographoes in 1357 patients. Biopsy was indicated in 413 cases. Among the malignancies, 23/214 (10%) were ILC. MR-M was performed with a 1.0 T whole body MRI system with a dynamic FLASH-3D sequence. Relative signal enhancement within lesions detected and morphologic pattern of contrast enhancement (mep) were determined. Three types of mep were distinguished: type 1 without contrast enhancement, type 2 with focal contrast enhancement, and type 3 with diffuse contrast enhancement of the glandular body. Results: Within MR-M alone, 19/23 (82.6%) of ILC were detected due to a mep type 2. Four ILC were false negative on MR-M (2 cases show mep type 1 or mep type 3). The sensitivity of Mx alone was 86.9% (20/23). When both Mx and MR-M were combined, all 23 ILC were detected. The addition of MR-M to Mx may increase sensitivity to about 100% in the detection of ILC. (orig.) [Deutsch] Material und Methode: Im Zeitraum 05/1993 bis 06/1996 fuehrten wir bei 1357 Patientinnen 1505 MR-Mammographien durch. In 413 Faellen wurde eine Probeexzision indiziert. Die histologische Untersuchung ergab in 214 Faellen einen malignen Tumor. Darunter befanden sich 23 ILC. Die MR-M wurden an einem 1,0 T MRT-System (Impact, Siemens, Erlangen) mit einer dynamischen FLASH 3D Sequenz durchgefuehrt. Neben dem prozentualen Anstieg der Signalintensitaet innerhalb einer Laesion haben wir fuer die Diagnostik folgende morphologische Befundmuster (BM) unterschieden: Typ 1: Keine Aufnahme, Typ 2: Fokale Aufnahme, Typ 3: Diffuse Aufnahme des Druesenkoerpers in der MR-M. Ergebnisse: Mit der MR-M konnten 19/23 (82,6%) der ILC anhand einer fokalen Zunahme der Signalintensitaet richtig positiv erkannt werden (BM Typ 2). Vier der ILC waren in der MR-M falsch negativ. In zwei Faellen (2/23) war keine Zunahme der Signalintensitaet zu verzeichnen (BM Typ 1). In zwei weiteren Faellen (2/23) maskierte eine diffuse Signalintensitaetszunahme des Druesenkoerpers (BM Typ 3) das ILC. Die Sensitivitaet der Mx lag bei 86,9% (20/23). Durch den additiven Einsatz der MR-M konnten alle 23 ILC diagnostiziert werden. (orig.)

  13. Studien zur Messung von Rekonstruktionseffizienz und Untergrund der $\\tau$-Lepton-Identifikation im Zerfall $Z\\to \\tau \\tau$ beim ATLAS-Experiment aus Daten

    CERN Document Server

    Johnert, Sebastian

    2008-01-01

    In dieser Diplomarbeit werden zwei Methoden vorgestellt, mit denen τ -Leptonen in den zuk ̈nf- u tigen Daten des ATLAS-Experiments untersucht werden sollen. Den ersten Teil bildet die Be- stimmung von Missidentifikationsraten von Jets aus QCD-2-Jet-Ereignissen als τ -Leptonen. Der zweite Teil ist die Entwicklung einer Methode zur Bestimmung der τ -Rekonstruktions- und -Identifikationseffizienz relativ zur μ-Effizienz. In diesem Zusammenhang werden invariante Massen aus Z → ll-Ereignissen bestimmt, die Massen aus Z → τ τ -Ereignissen mit denen aus Z → ee und Z → μμ verglichen, τ -Effizienzen gemittelt uber alle Bereiche und in verschiedenen ̈ o η-Bereichen berechnet sowie eine M ̈glichkeit zur Bestimmung von τ -Effizienzen in unterschied- lichen Transversalimpulsbereichen vorgestellt. Des Weiteren wird eine verbesserte Absch ̈tzung a des QCD-Untergrunds vorgenommen und das Verhalten der τ -Effizienz unter Ber ̈cksichtigung u des Triggers untersucht.

  14. Nudge-Ansätze beim nachhaltigen Konsum: Ermittlung und Entwicklung von Maßnahmen zum „Anstoßen“ nachhaltiger Konsummuster

    NARCIS (Netherlands)

    Thorun, Christian; Diels, Jana; Vetter, Max; Reisch, Lucia A.; Bernauer, Manueala; Micklitz, Hans-Wolfgang; Purnhagen, K.; Rosenow, Jan; Forster, Daniel

    2016-01-01

    This research project analyses the potential of nudges in the area of sustainable consumption focusing on ecological consumption. Nudges are regulatory instruments based on insights from psychology and behavioral economics and are applied to achieve behavior change. In the present report, the

  15. Spectroscopical plasma diagnostics for the procedure optimization in laser-beam high-speed cutting; Spektroskopische Plasmadiagnostik zur Verfahrensoptimierung beim Laserstrahl-Hochgeschwindigkeitsschneiden

    Energy Technology Data Exchange (ETDEWEB)

    Nate, M.

    2001-07-01

    In the present thesis the laser-induced plasma typical for the high- speed cutting process was studied in the region of the interaction zone. For this especially the absorption properties of the plasma for the incident laser radiation and their correlation with the maximally reachable cutting speeds. For this with methods of the spectroscopic plasma diagnostics the influence of different process parameters on the quantities characterizing the plasma, electron density and temperature, was determined. On the base of these values in the framework of an equilibrium model the densities of all particles contained in the plasma were determined. With these values the plasma absorption coefficient was subsequently calculated and the laser radiation absorbed in the plasma estimated.

  16. Investigation on working quality of laser beam cutting of composite materials. Final report. Untersuchung der Bearbeitungsgenauigkeit und Prozessfuehrung beim Laserstrahlschneiden von Verbundwerkstoffen und Werkstoffverbunden. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, M.; Mueller, R.

    1992-01-01

    Expanded use of composite materials often requires a cutting process to reach the desired shape of the work piece. In conventional mechanical cutting technologies like milling remarcable tool wear has to be considered due to the containing glass fibers which have a tremendous abrasive effect on the tool teeth. Here the laser beam is an alternative 'tool'. With this investigations the knowledge about the parameters of laser beam cutting of composites which determine working quality was increased. Requirements for an optimal cutting process and fundamental correlations between process parameters and working quality are presented. In absence of suitable criterions to estimate the working quality of laser beam cut composite materials, a suggestion of a DIN 2310, Part 7, 'Thermal Cutting, Laser Beam Cutting of Composites' is presented. (orig.) With 69 refs., 125 figs.

  17. Using CAD/CAM-systems for process optimization during laser beam cutting and surface treatment. CAD/CAM-gestuetzte Prozessauslegung beim Laserstrahlschneiden und -oberflaechenveredeln

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, W.; Trasser, F.J.; Wetzels, W. (Fraunhofer-Inst. fuer Produktionstechnologie, IPT, Aachen (Germany))

    1991-02-01

    Using technological modules in modern CAD/CAM-systems provides an efficient use of the available know-how. On the one hand, companies can save their know-how, on the other hand they can improve manufacturing quality as well as increase the productivity. Especially laser beam cutting allows an automatic process control - orientated on geometry aspects. Similar results can be shown for laser surface treatment as well, although up to now reducing of the programming time is the main task of technological modules for this application, including special algorithms for CNC-controlled rotation/swiveling of powder-nozzles and adjustment of the powder flow rate.

  18. The bypass solution as a capacity enhancing measure in connecting biogas plants to the grid; Die Bypass-Loesung als kapazitaetserhoehende Massnahme beim Netzanschluss von Biogasanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Grassmann, Nils [PwC Legal AG, Frankfurt am Main (Germany). Bereich Energierecht in der Region Sued; Reinhardt, Anja [PwC Legal AG, Muenchen (Germany)

    2012-07-01

    In spite of repeated amendments to the laws governing the connection of biogas plants to the grid there still remain unresolved disputes in practice. A significant issue in this regard concerns what is referred to as the bypass solution, where a connection to the general supply grid of the receiving grid operator is created and at the same time technical equipment is installed which provides a connection to an upstream grid to which biogas can be backfed in times of low grid load. The Upper Regional Court of Duesseldorf classifies constellations of this kind as a combined grid connection to two different grids. It argues that since the legislature has provided no regulations on this constellation there can be no legitimate right to obtaining a connection of this configuration. However, this line of argumentation does not appear compelling. The meaning and purpose of Articles 31 ff. of the Gas Network Access Ordinance and the wording of the relevant norms both speak in favour of considering bypass solutions as capacity-enhancing measures. The receiving (downstream) grid operator would then be obliged, under the general requirements, to create a grid connection and to draw the bypass solution into consideration as a special means of backfeeding. This would provide legal certainty for all involved and allow technically meaningful solutions to be implemented.

  19. CO{sub 2}-potential by usage of light materials in passenger cars; CO{sub 2}-Potenzial durch Leichtbau beim PKW

    Energy Technology Data Exchange (ETDEWEB)

    Rohde-Brandenburger, Klaus [Volkswagen AG, Wolfsburg (Germany). Abt. Fahrzeugtechnik; Obernolte, Jens [Volkswagen AG, Wolfsburg (Germany). Gesamtfahrzeug-Entwicklung fuer Fahrleistung, Verbrauch und Getriebeauslegung

    2009-07-01

    The question 'what is the effect of a weight change of 100 kg on fuel consumption in the european driving cycle NEDC?' will be answered for vehicles with gasoline and diesel engines. Therefore the mechanical energy for moving 100 kg through the NEDC is calculated. Considering the fact, that combustion engines have an almost constant efficiency for delivering difference loads in the lower speed/loadrange that are used for the NEDC, the mechanical energy is converted into fuel consumption and CO{sub 2}-emission. The maximum fuel consumption difference of 0,15 l/100 km per 100 kg can increase up to 0,4 l/100 km per 100 kg, if the transmission ratio or the engine size is adapted to constant acceleration performance. Values of about 1 l/100 km per 100 kg, that you can find in magazines or brochures of NGO's, are exposed as unrealistic. (orig.)

  20. Heat and mass transfer during the inductive skull melting process of glasses and oxides; Waerme- und Stofftransport beim induktiven Skull-Schmelzen von Glaesern und Oxiden

    Energy Technology Data Exchange (ETDEWEB)

    Nacke, Bernard; Niemann, Benjamin [Leibniz Univ. Hannover (Germany). Inst. fuer Elektroprozesstechnik; Schlesselmann, Dirk [Auer Lighting GmbH, Bad Gandersheim (Germany)

    2013-03-15

    The skull melting technology is a melting process for innovative materials in the range of glasses. A hitherto unknown problem under glass melting by means of this technology is the fact that the processes in the interior of the molten mass are still unknown. Under this aspect, the authors of the contribution under consideration present an overview of the inductive melting process for glasses in an inductor crucible developed at the Institute for Electrotechnology (Hanover, Federal Republic of Germany). A newly developed numerical model is presented in order to simulate the heat and mass transfer in a molten glass. This simulation enables a future optimization of the design of the inductor crucible and the melting process. The transient three-dimensional melting flow during the melting of glasses and oxides by means of the skull meeting process also can be simulated by the newly developed numerical model.

  1. The legal framework for data privacy and protection in smart metering and smart grids; Der Rechtsrahmen beim Datenschutz fuer Smart Metering und Smart Grids

    Energy Technology Data Exchange (ETDEWEB)

    Stamm, Markus [Alcatel-Lucent Deutschland AG, Nuernberg (Germany)

    2011-07-01

    The legal framework for data privacy and protection in Smart Meter and Smart Grid applications has been substantially changed through modifications of the German law on the supply of electricity and gas (Energiewirtschaftsgesetz - EnWG), especially through its sections 21c et seq. Nonetheless, these modifications have on partially attained the goal of the reform, to create a secure legal framework for the use of Smart Meters and Smart Grids, and some of the newly introduced regulations actually decrease the security of the framework through the use of systematically incorrect terminology. This article gives an overview of the content of the key regulations and the issues to be resolved which result from them. (orig.)

  2. Load-vs.-time functions resulting from the impact of missiles filled with a liquid; Last-Zeit-Funkionen beim Aufprall fluessigkeitsgefuellter Projektile

    Energy Technology Data Exchange (ETDEWEB)

    Bernhart, D. [Materialpruefungs- und Forschungsanstalt Karlsruhe (Germany)

    2007-10-15

    Considerations of possible external impacts on nuclear power plants require verification of the safety precautions in place. Especially the impact of large masses, such as a passenger aircraft, is a factor of major importance because of the damage potential it involves. The load impact resulting from an airplane crash was estimated already back in the 1960s. That approach, which was based on the conservation of momentum, was developed further in a modified form over the next few years. Recalculations of impact tests of a Phantom F-4 plane showed excellent agreement. The transferability to large passenger aircraft of this method of calculation has not been investigated so far. For this reason, the Institute for Solid Construction and Building Materials Technology of the University of Karlsruhe carried out small-scale tests with aluminium missiles. The geometry of the missiles and their stiffness distribution along the longitudinal axis were matched to those of a passenger aircraft. In addition, the influence of the speed of the aircraft on the force-vs.-time function, and the influence of various tank filling levels were studied. Another question to be answered is that of the influence of different angles of impact of the missiles. (orig.)

  3. Surface settlements during the tunnel drivage in loose rock. Prognosis, measurement and impact; Oberflaechensetzungen beim Tunnelvortrieb im Lockergestein. Prognose, Messung und Beeinflussung

    Energy Technology Data Exchange (ETDEWEB)

    Fillibeck, Jochen [Technische Univ. Muenchen (Germany). Zentrum fuer Geotechnik

    2012-11-01

    The realistic prediction of supplement in tunnel construction is essential to secure the acceptance of the construction measure in the population. In addition to numerical calculations particularly empirical processes are suitable whose input variables are derived from previous experiences. Empirical methods use the Gaussian function for the description of the settlement trough arising from the tunnelling at the surface. The contribution under consideration describes the method of Fillibeck allowing the determination of the input parameters for shotcrete drivages and shield drivages. This empirical method was derived from a large number of carefully selected and inspected measuring cross-sections.

  4. Localization and analysis of error sources for the numerical SIL proof; Lokalisierung und Analyse von Fehlerquellen beim numerischen SIL-Nachweis

    Energy Technology Data Exchange (ETDEWEB)

    Duepont, D.; Litz, L. [Technische Univ. Kaiserslautern (Germany). Lehrstuhl fuer Automatisierungstechnik; Netter, P. [Infraserv GmbH und Co. Hoechst KG, Frankfurt am Main (Germany)

    2008-07-01

    According to the standard IEC 61511 each safety-related loop is assigned to one of the four Safety Integrity Levels (SILs). For every safety-related loop a SIL-specific Probability of Failure on Demand (PFD) must be proven. Usually, the PFD calculation is performed based upon the failure rates of each loop component aided by commercial software tools. However, this bottom-up approach suffers from many uncertainties. Especially, a lack of reliable failure rate data causes many problems. Reference data collected in different environments are available to solve this situation. However, this pragmatism leads to a PFD bandwidth, not to a single PFD value as desired. In order to make a decision for a numerical value appropriate for the chemical and pharmaceutical process industry a data ascertainment has been initiated by the European NAMUR. Its results display large deficiencies for the bottom-up approach. The error sources leading to this situation are located and analyzed. (orig.)

  5. Clearance of radioactive materials during reactor dismantling. Permanent enclosure instead of demolition and renaturation?; Freigabe radioaktiven Materials beim AKW-Abriss. Dauerhafter Einschluss statt Rueckbau?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-07-01

    During reactor dismantling besides high-level radioactive wastes a large amount of low-level contaminated steel and concrete has to be disposed. In case that radioactivity falls below defined dose limits (10 micro Sv/person and year) these materials may be disposed in domestic waste landfill or in municipal incineration facilities. The issue is discussed in detail including the fact that many power plants are dismantled at the same time so that the contaminated materials might accumulate. Another issue is the occupational safety of contract workers during dismantling. The permanent enclosure could avoid this environmental contamination of decommissioned power plants might also be less expensive.

  6. Retrospective study on radiotherapy efficacy in case of painful heel spur; Retrospektive Studie ueber die Wirksamkeit der Strahlentherapie beim schmerzhaftem Fersensporn

    Energy Technology Data Exchange (ETDEWEB)

    Klossok-Niethammer, Ruth Giuliana

    2011-07-01

    Objective: The effect of radiotherapy in context of a plantar fasciitis in order to reduce pain was evaluated in this retrospective study. Patients and methods: The data of 188 patients who suffered of heel spur pain and who were irradiated in the period from 1994 to 2009 were evaluated in this study. All of them had at least one follow up examination after radiatiotherapy. The mean age amounted to 57 years. 76.5% of the patients were female. All patients described a local pain which was the basis for the indication. 74.4 % of the patients described pain especially under stress. The duration of anamnesis was averaged as follows: 15 % of the patients had pain for some weeks to 3 months, 43 % for 4 to 6 months, 28% even for 7 to 12 months. The period of medical history was longer than 12 months for 12 % of the patients in this study. 122 of 188 patients received orthopedic arch support (shoe inlays) as first therapy method. Most of the patients were irradiated using regular lateral opposing fields with photons of the energy 4 MV and 6 MV of a linear accelerator, applying a total dose of 6Gy in 6 fractions to 1,0Gy twice weekly. Only one patient was irradiated using a Co{sup 60} machine. The acquisition of data regarding the effect was performed on the last day of the radiotherapy and in 3 to 6 monthly follow ups. Additionally the doctors who attended the patients beyond the radiotherapy received a special questionnaire about the pain reduction, so that the follow up data could be completed. Results: On the last day of radiotherapy 120/188 patients (63,8%)reported an improvement of pain reduction, 7/188 patients (3,7%) absence of pain. For 52/188 patients (27.6 %) pain remained constant. At the second follow up examination after in the median 100 days the effect of radiotherapy of 165 patients could be evaluated, 43/165 patients (26 %) were pain free, 79/165 patients (47,8 %) reported an obvious pain reduction, and for 33/165 patients there was no pain improvement. At the third follow up examination after in median 503 days there were data of 94 patients that could be used for our study, 22/94 patients (23,4 %) felt a pain reduction and 56/94 patients (59,5 %) were completely painless. At the fourth follow up examination after in median of 1170 days patient database included 37 statements about pain. For 4/37 patients (10,8%) there was a pain reduction and for 32/37 patients (86,4 %) an absence of pain. After in median of 1590 days the fifth follow up took place, this showed statements of 84 patients about their pain. For 72/84 patients (85,7 %) radiotherapy achieved a complete absence of pain, an obvious improvement with 9/84 patients (10,7 %). Only 3/84 patients (3,5 %) described a steady pain symptomatology. All these results for pain reduction of 182 patients were achieved nearly without side effects, only 5 patients reported a light flush in the irradiated area. Conclusion: The radiotherapy of the painful heel spur appears highly effective, long-lasting and side-effect-free regarding to pain relief. The effect occurs often several months after radiotherapy, as far as it can be evaluated in this retrospective setting based on partially incomplete follow up data. We could not identify any prognostic factors.

