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

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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.

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)

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U.S. plastic surgeons who contributed to the Revue de Chirurgie Plastique and the Revue de Chirurgie Structive (1931-1938): "Giants" in our specialty.

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Rogers, B O

1999-01-01

The Revue de Chirurgie Plastique and the Revue de Chirurgie Structive, Brussels (1931-1938), edited by Maurice Coelst, M.D. from Brussels, were the first, full-fledged medical publications specifically devoted to plastic, reconstructive, and aesthetic surgery. Publishing original articles by J.W. Maliniac, J. Eastman Sheehan, and brief summaries of papers read at plastic surgery societies by C.R. Straatsma, L.A. Peer, G. Aufricht, and other well-known American plastic surgeons, these Revues drew attention to surgeons, most of whom were responsible for organizing the American Society of Plastic and Reconstructive Surgeons in 1931, the same year in which the Revue de Chirurgie Plastique first appeared.

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

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Donald M. Bryant

2017-01-01

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

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

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Eisthen, Heather L; Krause, Brianne Chung

2012-05-01

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

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

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Voss, S R; Shaffer, H B

2000-09-01

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

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

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

2014-01-01

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

[Thoughts on the Revue de Chirurgie Plastique (1931-34) and the Revue de Chirurgie Structive (1935-38)].

Science.gov (United States)

Vrebos, J

2007-08-01

The history of modern plastic surgery starts when a young, restless ENT man, Dr M. Coelst, started a training in Plastic Surgery with Sebileau in Paris and Joseph in Berlin. This man of vision and far-sighted imagination realized that the separated efforts and publications of so many pioneers, scaterred all over the world, would be lost if not gathered in a scientific journal only devoted to plastic surgery for the benefit of all. This brought him to the idea of establishing, in 1931, at his own initiative, the first international Journal of Plastic Surgery ever published, the Revue de Chirurgie Plastique, fifteen years before the USA Journal Plastic and Reconstructive Surgery and sixteen years before the British Journal of Plastic Surgery. The name of the journal was changed in 1935 to the Revue de Chirurgie Structive. Coelst' Revue was promptly accepted as the leading Journal of Plastic Surgery and all the internationally known plastic Surgeons contributed to it by scientific papers of great value, even today.

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

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

2016-02-04

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

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

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

2007-01-01

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

Experimentally induced metamorphosis in axolotls reduces regenerative rate and fidelity

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

2014-01-01

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

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

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

2011-10-01

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

British plastic surgeons who contributed to the Revue de Chirurgie Plastique and the Revue de Chirurgie Structive (1931-1938): "the Big Four" in their Speciality.

Science.gov (United States)

Rogers, B O

2001-01-01

The Revue de Chirurgie Plastique and the Revue de Chirurgie Structive, Brussels (1931-1938), edited by Maurice Coelst, M.D. from Brussels, were the first, full-fledged medical publications devoted specifically to plastic, reconstructive, and aesthetic surgery. Publishing original articles by H.D. Gillies, P.T. Kilner, A.H. McIndoe, and R. Mowlem--the "Big Four" as they were known to both English and American plastic surgeons--the Revues drew attention to these four surgeons who were mainly responsible for developing the prestige of English plastic surgery in the early 1930s.

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

DEFF Research Database (Denmark)

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

2017-01-01

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

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

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

2007-12-01

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

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

OpenAIRE

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

1988-01-01

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

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

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Sabina Wischin

2017-04-01

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

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

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

2002-09-01

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

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

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

2007-06-01

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

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

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.

Transgenesis in axolotl (Ambystoma mexicanum).

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Khattak, Shahryar; Tanaka, Elly M

2015-01-01

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

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

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Kevin W Hall

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

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

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.

Diffusion tensor tractography reveals muscle reconnection during axolotl limb regeneration.

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Cheng-Han Wu

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

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

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Micah D. Gearhart

2015-09-01

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

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

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.

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

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Zullian C

2016-01-01

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

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

DEFF Research Database (Denmark)

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

2017-01-01

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

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

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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.

EDITORIAL: | Oloyede | African Sociological Review / Revue ...

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

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

1998-12-15

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

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

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

2007-01-01

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

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

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Lemanski Sharon L

2009-09-01

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

Scientific contributions of U.S. plastic surgeons to the Revue de Chirurgie Plastique and the Revue de Chirurgie Structive, Brussels (1931-1938).

Science.gov (United States)

Vrebos, J

1999-01-01

The author emphasizes the close cooperation between U.S. plastic surgeons and the first international journal entirely devoted to plastic surgery, the Revue de Chirurgie Plastique (1931-1934) later to become the Revue de Chirurgie Structive (1935-1938) published under the editorship of Maurice Coelst, M.D. from Brussels. By the accurate recording of original articles, book reviews, proceedings of their annual meetings and summaries in three different languages (English, French, German), the author stresses the intense scientific dynamism and the achievements made by the U.S. pioneers of this new speciality, which really started during World War I.

Regulation of antibody synthesis in the X-irradiated Mexican axolotl

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Charlemagne, J.

1981-01-01

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

Regulation of antibody synthesis in the X-irradiated Mexican axolotl

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Charlemagne, J.

1981-09-01

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

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

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

2007-01-01

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

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

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.

Novel axolotl cardiac function analysis method using magnetic resonance imaging

NARCIS (Netherlands)

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

2017-01-01

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

Novel axolotl cardiac function analysis method using magnetic resonance imaging

NARCIS (Netherlands)

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

2017-01-01

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

African Sociological Review / Revue Africaine de Sociologie

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African Sociological Review / Revue Africaine de Sociologie

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African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 16, No 2 (2012) >. Log in or Register to get access to full text downloads.

Book Review | Oloyede | African Sociological Review / Revue ...

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Editorial | Oloyede | African Sociological Review / Revue Africaine ...

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African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 21, No 1 (2017) >. Log in or Register to get access to full text downloads.

African Sociological Review / Revue Africaine de Sociologie

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Third Worldism | Nash | African Sociological Review / Revue ...

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

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Ron Stewart

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

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

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.

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

EpiNet : Revue électronique de l'EPI, Année 2006, n° 81-90

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Viaud, Jean-Bernard

2006-01-01

Fayon, D. (2006). Les nouveaux outils en entreprise. EpiNet : Revue électronique de l'EPI (Enseignement Public & Informatique), jan. 2006, (81).a0601aArchambault, J.-P. (2006). Un dispositif départemental pour les TIC : le CRI de la Haute-Savoie. EpiNet : Revue électronique de l'EPI (Enseignement Public & Informatique), jan. 2006, (81).a0601bCaraballo, S., Cicala, R. (2006). Vers une Didactique de l'Informatique. EpiNet : Revue électronique de l'EPI (Enseignement Public & Informatique), jan. ...

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

Science.gov (United States)

Lee, Jangwoo; Gardiner, David M

2012-01-01

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

Regeneration of limb joints in the axolotl (Ambystoma mexicanum.

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Jangwoo Lee

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

Microarray Analysis of microRNA Expression during Axolotl Limb Regeneration

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

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.

The scientific contributions of British Plastic Surgeons to the Revue de Chirurgie Plastique and the Revue de Chirurgie Structive, Brussels (1931-1938).

Science.gov (United States)

Vrebos, J

2001-01-01

In 1931, Maurice Coelst, M.D. from Brussels started the publication of the first international journal of plastic surgery ever published: the Revue de Chirurgie Plastique (1931-1934), which eventually became the Revue de Chirurgie Structive (1935-1938). In 1936, he established the first European Society of Structive Surgery, which held its first congress in Brussels. Further congresses were held in London in 1937 and in Milan in 1938. It is the collaboration and the participation of British plastic surgeons in this Society, this journal, and these meetings that I want to stress, because I am firmly convinced that these documents fill a gap in the history of Plastic Surgery in Great Britain, since--as far as I know--no detailed information concerning this period was ever published in Plastic Surgery literature.

Revue de Médecine et de Pharmacie

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Journal Homepage Image. La Revue de Médecine et de Pharmacie is a semestrial publication of the Faculty of Medicine and Pharmaceutical Sciences of the University of Douala. It is destined to the university scientific community, physicians and other researchers in all countries who wish to make known the results of their ...

Network based transcription factor analysis of regenerating axolotl limbs

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Cameron Jo Ann

2011-03-01

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

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

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

2012-01-01

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

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

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Hans-Henning Epperlein

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

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

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

1998-12-15

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

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

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

2016-01-01

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

Formalisation de la chaine documentaire | Akbal | Revue d ...

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

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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.

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No Abstract Available Revue d'Information Scientifique & Technique Vol.10(1-2) 2000: 27-40. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/rist.v10i1.26727 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

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Axolotl cells and tissues enhances cutaneous wound healing in mice

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

2017-01-01

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

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

DEFF Research Database (Denmark)

Hansen, Kasper; Lauridsen, Henrik; Pedersen, Michael

2012-01-01

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

Bilateral breast fibromatosis: a rare case report | Fewou | Revue de ...

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

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

2013-11-01

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

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

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Finnson Kenneth

2010-02-01

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

Nový časopis "Revue pro právo a technologie"

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Matejka, Ján

-, č. 11 (2010), s. 61-62 ISSN 1210-6348 Institutional research plan: CEZ:AV0Z70680506 Keywords : Revue for law and technologies * Internet law * review of a new journal Subject RIV: AG - Legal Sciences

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

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Carlson, Bruce M.

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

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

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Kazumasa Mitogawa

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

Comparison of tissue processing methods for microvascular visualization in axolotls.

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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.

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

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

2015-12-01

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

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

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Chiara Zullian

2015-01-01

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

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

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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

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

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

2016-11-21

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

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

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

2013-08-01

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

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

International Nuclear Information System (INIS)

Tuchkova, S.Ya.

1976-01-01

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

Synthèse: Revue des Sciences et de la Technologie

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Synthèse : Revue des Sciences et de la Technologie is a half-yearly international peer-reviewed journal published by the Diroctorate of Publication of “Université Badji Mokhtar- Annaba” (Algeria) since 1996. Synthèse is a multidisciplinary journal. Its scope covers the fields of pure and applied science, natural and life ...

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

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Hélène Pelczar

2010-12-01

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

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

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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

EpiNet : Revue électronique de l'EPI, Année 2012, n° 141-150

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Archambault, Jean-Pierre

2012-01-01

Accès aux articles et documents dans le fichier attaché index.html. EPI, Archambault, J.-P. (2012). Éditorial : Une commission de l'Académie des Sciences sur l'enseignement de l'informatique. EpiNet : Revue électronique de l'EPI (Enseignement Public & Informatique), jan. 2012, (141). a1201a Archambault, J.-P. (2012). Au bout de dix ans de pratique du B2i, nous constatons un échec. EpiNet : Revue électronique de l'EPI (Enseignement Public & Informatique), jan. 2012, (141). a1201b Karsenti, ...

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Synthèse: Revue des Sciences et de la Technologie: Submissions

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Outre les articles relatant des contributions originales, la Revue des Sciences ... elles doivent être numérotées en chiffres arabes entre parenthèses au bord de la ... On écrira figure 1 ou tableau 1 en toutes lettres dans le texte lorsque cela fait ...

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

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

2002-01-01

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

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

Science.gov (United States)

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

1999-01-01

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

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

Science.gov (United States)

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

2014-06-01

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

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

Science.gov (United States)

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

2008-02-11

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

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

DEFF Research Database (Denmark)

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

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

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

Science.gov (United States)

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

2005-11-01

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

Synthèse: Revue des Sciences et de la Technologie - Vol 24 (2015)

African Journals Online (AJOL)

Synthèse: Revue des Sciences et de la Technologie - Vol 24 (2015) ... hygrothermique en eau douce sur un composite unidirectionnel verre-époxy · EMAIL ... Problèmes de type obstacle : algorithmes de résolution · EMAIL FREE FULL TEXT ...

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

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Samuels Amy K

2008-02-01

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

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

OpenAIRE

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

2012-01-01

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

Axolotl/Bichos Raros Crónica

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Susana Chávez-Silverman

2012-11-01

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

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

NARCIS (Netherlands)

Carlson, Bruce M.

1972-01-01

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

Découpage automatique de la vidéo en plans | Maredj | Revue d ...

African Journals Online (AJOL)

Revue d'Information Scientifique et Technique ... Temporal segmentation is a necessary first step to indexing digital video for browsing and retrieval. ... This paper describes an original approach for temporal segmentation algorithm of video based on Kolmogorve-Smirnov statistical test and using double thresholds to detect ...

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.

Review: Hérodote: Revue de géographie et de géopolitique, 2011/3, no. 142: Géopolitique du Sahara, Paris: La Découverte Besprechung: Hérodote: Revue de géographie et de géopolitique, 2011/3, Nr. 142: Géopolitique du Sahara, Paris: La Découverte

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Laurence Marfaing

2011-01-01

Full Text Available Review of the issue 2011/3, no. 142, of Hérodote: Revue de géographie et de géopolitique: Géopolitique du Sahara, Paris: La Découverte.Besprechung der Ausgabe 2011/3, Nr. 142, von Hérodote: Revue de géographie et de géopolitique: Géopolitique du Sahara, Paris: La Découverte.

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...

Société de l'information (Algerian) | Bounadja | Revue d'Information ...

African Journals Online (AJOL)

... la quelle, l'information est la base de toutes les activités scientifique, technique, économique, politique, sociale et culturelle. Mots clés: Société de l'information / Internet / Education / Formation / Industrie de l'information. Revue d'Information Scientifique & Technique Vol.9(1) 1999. http://dx.doi.org/10.4314/rist.v9i1.26724.

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

Energy Technology Data Exchange (ETDEWEB)

Turska, R.

1975-01-01

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

Resegmentation in the Mexican axolotl, Ambystoma mexicanum.

Science.gov (United States)

Piekarski, Nadine; Olsson, Lennart

2014-02-01

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

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

OpenAIRE

Phan, Anne Quy

2014-01-01

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

Une voix dans un chœur risque de n’être point entendue. André Gide et La Nouvelle Revue française, 1908-1914

NARCIS (Netherlands)

Koffeman, M.N.; Wittmann, Jean-Michel

2017-01-01

Cet article étudie la tension entre l’individualisme gidien et la collectivité littéraire que forme la première Nouvelle revue française. Entreprise commune par excellence, la revue gagne à être considérée dans son ensemble. Une lecture des sommaires de la NRF relativise le rôle de Gide et met en

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

Science.gov (United States)

Jarial, M S; Wilkins, J H

2003-10-01

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

Early regulation of axolotl limb regeneration.