  7. Sentinel lymph node mapping and biopsy in breast cancer - facts and unanswered questions; Waechterlymphknotendetektion und -Biopsie beim Mammakarzinom - Fakten und unbeantwortete Fragen

    Energy Technology Data Exchange (ETDEWEB)

    Czech, N. [Klinik fuer Nuklearmedizin, Universitaetsklinikum Schleswig-Holstein, Campus Kiel (Germany)

    2006-06-15

    The concept of sentinel lymph node (SLN) biopsy in breast cancer patients is rapidly becoming the standard of care [1]. The fast assent of this technique in clinical practise is the result of multiple factors, including accuracy of the technique, decreased morbidity, and supplying the pathologist with only few nodes which allows a more focused and sensitive histopathologic evaluation. The sentinel nodes are those most likely to contain tumour cells that have spread from the tumour. Histopathological evaluation of these nodes therefore can be an accurate predictor for metastases in the respective lymph node basin and can guide regional and systemic treatment. The SLN-biopsy concerns the identification and subsequent resection of the initial lymph nodes (SLN) which are draining the primary tumour. These nodes can be identified by radioguided lymphatic mapping and/or by visualisation of the nodes with vital blue dyes. Axillary lymph node dissection (ALND) and its morbidity can be avoided in patients with negative SLN. Despite the success and acceptance of lymphatic mapping, some controversies and questions remain unanswered. In this review, some of the most relevant clinical issues will be discussed. (orig.)

  8. Emotionen und Kontrollüberzeugungen beim komplexen Problemlösen : eine experimentelle Untersuchung anhand des computersimulierten Problemlöseszenarios FSYS 2.0

    OpenAIRE

    Spering, Miriam

    2001-01-01

    Diese Studie untersucht den Einfluss positiver und negativer Emotionen auf komplexes Problemlösen unter Berücksichtigung der Kompetenz- und Kontrollüberzeugungen als Traits. 74 studentische männliche und weibliche Probanden bearbeiteten das computersimulierte Szenario FSYS 2.0 (Wagener & Conrad, 1997), anhand dessen sich Aussagen sowohl über die Problemlösegüte als auch das Problemlöseverhalten (z.B. Informationsmanagement) treffen lassen. Emotionen wurden vor Beginn des Szenarios und nach de...

  9. Ecological comparison between hydrated lime and sodium bicarbonate when used for dry flue gas purification; Oekologischer Vergleich von Kalkhydrat und Natriumbicarbonat beim Einsatz in der trockenen Rauchgasreinigung

    Energy Technology Data Exchange (ETDEWEB)

    Wecker, Andreas [Federal German Association of the Lime Industry, Koeln (Germany)

    2009-07-01

    Lime plays an important role in environmental protection. Not only due to its properties but also due to its natural occurrence, it is suitable and accepted for universal application in the environment sector. Lime and its refined products can be used in various processes to remove the acid gases, the gaseous metal compounds and organic trace constituents from the flue gas of waste incineration plants. The choice of the suitable process depends on the raw gas load, the separation efficiency to be achieved and the way of recovery of the reaction product obtained as a result of flue gas cleaning. The dry sorption processes have been established for many years and have been continuously further developed, in which lime is injected into the flue gas flow and the reaction product is retained via a filtering separator. As an alternative to lime products, it is also possible, under certain boundary conditions, to use sodium hydrogen-carbonate NaHCO{sub 3} (below called sodium bicarbonate) as a basic reaction component in the dry sorption process. As opposed to calcium hydroxide, there are differences, for example as regards the reaction temperature required and the necessary amount of sorbent to achieve the desired purification effect. (orig.)

  10. Klimaänderung und die Vorverlegung des Brutbeginns beim Kiebitz (Vanellus vanellus) : 33-jährige phänologische Beobachtungen (1976-2008)

    OpenAIRE

    Kooiker, Gerhard

    2011-01-01

    Zwischen 1976 und 2008 stieg die Jahresdurchschnittstemperatur in Osnabrück um 1,3 °C dramatisch an. Die Erwärmung beschränkte sich im Wesentlichen auf das Winterhalbjahr. In den für Kiebitze relevanten Monaten der Ankunft, Vorbrut- und Brutphase (Februar, März, April) stiegen die über diesen Zeitraum gemittelten Temperaturen sogar um 2,0 °C an (1976 = 4,4 °C, 2008 = 6,4 °C). Das bedeutet eine jährliche Steigerung um 0,06 °C! In dem zugrundeliegenden 33-jährigen Zeitraum hat sich die Brutperi...

  11. A new and improved algorithm for the quantification of chromatin condensation from microscopic data shows decreased chromatin condensation in regenerating axolotl limb cells.

    Directory of Open Access Journals (Sweden)

    Julian Sosnik

    Full Text Available The nuclear landscape plays an important role in the regulation of tissue and positional specific genes in embryonic and developing cells. Changes in this landscape can be dynamic, and are associated with the differentiation of cells during embryogenesis, and the de-differentiation of cells during induced pluripotent stem cell (iPSC formation and in many cancers. However, tools to quantitatively characterize these changes are limited, especially in the in vivo context, where numerous tissue types are present and cells are arranged in multiple layers. Previous tools have been optimized for the monolayer nature of cultured cells. Therefore, we present a new algorithm to quantify the condensation of chromatin in two in vivo systems. We first developed this algorithm to quantify changes in chromatin compaction and validated it in differentiating spermatids in zebrafish testes. Our algorithm successfully detected the typical increase in chromatin compaction as these cells differentiate. We then employed the algorithm to quantify the changes that occur in amphibian limb cells as they participate in a regenerative response. We observed that the chromatin in the limb cells de-compacts as they contribute to the regenerating organ. We present this new tool as an open sourced software that can be readily accessed and optimized to quantify chromatin compaction in complex multi-layered samples.

  12. 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...

  13. 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

  14. 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

  15. 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

  16. Lymph scintigraphy and pre- and intraoperative gamma probe measurements for localization of sentinel lymph nodes (SLN) in breast cancer; Lymphszintigraphie sowie prae- und intraoperative Sondenmessung zur Darstellung des Sentinel Lymph Node (SLN) beim Mammakarzinom

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, W.; Czech, N.; Felde, U. zum; Kampen, W.U.; Henze, E. [Kiel Univ. (Germany). Klinik fuer Nuklearmedizin; Ostertag, H. [Kiel Univ. (Germany). Klinik fuer Gynaekologie und Geburtshilfe; Klutmann, S.; Bohuslavizki, K.H. [Universitaetskrankenhaus Eppendorf, Hamburg (Germany). Abt. fuer Nuklearmedizin; Luettges, J.; Sprenger, A. [Kiel Univ. (Germany). Inst. fuer Allgemeine und Pathologische Anatomie

    2000-05-01

    Aim of this study was to prove the clinical value of nuclear medicine procedures to detect the sentinel lymph node (SLN) for SLN biopsy. Methods: In 132 patients with breast cancer we performed lymph scintigraphy of the breast as well as both pre- and intraoperative gamma probe measurements correlating the results with the findings of histopathology. Results: SLN were detectable in 62 of 110 patients according to a sensitivity of 56% when scanning was performed only at 1-2 h p.i. while the sensitivity increased to 86% (19 of 22 pts.) if sequential images were acquired up to 2 h p.i. One or more SLN were identified by a handheld gamma probe transcutaneously prior to surgery in 96% (113 of 118 pts.) of the patients who showed up with no clinically suspected lymph node metastases. Intraoperatively, in additionally 2 patients the SLN could be found resulting in a sensitivity of 97% (115 of 118 pts.). In only 3 patients with clinically no tumor spread to axillary lymph nodes no SLN could be identified by the probe. Skip lesions, i.e. lymph node metastases in patients with tumorfree SLN, occurred in 2 cases: Due to SLN biopsy in these patients lymph node staging was false negative compared to conventional staging by means of axillary lymph node dissection. Conclusion: The results demonstrate a high preoperative detection rate of SLN in patients with breast cancer using lymph scintigraphy and gamma probe measurements. Thus, nuclear medicine is capable of providing the basic requirements for SLN biopsy in the daily routine. (orig.) [German] Ziel der vorliegenden Arbeit im Vorfeld einer geplanten Multicenterstudie zur Wertigkeit der Sentinel-Lymphknoten (SLN) Biopsie war, die Zuverlaessigkeit der SLN-Detektion mit nuklearmedizinischen Methoden im klinischen Routinebetrieb zu ueberpruefen. Methoden: Bei 132 Patientinnen mit stanzbioptisch gesichertem Mammakarzinom fuehrten wir eine Lymphszintigraphie der Brust sowie eine prae- und intraoperative Gammasondenmessung durch und korrelierten die Befunde mit den histopathologischen Ergebnissen. Ergebnisse: Die Lymphszintigraphie konnte unter Verwendung von statischen Einzelaufnahmen 1-2 h p.i. nur bei 62 von 110 so untersuchten Patientinnen einen SLN nachweisen entsprechend einer Sensitivitaet von 56%. Mittels Lymphsequenzszintigraphie lag die Sensitivitaet dagegen bei 86% (19 von 22 Pat.). Die praeoperative Gammasondenmessung detektierte mindestens einen SLN bei Patientinnen mit klinisch unauffaelliger Axilla in 96% (113 von 118 Pat.), intraoperativ fand sich bei 2 weiteren Patientinnen des SLN und die Sensitivitaet lag bei 97% (115 von 118 Pat.). Nur bei 3 Patientinnen mit klinisch unauffaelligen axillaeren Lymphknoten konnte mit der Sondentechnik kein SLN detektiert werden. Die histologische Aufarbeitung ergab bei 2 Patientinnen sogenannte skip lesions, d.h. Lymphknotenmetastasen bei tumorfreiem SLN, mit entsprechend alasch negativem Lymphknotenstaging durch die SLN-Biopsie. Schlussfolgerung: Mit der Lymphsequenzszintigraphie und der praeoperativen Gammasondenmessung lassen sich bei Mammakarzinompatientinnen der Lymphabstrom aus der Brust und SLN zuverlaessig darstellen. Die Nuklearmedizin kann somit die fuer die SLN-Biopsie erforderliche Methodik routinemaessig zur Verfuegung stellen. (orig.)

  17. Metastases in patients with malignant melanoma despite of negative sentinel lymph node: has the concept to be changed?; Metastasierung beim malignen Melanom trotz histologisch negativem Sentinel Lymph Node: muss das Konzept in Frage gestellt werden?

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, M.; Dresel, S.; Tatsch, K.; Hahn, K. [Muenchen Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Konz, B.; Schmid-Wendtner, M.H.; Sander, C.; Volkenandt, M. [Muenchen Univ. (Germany). Dermatologische Klinik und Poliklinik

    2000-11-01

    The aim of the present study was to prove the prognostic value of the SLN-concept in these patients. Methods: So far the clinical follow-up of 162 patients with histologically proven malignant melanoma and metastatically uninvolved (negative) SLN was investigated. Histological examination included standard methods (HE-Test) and special histochemical techniques (S-100, HMB-45). All patients underwent clinical examination, ultrasonic diagnosis of the regional lymph nodes, and X-ray of the chest every 3 months. Results: Despite of negative SLN-findings in 8/162 patients metastases of the malignant melanoma were found after a time period of 5-27 months. Three patients presented with recurrence in the previously mapped (negative) SLN-basin. In another case the scintigraphically visualized SLN could not be identified intraoperatively by means of the hand-held gamma probe. One patient showed intransit-metastases or skin-metastases, respectively; another patient recurred in the scar area. One patient showed hematogenic dissemination (liver) which is not detectable by lymphoscintigraphy; in another patient metastases were found outside the primary lymphatic basin (cervical). Conclusion: In our patient group 4,9% presented with metastases despite negative SLN while published data report up to 11% (observation period 35 months), among them only 3 patients (1,9%) being real concept failures. Our results underline that there is no evidence to change this concept in patients with clinically early stage. (orig.) [German] Ziel dieser klinischen Verlaufsuntersuchung war es, die prognostische Aussage dieses Konzeptes zu pruefen. Methoden: Es wurde der Verlauf von 162 Patienten mit gesichertem malignen Melanom und histologisch unauffaelliger SLN-Biopsie verfolgt. Die histologische Aufarbeitung umfasste Standardmethoden (HE-Faerbung) und spezielle immunhistochemische Techniken (S-100, HMB-45, Stufenschnitte). Die Nachsorge (klinische Untersuchung, Sonographie regionaler Lymphknoten und des Abdomens, Roentgen-Thorax) erfolgte vierteljaehrlich. Ergebnisse: Trotz negativem SLN zeigten 8/162 Patienten nach einer Beobachtungszeit von 5/27 Monaten eine Metastasierung. Bei drei Patienten konnte eine Lymphknotenmetastasierung in der SLN-Region gesichert werden, bei einem Patienten liess sich der praeoperativ szintigraphisch markierte SLN intraoperativ nicht sicher mittels Sonde lokalisieren. Ein Patient zeigte Intransit- bzw. Hautmetastasen, bei einem weiteren zeigte sich ein Narbenrezidiv. In einem anderen Fall ist von einer mit dieser Methode nicht erfassbaren haematogenen Streuung (Leber) auszugehen. Bei einem weiteren Patienten lag die Metastasierung ausserhalb des durch diese Lokalisationsmethode erfassten lymphogenen Abflussgebietes (zervikal). Schlussfolgerung: In unserem Kollektiv zeigten 4,9% der Patienten trotz negativem SLN eine Metastasierung; demgegenueber finden sich in der Literatur Angaben bis zu 11% (Beobachtungszeitraum bis 35 Monate). Davon kam es lediglich bei 3 Patienten (1,9%) zu einer Melanomprogression in der SLN-Region. Unsere Daten unterstreichen, dass derzeit keine Notwendigkeit besteht das SLN-Konzept bei Patienten im klinischen Stadium I und II zu aendern. (orig.)

  18. Silizium-Kohlenstoff-Hohlraumstrukturen als Anodenmaterial in Lithium-Ionen- und Lithium-Schwefel-Batterien: Paper präsentiert beim 15. Mitteldeutschen Anorganiker-Nachwuchssymposium, Leipzig, 31.8.2017

    OpenAIRE

    Baasner, Anne; Dörfler, Susanne; Althues, Holger; Kaskel, Stefan

    2017-01-01

    Die Nachfrage nach günstigen Batterien mit hohen Energiedichten hat in den letzten Jahren stark zugenommen. Silizium wird für die nächste Generation von Anodenmaterialien für Lithium-Ionen-Batterien hoch gehandelt. So hat es eine fast zehnmal höhere gravimetrische Kapazität (3590 Ah kg-1 Li15Si4) als die bisher eingesetzten Graphitanoden (370 Ah kg-1) [1]. Mit Lithium-Schwefel-Batterien ist theoretisch eine weitaus höhere Steigerung der Energiedichten möglich. Allerdings haben gegenwärtige Li...

  19. Implementation of a seawater cooling system in Eemshaven power plant (NL). A challenge of constructional and hydrological engineering; Umsetzung einer Meerwasserkuehlung beim Kraftwerk Eemshaven (NL). Eine bautechnische Herausforderung im Bereich Tief- und Wasserbau

    Energy Technology Data Exchange (ETDEWEB)

    Ulke, Bernd [RWE Technology GmbH, Eemshaven (Netherlands). Bauleitung STKW; Boerg, Bernd [Tiefbau GmbH Unterweser (TAGU), Oldenburg (Germany)

    2011-04-15

    RWE Eemshaven Holding B.V. is currently constructing a coal power plant with seawater cooling at Eemshaven (NL). The main coolant line will go under the dam and necessitates construction of a cooling water outlet structure, which is described in the article. The work done until December 2009, including construction of the first underwater concrete floor, was described in an earlier article (Bautechnik 87 (2010), pp. 294-297). (orig.)

  20. Effects of sunshades and daylighting systems on room climate in the new building of the Baden-Wuerttemberg office for listed buildings in Esslingen; Auswirkungen von Sonnenschutz/Tageslichtsystemen auf das Raumklima beim Neubau Landesdenkmalamt Esslingen

    Energy Technology Data Exchange (ETDEWEB)

    Buehler, H.J. [GN Bauphysik, Ingenieurgesellschaft mbH, Stuttgart (Germany)

    2003-07-01

    Visual and thermal comfort have a crucial influence on the well-being of the users. With conventional sun protective systems the simultaneous implementation of both requirements is hardly to be carried out. By means of retroflecting sun protective systems type RETROLux Therm can be achieved an optimal daylight illuminating and at the same time a minimization of the summer energy entry. There is for the angles of incidence conditions in the summer months total energy transmission factors (g-value) of 0.10 to expect with simultaneous visual communication with the environment. The sun protective effect is therefore comparable with a conventional external blind system, which exhibits however a substantially limited external outlook. Newest test certificates of the RetroLux Therm lamellas show that in connection with highly reflecting lamella surfaces total energy transmission factors under g=0.10 can be achieved. By thermal simulation calculations it could be proved that with the planned facade conception on basis of the retroreflection no disadvantages are to be expected regarding room climate and operating cost in relation to a conventional facade system with external blinds. The planned facade conception forms thereby together with the building-technical conception of the construction unit activation and the multi-functionally used edge strip a conclusive primary energetically favorable energy concept. (orig.)

  1. Radiation exposure to personnel involved in bone scans for horses with technetium 99m-diphosphonat; Strahlenexposition des Personals bei der Skelettszintigrafie mit Technetium-99m-Diphosphonat beim Pferd

    Energy Technology Data Exchange (ETDEWEB)

    Sommerfeld, Theresa Christine

    2016-07-01

    Key objective of this study has been the evaluation of radiation exposure of veterinarian personnel wearing dosimeters which were involved in equine scintigraphy. A survey, which was developed in parallel to this study, showed that personnel in equine horse clinics have often knowledge gaps about scintigraphy and the related radiation doses. The survey showed skepticism of the involved personnel towards the methods of bone scintigraphy as the impacts of expositions are barely known in common. The scintigraphic investigations and measurements were done at the horse clinic (department of surgery) in Giessen and were part of the routinely bone scanning of horses. A total of 33 bone scans were taken, covering either full- or half-body scintigraphies. Additional 10 bone scans covered measurements with and without the protection of a 0,5 mm lead-shield. The activity of involved personnel was monitored at four different positions: MP1 was associated with the position of the person preparing the radiopharmaceutical for injection, MP2 with the position at holding the horse during the bone scan, MP3 with the position at holding the horse's legs and to make sure that the horse was standing in the right position, MP4 with the position for the camera operator. Some more dose measurements were made from the horse body (MP5 and MP6) as well as in the control area (MP7). In order to analyze the patient's constitution, additional data like weight, size, body extent and length of the torso were additionally captured. The body data were collected to investigate exposure differences of rather big and heavy or small and thin horses. These data and the dosimeter at the horse body (MP5) enabled the correlation analysis between the horse body composition and the received dose rate of the personnel (MP2). MP1 received a mean dose of 11 μSv and a dose rate of 123 μSv/h, MP2 received 31 μSv for a whole-body and 23 μSv for a half-body bone scan. The dose rate of MP2 was 22 μSv/h. MP3 was measured with an averaged dose of 28 μSv for a whole- and 19 μSv for a half-body bone scan. The dose-rate for MP3 was 19 μSv/h. MP4 received 5 μSv for the whole-body scintigraphy and approximately 3 μSv for the incomplete body scintigraphy. The dose rate for MP4 was 3 μSv/h. The highest dose was recorded at MP2 and was caused by the close distance to the headbones of the horses. These bones have only a thin absorption layer which leads to a higher dose-rate in this area. A slightly correlation between the dose rate at MP2 and the body composition data of the horses was recognized. The dose rates went up when performing bone scans of horses with a heavy caliber and a higher bodyweight in general. The measurements at MP3 showed more variations than the ones at MP2, due to the different in soft tissue mass depending on body weight of the horses at this measuring point. The bladder as a big radiation source is covered well enough by surrounding soft-tissue which explains why MP3 did not reach a higher dose-rate standing next to this area. The comparison of the difference between the dose-rates of MP2 and MP3 has proven to be statistically significant with a p-value of 0.008. Through the enlarged distance between the radiation source and MP4, the camera operator received approximately factor 6 less of the dose received by the horse handler. MP1, MP2 and MP4 were selected for the series of comparative measurements with and without lead shield protection because the positions were limited in moving as well as the wearing of lead shields has been less hindering to the personnel. The results of the comparative measurement demonstrate up to 70 % dose reduction at all points if lead shields were used. Especially within the context of smaller doses radiation protection is in controversy discussion. The mandatory use of lead shield in nuclear-medical diagnostics is not regulated by law although the reduction of dose is evident by its use. Within the community of radiation experts the impact of the so called ''beam hardening effect'' under the lead shield appears in opposed discussions. Therefore each medical center handles the use of lead shields individually, a matter of fact which was also mirrored by the survey of this dissertation. With regards to lower radiation doses the ''Hypothesis of Hormesis'' is contradictory to the ICRP rules, which cover the ''Linear-No-Threshold-Model'' and the ''ALARA-Principle''. As of today none of the before mentioned principles are confirmed by scientific investigations. Hence, veterinarian personnel shall reduce the dose consumption by obeying the three main principles for radiation protection: ''Distance'', ''Shielding'' and ''Time of Exposure''.