Science.gov (United States)

Makanae, Aki; Satoh, Akira

2012-10-01

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

Geographical Journals in Spain : from Tradition to Fragmentation Les revues géographiques en Espagne : de la tradition à la fragmentation

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Aurora Garcia Ballesteros

2012-12-01

Full Text Available This article reviews the short and diversified history of the Spanish Geographical journals, within the framework of the general Spanish geographic tradition. During the second half of the 20th Century, a fragmentation of the university Geography groups took place with a multiplication of journals. This fragmentation appears as a big difficulty to reinforce and internationally disseminate the main results of Spanish geographical research. Through the most popular journals database it is possible to evaluate the impact of these Spanish journals, which is always very little. Some conclusions related to language and content problems are advanced in order to improve the knowledge of the great and diversified Spanish geography all around the world.Cet article analyse l’évolution brève et diversifiée des revues de géographie espagnoles, dans le contexte général de la tradition géographique. À partir de la deuxième moitié du XXème siècle il y eu une fragmentation des groupes de géographes universitaires ce qui a produit une multiplication des revues. Cette fragmentation devient la difficulté majeure pour l’internationalisation et la diffusion des principaux résultats de la recherche géographique espagnole. À travers des bases de données de revues les plus connues on a pu évaluer l’impact des revues espagnoles, qui est toujours très réduit. On avance finalement quelques conclusions relatives aux problèmes de la langue et des contenus de la majorité des articles des revues espagnoles comme explication de la méconnaissance de l’importance et de la diversité de la géographie espagnole dans le monde actuel.

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

DEFF Research Database (Denmark)

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

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

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

Science.gov (United States)

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

2004-06-01

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

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

Science.gov (United States)

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

2003-01-01

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

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

Science.gov (United States)

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

2011-09-01

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

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

Science.gov (United States)

Shioda, Chieko; Uchida, Kazuyuki; Nakayama, Hiroyuki

2011-08-01

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

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

Science.gov (United States)

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

2017-09-16

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

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

Science.gov (United States)

McCusker, Catherine; Bryant, Susan V.

2015-01-01

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

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

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Catalina Villalobos Díaz

2017-07-01

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

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

Science.gov (United States)

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

2015-01-01

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

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

Science.gov (United States)

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

2011-01-15

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

Proliferation zones in the axolotl brain and regeneration of the telencephalon

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Maden Malcolm

2013-01-01

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

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

NARCIS (Netherlands)

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

1978-01-01

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

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

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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

Première analyse du lectorat de la revue ALSIC

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Thierry Chanier

2000-06-01

Full Text Available Dans cet article nous tentons de cerner la nature et les centres d´intérêt du lectorat de la revue ALSIC, au cours des 21 premiers mois de son existence, de juin 1998 à février 2000. Nous présentons d´abord les sources d´information sur lesquelles est construite cette étude. Nous examinons les nombres d´accès mensuels sur notre site. Nous détaillons ensuite certaines caractéristiques de notre lectorat : répartition géographique, activités principales, langues objets d´attention. Enfin, nous décrivons les consultations des rubriques et de certains de nos articles.

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

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Xiaoping Chen

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

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

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Ji-Feng Fei

2014-09-01

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

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

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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

Drainage percutané de l'abcès du psoas: Notre expérience et revue ...

African Journals Online (AJOL)

M. Asseban

et al. Les abcès pyogènes secondaires du psoas: à propos de six cas et revue de la littérature. Rev Med Interne 2006;27:828–35. [3] Muttarak M, Peh WC. CT of unusual iliopsoas compartment lesions. Radiographics 2000. Oct; 20 Spec No: S53-S66. [4] Zissin R, Gayer G, Kots E, Werner M, Shapiro-Feinberg M, Hertz M.

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

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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

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

Science.gov (United States)

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

2015-08-01

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

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

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

2005-08-01

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

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

Science.gov (United States)

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

2011-07-01

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

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

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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.

Entre Classicisme et Modernité : La Nouvelle Revue Française dans le champ littéraire de la Belle Epoque

NARCIS (Netherlands)

Koffeman-Bijman, M.N.

2003-01-01

The literary review La Nouvelle Revue Française enjoys an enormous prestige in France. In Entre Classicisme et Modernité, Maaike Koffeman explores the origins of this legend of French literary life by means of a historical, literary and sociological analysis of the first years of the review s

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

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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.

"A big piece of news": Théodule Ribot and the founding of the Revue Philosophique de la France et de l'Etranger.

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Nicolas, Serge

2013-01-01

This paper describes the founding of the Revue Philosophique de la France et de l'Étranger by Théodule Ribot (1839-1916) in 1876. Like the English journal Mind, which was launched the same year, this journal introduced the new scientific psychology to France. Its founding increased Ribot's scientific credibility in psychology and led him to be regarded as the most distinguished French specialist in the field. First, we review the state of French philosophy at the time of the journal's founding, focusing on the three main French schools of thought in philosophy and on their relations with psychology. Second, after analyzing the preface written by Ribot in the first issue of the Revue Philosophique, we examine how the journal was received in French philosophical circles. Finally, we discuss its subsequent history, highlighting its founder's promotion of new ideas in psychology. © 2012 Wiley Periodicals, Inc.

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.

Relation de service, rapport social de service : Quelle grille d’analyse ? Analysing service relationships and service-based social relationships. Debate with the editors of the Nouvelle Revue du Travail Relación de servicio, vínculo social de servicio: ¿qué modelo analítico? Debate con la redacción de la Nouvelle Revue du Travail

Directory of Open Access Journals (Sweden)

Guillaume Tiffon

2013-03-01

Full Text Available Dans un échange avec la Nouvelle Revue du Travail, Pascal Ughetto et Philippe Zarifian prolongent la controverse sur les grilles d’analyse des services, en discutant les pré-requis sur lesquels reposent leurs postures respectives. Ce débat fait suite à leurs contributions dans le dossier Controverses de ce numéro « Relation de service, rapport social de service. Quelle grille d’analyse ? »In a conversation with the Nouvelle Revue du Travail, Pascal Ughetto and Philippe Zarifian address the controversy about service-related analytical grids, by focusing on the preconditions underlying each grid’s particular orientation. The debate follows their contributions to the Controverses special section found in a special issue called “Analysing service relationships and service-based social relationships”En una conversación con la Nouvelle Revue du Travail, Pascal Ughetto y Philippe Zarifian prolongan la controversia sobre los modelos analíticos de los servicios, debatiendo sobre los prerrequisitos en los cuales se apoyan sus respectivas posturas. Ese debate ha surgido tras sus contribuciones al número especial Controverses de esta edición “Relación de servicio, vínculo social de servicio. ¿Qué modelo analítico ?

Revue épidémiologique des blessures lors de la pratique du rugby à XV

OpenAIRE

Kaux, Jean-François; Julia, Marc; Chupin, Marie; Delvaux, François; Croisier, Jean-Louis; Forthomme, Bénédicte; Crielaard, Jean-Michel; LE GOFF, Caroline; Durez, Patrick; Ernst, Philippe; Guns, Sébastien; Laly, Arnaud

2014-01-01

Le rugby est un sport en plein développement. Sport de contact par excellence, il est à l’origine d’un nombre important de blessures. Au rugby à XV, l’incidence des blessures s’élève de 30 à 91/1000 heures de match. Cette revue épidémiologique des blessures chez le rugbyman évoque la localisation et le type de blessures, les causes, les moments des matches et de la saison auxquels elles se produisent, la position des joueurs et le type de terrain, ainsi que le temps d’absence des joueurs à la...

[Pharmaceutical, medical and cosmetic advertising in the revue "A Illustração (Paris, 1884-1892)].

Science.gov (United States)

Pereira, A L; Pita, J R

1996-01-01

Edited by a Portuguese publisher in Paris, in 15.000 copies, to be sold in Portugal and in Brazil, the revue A Illustração propagated the progress accomplished by French science and industry in the pharmaceutical, medical and cosmetic domaine. It followed with particular interest the work of Pasteur and nearly every advertisement that is published on the subject of health made reference to either medicine or products of French origin. Such advertisements reflect the great concern of the times with matters of hygiene, both public and private.

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.

Mixité sociale dans l'habitat. Revue de la littérature dans une perspective comparative

OpenAIRE

Kirszbaum, Thomas

2008-01-01

Cette revue de la littérature examine les politiques de diversité dans l’habitat d’un point de vue comparatif. Depuis qu’elle a été promue comme objectif central des politiques urbaines et du logement en France, la diversité (ou mixité) sociale dans l’habitat et les politiques publiques initiées en son nom, ont suscité une abondante littérature. De telles politiques existent aussi dans d’autres pays et s’accompagnent de débats importants dans les sciences sociales et le champ de l’évaluation ...

Effects of music and art education in early life and oral functions on the QOL of the Takarazuka Revue Company OG compared with general elderly females.

Science.gov (United States)

Masutani, Takiko; Yamamoto, Yasuji; Konishi, Junya; Maeda, Kiyoshi

2010-03-01

Today, Japan is becoming a super-aged society, with senior citizens already constituting over 21% of the population. In this situation, the question of how elderly people can extend their lives and enjoy independent lifestyles is becoming more important. The present study aims to clarify the relationship between the Quality of Life (QOL) of elderly females and their current oral functions and experiences of music and art education in early life. We carried out a survey study focusing on elderly females (Takarazuka Revue Company OG group and general female group) by carrying out a questionnaire survey and comparing cognitive function, oral examinations, cerebral atrophy in magnetic resonance imaging, and other characteristics. It was shown that the Takarazuka Revue Company OG group had greater hippocampal volumes and significantly higher cognitive functions than the general female group. In addition, in the general female group, there was a significant correlation between a decrease in the number of remaining teeth and a decrease in activities in daily living, but in the Takarazuka Revue Company OG group, no such correlation was observed. The results showed that those who have received art education as part of their careers over an extensive period since early life have higher levels of cognitive function, QOL, physical activity, social activity and life satisfaction compared with the general female group; showing that they sense a purpose in life and live with a positive attitude. In contrast, in the general female group, those who have continued to enjoy hobbies have higher levels of cognitive function, QOL, physical activity, social activity and life satisfaction than those who have not, thus showing that they live with a positive attitude.

Les déterminants de la conversion à l'agriculture biologique: une revue de la littérature économique.

OpenAIRE

Geniaux , Ghislain; Latruffe , Laure; Lepoutre , Jerome; Mzoughi , Naoufel; Napoleone , Claude; Nauges , Celine; Sainte-Beuve , Jasmin; SAUTEREAU , Natacha

2010-01-01

Livrable 1 EPAB (Evolution des Performances et formes d'organisations innovantes dans les transitions vers l’Agriculture Biologique) PEPP (Rôle de la Performance Economique des exploitations et des filières, et des Politiques Publiques, dans le développement de l’agriculture biologique en France); On se propose dans ce document de passer en revue les travaux principalement en économie, visant à identifier les déterminants des conversions des exploitations à l’agriculture biologique. Les docum...

Literaire strategieën: de drie satellieten van La Nouvelle Revue Française (1910-1914

Directory of Open Access Journals (Sweden)

Maaike Koffeman

2000-12-01

Full Text Available La Nouvelle Revue Française, opgericht in 1908 door een groep schrijvers rond André Gide, is het belangrijkste Franse literaire maandblad van het interbellum geweest. In de jaren voorafgaand aan de Eerste Wereldoorlog is de reputatie van het tijdschrift nog relatief bescheiden, maar er is al wel een duidelijke progressie te constateren. Deze is niet alleen toe te schrijven aan de inhoudelijke kwaliteit van de bijdragen, maar vooral ook aan de manier waaorp de redactie het tijdschrift promoot. De oprichters bedienen zich van een 'mutimedia-strategie': zij ontwikkelen rond de NRF verschillende nevenactiviteiten om de naamsbekendheid van het tijdschrift te vergroten en zijn literatuuropvattingen onder een breder publiek te verspreiden. 

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

International Nuclear Information System (INIS)

Teplits, N.A.

1975-01-01

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

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

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

1975-01-01

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

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

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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.

Les compétences infirmières forensiques en milieu carcéral face aux patients atteints de troubles mentaux: une revue de littérature étoffée

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Davet, Eloïse; Friedli, Karen; Machuret, Bastien; Reyff, Marie de

2015-01-01

Le but de cette revue de littérature étoffée est de mettre en évidence les compétences des infirmières forensiques travaillant, en milieu carcéral, avec des patients atteints de troubles mentaux.

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.

Comment fournir des soins infirmiers de qualité aux personnes migrantes de culture différente ?: une revue de littérature étoffée

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Conus, Emilie; Niggli, Martin

2013-01-01

Cette revue de littérature étoffée s’insère dans une problématique traitant du contexte migratoire actuel et des répercussions que cela a sur les soins infirmiers. En effet, elle porte sur les compétences infirmières lors de la prise en charge des patients migrants issus de culture différente.