  2. SPECT/CT for staging and treatment monitoring in oncology. Applications in differentiated thyroid cancer and liver tumors; SPECT/CT zum initialen Staging und Therapiemonitoring in der Onkologie. Indikationen beim differenzierten Schilddruesenkarzinom und bei Lebertumoren

    Energy Technology Data Exchange (ETDEWEB)

    Weber, K.; Berger, F.; Reiser, M.F. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Innenstadt, Institut fuer Klinische Radiologie, Muenchen (Germany); Mustafa, M.; Bartenstein, P.; Haug, A. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Klinik und Poliklinik fuer Nuklearmedizin, Muenchen (Germany)

    2012-07-15

    Hybrid imaging of function and morphology has gained significant importance for lesion detection and treatment monitoring in oncology. In patients with differentiated thyroid carcinoma (DTC) a planar whole body scan is carried out after radioiodine therapy (RIT) for staging. However, due to limited spatial resolution the diagnostic accuracy of this scintigraphy method is impaired. Radioembolization utilizing {sup 90}Yttrium loaded micro-spheres by selective internal radiotherapy (SIRT) allows a minor invasive therapy of primary and secondary liver tumors. In order to avoid side effects of the micro-spheres caused by an outflow into intestines, stomach or lungs, imaging the arteries supplying the liver has to be performed by means of technetium-99m macroaggregated albumin ({sup 99m}Tc-MAA) and scintigraphy. The limited morphological information supplied by scintigraphy is again a challenge in treatment monitoring. {sup 131}Iodine whole body scanning is used for staging in patients with DTC 3-4 days after ablation. Monitoring of the tumor marker thyroglobulin and selective radioiodine whole body scans are available for patients with a high risk profile in the further follow-up with imaging of the arteries supplying the liver by means of {sup 99m}Tc-MAA scintigraphy in preparation of SIRT. Single photon emission computed tomography/computed tomography (SPECT/CT) of the neck and thorax with a therapeutic activity of radioiodine for staging after ablation. Techniques include imaging of arteries supplying the liver by means of {sup 99m}Tc-MAA SPECT/CT before SIRT and evaluation and quantification of the uptake of liver tumors, especially in comparison to the uptake of liver parenchyma by means of SPECT/CT. Due to the integration of combined functional and morphological information SPECT/CT can be used to characterize the morphology and iodine uptake of lesions more accurately, resulting in optimized staging in patients with DTC in comparison to whole body iodine scans and SPECT/CT provides more accurate imaging of the arterial supply of the liver and of potential outflows of micro-spheres into other organs. SPECT/CT allows evaluation and quantification of the uptake of liver tumors. Improved postablative staging in patients with differentiated thyroid cancer by SPECT/CT in comparison to radioiodine whole body scans can be achieved. Improved planning and monitoring of SIRT therapies utilizing SPECT/CT leads to optimized therapeutic doses within liver lesions. Integration of SPECT/CT into the clinical standard for postablative staging in patients with DTC is recommended as well as utilization of SPECT/CT during the planning process, for dose calculation and treatment monitoring of SIRT therapies. (orig.) [German] In den letzten Jahren hat die Hybridbildgebung mit Verbindung von funktioneller und morphologischer Information zur Diagnostik zahlreicher Erkrankungen zunehmend an Bedeutung gewonnen. Bei Patienten mit differenziertem Schilddruesenkarzinom (DTC) wird nach erfolgter Radiojodtherapie (RJT) ein planares Ganzkoerperszintigramm zum Staging durchgefuehrt. Die diagnostische Genauigkeit dieser szintigraphischen Methode ist jedoch aufgrund limitierter raeumlicher Aufloesung begrenzt. Die Radioembolisation von mit {sup 90}Yttrium beladenen Mikrosphaeren (selektive interne Radiotherapie, SIRT) ermoeglicht eine wenig invasive Therapie primaerer und sekundaerer Lebertumoren. Zur Vermeidung von Nebenwirkungen der Mikrosphaeren durch einen Abstrom in Darm, Magen und Lunge muss vor Therapiebeginn eine Darstellung des durch die leberversorgenden Arterien versorgten Gebiets mittels {sup 99m}Tc-MAA ({sup 99m}Technetium-makroaggregiertes Albumin) und einer Szintigraphie erfolgen. Auch hier limitiert die begrenzte morphologische Information der Szintigraphie das Therapiemonitoring. {sup 131}Jod-Ganzkoerperszintigramm zum Nachweis einer erfolgreichen Ablation und Staging ca. 3-4 Tage postablativ bei Patienten mit DTC. Ueberwachung des Tumormarkers Thyreoglobulin, ergaenzt durch Radiojodganzkoerperszintigraphien im weiteren Follow-up bei besonderem Risikoprofil. Darstellung des durch die leberversorgenden Arterien versorgten Gebiets durch eine {sup 99m}Tc-MAA-Szintigraphie als Vorbereitung auf eine SIRT. ''Single photon emission computed tomography''/CT (SPECT/CT) der Hals- und Thoraxregion mit einer therapeutischen Aktivitaetsmenge Radiojod im Rahmen des postablativen Stagings. Darstellung der leberversorgenden Arterien mittels {sup 99m}Tc-MAA-SPECT/CT vor Beginn einer SIRT. Analyse und Quantifizierung des Speicherverhaltens der Lebertumoren, insbesondere im Vergleich zum Leberparenchym durch die SPECT/CT. Aufgrund der Kombination von funktioneller und morphologischer Information ist die SPECT/CT in der Lage, radiojodpositive Herde exakter morphologisch zu korrelieren, damit optimiertes Staging im Vergleich zur Ganzkoerperszintigraphie. Durch die zusaetzliche, von der SPECT/CT gebotene anatomische Information gelingt eine genauere Darstellung der arteriellen Versorgung der Leber sowie potenzieller Abstroeme der Mikrosphaeren in andere Organe. Darueber hinaus ermoeglicht die SPECT/CT eine Analyse und Quantifizierung des Speicherverhaltens der Lebertumoren. Verbessertes postablatives Staging bei Patienten mit differenziertem Schilddruesenkarzinom, insbesondere in Bezug auf das Auffinden von Lymphknotenmetastasen (LKM) im Vergleich zur ueblichen Radiojodganzkoerperszintigraphie. Verbesserte Planung und Durchfuehrung einer SIRT-Therapie bei Leberlaesionen; Optimierung der applizierten Dosis durch Einsatz der SPECT/CT. Integration der SPECT/CT in den klinischen Standard im Rahmen des postablativen Stagings bei Patienten mit DTC. Anwendung der SPECT/CT im Planungsprozess einer SIRT-Therapie sowie bei der Dosisberechnung. (orig.)

  3. Chronic intersticial lung disease in the horse- Findings in arterial bloodgas analysis, tracheobronchial mucus cytology and radiological examination of the thorax; Chronisch interstitielle Lungenerkrankung beim Pferd - Blutgasanalytische, sekretzytolytische und röntgenologische Befunde

    Energy Technology Data Exchange (ETDEWEB)

    Dieckmann, M. [Klinik fuer Pferde, Tieraerztliche Hochschule Hannover (Germany); Klein, H. J.; Deegen, E.

    1990-07-01

    In 12 horses chronic interstitial lung disease was diagnosed. All horses were referrred because of unexplained loss of performance. In general there was no history of respiratory problems; 4 horses showed nasal discharge and 2 horses coughed. Results of arterial bloodgas analysis, tracheobronchial mucus cytology and radiological examination of the lungs were found in a typical combination, and they were different from results found generally in horses suffering from chronic obstructive pulmonary disease. Mean value of arterial partial pressure of oxygen was 100,6 mm Hg, arterial partial pressure of carbon dioxide was 45,1 mm Hg and alveolo-arterial difference in oxygen 5,1 mm Hg, respectively. In tracheobronchial aspirates pulmonary alveolar macrophages and neutrophil granulocytes were found in a relation of 2,6 : 1. Chest radiographs of all horses showed diffuse interstitial pattern throughout the lung.

  4. Steering levies on the purchase of new cars for the reduction of CO{sub 2} emissions; Lenkungsabgaben zur Senkung des CO{sub 2}-Ausstosses beim Neuwagenkauf. Hintergrund, Mechanismen, Prognosen

    Energy Technology Data Exchange (ETDEWEB)

    Haan, P. de; Mueller, M.; Peters, A.; Hauser, A.

    2007-12-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) takes a look at the background, mechanisms and prognoses for the reduction of CO{sub 2} emissions of new cars. This report focuses on policy measures - specifically the collection of budget-neutral so-called 'feebates' - that aim to influence the behaviour of buyers of new cars as a means of enhancing energy efficiency and reducing CO{sub 2} emissions. Both the European Union and Switzerland are pursuing a three-pillar strategy in which agreements with manufacturers and importers (pillar 1) are supplemented by the provision of more detailed information for customers in the form of energy labels for new vehicles as well as catalogues listing levels of fuel consumption (pillar 2). Pillar 3 concerns measures aimed at influencing car buying behaviour, generally based on the use of the energy label for new vehicles in order to realise the existing potentials for reducing CO{sub 2} emissions. The report takes a look at Switzerland's car market, buying behaviour, information on efficient vehicles, acceptance factors and incentive schemes. The findings of the study are presented and commented on.

  5. Vergleich verschiedener Beurteilungsverfahren an Röntgenbildern des Ellbogengelenkes beim Deutschen Schäferhund und Rottweiler unter Berücksichtigung des Einflusses der Lagerung als Basis einer züchterischen Selektion gegen die Ellbogengelenksdysplasie

    OpenAIRE

    Klein, Sandra

    2010-01-01

    Ziel dieser Untersuchung war es, drei Bewertungsverfahren zur Beurteilung der Ellbogengelenksdysplasie bei Hunden der Rasse Deutscher Schäferhund und Rottweiler miteinander zu vergleichen. Hierbei sollte insbesondere ein Einfluss der Lagerung während der Röntgenaufnahme überprüft werden. Bewertet wurden Röntgenaufnahmen von 19.798 Deutschen Schäferhunden und 2.430 Rottweiler, von denen bereits ein offizieller ED – Befund vorlag. Es erfolgte eine Beurteilung entsprechend der zwei Punktesch...

  6. Visualization of the dissipation of energy during the cutting process. Presentation of energy value flows by means of dual energy signatures; Energieverschwendung beim Zerspanungsprozess sichtbar machen. Darstellung von Energiewertstroemen mittels dualer Energiesignaturen

    Energy Technology Data Exchange (ETDEWEB)

    Schillig, Rainer [Hochschule Aalen (Germany). Professur Fertigungsorganisation und Prozessmanagement; Kalhoefer, Eckehard [Hochschule Aalen (Germany). Stiftungslehrstuhl Spanende Fertigung; Stock, Timo [Hochschule Aalen (Germany). Studiengang Maschinenbau/Produktion und Management

    2012-09-15

    Lean production systems are the minimization of wastage. Therefore, process steps are divided in value-added and non-value-added process steps. Using the value stream analysis non-value-adding process shares can be identified easily.The main aim usually are the two factors processing time and inventory. By means of a cutting process, the authors of the paper under consideration report on a method which divides the process-related utilization of energy in value-adding and non-value-adding energy use. Due to the dual consideration of energy use, the energy consumption can be easily integrated in the value stream analysis.

  7. Development of a system for detection and diagnosis of errors in the operation of space HVAC systems; Entwicklung eines Systems zur Erkennung und Diagnose von Fehlern beim Betrieb von HLK-Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Bach, H.; Bauer, M.; Grob, R.F. [Stuttgart Univ. (Germany). Lehrstuhl fuer Heiz- und Raumlufttechnik

    1997-12-31

    Buildings with heating and space HVAC systems require considerable automatic control effort to ensure engergy-efficient operation. Faults are only to be avoided by the use of automatic fault detection systems. The contribution describes the procedure adopted in operation monitoring, the IKE system for fault detection and diagnosis, and the evaluation of the FDD system. (MSK) [Deutsch] Gebaeude mit heiz-und raumlufttechnischen Anlagen erfordern bei energetisch rationellem Bertrieb einen grossen Aufwand an Steuerungs-und Regelungstechnik. Um ohne Fehler zu arbeiten erfordert diese Steuerungs-und Regelungstechnik den Einsatz von automatischen Fehlererkennungssystemen. Im Folgenden werden die Vorgehensweise bei der Betriebsueberwachung, das IKE-System zur Fehlererkennung und Diagnose sowie die Evaluierung des FDD-Systems (Fault Detection and Diagnosis System) erlaeutert.

  8. Interferenz von Muttersprache und Zweitsprache auf eine dritte Sprache beim freien Sprechen -- ein Vergleich (Interference by the Native Language and a Second Language on a Third Language in Free Conversation -- A Comparison)

    Science.gov (United States)

    Stedje, Astrid

    1976-01-01

    Tests given at the German Institute of the University of Stockholm to 32 Finnish students studying German revealed that both their native language and their Swedish interfered with their learning German, in about equal degree overall. The mother tongue, Finnish, caused more interference errors in pronunciation. (Text is in German.) (IFS/WGA)

  9. Fast Expansion oder doch 4-Gate-Push? - Kompetenzerwerb und Transfer beim Spielen von Echtzeit-Strategiespielen im Mehrspielermodus am Beispiel von StarCraft II – Wings of Liberty.

    Directory of Open Access Journals (Sweden)

    Andreas Steininger

    2013-03-01

    Full Text Available Derzeit ist unklar, inwiefern in Computerspielen erworbene Kompetenzen in andere Kontexte transferiert werden. In der vorliegenden Arbeit wird der subjektiv wahrgenommene Wissenstransfer von 444 SpielerInnen und eines Online-Echtzeitstrategiespieles untersucht. Etwas weniger als die Hälfte der Befragten sehen einen Wissenstransfer im Bereich der sozialen Kompetenz, der Medienkompetenz, der persönlichkeitsorientierten Kompetenz und der kognitiven Kompetenz. Mehr als 50% der Befragten nehmen subjektiv einen Wissenstransfer im Bereich der sensomotorischen Kompetenzen und der Fremdsprachkenntnisse wahr.The transfer of competencies acquired in video games into other contexts is hardly researched yet. For this paper, the transfer of competencies is researched from players point of view. 444 players of a real time strategy game have been interviewed. Slightly less than 50% perceived a knowledge transfer for media competencies, personality, social competences and cognitive competencies. More than 50% perceived a transfer for sensomotor skills and foreign language competence.

  10. Constructing in the monument. Respecting the Old and mark the New. Cost-reliable planning during building upon existing structures; Bauen im Denkmal. Altes achten und Neues kenntlich machen. Kostensicher planen beim Bauen im Bestand

    Energy Technology Data Exchange (ETDEWEB)

    Schneider-Sorger, Roswitha [ORCA Software GmbH, Rosenheim (Germany)

    2011-07-01

    The revitalization of historically protected real estate is a passion of the owners - the family Werndl (Rosenheim, Federal Republic of Germany). In the case of the Old spinning mill in the Kolbenmotor near Rosenheim a whole district was arranged new. The highest premise of the planning team Quest Architekten GBR (Rosenheim, Federal Republic of Germany) was to respect and receive the rough charm of the building stock. This also becomes clear considering the two-storey Batteur building of 1862 being a component of the energy centre of the spinning mill. Once cotton was cleaned, now shops and gastronomy are in the ground floor as well as practices and office units in the upper floor.

  11. Changes of structure and properties in the heat-affected zone during the welding of high-strength aluminium alloys. Gefuege- und Eigenschaftsaenderungen in der Waermeeinflusszone beim Schweissen hochfester Aluminiumlegierungen

    Energy Technology Data Exchange (ETDEWEB)

    Umgeher, A. (Tyrolitschleifmittelwerke Swarovski KG, Schwaz (Austria)); Cerjak, H. (Technische Univ., Graz (Austria))

    High strength aluminium alloys like AlZnMgCu 1.5 are usually classified as 'non-weldable' alloys. If welding technologies such as TIG-plasma keyhole welding are used, it is possible to weld these alloys successfully. However, the heat input during welding affects the base material adjacent to the fusion zone. The main objective of this investigation was to study the change of microstructure and properties in this heat affected zone (HAZ) of high strength aluminium alloys. The base material was a high strength wrought aluminium alloy AlZnMgCu 1.5 (7075) in the T6 condition. The specimens were welded by TIG-plasma keyhole welding. Additionally, Gleeble welding simulation techniques were used. The specimens were investigated in the 'as welded' condition, 'naturally aged', 'artificially aged', and after a complete post weld heat treatment. The microstructure was investigated using light and electron microscopy. Hardness and electric resistivity measurements and DSC-analysis were made. (orig.)

  12. Rail travel with water and wind. Alternatives for more renewable energies with Germany's largest electricity consumer; Bahn fahren mit Wasser und Wind. Wege fuer mehr regenerative Energien beim groessten Stromverbraucher Deutschlands

    Energy Technology Data Exchange (ETDEWEB)

    Horenburg, Peter

    2012-07-01

    It is a core problem of the energy revolution: the fluctuating yields from renewable energy sources have to be integrated into the electricity supply without endangering its safety and economic feasibility. Here the Deutsche Bahn railway company provides a prime example: by 2020, the company intends to draw more than one third of the 12 billion kilowatthours it consumes each year from green electricity. Researchers have calculated that doubling the green electricity used today will increase the electricity costs by around five per cent. The German railway power grid is distinguished, however, by many unique features. (orig.)

  13. Effects of active influencing of drivers on passenger car safety in road traffic; Untersuchungen zur Auswirkung einer aktiven Fahrerbeeinflussung auf die Fahrsicherheit beim Pkw-Fahren im realen Strassenverkehr

    Energy Technology Data Exchange (ETDEWEB)

    Bielaczek, C.