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

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Badawy, Gamal; Reinecke, Manfred

2003-03-01

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

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

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Ericsson, Rolf; Olsson, Lennart

2004-08-01

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

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

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Cristian Aguilar

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

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

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

2010-01-15

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

JournalBase - Une étude comparative internationale des bases de données des revues scientifiques en sciences humaines et sociales (SHS

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Christine Kosmopoulos

2009-06-01

Full Text Available Pour la première fois en 2009 ont été ici présentés dans un tableau comparatif les contenus des bases de données qui recensent les revues en sciences humaines et sociales (SHS, du Web of Science (publié par Thomson Reuters et de Scopus (publié par Elsevier ainsi que des listes de référence European Reference Index for Humanities (ERIH (publiée par la Fondation européenne pour la Science et de l'AERES. Avec quelque 20 000 entrées, c’est une vue quasi exhaustive de la richesse des publications en sciences humaines et sociales qui est enfin apportée par ce tableau. La nomenclature adoptée pour classer les revues par discipline est celle en 27 postes de la Fondation Européenne pour la Science. Les affectations multiples révèlent la multidisciplinarité des revues, assez fréquente en SHS, mais parfois aussi les incohérences des bases de données qui n’ont pas été rectifiées.La recherche a été réalisée en 2008 avec le soutien financier du TGE Adonis du CNRS.Une mise à jour prochaine sera proposée en ligne.L’objectif final de ce projet, qui concerne l'ensemble de la communauté internationale en SHS, était de mettre en ligne, en version bilingue anglais/français, la base de données de JournalBase en mode interactif sur une plate-forme collaborative ainsi que le rapport final de l’étude, afin que les décideurs, les scientifiques, les experts de l'information scientifique disposent d’informations à jour et qu’ils puissent contribuer à faire avancer la réflexion sur ces questions, par l’échange d’expériences et de bonnes pratiques d’utilisation.Un article présentant l'historique du projet, la méthodologie mise en place et les difficultés rencontrées dans la comparaison des données a été publié le 8 janvier 2010. Il analyse également les premiers résultats.Désormais vous pouvez accéder à l'information intégrale de JournalBase sur le site : http://journalbase.cnrs.fr

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

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

2006-07-01

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

Proteomic analysis of blastema formation in regenerating axolotl limbs

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Nye Holly LD

2009-11-01

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

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

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Davidian, Asya; Malashichev, Yegor

2013-01-01

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

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

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Lehrberg, Jeffrey; Gardiner, David M

2015-01-01

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

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

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Jeffrey Lehrberg

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

Cotation des revues de géographie, impérialisme scientifique anglo-saxon et culture de l’excellence marchandisée Rankings of geographical journals, Anglo-Saxon scientific imperialism, and merchandised scientific excellence

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Christian Vandermotten

2012-12-01

Full Text Available Plus encore que d’autres sciences, du fait de l’inscription de ses recherches dans le local comme dans le global, la géographie souffre de la domination de la littérature anglo-saxonne dite internationale contrôlée par de grands groupes éditoriaux. Sur la base d’un dépouillement de 787 titres de revues géographiques et de l’analyse de leurs cotations, le biais de notoriété apparaît flagrant en faveur des revues publiées en anglais par les grands éditeurs commerciaux, sans commune mesure avec la qualité intrinsèque des publications. En outre, un biais est aussi évident en faveur des revues thématiques spécialisées, très souvent non spécifiquement géographiques, aux dépens des revues de géographie générale et des études régionales. Le recours à l’open access apparaît comme une des réponses de pays latins (France, Espagne, Brésil, Roumanie à cette domination. Cette contribution s’inscrit pleinement dans les efforts de l’Union Géographique Internationale de promouvoir une diffusion équilibrée et diversifiée de la recherche géographique mondiale.Yet more than for other sciences, due to researches coupling local and global, geography suffers from the domination of the “international” Anglo-Saxon literature controlled by the big publishers. On the basis of the collection of 787 geographical journals and the analysis of their rankings, a bias appears to be evident in favour of the journals published in English by the big commercial publishers, not related to the specific quality of the papers. Moreover, another bias is obvious in favour of the specialised topical journals, very often not specifically geographical ones, at the expense of the general geographical and area studies journals. The development of open access journals seems to be an answer of some Latin countries (France, Spain, Brazil, Romania to this imperialistic challenge. This paper is fully on line with the endeavours of the

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

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Diego de Jesus Chaparro-Herrera

2013-10-01

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

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

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

2008-07-15

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

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

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

2017-08-01

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

Littérature et sciences sociales dans l’espace romand, à propos d’un numéro de la revue A Contrario

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Provenzano, François

2007-01-01

La belle revue A Contrario consacre son dernier numéro (disponible en ligne) aux croisements variés entre la littérature et les sciences sociales, en particulier dans l’espace romand. Il ne s’agit pas, au fil de la dizaine de contributions qui constituent le dossier, de dégager un modèle théorique unique qui permettrait de penser l’articulation entre ces deux champs de connaissance. L’intérêt de ce numéro spécial tient précisément au fait qu’il propose une très riche variété de points de vue ...

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

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

2013-01-01

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

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

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

2012-01-01

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

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

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

2018-04-07

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

The LNG industry in 2011. Press revue

International Nuclear Information System (INIS)

2012-05-01

The outlook of the LNG industry in 2011 is presented as a revue of press articles: The role of LNG as a flexible and secure energy source as well as the prompt response to provide back-up through additional supplies and cargo diversions to compensate for the sudden loss of nuclear capacity in Japan - with sellers exercising due price restraint in view of the human tragedy - has been a credit to the industry. The increase in production capacity in 2009 and 2010, in particular from Qatar, had permitted the necessary buffer to cope much better with the demand surge than during past disruptions (such as the aftermath of the Chuetsu earthquake in late 2007). Undoubtedly, the marked shift over the last decade in the industry's prevailing business model towards global trade, destination flexibility and portfolio play has also facilitated the rapid response. As the total volume of LNG trade is very much determined by the availability of supply, 2011 has seen a growth of 9.4% over 2010, mainly as a result of the full availability of the six Qatar mega-trains over the past year. On the demand side the two traditional basins have shown very contrasting trends: 15% higher LNG off-take in Asia (the five major markets all increasing between 37.4% and 8.9%), versus a 1.7% decrease in the Atlantic Basin. Cargo diversions and an increasing number of reloads have boosted the exports from the Atlantic Basin to Asia in 2011 to more than 14 million tons (equivalent to more than 200 large size cargoes). Remarkable is also the fast growth in new markets in Latin America and in the Middle East - albeit from a small base - with counter-seasonal but varying demand, offering attractive arbitrage opportunities to portfolio play. Not surprising then that 2011 has seen another hike in spot and short-term trade, not just in absolute terms but also as a percentage of total trade (50% over 2010, 25.4% of total trade). The outlook for LNG is strong and its global demand prospects further

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

Science.gov (United States)

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

2011-01-01

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

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

Science.gov (United States)

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

2008-10-01

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

Introducing a European Partnership. First issue of 'European Nuclear Features'. A joint publication of atw, Nuclear Espana, Revue Generale Nucleare (2004)

International Nuclear Information System (INIS)

2004-01-01

'European Nuclear Features' is a joint publication of the three specialized technical journals, Nuclear Espana (Spain), Revue Generale Nucleaire (France), and atw - International Journal for Nuclear Power (Germany), planned for six issues annually. ENF is to further greatly the international European exchange of information and news about energy and nuclear power. News items, comments, and scientific and technical contributions will cover important aspects of the field. The first issue of ENF contains contributions about these topics, among others: - European Nuclear Society and Foratom: Strengthening the Nuclear Network. - Report: EPR - the European Pressurized Water Reactor. - Finland: Starting Construction of the Fifth Nuclear Power Plant. - Czech Republic: Nuclear Power Report for 2003/2004. - The Decommissioning Project of the Bohunice-1 and -2 Units. - FRM-II: TUM Research Neutron Source Generates Its First Neutrons. (orig.)

« Les usages avancés du téléphone mobile », revue Réseaux, La Découverte, volume 27, juillet-septembre 2009

Directory of Open Access Journals (Sweden)

Mathilde Cleret

2013-11-01

Full Text Available Le volume 27 de la revue Réseaux « Les usages avancés du téléphone mobile » aborde la question de la transformation des terminaux portables et de leurs usages. Il regroupe des études menées entre 2007 à 2009, dans le cadre d’un projet collaboratif « Mobile en ville » labellisé par le pôle de compétitivité Cap Digital. Il est constitué de six articles qui interrogent les nouvelles pratiques individuelles et collectives de la téléphonie mobile. Ils questionnent la façon dont s’articulent les no...

Les facteurs de motivation infirmière assurant la pérennité d'un soin de qualité afin de prévenir les infections nosocomiales en mileur hospitalier: une revue de littérature étoffée

OpenAIRE

Repond, Tracy; Rossier, Jean-Michel; Scrima, Katia

2013-01-01

Le but de cette revue de littérature est de relever les facteurs de motivation infirmière qui garantissent la pérennisation d’un comportement d’observance en ce qui concerne les mesures d’hygiène hospitalière afin de diminuer le taux d’infections nosocomiales.

Sorcières, 1976-1981. Etude d’une revue féministe. Master 1, Université de Lille III, (dir. Florence Tamagne, 2009

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Caroline Goldblum

2011-10-01

Full Text Available L’aventure Sorcières est une véritable épopée ; celle d’une revue de femmes qui voit le jour en 1976 au beau milieu de la décennie dite « des femmes » et en plein cœur de l’explosion de la presse féministe. Sorcières fut fondée par Xavière Gauthier dans le but de donner ou rendre la parole aux femmes pour qu’elles puissent exprimer leur créativité : « Je voudrais que Sorcières soit un lieu ouvert pour toutes les femmes qui luttent en tant que femmes, qui cherchent et disent (écrivent, chanten...

Carcinome à cellule vitreuse du col de l'utérus: à propos d'un cas et revue de littérature

Science.gov (United States)

Hakimi, Ihssane; Zazi, Abdelghani; Chahdi, Hafsa; Guelzim, Khalid; Kouach, Jaouad; Babahabib, Myabdellah; Elhassani, Myehdi; Rahali, Driss Moussaoui; Dehayni, Mohammed

2015-01-01

Le carcinome à cellule vitreuse du col de l'utérus est un type de histologique rare de cancer du col de l'utérus qui survient à un âge plus jeune, et s'associe au risque élevé d’échec thérapeutique et le pronostic est plus mauvais en comparaison au type cellulaire squameux. La radiothérapie est associée au risque diminué de récidive. Le but de cette étude est de récapituler à travers d'une observation et une revue de littérature les données sur l'incidence, le comportement clinique et la survie globale de patients avec le carcinome à cellule vitreuse du col de l'utérus. PMID:26664556

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

Science.gov (United States)

Piekarski, Nadine; Olsson, Lennart

2007-01-01

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

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

Science.gov (United States)

2015-08-01

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

Revue Française de Sciences Politique, n° 5-6, 2012, vol. 62, 300 p.Dossier : Retour sur les situations révolutionnaires arabes

OpenAIRE

Saradouni, Karim

2017-01-01

Ce numéro de la Revue Française de Sciences Politiques est consacré aux situations révolutionnaires dans le Monde arabe. Il se veut un retour sur les différents pays concernés par ce qu’il est convenu d’appeler « révolutions arabes ». Contrairement à la littérature prolixe en sciences sociales sur les causes et les conséquences des révolutions arabes, les contributeurs à ce dossier, interrogent, à partir des enquêtes de terrain, les situations révolutionnaires elles-mêmes et les processus qui...

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.

Revue of some dosimetry and dose assessment European projects

International Nuclear Information System (INIS)

Bolognese-Milsztajn, T.; Frank, D.; Lacoste, V.; Pihet, P.

2006-01-01

Full text of publication follows: Within the 5. Framework Programme of the European Commission several project dealing with dosimetry and dose assessment for internal and external exposure have been supported. A revue of the results of some of them is presented in this paper. The EURADOS network which involved 50 dosimetry institutes in EUROPE has coordinated the project DOSIMETRY NETWORK: the main results achieved within this action are the following: - The release on the World Wide Web of the EURADOS Database of Dosimetry Research Facilities; - The realisation of the report 'Harmonization of Individual Monitoring (IM) in Europe'; - The continuation of the intercomparisons programme of environmental radiation monitoring systems; - The realisation of the report Cosmic radiation exposure of aircraft crew. The EVIDOS project aimed at evaluating state of the art dosimetry techniques in representative workplaces of the nuclear industry with complex mixed neutron-photon radiation fields. This paper summarises the main findings from a practical point of view. Conclusions and recommendations will be given concerning characterisation of radiation fields, methods to derive radiation protection quantities and dosimeters results. The IDEA project aimed to improve the assessment of incorporated radionuclides through developments of advanced in-vivo and bioassay monitoring techniques and making use of such enhancements for improvements in routine monitoring. The primary goal was to categorize those new developments regarding their potential and eligibility for the routine monitoring community. The costs of monitoring for internal exposures in the workplace are usually significantly greater than the equivalent costs for external exposures. There is therefore a need to ensure that resources are employed with maximum effectiveness. The EC-funded OMINEX (Optimisation of Monitoring for Internal Exposure) project has developed methods for optimising the design and implementation of

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.

Carcinome épidermoïde Primitif de la Prostate: A propos d’un cas et revue de la littérature

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A. Bahloul

2016-12-01

Full Text Available Le cancer de la prostate est la tumeur maligne la plus fréquente chez l’homme. La grande majorité des tumeurs de la prostate est représentée par l’adénocarcinome prostatique (jusqu’à 95%. Le carcinome épidermoïde primitif est très rare et ne représente que 0,5% à 1% des carcinomes prostatiques. Jusqu’à 2014 seulement 24 cas ont été décrits dans la littérature. Nous rapportons un nouveau cas de carcinome épidermoide primitif de la prostate chez un jeune âgé de 48 ans diagnostiqué à un stade métastatique. Malgré une chimiothérapie à base de Cisplatine et Métoxantrone, le décès est survenu 2 mois après le diagnostic. A travers cette observation et une revue de la littérature, nous discutons les différents aspects cliniques, histologiques, thérapeutiques et pronostiques de cette tumeur.

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

Science.gov (United States)

2003-04-01

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

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

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Bryant Susan V

2009-01-01

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

Profiling neurotransmitter receptor expression in the Ambystoma mexicanum brain.

Science.gov (United States)

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

2013-03-22

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

A Formal Approach to Discourse Anaphora

Science.gov (United States)

1978-05-01

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

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

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Villiard Éric

2007-09-01

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

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

Science.gov (United States)

2010-01-01

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

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

Directory of Open Access Journals (Sweden)

Putta Srikrishna

2010-06-01

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

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...

Mbeubeuss Landfill : Exploring Options to Protect Health, the ...

International Development Research Centre (IDRC) Digital Library (Canada)

Extrants. Articles de revue. Forum urbain mondial du 19 au 23 juin 2006, Vancouver, 30 ans après Habitat I : une nouvelle vision des villes et une coalition mondiale pour agir. Articles de revue. Benefits of partnership in urban management. Articles de revue. Vertus du partenariat dans la gestion urbaine. Articles de revue.

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

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Carlos Díaz-Castillo

2017-11-01

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

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

Science.gov (United States)

2017-01-01

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

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

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

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

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

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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

Senescence gives insights into the morphogenetic evolution of anamniotes

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Éric Villiard

2017-06-01

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

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

Science.gov (United States)

Diogo, R; Tanaka, E M

2012-01-01

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

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

Science.gov (United States)

Diogo, R; Tanaka, E M

2012-12-01

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

Damned Words: The Use and Disuse of "Modern" as an Attribute for the Interpretation of Folk Customs in Theatrical Revue Stage and Costume Design at the Turn of the 1930s in Portugal

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Bártolo, Carlos

2016-07-01

Full Text Available O Notícias Ilustrado was published from 1928 to 1935, coinciding with the emergence of Salazar's dictatorship. Reporting the cosmopolitan life, it described itself as "the only graphic newspaper of modern and European appearance". Its collaborators included figures from among the Modernist generation that would later be associated with the regime's cultural policy. On its pages one can see a renewal of the theatrical revue format, it covered elements that were a repercussion of the Modernists' interest for folk art and the rediscovery of the national heritage. A straightforward analysis reveals that this reinterpretation of folk traditions was mainly addressed as modern up to the moment when an official culture policy was set; from 1933 onwards this modernity was veiled. In this analysis it could be perceived how similar works, by being addressed differently, could imply the different contexts of 1930s Portugal.