    1998-09-01

    The behaviour of car drivers in road traffic was investigated both in the `normal`, uninfluenced state and with supporting alarm systems informing the driver on critical situations. Systems of this kind may get more important as traffic density increases and increasingly comfortable cars cut the driver off from immediate feedback to recognize critical situations. The tests were carried out with fixted and with driver-adaptive alarm thresholds. Information was transmitted to the driver in the form of haptic/kinesthetic signals on the control elements for vehicle control, i.e. the steering wheel and the gas pedal. It is important to take account of the driver`s recognition of alarm signals under natural driving conditions as in road traffic. The best results were achieved with driver-adaptive alarm thresholds combined with the alarm signal `variable steering wheel control` which also met with high acceptance by the drivers. (orig.) [Deutsch] Die vorliegende Arbeit befasst sich mit der Untersuchung des Verhaltens von Pkw-Fahrern waehrend Fahrten im oeffentlichen Strassenverkehr im unbeeinflussten und durch Fahrer-Assistenz-Systeme beeinflussten Zustand des Fahrers, um die Auswirkung einer aktiven Fahrerunterstuetzung durch eine gezielte Warn-Signaluebermittlung an den Fahrer in kritischen Fahrsituationen zu untersuchen. Die Notwendigkeit einer solchen Untersuchung liegt einerseits in der staendig wachsenden Verkehrsdichte begruendet, die den Fahrer staerker belastet, andererseits aber auch in der durch verbesserten Komfort zunehmenden Entkopplung des Fahrers von der Umgebung, die sich im fehlenden Feedback zur Erkennung kritischer Fahrzustaende aeussert. - Es wurden, hinsichtlich des querdynamisch orientierten Kraftschlusspotentials, sowohl feste als auch fahreradaptive Warngrenzen definiert und ueberprueft. Die Informationsuebermittlung an den Fahrer wurde in Form von haptisch/kinaesthetischen Signalen (variable Betaetigungskraefte) an den Stellgliedern zur Fahrzeugfuehrung, dem Fahrpedal und der Lenkung, durchgefuehrt. - Ein sehr wichtiger Aspekt der Arbeit ist die Einbeziehung der Fahrerwahrnehmung von Warnsignalen unter natuerlichen Fahrerbelastungsbedingungen, wie sie in Feldversuchen im oeffentlichen Strassenverkehr gegeben sind. Dabei zeigten fahreradaptive Warngrenzen in Kombination mit den Warnsignalen `variable Lenkkraefte` den besten Erfolg hinsichtlich einer aktiven Fahrerbeeinflussung bei gleichzeitig hoher Akzeptanz dieses Systemansatzes. (orig.)

  14. Support of the Ukrainean Supervisory Authority during the extension of the improved operational NCP monitoring. Final report part III; Unterstuetzung der ukrainischen Aufsichtsbehoerde beim Ausbau der verbesserten betrieblichen KKW-Ueberwachung. Abschlussbericht Teil III

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, M.; Carl, H.

    2005-05-01

    Technical systems to improve the operational monitoring for the three units of the South Ukraine NPP and for the 1{sup st} unit of the Chmelnitzky NPP were put up by analogy with the systems for the Zaporoshye NPP and the Rovno NPP. For that up to 51 safety-relevant technological and 16 radiological parameters from every unit are available to the supervisory authority on-site and in the crisis centre in Kiev for collection and assessment. These parameters are transferred on-line by modern technical equipment once a minute. The developed evaluation software enables the visualisation of the monitoring results in form of diagrams, charts and graphs. By means of an archive modus the trends of all parameters can be analysed. With the integration of the technical equipment delivered for the sheltered room of the Zaporoshye NPP into the on-site existing remote monitoring system is it now possible to record and to evaluate essential safety-relevant parameters of the whole NPP also during severe accidents by means of modern technical equipment. (orig.)

  15. Phase transformation and local mechanical properties of TRIP steel in a simulated and real resistance spot weld process; Phasenumwandlung und lokale mechanische Eigenschaften von TRIP Stahl beim simulierten und realen Widerstandspunktschweissprozess

    Energy Technology Data Exchange (ETDEWEB)

    Brauser, Stephan

    2013-06-01

    TRIP steels give high strength along with good ductility owing to metastable austenite to martensite phase transformation (TRIP effect) caused by mechanical load. Under the extreme process-specific heating and cooling rates of resistance spot welding, these materials may undergo modifications in their austenite portion resulting in changed mechano- technological performance locally. The prime objective of this study was therefore to carry out microstructure analyses of the spot weld area in order to identify the modified portion of austenite and the resulting changes in local mechanical performance with special consideration of the TRIP effect. First, the metastable austenite portion in the unprocessed parent metal was quantified by in-situ diffraction using high energy synchrotron radiation. Next, the basic aspects of temperature dependent austenite transformation in the heating and cooling process were investigated in furnace experiments under defined temperature profiles. Continuative Gleeble tests and furnace experiments were conducted using various temperature profiles with different peaks occurring locally in the spot welding process in order to enable systematic assessment of the influence of temperature and of heating and cooling conditions on the austenite content under real conditions. Correlation experiments between the mechanical characteristics of thermally prepared tensile specimens and the metallographically and roentgenographically determined austenite contents allowed it to ascertain the metastable, i.e. transformable austenite portions. Finally, the results were evaluated concerning their transferability to real resistance spot welds. It was demonstrated that the austenite to martensite phase transformation can come into action only in a strongly localized material area in the transition zone between heat-affected zone and base metal. Consequently, the TRIP effect does not significantly affect the strength and ductility performance in the joining area of spot welded TRIP steels. The established mechanical characteristics were used as input data for numerical simulation of the spot weld ductility and strength performance. Here, the attention was focused on the necessity of implementing mechanical characteristics of the heat-affected zone for realistic tensile shear test modelling. [German] TRIP Staehle realisieren durch eine unter mechanischer Beanspruchung hervorgerufene Phasenumwandlung von metastabilen Austenit in Martensit (TRIP-Effekt) hohe Festigkeiten bei gleichzeitig guten Verformungseigenschaften. Waehrend der Verarbeitung dieser Werkstoffe mittels Widerstandspunktschweissen koennen unter den prozessspezifischen extremen Aufheiz- und Abkuehlraten Modifikationen des Austenitanteils hervorgerufen werden die als Folge lokal zu einer Aenderung der mechanisch-technologischen Eigenschaften fuehren. Wesentliche Zielsetzung der vorliegenden Arbeit war daher die Analyse der Gefuegestruktur im Bereich einer Punktschweissverbindung hinsichtlich der Aenderung des Austenitanteils und den daraus resultierenden Aenderungen der lokalen mechanischen Eigenschaften unter besonderer Beruecksichtigung des TRIP-Effekts. Durch in-situ Beugungsuntersuchungen mittels hochenergetischer Synchrotronstrahlung erfolgte zunaechst die Quantifizierung des metastabilen Austenitanteils im unbehandelten Grundwerkstoff. Darauf aufbauend wurden unter definierten Temperaturprofilen in Ofenversuchen die grundlegenden Aspekte der thermisch bedingten Austenitumwandlung im Aufheiz- und Abkuehlprozess untersucht. Durch Gleeble-Versuche und Ofenexperimente wurden weiterfuehrend verschiedene Temperaturprofile mit unterschiedlichen im Punktschweissprozess lokal vorliegende Spitzentemperaturen genutzt um eine systematische Bewertung des Einflusses der Temperatur und der Aufheiz- sowie der Abkuehlbedingungen auf den Austenitgehalt unter realen Bedingungen zu ermoeglichen. Durch Korrelationsuntersuchungen zwischen den mechanischen Kennwerten thermisch praeparierter Zugproben und den mittels Metallographisch wie auch roentgenographisch ermittelten Austenitgehalten konnten die metastabilen, d.h. umwandlungsfaehigen Austenitanteile bestimmt werden. Schliesslich erfolgte eine Bewertung hinschlich der Uebertragbarkeit der Ergebnisse auf reale Widerstandspunktschweissverbindungen. Es wurde dabei der Nachweis erbracht, dass die Austenit-Martensit-Phasenumwandlung lediglich in einem lokal eng begrenzen Werkstoffbereich am Uebergang WEZ/Grundwerkstoff wirksam werden kann. Demzufolge fuehrt der TRIP-Effekt zu keiner signifikanten Beeinflussung von Festigkeits- und Verformungseigenschaften im Fuegebereich von widerstandspunktgeschweissten TRIP Staehlen. Die ermittelten mechanischen Kennwerte wurden abschliessend als Eingangsdaten fuer die numerische Simulation des Verformungs- und Festigkeitsverhaltens von Punkschweissverbindungen genutzt. Dabei wurde insbesondere die Notwendigkeit der Implementierung von mechanischen Kenndaten der Waermeeinflusszone fuer eine realitaetsnahe Modellierung von Scherzugversuchen untersucht.

  16. Komplexe Normierungen – widerspenstige Effekte. Zur Rolle des Rechts beim Wandel der Geschlechterverhältnisse Complex Standardization—Unruly Effects. On the Role of Law in Changing Gender Relations

    Directory of Open Access Journals (Sweden)

    Ulrike Lembke

    2008-11-01

    Full Text Available Diese Dokumentation einer internationalen Tagung wartet mit sehr differenzierten Antworten zu der Frage auf, ob (auch mit den Mitteln des Rechts jener Wandel initiiert werden kann, der notwendig ist, um die Geschlechterverhältnisse gerecht(er zu gestalten. In den vielgestaltigen Beiträgen zu den Themenfeldern Arbeitswelt, Familie, Biopolitik und Einwanderungsgesellschaft wird deutlich, dass die Frage nach dem emanzipatorischen Potential von Recht zwar nur jeweils konkret beantwortet werden kann, der Austausch von Erfahrungen und Reflektionen jedoch unerlässlich ist für erfolgreiche feministische Rechtspolitiken.This documentation of an international conference provides varying answers to the question whether change, which is essential in forming gender relations in a more equitable fashion, can (also be initiated through the instruments of law. The varied contributions on the themes of work, family, biopolitics, and immigrant society make clear that while the question of the emancipatory potential of law can only partially be answered, the exchange of experiences and reflections is essential for successful feminist legal politics.

  17. Rubber friction and force transmission during the shearing process of actively-driven vacuum grippers on rough surfaces; Elastomerreibung und Kraftuebertragung beim Abscheren von aktiv betriebenen Vakuumgreifern auf rauen Oberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Kern, Patrick

    2016-12-21

    Nowadays, vacuum grippers come in many different shapes and sizes. Their stability is guaranteed through specially manufactured metal fittings. These fittings are non-positively and positively connected to the elastic part of the vacuum gripper. The design of the elastic part may vary, though. Elastomer components are used to ensure tightness for the negative pressure in the active cave chamber of the vacuum gripper, as well as for the transfer of shearing forces, which acting parallel to the surface. Some vacuum grippers feature one elastomer for both the sealing function and the transfer of shear forces; other gripper types are equipped with various elastomers for those applications. The vacuum grippers described in this work are equipped with structured rubber friction pads, their tightness being ensured by sealing lips made of a flexible foam rubber. A restraint system consisting of one or several vacuum grippers must be sized prior to its actual practical use. For the transmission of shearing forces, which acting parallel to the surface, it is necessary to take the tribological system, consisting of the suction element's elastomer and the base material, into account since these loads put shearing stress on the vacuum gripper. In practice, however, a standardized value is given for the coefficient of friction μ; i.e. the ratio of transmissible frictional force to the normal force. This does neither include a detailed description of the elastomer used nor of the roughness of the base material. The standardized friction coefficients cannot be applied to the practical design of restraint systems. The present work includes the analysis of the load transmission and the modeling of the friction coefficients μ on rough surfaces during the shearing process of actively-driven vacuum grippers. Based on current theories, the phenomenon of elastomeric friction can be attributed to the two main components of hysteresis and adhesion friction. Both components are presented and modeled at length in this work. In addition, the positive locking, which is not considered in rubber friction theories but allows an increase of the transferable shear forces and thus further contributes to the overall friction coefficient, is also examined here. With the help of a test program, all factors relevant to the shearing process of a vacuum gripper on a given surface and their effect on the tribological system will be analyzed in detail. These include essential influencing factors, i.e. operating temperature, shear speed, mixture composition of the elastomer, and the surface roughness. Moreover, the important factor of the structure of the rubber friction pads must also be considered. In this work, the overall friction coefficient model is based on existing rubber friction theories which describe the contributions of hysteresis and adhesive friction, and on a new approach of how positive locking also contributes to the result. Since the model of the overall friction coefficient is a theoretic one and not all required parameters can directly be measured, the friction model is related to the experimental results. Thus, the missing model parameters can be derived. As a result, it is possible to calculate the expected friction coefficient μ for any structure of rubber friction pads in compliance with the method presented in this work. Unlike the generalized friction coefficient μ data provided by the manufacturers, this friction model allows to realistically calculate friction coefficients and therefore to optimize the design of restraint systems for vacuum grippers.

  18. Experiences with the use of conservative tracers as an aid in transferring lysimeter results to the open field; Erfahrungen beim Einsatz von konservativen Tracern als Hilfsmittel zur Uebertragung von Lysimeterergebnissen auf Freilandflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, J.; Meissner, R.; Rupp, H. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Falkenberg (Germany). Lysimeterstation; Mueller, L.; Eulenstein, F. [Zentrum fuer Agrarlandschafts- und Landnutzungsforschung e.V. (ZALF), Muencheberg (Germany)

    1999-02-01

    Four lysimeter trials performed on an IS-type soil yielded an almost constant range of displacement of a tracer front (NO{sub 3} front) of 4.0 to 4.5 mm / l of seepage water (referred to a surface area of 1 m-2 and a depth of 1 m). This was experimental confirmation of a tentatively formulated simplified relationship between seepage water volume, vertical tracer displacement, and field capacity. The results were also in very good agreement with those of a control study in the open field carried out under similar hydrological, pedological, and agrotechnical conditions using lysimeters and Cl tracers for determining quantities of seepage water formation. As the present lysimeter trials mirror soil hydrological processes in the open field with sufficient accuracy, they appear well suited to take the place of the so often lacking territorial data as a means of validating mathematical models describing seepage-water-bound material export. [Deutsch] Auf der Basis von 4 Lysimeterversuchen konnte fuer die Bodenart IS ein nahezu konstanter Wertebereich fuer die Verlagerung einer Tracerfront (NO{sub 3}-Front) in Hoehe von 4,0 bis 4,5 mm/l Sickerwasser (bezogen auf eine Oberflaeche von 1 m{sup 2} und eine Tiefe von 1 m) ermittelt werden. Damit konnte die vereinfachte Beziehung zwischen Sickerwassermenge, Tracerverlagerungstiefe und Feldkapazitaet experimentell bestaetigt werden. Ein Vergleich zur Bestimmung der Sickerwassermengenbildung mit Hilfe von Lysimetern und durch Einsatz von Cl-Tracern unter aehnlich hydrologischen, pedologischen und agrotechnischen Bedingungen im Freiland wies eine hohe Uebereinstimmung auf. Da die hier durchgefuehrten Lysimeteruntersuchungen bodenhydrologische Prozesse von Freilandflaechen mit ausreichender Genauigkeit widerspieglen, erscheinen sie anstelle oft fehlender Gebietskenndaten zur Validierung von mathematischen Modellen zur Beschreibung sickerwassergebundener Stoffaustraege gut geeignet. (orig.)

  19. Ecological and economic assessment and optimisation of measures for in-house recycling in hot galvanizing plants; Oekologische und oekonomische Beurteilung und Optimierung von Massnahmen zur innerbetrieblichen Stoffkreislaufschliessung beim Feuerverzinken von Stahl

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, R.; Fleischer, G. [TU Berlin, Inst. fuer Technischen Umweltschutz, Lehrstuhl Abfallvermeidung und Sekundaerrohstoffwirtschaft, Berlin (Germany)

    2003-07-01

    Exemplary strategies for materials use and recycling in a plant for hot galvanizing of steel are reviewed from an ecological and economic viewpoint and optimized. The changes resulting from the optimization measures are assessed in terms of cost and potential ecological effects. The results of this assessment, which is based on the methodology published in DIN EN ISO 14040 ff, illustrate the potential contained in the recycling option. (orig.) [German] Fuer das Feuerverzinken von Stahlbauteilen werden beispielhaft Strategien zur innerbetrieblichen Stoffkreislaufschliessung oekologisch und oekonomisch beurteilt und optimiert. Die sich hinsichtlich der betrieblichen Stoff- und Energiefluesse durch Optimierungsmassnahmen ergebenden Veraenderungen werden in Bezug auf die Kostensituation des Unternehmens und die oekologischen potentiellen Auswirkungen beurteilt. Die Ergebnisse der Oekologischen Betriebsoptimierung, die unter Nutzung methodischer Elemente der Oekobilanzierung (DIN EN ISO 14040 ff) erzielt werden, verdeutlichen, welche Potentiale in einer weitgehenden Schliessung des Stoffkreislaufs liegen. (orig.)

  20. About the influence of the topography of the steel surface on faults during hot galvanizing of part loads; Zum Einfluss der Topographie der Stahloberflaeche auf Fehler beim Stueckgut-Feuerverzinken

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, W.D. [Institut fuer Korrosionsschutz GmbH, Dresden (Germany); Schubert, P.

    2002-03-01

    The topography of the steel surface can influence the formation of layers during hot galvanizing in many ways. Information is given on galvanizing faults caused by impressions in the steel surface (rolling and drawing ridges). Flux remainders accumulated in these impressions can be encapsulated in the zinc coating during hot galvanizing. This leads to cavities and pores in the coating or to sponge-like zinc raisings at its surface. The flux remainders from the zinc coating can boil during powder coating and lead to blisters and pimple-like rises in the coating. Therefore, steel surfaces designed for galvanizing should be even or only have flat impressions. (orig.)