Identification et prévention du risque suicidaire chez les personnes âgées résidant en EMS: une revue de la littérature soutenue par le modèle de l'adaptation de C. Roy : travail de Bachelor

OpenAIRE

Brandtner, Yasmina; Payré, Marie; Peyrot, Marion; Vulliet, Corentine; Maupetit, Christine

2015-01-01

Introduction. Le suicide est un problème majeur en santé publique en Suisse, où le taux de suicide est élevé. En parallèle, de nombreux enjeux sont liés au vieillissement de la population, parmi lesquels la demande croissante de soins en résidence médicalisée. Il existe peu de données sur les comportements suicidaires dans les nursing homes. Le but de cette revue synthétique de la littérature est de décrire l’épidémiologie du phénomène du suicide en nursing home, les facteurs de risques et le...

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

Science.gov (United States)

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

2015-06-02

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

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

Science.gov (United States)

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

2018-01-12

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

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

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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.

A lunguistica pour ses quarante ans

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Ludvik Horvat Le Doyen

2000-12-01

Full Text Available En tant que doyen de la Faculté des Lettres de l'Universite de Ljubljana, j'ai l'honneur d'introduire le volume qui celebre les quarante ans de publication de cette revue linguistique. La parution de la revue conçua à l' origine comme supplàment pour la linguistique non slave de la revue Slavistična revija (dont la renommée était déjà affirmée, eut lieu en 1958. Ses inspirateurs, ses fondateurs et ses premiers directeurs, auxquels nous gardons une profonde reconnaissance, furent l'italianiste Stanko Škerlj et le latiniste Milan Grošelj, professeurs de notre Faculté. Des sa quatrieme année ce modeste supplement devint revue autonome, telle que nous la connaissons aujourd'hui.

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

REVUE GENERALE

African Journals Online (AJOL)

MIN

Le trophoblaste humain se compose d'une population cellulaire hétérogène qui peut donner naissance à une variété de lésions trophoblastiques que l'on regroupe sous le terme de maladies .... cerveau et le foie sont les sites métastatiques les plus fréquents suggérant une dissémination hématogène prédominante.

Les Archives de l’anthropologie criminelle

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Martine Kaluszynski

2005-01-01

Full Text Available Un instrument moteur : La Revue, une ville destinée : LyonLa revue les Archives de l’anthropologie criminelle a plusieurs objectifs, politique en menant un débat avec Lombroso, un objectif scientifique, A. Lacassagne est avant tout le promoteur ambitieux de cette idée qui ne l’est pas moins, créer ce qui manquait alors aux chercheurs français dispersés : un organe. Un objectif “humain” enfin, puisque cette revue rassemble autour d’elle curieux, érudits, hommes de la profession ou tout autre.....

Advancing Knowledge and Practice to Systems Thinking to ...

International Development Research Centre (IDRC) Digital Library (Canada)

Extrants. Articles de revue. Advancing the application of systems thinking in health: advice seeking behavior among primary health care physicians in Pakistan. Articles de revue. Advancing the application of systems thinking in health : a realist evaluation of a capacity building programme for district managers in Tumkur, ...

Répercussions des techniques de procréation assistée sur les droits ...

International Development Research Centre (IDRC) Digital Library (Canada)

Critique of the Draft ART (Regulation) Bill and Rules, 2010. 46631. Dossiers. Welcome kit for parliamentarians policy brief : assisted reproductive technologies (ARTs). Téléchargez le PDF. Articles de revue. Abetting surrogacy. Téléchargez le PDF. Articles de revue. Assisted reproductive technologies : for whose benefit?

IMS Learning Design : la flexibilité pédagogique au service des besoins de la e-formation

NARCIS (Netherlands)

Burgos, Daniel; Arnaud, Michel; Neuhauser, Patrick; Koper, Rob

2005-01-01

Burgos, D., Arnaud, M., Neuhauser, P., Koper, R. IMS Learning Design : la flexibilité pédagogique au service des besoins de la e-formation. In La Revue de l'EPI. France: L'association Enseignement Public et Informatique [http://www.epi.asso.fr/revue/articsom.htm]. Available at

Petites considérations polémiques et néanmoins objectives sur la recherche (en littérature) et sa diffusion (électronique)

OpenAIRE

Dozo, Björn-Olav; Provenzano, François

2012-01-01

Le présent article fait écho à certains débats qui traversent les milieux de la recherche en sciences humaines et sociales. Les acteurs de la diffusion de la recherche se réunissent (compte rendu de la rencontre qui s’est tenue au 16e salon de la revue, ayant pour thème : « revues de sciences humaines au temps d'Internet : quelles promesses ? Quelles menaces ? »), une liste de diffusion/ discussion concernant les revues en Sciences Humaines et Sociales a été créée, différents acteurs (http://...

Éditorial

Directory of Open Access Journals (Sweden)

2008-04-01

Full Text Available Ce (double numéro de la Revue Archéologique du Centre de la France, qui paraît avec un peu de retard, marque en réalité la fin de la transformation de la revue papier vers l’électronique. Nos autorités scientifiques et administratives, qui ont dû faire face à d’innombrables difficultés, portent la responsabilité de ces hésitations, mais nous pouvons espérer que désormais les nouvelles structures de production, en la matière Revue.org, non seulement ne changeront plus mais surtout qu’elles ap...

Éditorial

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Nicole Rege Colet

2009-04-01

Full Text Available Au printemps 2006, Res Academica, la revue de l’Association internationale de pédagogie universitaire est entrée dans une phase de métamorphose. Guidée par le besoin d’améliorer la gestion et la production de la revue et d’en rationaliser le travail, motivée par le souci de proposer une revue en langue française de haut niveau scientifique dans le domaine de la pédagogie universitaire et de l’enseignement supérieur, l’AIPU a souhaité que Res Academica évolue pour répondre aux attentes de ses ...

Utilisation des terres, biocombustibles et développement rural dans l ...

International Development Research Centre (IDRC) Digital Library (Canada)

Soybean and the contribution of oilseeds to biodiesel production in Brazil. 47420. Articles de revue. Changes in hydrology and salinity accompanying a century of agricultural conversion in Argentina. Téléchargez le PDF. Articles de revue. Evaluating the consistency of the 1982-1999 NDVI trends in the Iberian Peninsula ...

High Flight: History of the U.S. Air Force Academy

Science.gov (United States)

2009-09-01

Modern Language Review/La Revue Canadienne des Langues Vivantes 64.1 (2007): 39-67. Gowaskie, Joe. "The Teaching of World History: A Status Report...Modern Language Review/La Revue Canadienne des Langues Vivantes 64.1 (2007): 39-67. Godrey, Mark F., Bruce A. Smith and Jock C.H. Schwank. "Visual

Collaboration pour l'analyse et l'innovation en matière de systèmes ...

International Development Research Centre (IDRC) Digital Library (Canada)

School health in South Africa : reflections on the past and prospects for the future. Téléchargez le PDF. Articles de revue. Health policy and systems research : needs, challenges and opportunities in South Africa - a university perspective. Téléchargez le PDF. Articles de revue. Whole-system change : case study of factors ...

Le Mouvement Social

OpenAIRE

FRIDENSON, Patrick

2003-01-01

J'ai la faiblesse d'affirmer que parmi les revues françaises d'histoire Le Mouvement Social est la revue qui a publié le plus d'articles et de comptes rendus en matière d'histoire des femmes et du gender. Chacun peut le vérifier grâce à nos pages Web sur le site Internet du Dictionnaire créé par Jean Maitron. Elles comportent la table des matières complète de la revue depuis sa fondation en 1960. Notre rédaction est extrêmement fière de ce résultat. Mais elle reconnaît qu'il a été difficile à...

Répertoire des thèses (2006 - mars 2011

Directory of Open Access Journals (Sweden)

2011-04-01

Full Text Available En Belgique francophonede Marneffe (Daphné, Entre modernisme et avant-garde. Le réseau des revues littéraires de l’immédiat après-guerre en Belgique (1919-1922Mots-clés : littérature belge, sociabilités intellectuelles, réseau, revues littéraires, modernisme, avant-garde.Langue du manuscrit :  françaisRésumé : L’ensemble des revues littéraires « modernistes et d’avant-garde » parues en Belgique immédiatement après la première guerre mondiale (jusqu’en 1922 est étudié dans une perspective d...

Répertoire des thèses 2006-2010

Directory of Open Access Journals (Sweden)

2010-12-01

Full Text Available En Belgique francophonede Marneffe (Daphné, Entre modernisme et avant-garde. Le réseau des revues littéraires de l’immédiat après-guerre en Belgique (1919-1922Mots-clés : littérature belge, sociabilités intellectuelles, réseau, revues littéraires, modernisme, avant-garde.Langue du manuscrit :  françaisRésumé : L’ensemble des revues littéraires « modernistes et d’avant-garde » parues en Belgique immédiatement après la première guerre mondiale (jusqu’en 1922 est étudié dans une perspective d...

Aquaculture intérieure et adaptation aux changements climatiques ...

International Development Research Centre (IDRC) Digital Library (Canada)

Téléchargez le PDF. Articles de revue. Learning about climate-related risks: decisions of Northern Thailand fish farmers in a role-playing simulation game. Téléchargez le PDF. Articles de revue. Effect of Water De-stratification on Dissolved Oxygen and Ammonia in Tilapia Ponds in Northern Thailand. Téléchargez le PDF.

Plan d'action stratégique du ROCARE - 2007-2011 | CRDI - Centre ...

International Development Research Centre (IDRC) Digital Library (Canada)

Téléchargez le PDF. Articles de revue. Recherche en éducation : 21 équipes bénéficient du programme de petites subventions Rocare 2007. Téléchargez le PDF. Articles de revue. Côte d'Ivoire : le réseau ouest africain de recherche en éducation (ROCARE) organise un séminaire sur la rédaction scientifique à Abidjan.

Surveillance urinaire des professionnels de la santé exposés aux antinéoplasiques dans le cadre de leur travail: revue de la littérature de 2010 à 2015

Science.gov (United States)

Poupeau, Céline; Roland, Christel; Bussières, Jean-François

2016-01-01

RÉSUMÉ Contexte Il existe de plus en plus de données sur la présence de traces de médicaments dangereux dans l’urine des professionnels de la santé exposés à ces médicaments. Objectif Présenter une revue de la littérature scientifique concernant la surveillance urinaire de professionnels de la santé exposés aux anti-néoplasiques dans le cadre de leur travail. Sources de données Recherche sur PubMed avec les Medical Subject Headings (MeSH) « occupational exposure » et « antineoplastic agents » ainsi que sur Google Scholar avec les termes « antineoplastic », « urine » et « occupational exposure ». Sélection des études et extraction des données L’examen a porté sur tous les articles en anglais et en français ayant trait aux professionnels de la santé exposés à des médicaments dangereux dans le cadre de leur travail, publiés entre le 1er janvier 2010 et le 31 décembre 2015. Les articles ne comportant pas de résultats urinaires et ceux concernant les vétérinaires ainsi que les revues de littérature, les éditoriaux, les lettres à la rédaction et les résumés de congrès ont été exclus. Synthèse des données Vingt-quatre articles ont été retenus. Les études ont été menées dans 52 établissements de santé provenant de sept pays. Elles regroupaient 826 travailleurs exposés à des médicaments dangereux et 175 témoins, notamment des infirmiers (n = 16 études), des pharmaciens (n = 10), des assistants techniques en pharmacie (n = 8), des médecins (n = 7), des aides-soignants (n = 2) et autres (n = 8). Différentes méthodes analytiques ont été utilisées pour quantifier la présence de 13 médicaments dangereux, principalement le cyclophosphamide (n = 16 études), les platines (n = 7) et l’alpha-fluoro-béta-alanine, un métabolite urinaire du 5-fluorouracile (n = 3). La proportion de travailleurs qui ont étés déclarés positifs s’étendait de 0 % (n = 10 études) à 100 % (n = 4). Si l’on ne retient que

Empirical Assessment of Lanius et al.s’ ’Functional MRI of EMDR in Peacekeepers’, a Review of the EMDR Literature and an annotated bibliography

Science.gov (United States)

2002-07-01

au fonctionnement du cerveau lors du SSPT (par exemple, le CRSNG ou les IRSC). Fait important, une revue critique de la recherche sur la...organismes de financement pour financer les recherches sur les processus de neurosciences 6ldmentaires associ~s au fonctionnement du cerveau dans le cas du...fonctionnement du cerveau lors du SSPT (par exemple, le CRSNG ou les IRSC). Fait important, une revue critique de la recherche sur la drsensibilisation des

Diversité, nuisances et modes de gestion des termites (Isoptera ...

African Journals Online (AJOL)

Ce travail présente la première liste des espèces de termites recensées, une revue de la littérature de leurs dégâts sur les essences botaniques et leurs modes de gestion dans les agrosystèmes au Sénégal entre 1966 et 2015. Elle a été faite sur la base d'une revue bibliographique existante et complétée par un récent ...

Building a New South Africa Volume 1 : Economic Policy | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

Un numéro spécial de la revue met en lumière les conclusions d'une étude financée par le CRDI sur le travail rémunéré des femmes. Policy in Focus publie un numéro spécial présentant des données probantes sur l'autonomisation des femmes sur le marché du travail. Voir davantageUn numéro spécial de la revue met en ...

Social Policy in a Global Society : Parallels and Lessons from the ...

International Development Research Centre (IDRC) Digital Library (Canada)

Un numéro spécial de la revue met en lumière les conclusions d'une étude financée par le CRDI sur le travail rémunéré des femmes. Policy in Focus publie un numéro spécial présentant des données probantes sur l'autonomisation des femmes sur le marché du travail. Voir davantageUn numéro spécial de la revue met en ...

2523-IJBCS-Article-Cheikh Amet Bassirou Sane

African Journals Online (AJOL)

hp

Ce travail présente la première liste des espèces de termites recensées, une revue de la littérature de leurs dégâts sur les essences botaniques et leurs modes de gestion dans les agrosystèmes au Sénégal entre 1966 et 2015. Elle a été faite sur la base d'une revue bibliographique existante et complétée par un récent ...

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...

Odborný zájem o menšiny na počátku 20. století a menšinové muzeum v Praze

Czech Academy of Sciences Publication Activity Database

Sulitka, Andrej

-, č. 1 (2014), s. 225-237 ISSN 0323-0619 Institutional support: RVO:68378076 Keywords : Czech minority trade unions in the early 20th century * Czech-German coexistence * Czech minorities in border areas * professional interest in minorities * the emergence of Minority Museum in Prague 1909 * The activities of the Museum * Private population census * questionnaire survey * publishing activity * Minority revue (1912-1913)/Menšinová revue (1912-1913) * Minority proceedings (1914)/Sborník menšinový (1914) Subject RIV: AC - Archeology, Anthropology, Ethnology

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

NARCIS (Netherlands)

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

1982-01-01

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

Development and regulation of response properties in spinal cord motoneurons

DEFF Research Database (Denmark)

Perrier, J F; Hounsgaard, J

2000-01-01

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

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

Science.gov (United States)

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

2016-08-01

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

TRACKING STEM CELLS IN AN INHERENTLY REGENRATIVE ENVIRONMENT

DEFF Research Database (Denmark)

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

2012-01-01

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

Recherches en didactique des mathématiques Volume 29/2 - 2009

OpenAIRE

Dorier, Jean-Luc; Robert, Aline

2009-01-01

La revue Recherches en didactique des mathématiques entend rendre compte des recherches fondamentales menées dans le cadre de la Didactique des Mathématiques. Il s’agit d’une revue de recherche qui publie des articles originaux concernant : - la détermination des faits pertinents de la communication didactique ; - l’analyse de situations d’enseignement créées par les professeurs ou proposées par l’expérimentateur ; - l’analyse des conduites et productions des élèves au cours d’un apprentissag...