  1. Inhibitor efficiency in long-time protection of steel tanks for the chemical surface preparation against local corrosion by process solutions containing hydrochloric acid; Inhibitorwirksamkeit beim Langzeitschutz von Stahlbehaeltern fuer die chemische Oberflaechenvorbereitung gegen oertliche Korrosion durch salzsaeurehaltige Prozessloesungen

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-02-01

    The efficiency of prevailing acid inhibitors is examined by age hardening heavy tank-steel plates in technically usual hot-galvanizing solutions for 1000 hours. With acid inhibitors local corrosion emerged as shallow pit formation first and foremost in hydrochlorid acid pickles (20 g/l HCl) at ambient temperature as well as in cleaners containing hydrochloric acid (10-30 g/l HCl) at 40 C when other conditions also applied. Above all, local corrosion was produced if the inhibitor concentration became too low (0.2 g/l) in connection with a minimum hydrochloric acid concentration (10-30 g/l). However, oxidizing agents like iron(III)-ions (5-10 g/l), atmospheric oxygen and free chlorine (100-1000 mg/l) lead to local corrosion, too. Local corrosion did not emerge in rinse baths (2-10 g/l HCl) and fluxing material solutions of zinc chloride and ammonium chloride (pH value: 2.0-5.5). Here uniform corrosion developed. Acid inhibitors turned out to be very effective against uniform corrosion in the examined long-time period (inhibiting values up to 99%). (Abstract Copyright [2004], Wiley Periodicals, Inc.) [German] Die Wirksamkeit handelsueblicher Saeureinhibitoren wird durch eine Auslagerung von Grobblechen aus Behaelterstahl ueber 1000 Stunden in technisch gebraeuchlichen Loesungen der Feuerverzinkung untersucht. Oertliche Korrosion ist als Muldenkorrosion in Gegenwart von Saeureinhibitoren vor allem in Salzsaeurebeizen (20 g/l HCl) bei Raumtemperatur und in salzsaeurehaltigen Reinigern (10-30 g/l HCl) bei 40 C aufgetreten, wenn Zusatzbedingungen erfuellt sind. Oertliche Korrosion wird vorwiegend durch eine Unterschreitung der Inhibitorkonzentration (0,2 g/l) in Verbindung mit einer minimalen Salzsaeurekonzentration (10-30 g/l) ausgeloest. Aber auch Oxidationsmittel wie Eisen(III)-Ionen (5-10 g/l), Luftsauerstoff und freies Chlor (100-1000 mg/l) fuehren zu oertlicher Korrosion. In Spuelbaedern (2-10 g/l HCl) und Flussmittelloesungen aus Zinkchlorid und Ammoniumchlorid (pH-Wert: 2,0-5,5) ist keine oertliche Korrosion entstanden, sondern Flaechenkorrosion. Im untersuchten Langzeitbereich sind Saeureinhibitoren gegen Flaechenkorrosion sehr gut wirksam (Hemmwerte bis 99%). (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  2. Experiments on the Haeffner effect i. e. isotope enrichment on passage of high current densities through metallic melts. [Lithium]. Versuche zum Haeffner-Effekt (Isotopenanreicherung beim Durchgang von Gleichstrom hoher Stromdichte durch Metallschmelzen)

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, G

    1962-01-01

    The Haeffner effect (E. Haeffner 1953) found first with mercury and later confirmed with several other metals consists in an enrichment of the lighter isotopes at the anode end, and of the heavier isotopes at the cathode end. In the present work measurements were made on molten lithium. To keep current intenisities within reasonable limits the experiments were done in steel capillaries of 0.6 mm inner diameter and lengths 22-43 cm. Current densities were 6000-7400 A/cm/sup 2/ and the duration 150 h. Neutron activation was used as isotope analysis method. Surprisingly and in contrast to previous measurements an enrichment of Li/sub 6/ of about 1% was found at the ends of the capillary relative to its middle. This was independent of the current direction. No explanation of the effect is given.

  3. Progress in biogas. Biogas production from agricultural biomass and organic residues. Pt. 1 and 2. Proceedings (oral presentations and poster presentations); Fortschritt beim Biogas. Biogas aus landwirtschaftlicher Biomasse and organischen Reststoffen. T. 1 und 2. Tagungsband. Vortraege and Poster

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Within the International Conference ''Progress in Biogas - Biogas production from agricultural biomass and organic residues'' at the University Hohenheim (Stuttgart, Federal Republic of Germany) from 18th to 21st September, 2007, the following lectures were held: (1) Global relevance and potential of bioenergy for regional development; (2) Biogas electricity for France feed-in tariff and some other things to know before entering French market; (3) Policy drivers and future prospects for on-farm anaerobic digestion in Northern Ireland; (4) Biogas in Belgium, a swot analysis; (5) Status and prospects of biogas energy use in Ukraine; (6) Recent developments in Chinese agricultural biogas production; (7) Opportunities for agricultural based biogas systems in the province of Ontario, Canada; (8) Pre-treatment and digestion of separated collected household waste in Sweden; (9) To the problem of monitoring measures and prophylaxis measures with the utilization of organic residual substances in biological gas facilities from hygienic view; (10) Fermenting residues from biological gas facilities - nutrients and pollutants, possibilities of application in the agriculture; (11) Treatment and utilization of fermentation residues; (12) Potential of residual gas of NaWaRo feeded biogas plants in Baden-Wuerttemberg; (13) Operating analytics of biogas plants to improve efficiency and to ensure process stability; (14) The potential of biogas and electric power production from subproducts in the sugar and alcohol industries by the application of anaerobic digestion; (15) Co-digestion plant in dairy cattle farm in Emilia Romagna region (Italy); (16) Facing operational problems in a biodigeser in Yuvientsa - Amazonian Region of Ecuador; (17) Biogas plant instead of milk cow - payment and occupation with the use of grassilage; (18) Biogas in ecologic agriculture - experiences from 3 years of fermentation of grass-clover ley; (19) Combined solar-biogas basis for the population social level raising; (20) Production of biogas with grassilage - when is this profitable?; (21) Biogas: Opportunity or threat for the agriculture; (22) Country report Cameroon; (23) Fruit wastes bioconversion for anaerobic co-digestion with pig manure. Process development for the recycling in decentralised farm scale plants; (24) A parameter estimation protocol for anaerobic digestion; (25) BABIU - a new process for production of biomethane from biogas; (26) Dry fermentation of organic wastes; (27) Biological production of hydrogen from agricultural raw materials and residual materials with subsequent methane step; (28) Two phase continuous digestion of solid manure on-farm; (29) Investigation and development of an optimal process of fermenentation of grassilage by a two-phase process operation; (30) Technical weak points at biogas plants - occasions, effects and measures; (31) Plant safety - a substantial component according to permission and availability of biogas plants; (32) Analysis and evaluation of alternative concepts of the energetic use of biogas and other biogenous gases; (33) Gas-side bundling of some biogas plants, gas processing and gas feeding; (34) Technical and economical demands to biogas production for feeding into the HD grid; (35) Thinking about the use of biogas from the view of heat utilization - development of concepts for bioenergy villages; (36) Biogas cogeneration plant in the practice: Behaviour of emission and performance; (37) The future of biogas in Europe: Visions and targets until 2020; (38) Two-stage dry-wet-fermentation - optimization of the hydrolysis for a short space-time-yields; (39) Manure-free fermentation of renewable raw materials; (40) Quantification of different microbial population in termophilic-dry anaerobic digestion; (41) The use of hydrolytic enzymes in agricultural biogas production; (42) A contribution to mobile online gas diagnostics according to the efficiency of biogas plants; (43) Genetic 'fingerprints' to characterize microbial communities during organic overloading and in large-scale biogas plants; (44) Codigestion of olive mill wastewater and swine manure using UASB bioreactors for biogas production; (45) Addition of fibre cracking enzymes according to the enhancement of yield of biogas of energy plants; (46) On-site consulting of operators of biogas plants; (47) Cooperation between energy economy and agriculture at Erdgas Suedwest (Concept of biogas upgrading as a cooperation perspective for gas utilities and agriculture); (48) Cooperative operator models for biogas plants with utilization of heat in municipal sites - a common community of agriculturists and an experienced contractor; (49) Risk and insurance management for biogas plants; (50) Experiences in the german-chinese market of biogas and utilization of CDM projects.

  4. Hemangiosarcoma after breast-conserving therapy of breast cancer. Report of four cases with molecular genetic diagnosis and literature review; Haemangiosarkom nach brusterhaltender Therapie beim Mammakarzinom. Vier Fallbeispiele mit molekulargenetischer Diagnostik und Literaturuebersicht

    Energy Technology Data Exchange (ETDEWEB)

    Nestle-Kraemling, Carolin [Universitaetsklinikum, Duesseldorf (Germany). Frauenklinik; Boelke, Edwin; Budach, Wilfried [Universitaetsklinikum Duesseldorf (DE). Klinik und Poliklinik fuer Strahlentherapie und radiologische Onkologie] (and others)

    2011-10-15

    Hemangiosarcomas of the breast represent a rare disease of the breast mainly occurring as secondary neoplasias with a latency of 5-10 years after primary treatment of breast cancer and are associated with an unfavourable prognosis. Radiation therapy, which is integrated within the concept of breast conserving therapy ranks as the main risk factor. In this report we describe the clinical course of 4 patients including their molecular genetic pattern and give a summary of the actual literature. Hemangiosarcomas occur as a secondary neoplasm with a latency of 5-10 years after primary treatment of breast cancer and have an unfavorable prognosis. A genetic predisposition is assumed, but we could not find a significant role of tumor suppressor genes BRCA1, BRCA2 or p53 in our patients. Due to limited data available for these tumors, recommendations for therapy include radical tumor resection achieving wide free margins and inconsistent regimens of chemo- and/or immunetherapy modalities. In the majority these are based on systemic therapy regimens for other cutaneous sarcomas, such as Kaposi's sarcoma. Efforts should be taken for a nation-wide systematic registration of all cases of post-irradiation hemangiosarcomas.

  5. Synopsis on selected hazard reports from Germany, Europe and international; Synopse zu ausgewaehlten Gefahrenberichten aus Deutschland, Europa und international. Eine Analyse im Rahmen des 4. Gefahrenberichts der Schutzkommission beim Bundesministerium des Innern

    Energy Technology Data Exchange (ETDEWEB)

    Atzl, Andreas [Karlsruher Institut fuer Technologie (KIT) (DE). Inst. fuer Regionalwissenschaft/Inst. fuer Staedtebau und Landesplanung (IfR/ISL); Lerch, Jennifer [Deutsche Gesellschaft fuer Internationale Zusammenarbeit (GIZ), Regionales Zentrum Saarland, Saarbruecken (Germany); Luxen, Johannes; Urban, Bert; Lackner, C.K. [Klinikum der Univ. Muenchen (DE). Inst. fuer Notfallmedizin und Medizinmanagement (INM)

    2012-07-01

    The Report covers the following issues in 6 sections (1) Introduction. (2) Procedures and methodology: selection of documents, qualitative pre-evaluation, quantitative analysis. (3) Results from the medical point of view: rush of patients in case of asymmetric threads; rush of casualties in case of natural disasters, medical care impairment in case of destroyed infrastructure; epidemics and pandemics; attacks or accidents in nuclear facilities; disturbance of the drinking water supply; CBRN (chemical, biological, radiation, nuclear) attacks. (4) Results from the point of view of environmental and engineering science: overview, asymmetric threat, climatic change, D (information and communication technologies) hazards; public supply in case of emergency. (5) Results from the point of view of social science: overview on the matrix; vulnerabilities, institutional challenges, self-protection, information and warning of the public. (6) Conclusions: dominance of asymmetric threat and need of systemic approaches in civil defense; supply of the public and critical infrastructures, transformation processes and challenges in civil defense; quality of documents and need of additional research on emergency protection.

  6. Percutaneous, radiology-assisted stent implantation by means of a novel prosthesis of the bile duct in cases of inoperable cholangioma. Perkutane radiologische Stentimplantation beim inoperablen Gallengangskarzinom mittels einer neuen Gallengangsprothese

    Energy Technology Data Exchange (ETDEWEB)

    Beck, A; Nanko, N [Freiburg Univ. (Germany, F.R.). Abt. Roentgendiagnostik; Milic, S [Consiglio Nazionale delle Ricerche, Rome (Italy); Volk, B [Freiburg Univ. (Germany, F.R.). Abt. Innere Medizin 1 (Haematologie und Onkologie)

    1989-07-01

    In case of malignant growth causing biliary obstruction, biliary decompression can be achieved by surgery, or by means of external/internal drainage. A novel stent with an F7 outer diameter can be percutaneously introduced and positioned through an F8 sluice, assisted by radiologic and cholangioscopic control, and can be dilated to the required diameter by means of a balloon catheter. The implentation can entirely be done through the sluice.

  7. The extrusion of AZ-series magnesium alloys - extending the processing limits by hydrostatic extrusion; Erweiterung der Prozessgrenzen beim Strangpressen von Magnesiumknetlegierungen der AZ-Reihe durch das hydrostatische Strangpressverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Swiostek, J. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung

    2008-12-04

    The present study is concerned with the analysis of the influence of hydrostatic extrusion on the microstructural development and mechanical properties of extruded profiles of the AZ-series magnesium alloys. This work also deals with the correlation between the microstructure and resulting mechanical properties for the case extruded profiles. (orig.)

  8. Adsorption, regeneration and reuse of activated carbon for elimination of COD from municipal waste water. Final report. Untersuchungen zur Aktivkohle-Adsorption, -Regeneration und Wiederverwendung beim Einsatz zur Elimination des CSB aus kommunalem Abwasser. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Sekoulov, I.; Holst, H.J.

    1994-02-01

    One practicability to reduce COD-loadings of secondary effluents is the activated carbon fixed bed-process. In this project activated carbons (GAC) of different raw products (peat, wood, coal) were loaded with filtrated municipal waste water (mean COD-concentration: 60 mg CSB/L). After the break-through of adsorption-colums, the carbon was regenerated by means of superheated steam (optimal conditions: [theta]=300 C, pressure=2 bar, thermal energie=10 KW). Regeneration experiments demonstrated, that the results of steam-treatment of GAC is independent in respects to the preloading of activated carbons and the raw products. The mass of COD, detected in the condensed (liquid) steam-phase, always was in quantity about 10% of the further COD adsorbed to the GAC. Gaseous reaction products could not evaluated by means of the experimental design. But former perculation cycles of steam-treated carbons and measurments of the specific area (BET-method) indicated, that the adsorption-capacity of regenerated GAC seams to be in the same quantity, than unloaded carbons. Measurements (GC/MS) of single organic components showed, that humic-substances are catalysed at steam temperatures about 300 C. It seams, that chlorinated hydrocarbons could formed by means of this regeneration method. BOD experiments demonstrated, that substances of the steam-treatment could be biological degraded about 50% to 60%. (orig.)

  9. Industrie 4.0. Standort Deutschland im internationalen Kontext: Vortrag gehalten beim 70. Deutschen Betriebswirtschafter-Tag, Digitalisierung, Vernetzung und disruptive Geschäftsmodelle - Betriebswirtschaftliche Implikationen des wirtschaftlichen Wandels, 28./29. September 2016, Düsseldorf

    OpenAIRE

    Bauernhansl, Thomas

    2016-01-01

    Der Vortrag "Industrie 4.0: Standort Deutschland im internationalen Kontext" behandelt folgende Themenkomplexe: - Internationaler Vergleich - Der Wettlauf um die Wertschöpfunghat begonnen - Digitale Transformation - Wo steht Deutschland international?

  10. Influence of the spray characteristics of a piezo-A-nozzle on the inflammation at spray guided combustion processes; Einfluss der Spraycharakteristik einer Piezo-A-Duese auf die Entflammung beim strahlgefuehrten Brennverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Breuninger, Tobias; Schmidt, Juergen [Magdeburg Univ. (DE). Inst. fuer Stroemungstechnik und Thermodynamik (ISUT); Hese, Martin; Tschoeke, Helmut [Magdeburg Univ. (DE). Inst. fuer Mobile Systeme (IMS); Kufferath, Andreas [Robert Bosch GmbH, Schwieberdingen (Germany); Altenschmidt, Frank [Daimler AG, Stuttgart (Germany)

    2011-07-01

    The spray-guided combustion process offers a significant potential for improvement on the fuel consumption in partial-load engine operation. Due to the very close positioning of the injector to the spark plug, there is only very little time for the fuel mixture generation which leads to the presence of still liquid fuel particles next to already evaporized one. Furthermore the fuel-mixture generation is primarily driven by the dynamics of the fuel spray. In this article the spray characteristics of a Piezo-A-injector under pressure-chamber conditions as well as the combustion behavior on a one-cylinder test motor are analyzed. The global spray dispersion is analyzed using high-speed visualization while laser-optical measurements are used to observe the ignition-area. The mean diameter as well as the velocity of fuel droplets are determined using the phase-doppler-anemometry (PDA). An extinction-measuring methodology is used to quantify the liquid fuel particles. Analyzing the evaluated misfire-rate as a function of the spray-attributes allows for rating the spray-sections according to their ignition behavior. (orig.)

  11. Accident or maltreatment? Radiographic X-ray patterns in non-accidental trauma. The concept of sentinel injuries; Unfall oder Misshandlung? Radiologische Befunde beim nichtakzidentiellen Trauma. Das Konzept der ''sentinel injuries''

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, F.W.; Sorge, I.; Roth, C. [Uniklinikum Leipzig AoeR, Abteilung fuer Kinderradiologie, Leipzig (Germany); Gosemann, J.H. [Universitaetsklinikum Leipzig, Uniklinikum Leipzig AoeR, Klinik und Poliklinik fuer Kinderchirurgie, Leipzig (Germany)

    2016-05-15

    The focus of this review article is on child abuse and the radiographic pattern of X-ray findings. The radiologist should be able to recognize typical injuries resulting from child abuse. In some cases the findings are highly specific for abuse and these include metaphyseal corner fractures of the long bones in children aged up to 24 months. In other cases the fractures are not specific but highly indicative of child abuse: rib fractures, for example can be associated with child abuse in more than 50 % of the cases; however, maltreatment is difficult to diagnose without taking the entire pattern of skeletal findings into consideration so that a radiological screening of the entire skeleton is often necessary. The concept of sentinel injuries might be helpful for deciding in which cases a complete skeletal screening should be performed. In the age group up to 24 months old a complete skeletal status (with some exceptions) is recommended if one of the three sentinel injuries of rib fractures, intracranial bleeding and abdominal trauma is present. (orig.) [German] Die Kindesmisshandlung und ihre radiologischen Befundmuster sind Gegenstand dieser Uebersicht. Der Radiologe sollte in der Lage sein, typische Verletzungen als Misshandlungsfolge zu erkennen. In Einzelfaellen ist der Befund hochspezifisch fuer eine Misshandlung. Hierzu zaehlen z. B. metaphysaere Kantenabsprengungen an den langen Roehrenknochen bei bis 24 Monate alten Kindern. In anderen Faellen sind die Frakturen nicht spezifisch, aber hochsensitiv fuer das Vorliegen einer Misshandlung, z. B. bei Rippenfrakturen, die in ueber 50 % der Faelle mit einer Misshandlung assoziiert sein koennen. Die Misshandlung kann allerdings oft nur aus der Zusammenschau der unterschiedlichen Befunde, also nach Beurteilung des gesamten Skelettstatus, diagnostiziert werden. Fuer die Entscheidung, in welchen Faellen ein kompletter Skelettstatus angefertigt werden sollte, stellt sich das Konzept der ''sentinel injuries'' als hilfreiches Tool heraus. In der Altersgruppe bis 24 Monate wird hierbei (mit Ausnahmen) ein kompletter Skelettstatus bei den 3 ''sentinel injuries'' Rippenfrakturen, intrakranielle Blutung und Abdominaltrauma empfohlen. (orig.)

  12. Combined intraoperative and external irradiation of the celiac artery in the rabbit: Effects on gastric mucosal blood flow; Kombinierte intraoperative und externe Bestrahlung der Arteria coeliaca beim Kaninchen: Auswirkungen auf die Durchblutung der Magenschleimhaut

    Energy Technology Data Exchange (ETDEWEB)

    Doerr, W. [Universitaetsklinikum Carl Gustav Carus, Dresden (Germany). Klinik und Poliklinik fuer Strahlentherapie]|[GSF-Inst. fuer Strahlenbiologie, Oberschleissheim (Germany); Kallfass, E. [GSF-Inst. fuer Strahlenbiologie, Oberschleissheim (Germany); Berg, D. [GSF-Inst. fuer Strahlenbiologie, Oberschleissheim (Germany); Kummermehr, J. [GSF-Inst. fuer Strahlenbiologie, Oberschleissheim (Germany)

    1996-12-01

    Aim: To demonstrate changes in gastric mucosal blood flow caused by intraoperative radiotherapy of the celiac artery combined with external radiotherapy of the upper abdomen in a rabbit model. The study was designed to identify a possible correlation between a radiation-induced reduction in mucosal blood flow and the induction of gastric ulcer. Material and Method: Intraoperative radiation doses of 0 or 30 Gy were given to the celiac artery in rabbits. After a delay of 14 days external radiotherapy of the upper abdomen with 3x4 Gy/week to a maximum total dose of 40 Gy was initiated. Gastric mucosal blood flow was assessed by intraventricular injection of radioactively-labelled microspheres (15 {mu}m) followed by measurement of radioactivity in the mucosa. The injections were performed at various time intervals between 2 and 63 days after intraoperative radiation. Results: Intraoperative radiotherapy, including sham-intraoperative radiation, resulted in a transitory reduction of mucosal blood flow by about 50% of the control value on day 7. After a temporary recovery by day 14, a marked and permanent reduction in blood flow was assessed after week 6. This time corresponds to the time of development of gastric ulcer. Conclusions: A relationship between the time of ulcer development and of reduced gastric mucosal blood flow was observed after combined intraoperative and external radiotherapy. The mechanical component of intraoperative treatment has to be emphasized. Reduced blood flow was also seen after intraoperative radiotherapy alone, without an induction of ulcer by this treatment. Hence additional mucosal damage by external radiation must be present for the induction of gastric ulcer. (orig.) [Deutsch] Ziel: Untersuchung der Veraenderungen der Magenschleimhautdurchblutung am Kaninchen als Folge einer kombinierten intraoperativen Bestrahlung der Arteria coeliaca und externen Bestrahlung des Oberbauchs. Durch diesen Ansatz sollte ein moeglicher Zusammenhang zwischen einer strahleninduzierten Minderdurchblutung und der Genese von Magenulzerationen dargestellt werden. Material und Methode: Die intraoperative Bestrahlung der Arteria coeliaca erfolgte mit 0 bzw. 30 Gy. Nach einer Pause von 14 Tagen wurde eine externe Bestrahlung des Oberbauches mit 3x4 Gy/Woche bis zu einer Gesamtdosis von 40 Gy angeschlossen. Die Messung der Durchblutung der Magenschleimhaut wurde mittels intraventrikulaerer Injektion radioaktiv markierter Mikrophaeren (15 {mu}m) und Bestimmung der Aktivitaet in der Magenschleimhaut durchgefuehrt. Diese Messungen erfolgten zu verschiedenen Zeitpunkten zwei bis 63 Tage nach intraoperativer Bestrahlung. Ergebnisse: Die intraoperative Bestrahlung, auch die Scheinbestrahlung, fuehrt zu einer transienten Verminderung der Schleimhautdurchblutung bis zu etwa 50% des Normalwertes an Tag 7. Nach einer voruebergehenden Erholung bis zu Tag 14 tritt ab der sechsten Woche eine deutliche und anhaltende Minderdurchblutung ein. Dieser Zeitraum deckt sich mit dem Termin der Ulkusentstehung. Schlussfolgerungen: Es besteht ein zeitlicher Zusammenhang zwischen der Ausloesung von Magenulzerationen und eine Reduktion der Schleimhautdurchblutung durch kombinierte intraoperative und externe Strahlentherapie. Hierbei ist die mechanische Komponente der intraoperativen Radiotherapie besonders hervorzuheben. Die reduzierte Durchblutung laesst sich auch nach alleiniger intraoperativer Radiotherapie nachweisen, ohne dass hier jedoch Ulzera auszuloesen sind. Eine zusaetzliche direkte Schleimhautschaedigung durch die externe Bestrahlung ist somit fuer die Ausloesung von Magenulzerationen von Bedeutung. (orig.)

  13. Maximizing the CO{sub 2} separation in the Oxyfuel coal-fired process with cryogenic air separation plant; Maximierung der CO{sub 2}-Abtrennung beim kohlebefeuerten Oxyfuel-Prozess mit kryogener Luftzerlegungsanlage

    Energy Technology Data Exchange (ETDEWEB)

    Dickmeis, Jens

    2015-07-01

    In this work the influence of a maximised carbon capture rate on the overall process of an Oxyfuel coal-fired power plant is evaluated. The capture rate is increased by implementing an additional capture process as a complement to the partial condensation process. This additional process can either be a membrane process or a pressure swing adsorption. The processes are evaluated with commercial modelling tools.

  14. MRI, CT, and sonography in the preoperative evaluation of primary tumor extension in malignant pleural mesothelioma; MRT, CT und Sonographie in der praeoperativen Beurteilung der Primaertumorausdehnung beim malignen Pleuramesotheliom

    Energy Technology Data Exchange (ETDEWEB)

    Layer, G.; Steudel, A.; Schild, H.H. [Radiologische Universitaetsklinik Bonn (Germany); Schmitteckert, H.; Tuengerthal, S.; Schirren, J. [Thoraxklinik Heidelberg-Rohrbach (Germany); Kaick, G. van [Deutsches Krebsforschungszentrum Heidelberg (Germany). Schwerpunkt fuer Onkologische Diagnostik und Therapie

    1999-04-01

    Purpose: Evaluation of the diagnostic value of the imaging modalities computed tomography (CT), magnetic resonance imaging (MRI), and thoracic sonography in the preoperative staging of malignant pleural mesothelioma. Results: The accuracy rates for CT were 85%, 98%, 83%, 73%, 71%, and 83%. MRI had an accuracy of 71%, 92%, 71%, 83%, 71%, and 96%, the thoracic ultrasound examinations of 76%, 63%, 51%, 60%, 71% and 89%. Conclusions: According to these results CT remains the method of choice in the preoperative assessment of T-stage of malignant pleural mesothelioma. MRI is of nearly the same value, but is not a must. Sonography may be supplementary method for operation planning. (orig./AJ) [Deutsch] Ziel: Evaluation der diagnostischen Wertigkeit der Schnittbildverfahren MRT, CT und Sonographie in der praeoperativen Diagnostik des Pleuramesothelioms. Ergebisse: Die Treffsicherheiten betrugen fuer die genannten anatomischen Regionen im CT 85%, 98%, 83%, 73%, 71%, und 83%, im MRT 71%, 92%, 71%, 83%, 71% bzw. 96%, waehrend sich fuer die thorakale Ultraschalluntersuchung Treffsicherheiten von 76%, 63%, 51%, 60%, 71% und 89% errechneten. Schlussfolgerungen: Die CT bleibt damit das Verfahren erster Wahl in der praeoperativen Diagnostik des malignen Pleuramesothelioms. Eine unbedingte Forderung nach praeoperativer Durchfuehrung einer MRT-Untersuchung ergibt sich nach der vorliegenden Studie nicht. Die Sonographie des Thorax und oberen Abdomens liefert einen wichtigen ergaenzenden Beitrag bei der Planung der Operation des malignen Pleuramesothelioms. (orig./AJ)

  15. Progress in biogas. Biogas production from agricultural biomass and organic residues. Pt. 1 and 2. Proceedings (oral presentations and poster presentations); Fortschritt beim Biogas. Biogas aus landwirtschaftlicher Biomasse and organischen Reststoffen. T. 1 und 2. Tagungsband. Vortraege and Poster

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Within the International Conference ''Progress in Biogas - Biogas production from agricultural biomass and organic residues'' at the University Hohenheim (Stuttgart, Federal Republic of Germany) from 18th to 21st September, 2007, the following lectures were held: (1) Global relevance and potential of bioenergy for regional development; (2) Biogas electricity for France feed-in tariff and some other things to know before entering French market; (3) Policy drivers and future prospects for on-farm anaerobic digestion in Northern Ireland; (4) Biogas in Belgium, a swot analysis; (5) Status and prospects of biogas energy use in Ukraine; (6) Recent developments in Chinese agricultural biogas production; (7) Opportunities for agricultural based biogas systems in the province of Ontario, Canada; (8) Pre-treatment and digestion of separated collected household waste in Sweden; (9) To the problem of monitoring measures and prophylaxis measures with the utilization of organic residual substances in biological gas facilities from hygienic view; (10) Fermenting residues from biological gas facilities - nutrients and pollutants, possibilities of application in the agriculture; (11) Treatment and utilization of fermentation residues; (12) Potential of residual gas of NaWaRo feeded biogas plants in Baden-Wuerttemberg; (13) Operating analytics of biogas plants to improve efficiency and to ensure process stability; (14) The potential of biogas and electric power production from subproducts in the sugar and alcohol industries by the application of anaerobic digestion; (15) Co-digestion plant in dairy cattle farm in Emilia Romagna region (Italy); (16) Facing operational problems in a biodigeser in Yuvientsa - Amazonian Region of Ecuador; (17) Biogas plant instead of milk cow - payment and occupation with the use of grassilage; (18) Biogas in ecologic agriculture - experiences from 3 years of fermentation of grass-clover ley; (19) Combined solar-biogas basis for the population social level raising; (20) Production of biogas with grassilage - when is this profitable?; (21) Biogas: Opportunity or threat for the agriculture; (22) Country report Cameroon; (23) Fruit wastes bioconversion for anaerobic co-digestion with pig manure. Process development for the recycling in decentralised farm scale plants; (24) A parameter estimation protocol for anaerobic digestion; (25) BABIU - a new process for production of biomethane from biogas; (26) Dry fermentation of organic wastes; (27) Biological production of hydrogen from agricultural raw materials and residual materials with subsequent methane step; (28) Two phase continuous digestion of solid manure on-farm; (29) Investigation and development of an optimal process of fermenentation of grassilage by a two-phase process operation; (30) Technical weak points at biogas plants - occasions, effects and measures; (31) Plant safety - a substantial component according to permission and availability of biogas plants; (32) Analysis and evaluation of alternative concepts of the energetic use of biogas and other biogenous gases; (33) Gas-side bundling of some biogas plants, gas processing and gas feeding; (34) Technical and economical demands to biogas production for feeding into the HD grid; (35) Thinking about the use of biogas from the view of heat utilization - development of concepts for bioenergy villages; (36) Biogas cogeneration plant in the practice: Behaviour of emission and performance; (37) The future of biogas in Europe: Visions and targets until 2020; (38) Two-stage dry-wet-fermentation - optimization of the hydrolysis for a short space-time-yields; (39) Manure-free fermentation of renewable raw materials; (40) Quantification of different microbial population in termophilic-dry anaerobic digestion; (41) The use of hydrolytic enzymes in agricultural biogas production; (42) A contribution to mobile online gas diagnostics according to the efficiency of biogas plants; (43) Genetic 'fingerprints' to characterize microbial communities during organic overloading and in large-scale biogas plants; (44) Codigestion of olive mill wastewater and swine manure using UASB bioreactors for biogas production; (45) Addition of fibre cracking enzymes according to the enhancement of yield of biogas of energy plants; (46) On-site consulting of operators of biogas plants; (47) Cooperation between energy economy and agriculture at Erdgas Suedwest (Concept of biogas upgrading as a cooperation perspective for gas utilities and agriculture); (48) Cooperative operator models for biogas plants with utilization of heat in municipal sites - a common community of agriculturists and an experienced contractor; (49) Risk and insurance management for biogas plants; (50) Experiences in the german-chinese market of biogas and utilization of CDM projects.

  16. 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...

  17. 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

  18. 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

  19. 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...

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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...

  6. 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.

  7. Can the 'Assessment Drives Learning' effect be detected in clinical skills training? - Implications for curriculum design and resource planning [Der “Assessment Drives Learning”-Effekt beim Training klinisch-praktischer Fertigkeiten - Implikationen für die Curriculumsgestaltung und die Planung von Ressourcen

    Directory of Open Access Journals (Sweden)

    Buss, Beate

    2012-11-01

    Full Text Available [english] Purpose: The acquisition of clinical-technical skills is of particular importance for the doctors of tomorrow. Procedural skills are often trained for the first time in skills laboratories, which provide a sheltered learning environment. However, costs to implement and maintain skills laboratories are considerably high. Therefore, the purpose of the present study was to investigate students’ patterns of attendance of voluntary skills-lab training sessions and thereby answer the following question: Is it possible to measure an effect of the theoretical construct related to motivational psychology described in the literature – ‘Assessment drives learning’ – reflected in patterns of attendance at voluntary skills-lab training sessions? By answering this question, design recommendations for curriculum planning and resource management should be derived.Method: A retrospective, descriptive analysis of student skills-lab attendance related to voluntary basic and voluntary advanced skills-lab sessions was conducted. The attendance patterns of a total of 340 third-year medical students in different successive year groups from the Medical Faculty at the University of Heidelberg were assessed.Results: Students showed a preference for voluntary basic skills-lab training sessions, which were relevant to clinical skills assessment, especially at the beginning and at the end of the term. Voluntary advanced skills-lab training sessions without reference to clinical skills assessment were used especially at the beginning of the term, but declined towards the end of term.Conclusion: The results show a clear influence of assessments on students’ attendance at skills-lab training sessions. First recommendations for curriculum design and resource management will be described. Nevertheless, further prospective research studies will be necessary to gain a more comprehensive understanding of the motivational factors impacting students’ utilisation of voluntary skills-lab training in order to reach a sufficient concordance between students’ requirements and faculty offers, as well as resource management.[german] Zielsetzung: Die Vermittlung klinisch-praktischer Fertigkeiten ist von entscheidender Bedeutung für die Berufsfähigkeit angehender Ärzte. Prozedurale Fertigkeiten werden dabei häufig zu allererst in sogenannten Skills-Labs trainiert, die eine geschützte Lernumgebung gewährleisten. Die Implementierung und auch Pflege von Skills-Labs stellt allerdings eine nicht geringfügige finanzielle Herausforderung dar. Aus diesem Grund hat sich die vorliegende Arbeit zum Ziel gesetzt, die Besuchsfrequenzen und –muster im Rahmen freiwilliger Skills-Lab-Unterrichtseinheiten zu untersuchen, um folgende Frage zu beantworten: Kann der in der Literatur beschriebene, motivationspsychologische Effekt des “Assessment drives learning” festgestellt werden und spiegelt sich dieser in dem Besuchsverhalten von Studierenden in freiwilligen Skills-Lab-Unterrichtseinheiten wider? Ausgehend von den Studienergebnissen sollen Empfehlungen für die Curriculumsplanung und das Ressourcenmanagement abgeleitet werden.Methode:. Eine retrospektive, deskriptive Analyse studentischen Inanspruchnahmeverhaltens sowohl von freiwilligen „Basic“- als auch „Advanced“ Skills-Lab-Unterrichtseinheiten wurde durchgeführt. Hierzu wurden Teilnahmemuster von 340 Medizinstudierenden des dritten Studienjahres verschiedener Jahrgänge an der Medizinischen Fakultät Heidelberg näher untersucht.Ergebnisse: Die Studierenden zeigten besonders zu Beginn und am Ende des Semesters eine Präferenz für die Teilnahme an freiwilligen “Basic“ Skills-Lab-Unterrichtseinheiten, die für die klinisch-praktische Prüfung relevant sind. Freiwillige “Advanced“ Skills-Lab”-Unterrichtseinheiten ohne Bezug zur klinisch-praktischen Prüfung wurden vor allem zu Beginn des Semesters genutzt, mit einem Rückgang der Besuche gegen Ende des Semesters.Fazit: Die Ergebnisse zeigen einen deutlichen Einfluss klinisch-praktischer Prüfungen auf die studentischen Teilnahmen an Skills-Lab-Unterrichtseinheiten. Empfehlungen für die Planung des Curriculums und das Ressourcenmanagement werden dargestellt. Weitere, prospektive Studien sind erforderlich, um ein umfassenderes Verständnis motivationaler Faktoren zu entwickeln, die Studierende dazu veranlassen, freiwillige Skills-Lab-Unterrichtseinheiten zu besuchen. Damit kann eine noch erfolgreichere Abstimmung zwischen studentischen Anforderungen und Fakultätsangeboten sowie ein effizientes Ressourcenmanagement erzielt werden.

  8. Basic concepts and estimated maximum possible employment effects of a consistent development of renewable energy systems in Nordrhein-Westfalen. 1st technical report; Konzeptionelle Grundlagen und Abschaetzung zukuenftig maximal moeglicher Bruttobeschaeftigungseffekte beim Ausbau erneuerbarer Energiesysteme in Nordrhein-Westfalen. 1. Technischer Fachbericht

    Energy Technology Data Exchange (ETDEWEB)

    Mohr, M.; Ziegelmann, A.; Unger, H.