Elisabeth Badinter, Fausse route

OpenAIRE

Martin-Juchat, Fabienne

2013-01-01

Elisabeth Badinter, philosophe de formation, est l’auteure de nombreux ouvrages sur la condition féminine et les rapports hommes/femmes dans la société. Avec Fausse route, elle signe une vision polémique du féminisme occidental. Son ouvrage a suscité de nombreuses critiques de femmes dans diverses revues destinées au grand public. Hélène Strohl, recenseur de la revue Culture en mouvement, conclut que cet ouvrage est peu scientifique, sujet à caution : « Argument contre argument, amalgame cont...

American Studies Association — Crossroads of Cultures, Atlanta, Ga., Nov. 11-14, 2004

OpenAIRE

Pothier, Jacques

2006-01-01

Dans le cadre de son congrès annuel et à l’initiative de sa présidente en exercice, Shelley Fisher Fishkin, l’American Studies Association avait lancé une International Initiative : inviter les représentants de toutes les associations d’études américaines du monde. Parallèlement, American Quarterly, la revue de l’Association, invitait les directeurs des rédactions des revues américanistes.Je représentais donc l’AFEA, la RFEA et Transatlantica.Qu’est-ce que l’American Studies Association ?Le C...

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.

Visualisation of animal anatomy using MRI and CT

DEFF Research Database (Denmark)

Lauridsen, Henrik; Hansen, Kasper; Pedersen, Michael

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

Evolution of the head-trunk interface in tetrapod vertebrates

Science.gov (United States)

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

2016-01-01

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

revue bibliographique des représentations analytiques de coefficients d'activité ioniques moyens dans les solutions binaires électrolytiques Bibliographic Review of Analytic Equations of Mean Lonic Activity Coefficients in Electrolytic Binary Solutions

Directory of Open Access Journals (Sweden)

Cruz J. -L.

2006-11-01

Full Text Available Le calcul de certaines propriétés à l'équilibre, de systèmes électrolytiques, nécessite la connaissance des coefficients d'activité en phase liquide des constituants de ces systèmes. L'estimation du coefficient d'activité ionique moyen de l'électrolyte permet, pour des systèmes binaires, de calculer ces coefficients d'activité. Dans cette revue bibliographique sont présentées les principales expressions analytiques, de coefficients d'activité ioniques moyens, fournies par la littérature. II est possible de classer ces expressions en plusieurs grandes catégories en fonction des modèles dont elles dérivent. Des critères de choix, de l'une ou l'autre de ces équations, sont proposés suivant le type de système électrolytique et le domaine de concentration étudiés. Liquid-phase activity coefficients must be known in order to calculate various equilibrium properties of electrolytic systems. For binary systems, these coefficients can be calculated by estimating the mean ionic activity coefficient of the electrolyte. This bibliographic review describes the principal analytic equations for mean ionic activity coefficients found in the literature. These equations can be classified in several major categories according to the theoretical model from which they are derived. Some criteria are proposed for choosing one or another of these equations on the basis of the type of electrolytic system and the concentration range studied.

Transformation

OpenAIRE

Magnani, Eliana

2012-01-01

Avec le numéro 16, le Bucema inaugure une nouvelle formule éditoriale et de diffusion. Doté maintenant d’un comité de rédaction et d’un conseil scientifique, ayant mis en place une démarche d’évaluation des contributions, le Bucema devient une revue à comité de lecture consacrée aux études sur le Moyen Âge, tournée vers la communauté scientifique internationale. La nouvelle politique éditoriale de la revue, outre le souci d’exigence scientifique, met l’accent sur l’interdisciplinarité — scien...

Présentation

Directory of Open Access Journals (Sweden)

Anne Herschberg Pierrot

2009-01-01

Full Text Available Ce premier dossier de la revue Flaubert. Revue Critique et Génétique réunit des recherches récentes de la génétique flaubertienne et de la critique sur Flaubert. À partir de la première Tentation de saint Antoine, mais surtout de Salammbô à Bouvard et Pécuchet, Flaubert inaugure un travail d’écrivain-chercheur, puisant dans les sources antiques et contemporaines non de simples renseignements, mais un ensemble de discours, sur l’antiquité et sur le monde moderne, qui servent de tremplin à l’im...

Présentation

OpenAIRE

Anne Herschberg Pierrot

2009-01-01

Ce premier dossier de la revue Flaubert. Revue Critique et Génétique réunit des recherches récentes de la génétique flaubertienne et de la critique sur Flaubert. À partir de la première Tentation de saint Antoine, mais surtout de Salammbô à Bouvard et Pécuchet, Flaubert inaugure un travail d’écrivain-chercheur, puisant dans les sources antiques et contemporaines non de simples renseignements, mais un ensemble de discours, sur l’antiquité et sur le monde moderne, qui servent de tremplin à l’im...

Éditorial

Directory of Open Access Journals (Sweden)

Esther Cloutier

2007-05-01

Full Text Available Bonjour, Nous sommes heureux de vous présenter ce nouveau numéro de la revue PISTES. Nous voulons tout d’abord vous informer que notre revue est maintenant indexée dans PsycInfo ce qui constitue une nouvelle reconnaissance scientifique. Nous tenons à remercier tous les collaborateurs qui ont contribué à ce succès. Ce numéro aborde plusieurs thèmes de recherche reliés au travail et à la santé des personnes. En premier lieu, Geneviève Baril-Gingras, Marie Bellemare et Jean-Pierre Brun présenten...

Éditorial

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Joanne Vajda

2011-06-01

Full Text Available La revue In Situ, revue des patrimoines a ouvert ses colonnes à l’équipe de recherche qui travaille depuis 2006 sur les guides de voyage et de tourisme à travers une collaboration entre le Pôle des Sciences de la Ville (Université Paris Diderot-Paris 7, le Centre André Chastel (Université Paris Sorbonne-Paris IV et la Direction Générale des Patrimoines (Ministère de la Culture et de la Communication. En 2010, le cercle des partenaires s’est élargi à l’École nationale supérieure des science...

ELLE : un outil d’émancipation de la femme entre journalisme et littérature 1945-1960 ?

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Karine Grandpierre

2012-05-01

Full Text Available ELLE est un magazine international, sur une tranche haut de gamme, véhiculant des modes, au-delà des modèles exclusivement français. Le propos de sa créatrice Hélène Gordon-Lazareff était : Faire un journal de mode, mais pas seulement. Un journal moderne. Pratique. Avec des photos. Donc des photographes. Mais qui ne soit pas une revue. D’ailleurs, les revues comme Vogue faisaient la part belle à l’illustration, et peu à la photo. Un journal qui s’adresse à toutes les femmes. Et qui soit cepen...

Comment les différences entre consommateurs francophones et néerlandophones sont-elles perçues et prises en compte par les professionnels du marketing en Belgique, dans le domaine du B2C ?

OpenAIRE

Willems, Robin

2015-01-01

L'objectif du mémoire est de comprendre comment les différences entre les consommateurs francophones et néerlandophones de Belgique sont perçues et prises en compte par les professionnels du marketing dans le domaine du B2C. La méthodologie d'étude consiste premièrement en une revue de la littérature sur les thèmes du marketing multiculturel et des différences entre francophones et néerlandophones de Belgique. Sur base de cette revue de littérature et d'interviews, des hypothèses de recherche...

Développement folliculaire ovarien et ovulation chez les mammifères

OpenAIRE

Monniaux , Danielle; Caraty , Alain; Clement , Frederique; Dalbiès-Tran , Rozenn; Dupont , J.; Fabre , Stéphane; Gérard , N.; Mermillod , Pascal; Monget , Philippe; Uzbekova , Svetlana

2009-01-01

Cette revue présente l’état des connaissances sur la folliculogenèse et l’ovulation chez les mammifères. La folliculogenèse basale est une phase de croissance folliculaire lente, au cours de laquelle l’ovocyte acquiert la compétence méiotique. La folliculogenèse terminale est une phase de développement rapide, au cours de laquelle le follicule ovulatoire est sélectionné et termine sa maturation, tandis que l’ovocyte acquiert la compétence au développement. La revue décrit les différents chang...

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...

Les cinq premières années de Sociologie

OpenAIRE

Paugam, Serge

2015-01-01

Sociologie a publié son premier numéro en 2010. Nous fêtons donc avec le numéro 1 de 2015 son cinquième anniversaire. Plusieurs revues de sociologie ont été créées en 1960, notamment la Revue française de sociologie, Sociologie du travail et les Archives européennes de sociologie. Elles constituent aujourd’hui des références incontournables pour les sociologues. Trouver sa place, cinquante après, dans ce paysage éditorial n’allait pas de soi et d’aucuns ont vu dans la création de Sociologie u...

La place de la relation soignant-soigné dans l'approche de soins transculturelle: travail de Bachelor

OpenAIRE

De Beul, Nathalie; Martinez, Cristian; Toppo, Marie-Laure; Diby, Marc

2014-01-01

Introduction: En Suisse, en lien avec le phénomène migratoire, la prise en soin de patients de culture différente se révèle être fréquente. L’approche des soins transculturelle est déjà abordée par d’autres disciplines. Objectif: L’objectif de cette revue de littérature est de définir quelle est la place de la relation soignant-soigné dans l’approche de soins transculturelle. Méthode: Revue de littérature utilisant les bases de données Pubmed, Cinahl, Psychinfo entre 2000 et 2014. Sur 7'761 a...

Contributions à l’institutionnalisme commonsien. Une introduction

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Jean-Jacques Gislain

2010-12-01

Full Text Available Depuis quelques années l’économie politique francophone s’intéresse au cadre d’analyse institutionnaliste élaboré par John Rogers Commons (1862-1945. Outre de nombreux articles épars dans diverses revues économiques, plusieurs numéros spéciaux de revue lui ont été consacrés. Un ouvrage de référence est disponible sur cet auteur et, régulièrement, des ateliers de colloque lui sont consacrés ; un colloque international lui ayant été exclusivement consacré en 2008. Sous la direction de Bruno Th...

Título da página electrónica: Multitudes Web

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Pedro Araújo

2012-10-01

Full Text Available Página de uma revista política, cultural e artística votada à análise de todas as formas de dominação e dos movimentos sociais visando a emancipação social. Além da Revue Multitudes, disponível online, encontram-se igualmente na página análises da actualidade, um espaço de debate, complementos à revista com diversas contribuições internacionais e um arquivo onde é possível aceder às revistas Futur Antérieur e Alice, Revue Critique du Temps. A revista Multitudes integra a rede Eurozine.

Éditorial

Directory of Open Access Journals (Sweden)

Françoise Demaizière

2009-12-01

Full Text Available Ce volume 12, 2009 d'Alsic est le premier volume à être publié d'emblée sur le portail de revues.org. Nous remercions l'équipe de revues.org pour son aide dans ce qui fut, pendant cette année, un apprentissage de nouvelles procédures de mise en ligne pour plusieurs d'entre nous. Merci également à Cécile Zanetta qui nous accompagne dans cette aventure. Le volume a été légèrement affecté par les changements dans la chaîne d'édition et quelques articles que nous aurions souhaité publier en 2009 ...

La sélection d'Aldébaran

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Françoise Acquier

2014-09-01

Full Text Available Aldébaran est une revue électronique en libre accès qui propose une sélection de ressources documentaires en sciences humaines à travers des notices de sites et des conseils de recherche. Les notices présentées dans ce numéro ont été rédigées par Françoise Acquier (CRESSON, Grenoble, Fabrice Melka (IMAF, Julien Gillet (Cléo et Véronique Ginouvès (MMSH USR3125. Afriterra. The Cartographic Free Library http://aldebaran.revues.org/6775 La fondation Afriterra, à but non lucratif, est une bibl...

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.

Book Reviews / Revues de Livres

African Journals Online (AJOL)

Winnie

environmental and cultural forces as these interact with personal and interpersonal factors.The section includes a discussion on the prevalence of risky sexual ... therapy in South Africa fail to integrate treatment and prevention, the epidemic is likely to continue to rise'. Section 4 discusses issues related to 'focal groups' or.

Revue Burkinabè de droit

African Journals Online (AJOL)

la RBD se compose de trois parties : doctrine - jurisprudence - chronique de législation. La partie doctrine comprend des articles de droit de burkinabè, écrits essentiellement par les enseignants de l'UFR/Sciences Juridiques et Politiques. La partie jurisprudence comprend une sélection des décisions et arrêts des ...

Book Reviews / Revues de Livres

African Journals Online (AJOL)

epidemic is shifted to rural areas as migrant workers return to their homes once full-blown AIDS has evolved.This cost is increased as support from the ... significant portion of production as well as employing the majority of workers. In addition, small-scale and subsistence agriculture remains an important component of ...

La sélection d'Aldébaran

Directory of Open Access Journals (Sweden)

Françoise Acquier

2013-12-01

Full Text Available Aldébaran est une revue électronique en libre accès qui propose une sélection de ressources documentaires en sciences humaines à travers des notices de sites et des conseils de recherche. Les notices présentées dans ce numéro ont été rédigées par Véronique Ginouvès (MMSH USR3125 et Françoise Acquier (CRESSON. Arab Cinema Directory [http://aldebaran.revues.org/6945] Le site  « Arab Cinema Directory » rassemble des informations sur plus de 6 500 films arabes depuis les années 1930 jusqu'à auj...

L'impact de la relation soignant-soigné dans la prise en soin de la douleur aigüe en post-opératoire chez l'adulte: travail de Bachelor

OpenAIRE

Ferrero, Mathilde; Gaspar, Catherine; Pacini, Wendy

2017-01-01

Contexte : L’incidence de la douleur post-opératoire (DPO) n’a cessé d’augmenter ces dernières années. Elle constitue une préoccupation majeure au vu de ses effets délétères sur la qualité de vie et sur le système de santé. Les infirmiers-ères occupent une place centrale dans la gestion de l’antalgie. Objectif : L’objectif de cette revue de littérature est d'identifier l’impact de l’interaction soignant-soigné dans la prise en soin de la douleur post-opératoire. La revue de la littérature est...