    1995-12-01

    In the First Technical Report the fundamental ideas for the realization of this project are presented and the future possible maximum gross employment effects of an expansion of renewable energy systems in North-Rhine-Westphalia with consideration of the present-day cost structure are quantified in an initial stage. In this connection gross employment effects are defined as exclusive positive job effects without consideration of possible negative employment effects on the basis of less investments in other sectors of the economy. Based on a subdivided presentation of the intended course of the project and a formulation of its main objectives, a detailed description of the theoretical background of the applied methods of input-output analysis is provided. After the presentation of some different methods and the necessary assumptions, the analysis takes the so-called `Keynesian income multiplier` into account to accommodate the effects of an increase in national income. To use a known investment distribution, grouped in 21 sub-divisions according to categories of applications, within the scope of an input-output-analysis, the investments are converted. After the determination of the matrices, necessary to quantify employment effects, the maximum possible gross effects concerning the future job market of the Federal Republic of Germany will be assessed with consideration of the fluctuations in productivity on sector level. A total of 700.000 new jobs can be expected, of which about 27% are due to the increase of personal disposable income and the resulting rise in consumer spending respectively. (orig./UA) [Deutsch] Im vorliegenden 1. Technischen Fachbericht werden konzeptionelle Grundlagen zur Realisierung des Vorhabens eroertert und es wird eine erste Abschaetzung der potentiellen Bruttobeschaeftigungswirkungen eines Ausbaus erneuerbarer Energiesysteme in Nordrhein-Westfalen durchgefuehrt. Unter Bruttobeschaeftigungswirkungen werden dabei ausschliesslich positive Arbeitsplatzwirkungen ohne Beruecksichtigung moeglicher negativer Beschaeftigungseffekte aufgrund von Minderinvestitionen in anderen Wirtschaftsbereichen verstanden. Im Anschluss an die gegliederte Darstellung des geplanten Projektablaufs und Formulierung der einzelnen Zielsetzungen wird die fuer die Untersuchung notwendige Methode der Input-Output-Analyse vorgestellt. Neben der Erlaeuterung verschiedener Modelle und der notwendigen Annahmen wird die gewaehlte Analysemethode um den sogenannten `Keynes`schen Einkommensmultiplitkator` erweitert, um auch Auswirkungen eines erhoehten privaten Konsums zu beruecksichtigen. Eine nach 21 verschiedenen Nutzungsarten gegliederte Investitionsverteilung wird daran anschliessend zusammengefasst und fuer die Verwendung im Rahmen einer Input-Output-Analyse umgerechnet. Nach der Bestimmung der fuer die Quantifizierung der Beschaeftigungswirkungen notwendigen Berechnungsmatrizen koennen schliesslich die fuer den bundesdeutschen Arbeitsmarkt zu erwartenden Bruttobeschaeftigungseffekte in erster Naeherung ermittelt werden, wobei sektorielle Produktivitaetsaenderungen bis zum Zeitpunkt der Investitionen beruecksichtigt werden. Es ergeben sich insgesamt rund 700.000 neue Arbeitsplaetze, von denen etwa 27% auf die Erhoehung der verfuegbaren Einkommen bzw. den damit verbundenen Anstieg des privaten Konsums zurueckzufuehren sind. (orig./UA)

  9. Studies for reconstruction efficiency and background measurements of {tau} lepton identification in Z {yields} {tau}{tau} decays in data of the ATLAS experiment; Studien zur Messung von Rekonstruktionseffizienz und Untergrund der {tau}-Lepton-Identifikation im Zerfall Z {yields} {tau}{tau} beim ATLAS-Experiment aus Daten

    Energy Technology Data Exchange (ETDEWEB)

    Johnert, Sebastian

    2008-11-15

    In this diploma thesis two methods are presented, by which {tau} leptons shall be studied in the future data of the ATLAS experiment. The first part is formed by the determination of misidentification rates of jets from QCD 2-jet events as {tau} particles. The second part is the development of a method for the determination of the {tau} reconstruction and identification efficiency relatively to the {mu} efficiency. In this connection invariant masses from Z{yields}ll events are determined, the masses from Z{yields}{tau}{tau} events compared with those from Z{yields}ee and Z{yields}{mu}{mu}, {tau} efficiencies averaged over all ranges and in different {eta} ranges calculated as well as a mehtod for the determination of {tau} efficiencies in different transverse-momentum ranges presented. Furthermore an improved estimation of the QCD background is performed and the behaviour of the {tau} efficiency under regardment of the trigger studied. [German] In dieser Diplomarbeit werden zwei Methoden vorgestellt, mit denen {tau}-Leptonen in den zukuenftigen Daten des ATLAS-Experiments untersucht werden sollen. Den ersten Teil bildet die Bestimmung von Missidentifikationsraten von Jets aus QCD-2-Jet-Ereignissen als {tau}-Leptonen. Der zweite Teil ist die Entwicklung einer Methode zur Bestimmung der {tau}-Rekonstruktions und -Identifikationseffizienz relativ zur {mu}-Effizienz. In diesem Zusammenhang werden invariante Massen aus Z {yields} ll-Ereignissen bestimmt, die Massen aus Z {yields} {tau}{tau}-Ereignissen mit denen aus Z {yields} ee und Z {yields} {mu}{mu} verglichen, {tau}-Effizienzen gemittelt ueber alle Bereiche und in verschiedenen {eta}-Bereichen berechnet sowie eine Moeglichkeit zur Bestimmung von {tau}-Effizienzen in unterschiedlichen Transversalimpulsbereichen vorgestellt. Des Weiteren wird eine verbesserte Abschaetzung des QCD-Untergrunds vorgenommen und das Verhalten der {tau}-Effizienz unter Beruecksichtigung des Triggers untersucht. (orig.)

  10. Was Hänschen nicht lernt, lernt Hans durch Weiterbildung: Die Bibliothek eines Gesundheitsunternehmens als kompetenter Partner beim lebenslangen Lernen / What you do not learn as a child, you will learn through further education: The library of a health enterprise as a competent partner in lifelong learning

    Directory of Open Access Journals (Sweden)

    Schröder, Alexander

    2008-12-01

    Full Text Available The traditional wise saying "you can’t teach an old dog new tricks“ has long been outdated. The most important production factor in the establishing of a “health” service is no doubt the human capital. Well trained, highly qualified people who are able to learn further are needed in order to provide the patients with a service at its highest quality. This means, that the success of an enterprise in the health market resides in its ability to make it possible for its employees to acquire a lifelong education. The strategy of the HELIOS hospitals has thus been to increase the knowledge of its employees and to provide the optimal conditions for the appropriation of further knowledge. The aim is to gather the existing knowledge structures of the concern and to make it easily available on a platform. The central library of the concern is used as an example to illustrate how the library services can also be brought into the knowledge landscape of a health concern and how they could be linked with strategic partners in the field of knowledge.

  11. 20 January 2011 - Hessischer Minister für Bundesangelegenheiten und Bevollmächtigter des Landes beim Bund, Hessen, Germany M. Boddenberg signing the guest book with CERN Director-General R. Heuer and Head of International Relations F. Pauss; in the ALICE surafce exhibition and underground experimental area with P. Braun-Munzinger, V.Lindenstruth and Adviser R. Voss.

    CERN Multimedia

    Maximilien Brice

    2011-01-01

    Michael Boddenberg, Hessian Minister for Federal Affairs and Representative of Hessen in the Federal Government, visited CERN on 20 January. His tour included the ALICE experiment, the LHC tunnel, the CERN Computer Centre and CERN Control Centre.

  12. Material science studies on the formation and growth of pores in the production and creep of single-crystal nickel-based superalloys; Werkstoffwissenschaftliche Untersuchungen zur Bildung und zum Wachstum von Poren bei der Herstellung und beim Kriechen einkristalliner Nickelbasis-Superlegierungen

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Heinrich Joergen

    2015-02-20

    Single crystal Ni-base superalloys (SX) are used for blades in fossil fuel fired power plants and aero engines. Here they have to withstand high mechanical stresses at temperatures close to their melting point. The blades are manufactured by a Bridgman type of directional solidification, followed by a multiple step heat treatment. During the dendritic solidification, pores can form due to undissolved gas, macroshrinkage by inadequate gating and microshrinkage caused by poor feeding between dendrites. Additional pores can form in the interdendritic regions during the multiple step heat treatment which follows solidification. It is believed, that these pores form on the basis of a Kirkendall effect which accounts for the fast diffusion of Al atoms away from microstructural regions with non-equilibrium γ/γ' eutectic. During creep, pores can grow and change their shapes. It has been shown, that during creep in the high temperature / low stress regime new pores form, which are smaller than those pores that can be found in the undeformed material. In the present work, the evolution of porosity in the single crystal Ni-base superalloy ERBO/1 during processing and creep is investigated. Quantitative microstructural analyses were performed on metallographic cross sections. Sampling fields of 4500 x 1000 μm{sup 2} were investigated by using a combination of scanning electron microscopy with quantitative image analysis. Interrupted creep tests with a miniature tensile creep specimen were performed with load direction parallel to left angle 100 right angle and left angle 110 right angle direction, respectively. Pore parameters (area, perimeter, Feret's diameter) for individual pores were obtained and two form factors were introduced. The evolution of the compiled statistical distributions of pore parameters and shape factors are discussed. The results are compared to recent findings by Link et al., 2006 and Maelzer et al., 2007. In the present study it was shown that the quantitative metallographic approach is able to qualitatively reproduce all important details of porosity evolution, which were identified by Link et al. using synchrotron radiation. Pores which the metallographic method detects directly after casting appear in a low density (17 pores/mm{sup 2}) and show very broad log-normal size distributions. Solidification pore sizes (in terms of pore areas on the metallographic cross section) can vary from 2 to 200 μm{sup 2}. During the multiple step homogenization heat treatment of ERBO/1, new pores form and the pore density increases to 34 pores/mm{sup 2}. Simultaneously, one can detect an increase in average pore sizes. The size distribution of pores shifts to higher values. During high temperature and low stress creep, new small pores form (pore density increases to values ranging from 139 pores/mm{sup 2} to 193 pores/mm{sup 2}) and the size distributions evolve from unimodal (as-cast and heat treated material state, prior to creep) to bimodal (early stages of creep). The present study furthermore represents the missing link between the synchrotron studies of Link et al., 2006 regarding the evolution of porosity and the metallographic investigations of Maelzer et al., 2007, who investigated the role of pores with respect to creep rupture. The advantage of the present study is that both, the investigation of porosity evolution and the investigation on the role of pores on creep rupture, were performed with one alloy at the same temperature/stress conditions. It has been shown, that the distribution of pores in the material and the alignment of pores relative to the loading direction are important. Maelzer et al. showed, that creep specimens with pores aligned parallel to the loading direction ([001] specimens) showed higher rupture strains compared to specimens, where pores were aligned perpendicular to the loading direction ([110] specimens). These findings have been confirmed by the present study. The metallographic results, presented in this work, suggest that creep rupture is associated with the formation of microcracks at larger solidification and heat treatment pores, which can grow, interlink and initiate final creep rupture. Creep pores appear, due to their size, to be less important with respect to creep rupture. The alignment of pores along the dendrites and their relative position to the loading direction are the key factors, that can limit creep life. Finally, the influence of the crystallographic orientation on the evolution of porosity was investigated. It has been shown, that there are no fundamental differences of the size and shape factor distributions, when [001] and [110] oriented specimens are compared, but there are differences in the appearance of crystallographic facets and an orientation dependency of pore growth is suggested.

  13. In competition for the best energy-plus building. German teams score at Solar Decathlon Europe 2012 with architecture, engineering and marketing opportunities; Im Wettkampf um das beste Plusenergiehaus. Deutsche Teams punkten beim Solar Decathlon Europe 2012 mit Architektur, Konstruktion und Vermarktungschancen

    Energy Technology Data Exchange (ETDEWEB)

    Gintars, Dorothee

    2012-07-01

    For the competition, 18 interdisciplinary student teams from all over the world developed and built houses that generate at least as much energy - using solar systems - as they consume. They were supported by their universities, researchers and companies. From Germany, students took part from Hochschule Konstanz University of Applied Sciences (HTWG) and RWTH Aachen University, supported with government energy research funds. Whereas the design from Constance has perfected a modular construction system, with the Aachen team the focus is on recycling. After ten disciplines, the two homes achieved 4{sup th} and 5{sup th} places. (orig.)

  14. Studies on the widening of the variation of the fatty acid pattern in flax (Linum usitatissimum L. ) by means of interspecific hybridisation and in-vitro techniques. Untersuchungen zur Erweiterung der genetischen Variation des Fettsaeuremusters beim Lein (Linum usitatissimum L. ) mit Hilfe von Artkreuzungen und in vitro Techniken

    Energy Technology Data Exchange (ETDEWEB)

    Nickel, M.

    1993-01-01

    Oil flux genotypes with strongly divergent fatty acid compositions of the seed oil are vegetable raw materials of great interest to industrial users, notably to manufacturers of edible oils and dietetic products. Compared with the moderately variable fatty acid pattern of Linum usitatissimum that of wild forms shows a far greater scatter. The studies on the widening of the genetic variation of the fatty acid pattern in cultivated flax by means of interspecific hybridization and embryo cultures have revealed the possibilities offered by, and limits to, these methods. Optimisation of the embryo culture techniques have for the first time made it possible to regenerate plants from globular embryos obtained by interspecific hybridization between Linum usitatissimum and L. monogynum. (orig./EF)

  15. Impact of pretreatment variables on the outcome of {sup 131}I therapy with a standardized dose of 150 Gray in Graves` disease; Einfluss praetherapeutischer Variablen auf die Wirkung einer standardisierten {sup 131}J-Therapie mit 150 Gray beim Morbus Basedow

    Energy Technology Data Exchange (ETDEWEB)

    Pfeilschifter, J. [Heidelberg Univ., Radiologische Klinik (Germany). Abt. fuer Nuklearmedizin; Elser, H. [Medizinische Universitaetsklinik und Poliklinik Heidelberg (Germany). Abt. fuer Innere Medizin I; Haufe, S. [Medizinische Universitaetsklinik und Poliklinik Heidelberg (Germany). Abt. fuer Innere Medizin I; Ziegler, R. [Heidelberg Univ., Radiologische Klinik (Germany). Abt. fuer Nuklearmedizin; Georgi, P. [Medizinische Universitaetsklinik und Poliklinik Heidelberg (Germany). Abt. fuer Innere Medizin I

    1997-04-01

    Aim: We examined the impact of several pretreatment variables on thyroid size and function in 61 patients with Graves` disease one year after a standardized [131]I treatment with 150 Gray. Methods: FT3, FT4, and TSH serum concentrations were determined before and 1.5, 3, 6, and 12 months after therapy. Thyroid size was measured by ultrasound and scintigraphy before and one year after therapy. Results: One year after therapy, 30% of the patients had latent or manifest hyperthyroidism, 24% were euthyroid, and 46% had developed latent or manifest hypothyroidism. Age and initial thyroid volume were major predictors of posttherapeutical thyroid function. Thus, persistent hyperthyroidism was observed in 70% of the patients age 50 years and older with a thyroid size of more than 50 ml. With few exception, thyroid size markedly decreased after therapy. Initial thyroid size and age were also major predictors of posttherapeutical thyroid volume. Thyroid size normalized in all patients younger than 50 years of age, independent from initial thyroid size. Conclusion: Radioiodine treatment with 150 Gray causes a considerable decrease in thyroid size in most patients with Graves` disease. Age and initial thyroid volume are important determinants of thyroid function and size after therapy and should be considered in dose calculation. (orig.) [Deutsch] Ziel: Bei 61 Patienten mit einem Morbus Basedow haben wir den Einfluss praetherapeutischer Variablen auf die Funktion und das Volumen der Schilddruese ein Jahr nach einer {sup 131}J-Therapie mit 150 Gray untersucht. Methoden: FT3, FT4, und TSH wurden vor Therapie und eineinhalb, 3, 6 und 12 Monate nach Therapie gemessen. Das Schilddruesenvolumen wurde vor Therapie und ein Jahr nach Therapie sonographisch und szintigraphisch bestimmt. Ergebnisse: Ein Jahr nach Therapie waren 30% der Patienten latent oder manifest hyperthyreot, 24% euthyreot, und 46% latent oder manifest hypothyreot. Lebensalter und Ausgangsvolumen der Schilddruese waren die Hauptpraediktoren der posttherapeutischen Schilddruesenfunktion. Der Anteil an persistierenden Hyperthyreosen war bei aelteren Patienten mit einem Schilddruesenvolumen groesser 50 ml mit ueber 70% besonders hoch. Bei fast allen Patienten kam es zu einer deutlichen Verkleinerung der Schilddruese. Ausgangsvolumen und Lebensalter waren auch hier die Hauptpraediktoren der posttherapeutischen Schilddruesengroesse. Bei allen Patienten juenger als 50 Jahre kam es sogar unabhaengig von der Ausgangsgroesse zu einer Normalisierung des Schilddruesenvolumens. Schlussfolgerung: Eine Radiojodtherapie mit 150 Gray fuehrt bei den meisten Patienten mit einem Morbus Basedow zu einer deutlichen Verkleinerung der Schilddruese. Alter und initiales Volumen haben einen wesentlichen Einfluss auf die Funktion und Groesse der Schilddruese nach Therapie und sollten bei der Dosisfestlegung beruecksichtigt werden. (orig.)

  16. Analysis of the public debate on health hazards due to high-voltage transmission lines. Recommendations for the radiation protection related communication with respect of grid extension; Analyse des oeffentlichen Diskurses zu gesundheitlichen Auswirkungen von Hochspannungsleitungen. Handlungsempfehlungen fuer die strahlenschutzbezogene Kommunikation beim Stromnetzausbau

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Florian; Kuehne, Olaf; Jenal, Corinna; Sanio, Tina [Hochschule Weihenstephan-Triesdorf, Freising (Germany). Lehrgebiet Laendliche Entwicklung/Regionalmanagement; Langer, Kerstin [Hochschule Weihenstephan-Triesdorf, Freising (Germany). Lehrgebiet Kommunikation und Partizipation in der Landschaftsarchitektur; Igel, Michael [Hochschule fuer Technik und Wirtschaft des Saarlandes, Saarbruecken (Germany). Lehrgebiet Elektrische Energieversorgung und Gebaeudesystemtechnik

    2016-05-15

    With its phase-out of nuclear power generation and the expansion of renewably sourced energy, the German energy turnaround ('Energiewende') has radically changed existing power supply structures, with wide geographical repercussions. One aspect of this is changes to the national power grid. Existing networks are to be upgraded and new long-distance north-south power-lines built. This creates resistance and conflict. Commissioned by the Federal Office for Radiation Protection, and the Federal Ministry of the Environment, Nature Conservation, Building and Nuclear Safety, the research project entitled Analysis of public discourse on the health impacts of high-voltage power lines - recommendations for action in radiation-protection discourse related to the extension of the power grid starts precisely at the point of conflict. It first investigates from a discourse theory perspective how power grid extensions and possible health-related consequences are communicatively constructed, and what argumentation patterns dominate the discussion. From this it derives recommendations for action, with a focus on health politics information and discourse. Behind the research project stands a socio-constructivist discourse theory that sees 'social reality' not as a given but as a socially evolved entity, and its meanings, therefore, not as stable but as subject to change. The central mechanism for the communication of an objectivized social world is language. The analyses undertaken here of power grid extension are based on a methodological mix of quantitative and qualitative elements that facilitates both the differentiation of central issues and detailed examination of individual aspects. Analysis focuses on the discussion of health issues not only in the relevant literature and on civic initiative websites, but also in the first 50 Google hits, in articles from the Sueddeutsche Zeitung (SZ) and Focus, and in talk shows. The resultant discourse analysis highlights the decisive role played by different social systems and their specific logics in any evaluative judgment. While industry and politics argue from the technological and economic need for new long-distance power lines, and urge this as the basis for their legitimacy, citizens' initiatives base their objections on emotional and aesthetic grounds, rejecting the change to their domestic and social environment as a looming threat, with all its negative connotations. Plans are regularly criticized for their impact on landscape, nature conservation, local economies, tourism, and health. Citizens' initiatives almost unanimously cite health risks and fears in connection with electro/magnetic fields, while the advocates of grid extension - the Federal Network Agency and transmission system operators - take a variety of approaches to this matter. The Federal Network Agency generally marginalizes health issues, and does so in specialist language, or in terms that demand in-depth study. On the other hand Amprion GmbH, as one of the operators, uses language that is readily accessible to laypeople, and its explanations leave less room for doubt than do those of the Federal Network Agency. Amprion argues that it can fulfill its task within the existing legislative framework. Nevertheless, health issues are not the company's main concern. TenneT TSO GmbH takes a more comprehensive approach, and its statements are more readily understandable, even though they also tend to use specialist language, citing scientific studies and generally softening risk. Sound scientific results are so far notably lacking, but improved communication of the known pros and cons of this technology is also urgently required. Another consistent factor is the problematic light in which previous grid extension plans and implementation processes are typically set, and the massive civic protests to which this has at various times given rise. Transmission system operators should have learnt by now to involve citizen groups more actively in their extension plans: the desire for consultation is stronger and more vocal than it used to be. The Bavarian approach was different. The health impact of the plans was not ignored, but constituted only one among several other lines of argument, such as violation of the landscape, loss of 'home' environment, or economic impairment (especially a drop in property values - above all in the value of one's own property). In these contexts, electrosmog, electro/magnetic fields, and space charge clouds (corona discharges) become undispelled fears, or risks that are viewed as factually given rather than as 'under certain circumstances possible'. Against such opposition, to insist on the need for overhead power lines is viewed as morally depraved. In sum, the underlying need for grid extension and the technology involved on the one hand, and issues of landscape, natural environment, health, and local economies, as well as participation in the decision-making process on the other, form central fields of conflict to be negotiated at cognitive, emotional and aesthetic levels of discourse. For all these issues, recommendations geared to specific target groups can be drawn up. In accordance with the different logical systems of the protagonists, health issues in particular are approached differently, which suggests the need for a more forceful widening of perspectives. The information and communication materials produced so far by industry, politics and the grid extension lobby tends to hinder rather than help understanding of the issues by lay audiences. This state of affairs must be remedied if a cognitive dimension is to be introduced into arguments whose basis is as yet predominantly emotional and aesthetic. In this sense, a toolbox developed for professionals of the Federal Office for Radiation Protection provides a range of instruments for dealing with identified problems and situations within the conflict fields analyzed in this study.