Boris Mouravieff, Écrits sur Ouspensky, Gurdjieff et sur la Tradition ésotérique chrétienne

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Olivier Santamaria

2009-06-01

Full Text Available La maison Dervy vient de publier, à l’initiative de l’Association Boris Mouravieff, un recueil d’une dizaine articles parus entre 1954 et 1961 notamment dans la « Revue Suisse d’Histoire » et dans la revue belge « Synthèses », lesquels étaient devenus à peu près introuvables. Les sujets abordés sont divers : certains articles traitent de théologie politique (« Le problème de l’homme nouveau », « Liberté, égalité, fraternité », « L’Histoire a-t-elle un sens ? » ou d’histoire religieuse (« Des...

Une transition toute en douceur

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Denys Denis

2011-05-01

Full Text Available C’est avec beaucoup de fierté que nous vous présentons ce premier numéro de l’année 2011 qui marque notre entrée en fonction à titre de coéditeurs de la revue. Bien que présent(es sur le comité d’édition depuis de nombreuses années, nous réalisons maintenant l’ampleur du travail accompli par nos prédécesseurs – fondateurs de la revue – pour vous assurer des parutions de qualité, fidèles à la tradition établie depuis maintenant 13 ans. Beaucoup de travail certes, mais qui s’accompagne d’un pl...

Maltraitance envers les enfants déclarée par les jeunes eux-mêmes à l'occasion d'enquêtes représentatives de la population : revue systématique

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Jessica Laurin

2018-01-01

Full Text Available Introduction : Cette revue systématique a permis de recenser des enquêtes sur les jeunes représentatives de la population et comportant des questions sur la maltraitance envers les enfants déclarée par ces derniers. Nous avons également examiné la qualité des données et les questions d’ordre éthique pertinentes pour la collecte de données sur la maltraitance. Méthodologie : Nous avons effectué une recherche dans diverses bases de données en ligne pour sélectionner les articles publiés entre janvier 2000 et mars 2016 qui contenaient des données représentatives de la population mesurant la maltraitance envers les enfants. Les critères d’inclusion ont été établis a priori et deux examinateurs ont évalué indépendamment l'un de l'autre les articles pour s’assurer que les critères étaient respectés et pour vérifier l’exactitude des données extraites. Résultats : Au total, 73 articles portant sur 71 enquêtes ont répondu aux critères d’inclusion. Nous avons relevé diverses stratégies visant à assurer l’exactitude des renseignements et à atténuer la détresse des participants à l’enquête. Conclusion : L'ampleur des efforts déployés pour mesurer la prévalence de la maltraitance envers les enfants est le reflet de l'importance accordée à cette dernière à l'échelle de la planète. Malgré des connaissances incomplètes en matière de pratiques exemplaires liées à l’éthique et de qualité des données, il est possible de recueillir efficacement auprès des jeunes eux-mêmes des données sur la maltraitance dont ils font l'objet.

IFRS 9 : Nieuwe waarderingsgrondslagen voor financiële instrumenten

NARCIS (Netherlands)

Vergoossen, R.G.A.

2009-01-01

De International Financial Reporting Standards (IFRSs) krijgen wereldwijd steeds meer voet aan de grond. Desalniettemin is er kritiek op de IFRSs. In dit artikel passeren een aantal kritiekpunten de revue.

Editorial

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Christian Lefèvre

2009-12-01

Full Text Available Bernard Jouve nous a quittés en avril dernier. L’idée de monter une revue en ligne sur la question des métropoles est venue de lui. C’est Bernard qui m’a convaincu de l’intérêt et du bien fondé d’une telle aventure et en 2005 c’est lui qui a pris son bâton de pèlerin pour trouver les ressources financières pour donner corps à ce projet. Depuis je peux dire, que même si nous étions co-rédacteurs en chef, c’est encore lui qui assurait la plus grosse part du travail. Aujourd’hui la revue est orp...

Îles et continents

OpenAIRE

Resztak, Karolina; Sanson, Hervé

2017-01-01

Ce numéro huit de la revue Continents manuscrits, à l’enseigne des « Iles et continents », se veut un numéro de varias, une fois n’est pas coutume. Iles et continents car : du Congo aux Antilles, en passant par l’Amérique du Nord, le numéro assume sa géographie plurielle, polycentrée. Le panorama d’auteurs représentés dans la revue est riche et varié : de Joseph Zobel à Sony Labou Tansi, d’Aimé Césaire à Nathanaël, ou René Maran, c’est bien des cartographies mises en relation que ce numéro té...

La Bohême aux XIVe et XVe siècles

Czech Academy of Sciences Publication Activity Database

Nejedlý, Martin; Svátek, Jaroslav

-, č. 67 (2014), s. 5-10 ISSN 0751-2708 Institutional support: RVO:67985955 Keywords : Bohemia * Late Middle Ages * Hussites * Czech literature Subject RIV: AB - History http:// medieval es.revues.org/7362

JOURN AL OFTHE CAMEROON ACADEMY OFSCIENCES

African Journals Online (AJOL)

implications in education for Information professionals have been drawn and relationships to the ... REVUE DE LACADEMIE DES SCIENCES Dt} CAMEROUN Vol.2 No.1 (2002) ..... ematical equality between the goals and the achievements.

African Journal of Science and Technology

African Journals Online (AJOL)

PROMOTING ACCESS TO AFRICAN RESEARCH ... The African Journal of Science and Technology (AJST) is a biannual technical publication ... Le Journal Africain de Science et de Technologie est une revue scientifique du Journal Africain ...

Ecohealth Emerging Infectious Diseases Research Initiative (EcoEID)

International Development Research Centre (IDRC) Digital Library (Canada)

The emphasis will be on capacity building, networking and policy impact at the regional level. Lessons learned from .... Articles de revue. Disability weight of Clonorchis sinensis infection : captured from community study and model simulation.

Gestion des côtes marocaines : renforcement des capacités d ...

International Development Research Centre (IDRC) Digital Library (Canada)

-lying coastal zone of Mediterranean East Morocco. Download PDF. Journal articles. Revue de presse succincte sur les activités du projet ACCMA. Download PDF. Journal articles. Challenges and possibilities in climate change education.

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

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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

L'apprentissage des langues médiatisé par les technologies (ALMT – Étude d'un domaine de recherche émergent à travers les publications de la revue Alsic Technology-mediated language learning: an emergent research domain under study through the review of a French scientific journal's publications

Directory of Open Access Journals (Sweden)

Nicolas Guichon

2012-11-01

Full Text Available Dans cette étude, il est postulé que l'apprentissage des langues médiatisé par les technologies (ALMT est un domaine de recherche qui s'intéresse au développement et à l'intégration des technologies dans l'enseignement-apprentissage d'une langue. Ce domaine étant émergent, la présente recherche vise tout d'abord à comprendre comment s'est formée la communauté de chercheurs autour de cet objet. Puis, à travers l'analyse critique de 79 articles publiés dans la revue en ligne francophone Alsic entre 1998 et 2010, la présente contribution s'emploie à définir les contours épistémologiques de ce domaine en étudiant les moyens de production de connaissance.In this study, it is postulated that technology mediated language learning is a research domain that focuses on the design and integration of technologies for language learning and teaching. Because this domain is emergent, the present study first aims at understanding how a community of researchers has developed around this object. Then, thanks to the critical analysis of 79 articles published in Alsic, a French-speaking online journal, the present article endeavours to define the epistemological contours of this research domain by studying the means employed to produce knowledge.

Le CERN et les Institutions

CERN Document Server

Barbalat, Oscar

1996-01-01

Une première partie de l'exposéŽ sera consacrée àˆ une brève description des principaux organes de l'Union EuropéŽennne: Conseil, Parlement et Commission ainsi que la structure de la Commission. On passera ensuite en revue le Programme-Cadre de Recherche et DéŽveloppement Technologique et les principaux programmes spéŽcifiques auxquels participe le CERN (ESPRIT, ACTS, TMR) On situera ensuite les autres organisations et initiatives scientifiques européŽennes (ESA, ESO, ESRF, JET, ISTC, EUREKA, ...) pour terminer par une brève revue des relations entre le CERN avec ces difféŽrentes institutions en déŽveloppant plus particulièrement celles avec la Commission.

L'archéologie des lieux d'exécution en République Tchèque et en Basse-Silésie (Pologne)

Czech Academy of Sciences Publication Activity Database

Mašková, Pavlína; Wojtucki, D.

-, 05 janvier (2016), s. 1-20 E-ISSN 2108-6907 Institutional support: RVO:67985955 Keywords : gallows * burials of the executed criminals * atypical, deviant burials * disreputable persons Subject RIV: AB - History https://criminocorpus.revues.org/3115

Saksamaa teatrilavadel taas 1920. aastad / Erkki Otsman

Index Scriptorium Estoniae

Otsman, Erkki, 1966-

2006-01-01

Berliinis ja Hamburgis nähtud kabaree-etendustest : Bertolt Brechti "Kolmekrossiooper" Berliini uues teater-kontserdisaalis Admiralspalast (lavastaja Klaus Maria Brandauer), Max Raabe ja Palast Orchesteri kontsertetendus "Palast Revue" Hamburgi Thalia teatris, Georgette Dee kontsert Brechti lauludest

Ambulance Services of Lagos State, Nigeria

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Nous avons revu le nombre et le type des urgences ... system and make recommendations for further improvement. SUBJECTS ... the majority of the cases that were seen with road traffic accident ... Departments (ED), the control rooms and.

Agronomie Africaine: Editorial Policies

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, (AISA), leur Association, d'une Revue Scientifique dénommée "AGRONOMIE AFRICAINE" (Agron. Afr.) les chercheurs Ivoiriens engagés dans la recherché agronomique entendent apporter leur modeste contribution la diffusion de ...

qualite des rejets industriels textiles et ses repercussions

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client

plantules. Les plants de riz croissent normalement jusqu'à la maturation. ..... endogenous and exogenous abscisic acid». Revue ... [28] - A.J. JOSHI, H. HINGLAJIA, « Effects of chloride and sulphate on seed germination in Prosopis juliflora.

Gérer une revue de presse

CERN Document Server

Chartier, Lise

2005-01-01

Cet ouvrage approfondit les notions telles que la collecte des nouvelles, le droit d'auteur, l'évaluation des besoins; il s'intéresse aux contenus, formats et fournisseurs; il explore les outils de consultation, d'évaluation et de recherche; il propose des modèles de budget, de profils d'intérêts et d'appels de propositions.

Revue d'Information Scientifique et Technique

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The review aims at publishing research papers on any topic related to information processing at the digital age which includes but is not limited to: digital Libraries, Digital Humanities and Heritage, Artificial Intelligence, Natural Language Processing, Semantic Web Technologies, Linked Data, Databases, big data, Machine ...

La projection par plasma : une revue

Science.gov (United States)

Fauchais, P.; Grimaud, A.; Vardelle, A.; Vardelle, M.

The quality of a plasma sprayed coating depends on numerous parameters that start to be understood due to the recent progresses in modelling and measurement techniques for plasma jets, momentum, heat and mass transfers between plasma and particles, the way the particules splat and cool down upon impact on the substrate or the previously deposited layers. In this paper, first are recalled the used measurement techniques and their limitations both for plasma jets and particles in flight. Then are underlined the importance of the different phenomena envolved in the transfers between plasma and particles such as steep temperature and chemical species density gradients around the particles, heat propagation phenomenon especially for ceramic particles and the connected evaporation effect, rarefaction effect which occurs even at atmospheric pressure. The problems related to the size and injection velocity distributions which determine the trajectory distributions and the heat treatments undergone by the particles are treated. The study of plasma generation shows on one hand for d.c. arc plasma torches the drastic influence on the plasma jets lengths and diameters of the gas injection chamber design, the gas nature, the design of the arc chamber and nozzle, the surrounding atmosphere (especially air pumping which cools down very fast the plasma) and on the other hand for RF plasmas the importance of the particle injection design to avoid the coupling between the RF discharge and the carrier gas with the particles. All these points are illustrated with examples of coatings of alumina, zirconia carbide and nickel particles. The way the particles splat is then studied with the chemical reactions in flight, the fast quenching of the particles and the resulting cristalline structures, the coating adhesion and also the residual stesses and their control through that of the temperature gradients into the coatings during spraying. At last a few actual and potential applications are presented in the fields of aeronautics and mechanics. La qualité d'un dépôt projete par plasma dépend de nombreux paramètres que l'on commence à mieux appréhender du fait des progrès de la modélisation et de la métrologie tant des écoulements plasmas que des transferts plasma-particules ou que des conditions d'écrasement et de refroidissement des particules lors de leur impact sur le substrat ou les couches déjà déposées. Les techniques de mesure utilisdes et leurs limitations sont d'abord rappelées tant pour les jets de plasma que pour les particules en vol et l'importance des différents phénomènes intervenant dans les transferts plasma-particules est soulignée : gradients de température et de concentration d'espèces chimiques très élevés autour des particules, effets de propagation de la chaleur, notamment pour les particules céramiques, effet d'évaporation, effet de raréfaction sensible dès la pression atmosphérique. Les problèmes de distribution de taille et de vitesse d'injection des particules sont également abordés car ils conditionnent les distributions de trajectoires et donc le traitement des particules dans le jet de plasma. La génération du plasma montre d'une part 1'influence considérable de l'injection du gaz, de sa nature, du dessin de la chambre d'arc et de la tuyère ainsi que du pompage de l'air ambiant sur la longueur des jets de plasma d'arc et d'autre part les problèmes d'injection pour éviter le couplage avec la décharge dans les jets de plasmas R.E Tout ceci est illustré avec des exemples de dépôt d'alumine, de zircone, de cermet carbure et de nickel. L'écrasement des particules est ensuite abordé avec les problèmes de réactions chimiques, de trempe ultra-rapide et donc de structure cristalline des dépôts, d'adhdsion mais aussi de containtes résiduelles et de leur contrôle via les gradients de température dans les dépôts pendant le tir. Enfin quelques applications actuelles sont présentées notamment pour l'aéronautique et la mécanique.

"Lands below the Winds" as Part of the Persian Cosmopolis: An Inquiry into Linguistic and Cultural Borrowings from the Persianate societies in the Malay World

Czech Academy of Sciences Publication Activity Database

Petrů, Tomáš

2016-01-01

Roč. 27, č. 1 (2016), s. 147-161. ISBN 979-10-320-0066-3. ISSN 1620-3224 Institutional support: RVO:68378009 Keywords : Persian language * culture * Malay World Subject RIV: AB - History http://moussons.revues.org/3572

Des batisseurs d'univers creent au CERN de minuscules antimondes

CERN Multimedia

2003-01-01

"Apres des annees de travail des physiciens du CERN en creant artificiellement des dizaines de milliers de minuscules antimondes - des atomes d'antihydrogene - dont la revue Nature rend compte dans son edition du 18 septembre 2002" (1 page).

Case series

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immunocompétent. Revue des Maladies Respiratoires. 2007;. (24 ):104. Google Scholar. 4. Al Tawfik JA. Multifocal systemic tuberculosis: the many faces of an old nemesis. Med Sci Monit. 2007;(4):CS56-. 60. PubMed | Google ...

La societé camerounaise d'ophtalmologie rapport du 17ème ...

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Problems of Planning Economic Policy

NARCIS (Netherlands)

J. Tinbergen (Jan)

1998-01-01

textabstractReprint of the orginally published version in International Social Science Journal (UNESCO), Vol. 11, No.3, 1959, pp. 351-360. In French: La Planification de la Politique Economique, Revue Internationale des Sciences Sociales, 1998, pp. 383-392

Negotiating Marriage on the Eve of Human Rights | Besendahl ...

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Alephweb: a search engine based on the federated structure ...

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Alternative Public Service Delivery Models in Health, Water and ...

International Development Research Centre (IDRC) Digital Library (Canada)

Documents. Debating supply and demand characteristics of bulk infrastructure : Lesotho-Johannesburg water transfer. Documents. Transformation in infrastructure policy from apartheid to democracy. Documents. Immigration and homelessness in the new South Africa. Articles de revue. Minding the undertow : assessing ...

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

Science.gov (United States)

Meulemans, Daniel; Bronner-Fraser, Marianne

2002-01-01

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

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

Science.gov (United States)

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

2016-09-01

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

Le lobe pulmonaire azygos: description anatomique d'un cas et ...

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Le lobe pulmonaire azygos: description anatomique d'un cas et revue de la ... de la veine azygos qui cravate anormalement le lobe supérieur du poumon droit. ... fortuite chez un homme de 69 ans souffrant d'un cancer broncho-pulmonaire.

Negotiating Marriage on the Eve of Human Rights | Besendahl ...

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African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 8, No 1 (2004) >. Log in or Register to get access to full text downloads.

Browse Title Index

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Vol 19, No 3 (2017), La reinsertion sociale des enfants en difficultes dans les centres etatiques du ... Vol 15, No 3 (2013), La science administrative, Abstract ... salivaires accessoires de siege jugale a propos d'un cas et revue de la litterature.

2755-IJBCS-Article-Zinga Koumba Christophe R

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3College of Bioresource Science, Nihon University, Fugisawa City, Kanagawa 252-0880, Japan. 4Primate .... mode d'interaction sociale (Tutin et al., 1997 ;. Furuichi et al. ... littérature de la flore du Gabon (Raponda- ..... Revue d'Élevage et.

Editorial

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of Reproductive Health (Revue africaine de la santé de ... comme une évidence de la persécution sociale continue ... La littérature est remplie de beaucoup de ... de reproduction et Doyen, College of Medical Sciences, University of Benin,.

Oryza glaberrima

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GNACADJA

Technologies Alimentaires, Faculté des Sciences Agronomiques, Université .... dans la mesure où la littérature a montré que ... culturelle, sociale et symbolique. ..... Revue. Ivoirienne d'Histoire, 19 : 41 - 60. Yacouba AS, Moussa OZ, Kadri A, ...

Les obstacles à l'émergence de la citoyenneté dans l'Égypte post-révolutionnaire

Czech Academy of Sciences Publication Activity Database

du Roy, G.; Steuer, Clément

2015-01-01

Roč. 46, č. 1 (2015), s. 49-66 ISSN 1782-1592 Institutional research plan: CEZ:AV0Z9021901 Institutional support: RVO:68378009 Keywords : Egypt * citizenship * political science Subject RIV: AD - Politology ; Political Science s http://rsa.revues.org/1374

Etude épidemiologique de l'hypertension arterielle chez les ...

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Les complications medicales a la phase aigue des accidents ...

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Malnutrition aiguë sévère chez les enfants de 6 à 59 mois ...

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Bacteriological profile in neonatal sepsis at the University teaching ...

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Prévalence du carcinome Hépatocellulaire chez les porteurs d ...

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Nutritional Profile in Households of HIV-Infected Patients receiving ...

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Omphalite compliquée de sepsis sévère et d' anasarque chez un ...

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Accurate Diagnosis of Pediatric Active Tuberculosis and Disease ...

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Cancers urogénitaux dans la région du littoral-Cameroun ...

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Présentation clinique, biologique et facteurs de risque du ...

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Acral lentiginous melanoma in a pregnant African albino, atypical ...

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Uptake of Anti rabies vaccine by users of the Anti rabies centre ...

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Crisis, Capital, Compromise: Mining and Empowerment in Zimbabwe

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African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 12, No 1 (2008) >. Log in or Register to get access to full text downloads.

L'idée de `science sociales' | Mbembe | African Sociological Review ...

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Ju/'hoansi Adaptations to a Cash Economy | McCall | African ...

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Annonce du diagnostic et rupture biographique | Francine | African ...

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Adolescent Sexuality and Culture: South African Mothers` Perspective

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Johann Graaff. What is Sociology? Cape Town. Oxford University ...

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Land use correlates of street children in Ogbomoso, Nigeria ...

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Postcolonial debates in Germany – An Overview | Pape | African ...

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JournalBase. Comparer les bases de données scientifiques internationales en sciences humaines et sociales (SHS

Directory of Open Access Journals (Sweden)

Denise Pumain

2010-01-01

Full Text Available Cet article dresse un tableau comparatif des contenus des bases de données et des listes de référence qui recensent les revues en sciences humaines et sociales (SHS. Il s’appuie sur JournalBase publié le 25 juin 2009 dans Cybergeo. Cette étude porte sur les bases AHCI et SSCI du Web of Science (publié par Thomson Reuters, de Scopus (publié par Elsevier, du European Reference Index for Humanities (ERIH (publié par la Fondation européenne pour la Science et de l’AERES (Agence pour l’évaluation de la recherche en France. La recherche a été réalisée en 2008 avec le soutien financier du TGE Adonis du CNRS. Avec quelque 20 000 entrées correspondant à environ 10 000 journaux différents, c’est une vue quasi exhaustive de la richesse des publications en sciences humaines et sociales qui est apportée par ce tableau. La nomenclature adoptée pour classer les revues par discipline est celle en 27 postes de la Fondation Européenne pour la Science. Les affectations multiples révèlent la multidisciplinarité des revues, assez fréquente en SHS, mais parfois aussi les incohérences des bases de données qui n’ont pas été rectifiées.L’article présente l’historique du projet, la méthodologie mise en place par les auteurs, les difficultés rencontrées dans la comparaison des données. Les premiers résultats mettent en évidence une couverture plus large de la liste ERIH pour les sciences humaines et une surreprésentation des revues anglophones dans les bases de données commerciales pour l’ensemble des disciplines. L’objectif de ce travail est d’alerter sur les contenus de ces bases de données, au moment où les outils bibliométriques soulèvent maints débats quant à leur application dans le champ des sciences humaines et sociales.

Water Security in Periurban South Asia : Adapting to Climate ...

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Articles de revue. Hydro-meteorological trends in Southwest Coastal Bangladesh : perspectives of climate change and human interventions. Rapports. Improving flood management planning in Thailand : a case of Chao Phraya river basin. Rapports. Communicating climate change risks for adaptation in coastal and delta ...

2276-IJBCS-Article-Djibril Badiane

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aspects de la problématique de gestion des insectes ravageurs du cotonnier sont passés en revue. © 2015 International Formulae ... des décennies un contrôle satisfaisant de l'ensemble des ... influencer la dynamique spatio-temporelle de.

le recours a l'avortement a antananarivo (madagascar)

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... Marseille, cedex 03; 2Université d'Antananarivo – Faculté des lettres et sciences humaines Madagascar. .... toutes les conséquences psychologiques, sociales, ..... souvent décrites dans la littérature comme un ..... Une revue de la littérature.

Mise au point d'un indice précis pour évaluer le risque de morbidité ...

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Extrants. Articles de revue. Assessment of nutritional status in Indian preschool children using WHO 2006 Growth Standards. Téléchargez le PDF. Rapports. Sensitive index to assess risk of morbidity in under-nutrition : final report. Téléchargez le PDF ...

Résultats de recherche | Page 28 | CRDI - Centre de recherches ...

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Commission sur la Syrie de la revue The Lancet. L'objectif de la Commission est de mobiliser la communauté internationale afin de répondre aux besoins actuels et futurs en matière de santé de la population syrienne. Webpage.

Résultats de recherche | Page 25 | CRDI - Centre de recherches ...

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Commission sur la Syrie de la revue The Lancet. L'objectif de la Commission est de mobiliser la communauté internationale afin de répondre aux besoins actuels et futurs en matière de santé de la population syrienne. Webpage.

6 - Article Perret

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Administrateur

La Caisse Nationale de Retraite (CNR) : elle gère les pensions et allocations de ...... politique de population en Algérie», Revue Sciences Humaines, n°12, p. ... Source : U.S. Census Bureau, International Data Base (http://www.coopami.org).

IN SEARCH OF THE ORIGINAL TEXT IN MARK 9:38

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“Teacher, we saw someone in your name driving out demons and we tried .... Luke.” Maybe Lagrange and Taylor and Cranfield deserve more attention. 5. ..... Justin). In the Revue Biblique (Hendriks 2007:266-271) I divided Mark 8:26 into five ...

Adaptation and Livelihood Resilience | CRDI - Centre de recherches ...

International Development Research Centre (IDRC) Digital Library (Canada)

Extrants. Articles de revue. Engendering adaptation to climate variability in Gujarat, India. Rapports. Exploring linkages between adaptation and development : proceedings of The Scientific and Technical Conference On Adapting to Climate Change in Asia, August 29-30, 2009, Hotel Hyatt Regency, Kathmandu, Nepal ...

O jornalista gastronômico e a arte de julgar

Directory of Open Access Journals (Sweden)

Márcia Atália Pietrolungo

2011-10-01

Full Text Available Resumo: Análise do julgamento de gosto e das imagens de jornalista produzidas nas revistas gastronômicas Saveurs, GaultMillau, La Bonne Cuisine e Cuisine et Vins de France, à luz da análise semiolinguística do discurso de Patrick Charaudeau e de conceitos sociológicos de Pierre Bourdieu.Palavras-chave: Análise do discurso; semiolingüística; revista; gastronomia.Résumé: Ce travail propose une analyse du jugement de goût et des images du journaliste gastronomique, présentes dans les revues Saveurs, GaultMillau, La Bonne Cuisine e Cuisine et Vins de France, à partir de la théorie sémiolinguistique du discours de Patrick Charaudeau et des concepts sociologigues de Pierre Bourdieu. Mots-clés: Analyse du discours; sémiolinguistique; revue; gastronomie.Keywords: Discourse analysis; semiolinguistics; magazine; gastronomy.

Working methods experimentation: Bauzot deposit, Bauzot and La Faye deposits - Empty room with initial thin veins sub-layers; Essais de methodes d'exploitation: Gisement de Bauzot, Gisements de Bauzot et La Faye - Chambre vide avec sous-niveaux prealables en filons minces

Energy Technology Data Exchange (ETDEWEB)

Paucard, A. [Division de Grury, Direction des recherches et exploitations minieres, Commissariat a l' energie atomique et aux energies alternatives - CEA (France)

1959-07-01

The Bauzot deposit was one of the first small CEA workings, and thus served as a guinea-pig for the testing of several working methods. The lessons learned at Bauzot render the rapid choice of a suitable method for the working of large CEA deposits possible. Reprint from 2 papers published in 'Revue de l'Industrie Minerale', vol. 40, n. 12, dec 1958, and Nov 1958, p. 831-843 [French] Le gisement de Bauzot a ete un des premiers petits gisements equipes du CEA. Il a servi de champ d'experience. Plusieurs methodes d'exploitation ont ete essayees. Les renseignements qui ont ete tires de ces essais permettront de choisir rapidement une methode parfaitement adaptee aux gisements importants du CEA. Reproduction de deux article publie dans la 'Revue de l'Industrie Minerale', vol. 40, n. 12, dec 1958, et Nov 1958, p. 831-843.

Adaptation to the Impacts of Sea Level Rise in the Nile Delta Coastal ...

International Development Research Centre (IDRC) Digital Library (Canada)

Extrants. Articles de revue. Facing the Tide - REVOLVE Magazine: Water Around the Mediterranean. Téléchargez le PDF. Rapports. Adaptation to the impacts of sea level rise in the Nile Delta coastal zone, Egypt : final project report. Téléchargez le PDF ...

Research

African Journals Online (AJOL)

abp

14 oct. 2017 ... ... 2Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso, 3Centre .... La littérature suggère qu'une meilleure ... par deux Centres de Santé et de Promotion Sociale (CSPS), une ..... Revue de Gériatrie.

Le pneumothorax spontané comme une manifestation évolutive de ...

African Journals Online (AJOL)

Le pneumothorax spontané comme une manifestation évolutive de la polyarthrite rhumatoide: à propos d'une observation clinique et revue de la litterature. Magaye Gaye, Assane Ndiaye, Mouhamed Lamine Fall, Souleymane Diatta, Papa Adama Dieng, Papa Salmane Ba, Amadou Gabriel Ciss, Mouhamadou Ndiaye ...

Lutter contre la pollution dans les zones côtières | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

... de physiologie et la Society of Environmental Toxicology and Chemistry. Auteur de plus d'une centaine d'articles parus dans des revues à comité de lecture, ... des chercheurs les plus cités, préparée par l'Institute for Scientific Information.

Journal of Librarianship and Information Science in Africa ...

African Journals Online (AJOL)

Author Guidelines. The Journal of Librarianship and Information Science in Africa (JLISA)/Revue de Bibliotheconomie et Science de l'information en Afrique is expected to explore the range of issues and problems of concern to librarians, information scientists and other information professionals especially in Africa.

Science et Technique, Sciences de la Santé: Submissions

African Journals Online (AJOL)

Science et technique, revue scientifique du Centre national de la recherche ... VI. Page de titre. Elle doit comprendre : Titre : le titre qui doit être court, précis, ... éléments originaux qui concernent notamment la démarche diagnostique ou le ...

Journal of the Cameroon Academy of Sciences

African Journals Online (AJOL)

Revue de L'academie des Sciences du Cameroun The Journal of the Cameroon Academy of Sciences is a multi-disciplinary publication devoted to all aspects of fundamental and applied research. It also publishes topical reviews on science and technology in development, arts, humanities and culture.

Weather and Climate Extremes.