  17. Prenatal, transplacental uptake of polychlorinated biphenyls and hexachlorobenzene in humans. Pt. 3.. Personal characteristics (gestational age, birth weight, maternal age, smoking habits of the parents) and geographic differences; Praenatale, transplazentare Uebertragung von polychlorierten Biphenylen und Hexachlorbenzol beim Menschen. T. 3. Personenbezogene Einflussfaktoren (Gestationsalter, Geburtsgewicht, muetterliches Alter, Tabakkonsum der Eltern) und geographische Unterschiede

    Energy Technology Data Exchange (ETDEWEB)

    Lackmann, G.M. [Duesseldorf Univ. (Germany). Zentrum fuer Kinderheilkunde

    2001-07-01

    It was the aim of the present study to investigate the influence of personal characteristics, like gestational age, birth weight, maternal age, smoking habits of the parents, and geographic origin, on the neonatal pollution with these harmful substances. Methods: Cord blood samples were taken from 200 full-term, healthy neonates born in Fulda or Duesseldorf, respectively, in 1998. The samples were immediately centrifuged, and serum was stored at-20 C up to analysis, which was performed in 1999. The parents must have lived life-long in each town and should never accidentally or at their working places have been exposed to high concentrations of PCBs or HCB. Six PCB congeners (28, 52, 101, 138, 153, and 180) and HCB were analysed with capillary gas-chromatography with electron capture detection. Results: We could demonstrate a statistically significant correlation between the prenatal uptake of PCBs and HCB and the gestational age of the newborns as well as the maternal age in the study group of 199 newborns (one child was excluded because of unusually high PCB values). Thereby, neonates born in the 42. week had 3.5-fold higher PCB values than children born in the 38. week, and newborns of a 50-year-old mother showed up to 500% higher values than children of a 20-year-old woman (p < 0.0001). A correlation with birth weight was not found. Furthermore, newborns of active smoking women exhibited significantly higher PCB and HCB values than children of passive smoking or non-smoking mothers. Prenatal uptake of PCBs was not different with regard to the geographic origin of the newborns, i.e. Fulda or Duesseldorf, whereas newborns from Duesseldorf showed about 62% higher HCB concentrations. (orig.) [German] Ziel der vorliegenden Untersuchung war es, den Einfluss personenbezogener Charakteristika, wie des Gestationsalters, des Geburtsgewichts, des muetterlichen Alters und des Tabakkonsums der Eltern, sowie geographischer Unterschiede auf die neonatale Schadstoffbelastung zu untersuchen. Methode: Es wurde von insgesamt 200 gesunden, reifen Neugeborenen, die 1998 entweder in Fulda oder in Duesseldorf geboren wurden, eine Nabelschnurprobe gewonnen. Die Eltern aller Kinder waren dabei zeitlebens in der betreffenden Stadt ansaessig und niemals beruflich oder akzidentell hohen PCB- oder HCB-Belastungen ausgesetzt. Das Serum wurde umgehend bei -20 C tiefgefroren; die Analysen wurden geschlossen und verblindet 1999 durchgefuehrt. Dabei wurden die sechs PCB-Kongenere 28, 52, 101, 138, 153 und 180 sowie HCB kapillar-gaschromatographisch mit ECD-Detektion bestimmt. Ergebnisse: Im Gesamtkollektiv (n = 199) - ein Kind wurde wegen ungewoehnlich hoher PCB-Konzentrationen von der Auswertung ausgeschlossen - fanden wir eine signifikante Korrelation zwischen der Schwangerschaftsdauer sowie dem muetterlichen Alter und der praenatalen Schadstoffakkumulation, wobei Kinder der 42. SSW um den Faktor 3,5 hoehere PCB-Konzentrationen aufwiesen, als Kinder der 38. SSW, und Neugeborene einer 50-jaehrigen Frau bis 500% hoehere PCB-Werte, als Kinder einer 20-jaehrigen Mutter (p < 0,0001). Ein Zusammenhang zum Geburtsgewicht bestand nicht. Ausserdem konnten wir zeigen, dass Neugeborene aktiv rauchender Muetter signifikant hoehere PCB- und HCB-Konzentrationen aufwiesen, als Kinder passiv oder nicht rauchender Muetter. Es bestand kein Unterschied in der praenatalen PCB-Akkumulation zwischen den Kindern aus Fulda und denen aus Duesseldorf, waehrend letztere um 62% hoehere HCB-Werte aufwiesen. (orig.)

  18. Prevalence of iodine- and thyroglobulin-negative findings in differentiated thyroid cancer. A retrospective analysis of patients treated from 1961 to 1998 in a university hospital; Haeufigkeit lod- und hTG-negativer Befunde beim differenzierten Schilddruesenkarzinom. Eine retrospektive Analyse der von 1961 bis 1998 in einer Universitaetsklinik behandelten Patienten

    Energy Technology Data Exchange (ETDEWEB)

    Klutmann, S.; Jenicke, L.; Geiss-Toenshoff, M.; Bohuslavizki, K.H.; Mester, J.; Clausen, M. [Universitaetskrankenhaus Eppendorf, Hamburg (Germany). Abt. fuer Nuklearmedizin

    2001-10-01

    Aim: The prevalence of iodine- and thyroglobulin-negative findings was evaluated in all patients with differentiated thyroid cancer (DTC) treated from 1961 until 1998 at the Department of Nuclear Medicine, University Hospital Hamburg-Eppendorf. Methods: A total of 490 patients with papillary thyroid cancer (PCA) and 242 patients with follicular thyroid cancer (FCA) were analyzed retrospectively. Patients were divided into four groups: 1: no recurrence, 2: recurrent disease, 3: primary metastatic/progressive disease and 4: inconclusive follow-up. Results of iodine scan, serum-TG, and additional imaging modalities as well as histology were compared in all patients. Results: 21/490 (4,3%) of patients with PCA and 16/242 (6,6%) with FCA suffered from recurrent disease. 62/490 (12,7%) of patients with PCA and 59/242 (24,4%) with FCA had primary metastatic/progressive disease. 12/21 patients with PCA and 12/16 with FCA showing up with recurrent disease had a negative iodinescan. 11/21 of patients with PCA and 4/16 with FCA and tumor recurrence had negative serum-TG levels. 14/62 patients with PCA and 14/59 with FCA presenting with primary metastatic/progressive disease had negative iodinescan. 14/62 patients with PCA and 6/59 with FCA had negative serum-TG. Conclusion: The prevalence of iodine-negative recurrent/metastatic disease is in accordance to the literature, whereas the prevalence of TG-negative recurrent/metastatic was noted higher than reported previously. Thus, the commonly used follow-up scheme of DTC is confirmed. However, iodine scan should be regularly performed in patients with high risk of recurrence. (orig.) [German] Ziel: Retrospektiv wurden alle von 1961 bis 1998 in der Abteilung fuer Nukleamedizin des Universitaetsklinikums Hamburg-Eppendorf behandelten Patienten mit einem differenzierten Schilddruesenkarzinom bezueglich des Anteils lod- und/oder hTG-negativer Rezidive analysiert. Methoden: Es wurden 490 Patienten mit einem papillaeren Schilddruesenkarzinom (PCA) und 242 Patienten mit einem follikulaeren Schilddruesenkarzinom (FCA) untersucht. In Abhaengigkeit vom Krankheitsverlauf erfolgte eine Einteilung 1: kein Rezidiv, 2: Rezidiv, 3: primaer metastasierender/persistierender Verlauf und 4: unklarer Verlauf. Fuer alle Patienten wurden die Ergebnisse der lodszintigraphie, der hTG-Bestimmungen sowie weiterer bildgebender Verfahren und Histologie miteinander verglichen. Ergebnisse: 21/490 (4,3%) der Patienten mit PCA und 16/242 (6,6%) mit FCA erlitten ein Rezidiv. Bei 62/490 (12,7%) mit PCA und 59/242 (24,4%) mit FCA fand sich ein primaer metastasierender/persistierender Verlauf. Bei nachgewiesenem Rezidiv wiesen 12/21. Patienten mit PCA und 12/16 mit FCA keine ladspeicherung auf. Bei 11/21 mit PCA und 4/16 mit FCA und einem Tumorrezidiv fand sich kein erhoehter hTG-Wert. Bei primaer metastasierendem/persistierendem Verlauf wiesen jeweils 14/62 Patienten mit PCA und 14/59 mit FCA keine lodspeicherung auf. Bei 14/62 Patienten mit PCA und 6/59 mit FCA fand sich kein erhoehter hTG-Wert. Schlussfolgerung: Diese Ergebnisse bestaetigen einerseits die in der Literatur angegebenen Haeufigkeiten lodnegativer Rezidive/Metastasen, andererseits fanden sich hTG-negative Rezidive/Metastasen haeufiger. Das derzeit gueltige Nachsorgeschema wird durch die vorliegende Analyse grundsaetzlich bestaetigt. Von regelmaessigen lodszintigraphien profitieren hierbei insbesondere Patienten mit einem erhoehten Rezidivrisiko. (orig.)

  19. Studies on the influence of processing methods on the corrosion characteristics of electroslag-tape-plating with NiMo16Cr16Ti. Untersuchungen zum Einfluss der Prozessfuehrung auf die Korrosionseigenschaften beim Elektroschlacke-Bandplattieren mit NiMo16Cr16Ti

    Energy Technology Data Exchange (ETDEWEB)

    Blum, J

    1991-01-01

    The aim of the project was to demonstrate an economic possibility of using NiMo16Cr16Ti reliably as a plating material with simple to use methods. For this, the electroslag and submerged arc welding with tape electrodes as a coating technology are compared with each other. As the research showed, it is possible to coat large surface area, thick walled components economically with NiMo16Cr16Ti using electroslag (RES) tape plating. The choice of powder is important for the hot crack freedom and the precipitation poverty and thus the corrosion resistance of the plating. The silicon content was proved to be of importance in the plating. With the right choice of powder, the second layer already possesses the endurance of laminated materials against intercrystalline corrosion in coating tests as well as against pitting in a 10% FeCl{sub 3} solution. The coating capability lies at 0.5 m{sup 2}/h. - In addition the use of video thermography for on-line surveillance of seam on RES plates is documented. The evaluation of the pictures makes possible the targeting of the external magnets and thus the influencing of the melting bath flux. (orig./RHM) With 80 figs., 12 tabs.

  20. Transmission contracts and procurement law. Applicability of the instructions of the procurement law to the selection procedure in the connection with the conclusion of transmission contracts according to paragraph 46 EnWG?; Konzessionsvertraege und Vergaberecht. Anwendbarkeit der Vorschriften ueber das Vergaberecht auf das Auswahlverfahren beim Abschluss von Wegenutzungsvertraegen nach paragraph 46 EnWG?

    Energy Technology Data Exchange (ETDEWEB)

    Niehof, Roland

    2011-01-15

    The conclusion of transmission contracts between the municipalities and the operators of supply lines (electricity, natural gas) is regulated by law. paragraph 46 of the Energy Economy Law (EnWG) describes the requirements concerning the selection a power supply company and concerning the procedure to be followed. The contribution under consideration examines whether the regulations of the procurement right can be applied directly or similarly beside paragraph 46 EnWG to the conclusion of transmission contracts. The author of the contribution under consideration deals with the newer jurisdiction of the European Court of Justice.

  1. The hearing at the Federal Constitutional Court on the nuclear phase-out. No space left for legal ''tricks''; Die Verhandlung beim Bundesverfassungsgericht ueber den Kernenergieausstieg. Kein Raum fuer juristische ''Zaubertricks''

    Energy Technology Data Exchange (ETDEWEB)

    Leidinger, Tobias [Luther Rechtsanwaltsgesellschaft, Duesseldorf (Germany)

    2016-05-15

    Can lawyers do magic? At least some lawyers believe (even) to do. But does this work? Observers of the hearing of the German Constitutional Court trying the nuclear phase and the revision of the German Atomic Act on 15/16 March 2016 may believe it. The German Constitutional Court is trying the constitutional complaint proceedings of E.ON, RWE and Vattenfall on the legality of nuclear phase-out in Germany, essentially to the question of the compatibility of this law with the fundamental rights of the operating companies, in particular their right to property, to freedom of occupation, to equal treatment and protection of legitimate expectations.

  2. Demolition to Green-Field conditions of the FRJ-1 (MERLIN) research reactor. Successes and hurdles in the demolition of a research reactor of the megawatt class; Der Rueckbau des Forschungsreaktors FRJ-1 (MERLIN) bis zur 'Gruenen Wiese'. Erfolge und Huerden beim Rueckbau eines Forschungsreaktors der Megawatt-Klasse

    Energy Technology Data Exchange (ETDEWEB)

    Stahn, Burkhard; Printz, Rudolf; Matela, Karel; Zehbe, Carsten; Stauch, Bernhard; Zander, Iven [Forschungszentrum Juelich GmbH, Juelich (Germany)

    2010-02-15

    The Juelich-1 Research Reactor (FRJ-1), also referred to as MERLIN (Medium Energy Research Light Water Moderated Industrial Nuclear Reactor), was a light-water moderated and cooled swimming pool reactor of British design. The cornerstone in the erection of the reactor building was laid on June 11, 1958. Reactor operation was started on February 23, 1962. The plant was last run at a thermal power of 10 MW and shut down for good in 1985 after 23 years of operation. After the fuel elements had been removed and most of the experimental installations dismantled, some first steps towards demolition were taken in 1995. Demolition on a large scale began in 1996. September 8, 2008 was a special day: On the area of the former reactor hall, an oak tree was planted as a symbol of the 'green field' and of the original oak wood which had to make way for the construction of reactors in Juelich. An oak tree now stands in the place of the reactor unit. Was that all? It was not, for there were ancillary systems, operations, utility and hygiene buildings which had to be pulled down. Decontamination and clearance measurements were completed. The application for clearance was prepared and completed. Conventional demolition was started in 2009. After completion of that step, the last chapter about demolition of the FRJ-1 research reactor has been written, and the book can be closed. (orig.)

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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)

  8. 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...

  9. 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....

  10. 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.)

  11. 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.

  12. 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

  13. 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...

  14. 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 .

  15. 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...

  16. 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...

  17. Investigations to single and combined effects of organic pollutants (PAH, PCB) and heavy metals (Cd, Cu) on biomass production and soil-plant transfer by cultivation of raw and energy plants. Final report; Bodenoekologische Untersuchungen zur Wirkung und Verteilung von organischen Stoffgruppen (PAK, PCB) in ballungsraumtypischen Oekosystemen. Untersuchungen zu Einzel- und Kombinationswirkungen von organischen Schadstoffen (PAK, PCB) und Schwermetallen (Cd, Cu) auf Biomasseertrag und Boden-Pflanze-Transfer beim Anbau von Rohstoff- und Energiepflanzen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Metz, R.; Dorn, J.; Sauer, W.

    1997-05-01

    Together with polycyclic aromatic hydrocarbons, polychlorinated biphenyls and heavy metals other elements and compounds as well as nutrients are present in typical contaminated areas like sewage fields. They are found as mixed undisturbed contamination and the transfer of these pollutants into food or forage plants is dangerous for people. So far investigations of ecological effects of these substances are focused mainly on single agents or on some agents of the same chemical group. But in most cases the mixture of different chemical compounds in extremely contaminated fields cause synergistic effects resulting in yield reduction and decrease of microbiological activity. Therefore the aim of the present report is to show combined effects of selected organic pollutants (benzo-a-pyren, 2,2`, 5,5` tetrachlorbiphenyl) and heavy metals (cadmium, copper) on parameters of soil biology, biomass production and pollutant uptake by plants. Resulting changes of cellulose decomposition, CO{sub 2}-release from soil and N-mineralization after separated and combined enrichment of weakly polluted sewage field soil with said pollutants up to concentrations of extremely polluted sewage field soils are presented in this paper. Data of yields and pollutant contents of plants (rye, maize and potatoes) cultivated on experimental soils are summarised and ecotoxicological risks resulting form pollutants and their interactions discussed. (orig.) [Deutsch] Polycyclische aromatische Kohlenwasserstoffe, Polychlorierte Biphenyle und Schwermetalle sind zusammen mit anderen Elementen und Verbindungen u.a. auch mit Naehrstoffen als gemischte gewachsene Kontamination in ballungsraumtypischen Belastungsflaechen (z.B. Rieselfelder) vorhanden und stellen bei einem Transfer in Nahrungs- und Futterpflanzen eine besondere Gefaehrdung fuer den Menschen dar. Bei Untersuchungen hinsichtlich oekosystemarer Konsequenzen dieser Substanzen wurden bisher vor allem Einzelstoffbetrachtungen angestellt bzw. mehrere Vertreter einer Stoffgruppe untersucht. Ursache fuer Ertragsdepressionen und Minderungen der mikrobiellen Aktivitaet auf hocheblasteten Flaechen ist aber immer eine Komplexwirkung der verschiedenen Bodeninhaltsstoffe, so dass sich synergistische Effekte einstellen koennen. Im vorliegenden Bericht wird daher die kombinierte Wirkung ausgewaehlter organischer Schadstoffe (Benzo-a-pyren, 2,2`, 5,5` Tetrachlorbiphenyl) sowie relevanter Schwermetalle (Cadmium, Kupfer) auf bodenmikrobiologische Parameter, Biomasseproduktion und Schadstoffpflanzenaufnahme erfasst und aufgetrennt. Veraenderungen von CO{sub 2}-Freisetzung, Cellulosezersetzung und N-Mineralisierung in einem schwachbelasteten Rieselfeldboden nach dessen Einzelstoff- bzw. Mischanreicherung mit den genannten Schadstoffen in Konzentrationen, wie sie in hochbelasteten Rieselfeldern vorliegen, werden dargestellt. Desweiteren erfolgt eine umfangreiche Auswertung der Daten zu Ertraegen und Schadstoffgehalten der auf den Versuchsboeden geprueften Pflanzen (Roggen, Mais und Kartoffeln). Oekotoxikologische Risiken der untersuchten Schadstoffe und ihre Wechselbeziehungen untereinander werden diskutiert. (orig.)

  18. 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

  19. 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.

  20. 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, ...

  1. 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

  2. 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.

  3. 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.)

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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)

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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-...

  18. 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...

  19. 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.

  20. 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.

  1. 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...

  2. 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)

  3. 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.

  4. 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 ...

  5. 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.

  6. 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.)

  7. 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...

  8. 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.)

  9. 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.)

  10. 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

  11. 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

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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...

  17. 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.)

  18. 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.

  19. 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...

  20. 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...

  1. 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

  2. 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 ...

  3. 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.

  4. 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...

  5. 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...

  6. 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.

  7. 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...

  8. 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).

  9. 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...

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.)

  19. 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.)

  20. 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.)

  1. 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)

  2. 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.)

  3. 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...

  4. 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.)

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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...

  13. 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...

  14. 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.

  15. 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.

  16. 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

  17. 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.

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