Science.gov (United States)

1997-09-01

Company. Fantoli, A. (1954). / valori medi della temperatura in Libia. Bulletin of the Italian Geographical Society (Italian), Series. 8, 7, 59-71...Fantoli, A. (1958). La piu aha temperatura del mondo [The highest temperature in the world]. Revue of Aeronautical Meteorology (Italian), 18(3), 53

Developer Network : Open Source Personal Digital Assistant ...

International Development Research Centre (IDRC) Digital Library (Canada)

Articles de revue. Handheld computers for survey and trial data collection in resource-poor settings : development and evaluation of PDACT, a Palm TM pilot interviewing system ... L'Initiative des conseils subventionnaires de la recherche scientifique en Afrique subsaharienne remporte le prix de la diplomatie scientifique.

La résilience et les petits exploitants agricoles africains : accroître la ...

International Development Research Centre (IDRC) Digital Library (Canada)

Articles de revue. Farmers' perceptions lead to experimentation and learning. Téléchargez le PDF. Rapports. Lack of resilience in African smallholder farming : exploring measures ... L'Initiative des conseils subventionnaires de la recherche scientifique en Afrique subsaharienne remporte le prix de la diplomatie scientifique.

Enhancing Climate Change Adaptation in Agriculture and Water ...

International Development Research Centre (IDRC) Digital Library (Canada)

Articles de revue. On the development of climate data visualization tool for interpretation of empirical results from climate model : does it add value to different stakeholders? ... L'Initiative des conseils subventionnaires de la recherche scientifique en Afrique subsaharienne remporte le prix de la diplomatie scientifique.

Travaux de l'Health Enterprise Architecture Laboratory (HEAL ...

International Development Research Centre (IDRC) Digital Library (Canada)

Extrants. Articles de revue. Position paper : researching and developing enterprise architectures for health information systems in developing African countries. Téléchargez le PDF ... L'Initiative des conseils subventionnaires de la recherche scientifique en Afrique subsaharienne remporte le prix de la diplomatie scientifique.

African Journal of Neurological Sciences - Vol 33, No 1 (2014)

African Journals Online (AJOL)

Mucocele fronto-ethmoïdale geante avec extension intracranienne: a propos d'un cas et revue de la litterature · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. A Kabre, DS Zabsonre, Y Haro, 50-54 ...

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

HUMAN PARAGONIMIASIS IN AFRICA

African Journals Online (AJOL)

Emmanuel Ameh

this disease, training of technicians in anti-tuberculosis centers would be the most realistic attitude to detect mycobacteria and/or Paragonimus eggs during the same sputum examination. Key words: Paragonimus spp., Africa, human paragonimiasis, intermediate hosts, tuberculosis. Résumé. Une revue sur la paragonimose ...

Public Sector Perspectives i RS

DEFF Research Database (Denmark)

Kiertzner, Lars

2006-01-01

De særskilte PSP omkring anvendelse af IAASB-standarder inden for offentlig revision, kommenteres systematisk. FSR/REVU har valgt ikke at implementere disse særlige afsnit i de danske revisionsstandarder. Generelt er PSP meget generelle. Overordnet gælder det, at de almindelige revisionsstandarde...

Résilience et moyens de subsistance au lendemain de catastrophes ...

International Development Research Centre (IDRC) Digital Library (Canada)

Articles de revue. Engendering adaptation to climate variability in Gujarat, India. Téléchargez le PDF. Rapports. Exploring linkages between adaptation and development : proceedings of The Scientific and Technical Conference On Adapting to Climate Change in Asia, August 29-30, 2009, Hotel Hyatt Regency, Kathmandu, ...

2805-IJBCS-Article-Eliasse Dieme

African Journals Online (AJOL)

hp

Contamination des céréales par l'aflatoxine en Afrique : revue des méthodes de lutte existantes ..... pratiques de gestion agricole qui augmentent les rendements des cultures ... technologie de contrôle au champ de l'aflatoxine est utilisée au ...

Case series

African Journals Online (AJOL)

abp

29 juin 2017 ... littérature pour les hémoglobinopathies [11, 12]. L'anisocytose ... protection sociale dans notre pays pour toutes les couches de la société et la .... journal of medical sciences. 2010; 8(1): 71- ... Revue Marocaine de Médecine ...

Les Cahiers du CREAD

African Journals Online (AJOL)

Admin

6 juil. 2007 ... littérature sur le développement économique la thèse d'une alternative de développement ...... emploi ? , In Revue Tiers-monde, Volume 29, n°114. Bouyacoub A ... Alfa/Maghreb et sciences sociales, IRMC, Tunis. (Sous la ...

Author Details

African Journals Online (AJOL)

Les Troubles Musculosquelettiques (Tms) En Milieu Portuaire : Cas Des Dockers Professionnels Du Port Autonome De Lome (Pal). Abstract · Vol 15, No 3 (2013) - Articles Etude anatomique et radiologique de jumeaux conjoints thoraco omphalopages nes vivants : a propos de deux cas avec revue de la litterature

Text Mining et annotation sémantique pour l’Information Scientifique

OpenAIRE

2013-01-01

Un exemple d'application des technologies d'enrichissement sémantique et d'analyse de la littérature scientifique pour assister un travail de revue scientifique sur la place de la transgénèse dans la lutte contre les maladies des grandes cultures.

Improvement of the heat exchanges by application of an electric field in the boiling freon 12; Amelioration des echanges thermiques par application d'un champ electrique dans le freon 12 bouillant

Energy Technology Data Exchange (ETDEWEB)

Bonjour, Emmanuel; Verdier, Jacques; Weil, Louis [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes Nucleaires de Grenoble (France)

1960-07-01

lt was already known that the heat exchanges by simple convection are considerably improved by the application of an electric field, but no study about the effect of this field when there is ebullition has been issued until now. The authors indicate the result of their experimental investigations which present a very great interest for the increase of the efficiency of the refrigeration cycles. Reprint of a paper published in Revue generale du froid, Sep 1960 [French] On savait deja qu'il etait possible d'ameliorer sensiblement les echanges thermiques dus a la simple convection par l'application d'un champ electrique, mais jusqu'a present, il n'existait pas de resultats concernant l'effet de ce champ en presence d'ebullition. Les auteurs indiquent les resultats de leur investigation experimentale qui presente un tres grand interet pour l'accroissement de l'efficacite du cycle de refrigeration. Reproduction d'un article publie dans Revue generale du froid, Sep 1960.

After Imagining/ Après l'imaginer: Imaginations

Directory of Open Access Journals (Sweden)

Managing Editors

2010-12-01

Full Text Available We welcome you to Imaginations: Journal of Cross-Cultural Image Studies / Revue d’études interculturelles de l’image, an open-access online peer-reviewed journal born out of research and developments in cross-cultural and intersecting epistemological fields that have at their root a determined focus on the role and power of the image in contemporary culture and in cultural communications. Nous vous souhaitons la bienvenue à Imaginations: Journal of Cross-Cultural Image Studies / Revue d’études interculturelles de l’image, un journal en ligne à accès libre dont les contributions sont préalablement soumises à un comité de révision par les pairs. Cette publication est le fruit d’un vif intérêt pour la recherche et la pratique au croisement de multiples champs épistémologiques et interculturels autour du rôle et de la puissance de l’image dans la société et les média contemporains.

African Sociological Review / Revue Africaine de Sociologie

African Journals Online (AJOL)

Journal Home > Vol 21, No 2 (2017). Log in or Register to ... Relevant work from elsewhere will however also be considered. ... Women and Liberal Peacebuilding in Post- Conflict Northern Uganda: community social work agenda revisited?

African Sociological Review / Revue Africaine de Sociologie

African Journals Online (AJOL)

A Review of Ulf Engel and Joāo Gomes Porto,eds., 2010, Africa's New Peace and Security Architecture: Promoting Norms, Institutionalizing Solutions, Ashgate Publishers, England and USA, ISBN 978 0 7546 7606 5 pbk. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD ...

Book Reviews | Wood | African Sociological Review / Revue ...

African Journals Online (AJOL)

Oxford University Press. R. Whitley, 1999. Divergent Capitalisms:The Social Structuring and Change of Business Systems. Oxford University Press. R.Whitley and P.H. Kristensen, (eds.) 1997, Governance at work: The Social Regulation of ...

Modélisation et estimation de la valeur de la terre agricole dans la ...

African Journals Online (AJOL)

Afrique Science: Revue Internationale des Sciences et Technologie ... avec le mode d'accès traditionnel au profit d'un mode d'accès moderne à la terre agricole devenue ... et à définir les règles du fonctionnement du marché de terre agricole.

Des systèmes agroalimentaires bénéfiques pour les populations ...

International Development Research Centre (IDRC) Digital Library (Canada)

Documents. Baobab : a magazine on drylands development and sustainable agriculture, issue 61, March 2011. Téléchargez le PDF. Articles de revue. Integrating scientific and farmers' perception towards evaluation of rain-fed agricultural technologies for sorghum and cowpea productivity in Central Kenya. Téléchargez le ...

Author Details

African Journals Online (AJOL)

2016) - Articles Un cas d'angiosarcome de l'oreille externe. Abstract PDF · Vol 25, No 1 (2016) - Articles Tumeur phyllode chez une jeune adolescente de 12 ans: à propos d'un cas et revue de la littérature. Abstract · Vol 25, No 1 (2016) - Articles

On Research Methodology in Applied Linguistics in 2002-2008

Science.gov (United States)

Martynychev, Andrey

2010-01-01

This dissertation examined the status of data-based research in applied linguistics through an analysis of published research studies in nine peer-reviewed applied linguistics journals ("Applied Language Learning, The Canadian Modern Language Review / La Revue canadienne des langues vivantes, Current Issues in Language Planning, Dialog on Language…

Journal of Librarianship and Information Science in Africa

African Journals Online (AJOL)

The Journal of Librarianship and Information Science in Africa (JLISA)/Revue de Bibliotheconomie et Science de l'information en Afrique is expected to explore the range of issues and problems of concern to librarians, information scientists and other information professionals especially in Africa and aims to publish articles, ...

Original Paper Typologie et rentabilité des systèmes de production ...

African Journals Online (AJOL)

d'affaire du secteur primaire après les produits avicoles avec 9,7% .... Les autres dépenses (eau, soins ... (Enseignement général) sous des formes et à ...... bovins laitiers en zone montagneuse d'Algérie. Revue d'Elevage et de. Médecine.

African Climate Change Fellowship | CRDI - Centre de recherches ...

International Development Research Centre (IDRC) Digital Library (Canada)

Extrants. Articles de revue. Spatial fields' dispersion as a farmer strategy to reduce agro-climatic risk at the household level in pearl millet-based systems in the Sahel : a modeling ... L'Initiative des conseils subventionnaires de la recherche scientifique en Afrique subsaharienne remporte le prix de la diplomatie scientifique.

Case report

African Journals Online (AJOL)

abp

11 oct. 2013 ... &Corresponding author: Dr Andonaba Jean Baptiste, Institut Supérieur des Sciences de la Santé, Université Polytechnique de Bobo-Dioulasso. .... démunis et sans couverture sociale (assurance-maladie). ... de la littérature avec 4/6 cas de scrofuloderme (Figure 5). .... Revue des Maladies Respiratoires.

Scolarisation

African Journals Online (AJOL)

sulaiman.adebowale

4 mars 2008 ... Conseil pour le développement de la recherche en sciences sociales en ... en Algérie la femme en elle-même n'a pas de position sociale, .... Littérature .... CENEAP, 2001, Genre et développement en Algérie, revue n° 19.

The Pragmatics of Critiquing

Science.gov (United States)

2006-02-01

philosophie (logique et argumentation), de la linguistique, de la psychologie et de la sociologie , ce document propose une étude de la critique...linguistique, de la psychologie et de la sociologie . Elle présente une revue exhaustive de l’analyse de l’argument et de l’argumentation qui nous

The Challenges of Studying the African Diasporas | Zeleza | African ...

African Journals Online (AJOL)

African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 12, No 2 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. The Challenges of ...

Case report

African Journals Online (AJOL)

ebutamanya

2016-03-24

Mar 24, 2016 ... Onset of polymyositis with autoantibodies to threonyl. tRNA synthetase during pregnancy. J Rheumatol. 1994 Aug;. 21(8):1564-6.PubMed | Google Scholar. 9. Huong DLT, Wechsler B. Maladies systémiques pendant la grossesse. Revue du Rhumatisme. 2005 ;72 (8): 744-. 749. PubMed | Google Scholar.

Risque de grippe aviaire : caractérisation et dynamique de l'élevage ...

International Development Research Centre (IDRC) Digital Library (Canada)

Thought and Measures of Supply Chain Management to Reinforce Food Quality and Safety [Chinese language]. Téléchargez le PDF. Articles de revue. Impact of the IDRC project interventions on the KAP changing of the backyaders in relation to the reduction and management of avian influenza risk [Vietnamese language].

Globalisation, Equity and Social Development | Mkandawire ...

African Journals Online (AJOL)

African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 6, No 1 (2002) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Globalisation, Equity and ...

Globalisation and Migration in Africa | Akokpari | African Sociological ...

African Journals Online (AJOL)

African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 4, No 2 (2000) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Globalisation and Migration in ...

Globalisation and Social Sciences in Africa | Sawyerr | African ...

African Journals Online (AJOL)

African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 3, No 1 (1999) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Globalisation and Social ...

O «Anstoss» fichteano: ensaio de elucidação de uma metáfora

Directory of Open Access Journals (Sweden)

Pierre-Philippe Druet

2017-02-01

Full Text Available O presente texto apareceu pela primeira vez, sob o título de L'«Anstoss» fichtéen: essai d'élucidation d'une métaphore. In: Revue Philosophique de Louvain. Quatrième série, Tome 70, N°7, 1972. pp. 384-392.

Résultats de recherche | Page 7 | CRDI - Centre de recherches pour ...

International Development Research Centre (IDRC) Digital Library (Canada)

Ce projet, mis en place par l'Instituto Nacional de Salud Pública du Mexique, consiste à entreprendre une série d'études préliminaires pour contribuer aux travaux de la nouvelle commission sur la lutte antitabac à l'échelle mondiale de la revue Th. Projet ...

Potentiel antiradicalaire des extraits de feuilles de Bersama ...

African Journals Online (AJOL)

BENE KOUADIO

Catalogue Systématique, Biogéographie et Ecologie. Conservatoire et Jardin. Botanique : Génève,. Switzerland,. Boisiera 57 ; 396. Bougandoura. N,. Bendimerad. N. 2013. Évaluation de l'activité antioxydante des extraits aqueux et méthanolique de Satureja calamintha ssp. Nepeta (L.) Briq. Revue « Nature &. Technologie.

Irradiation inhibits the regeneration of aneurogenic limbs

International Nuclear Information System (INIS)

Wallace, H.; Maden, M.

1976-01-01

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

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

NARCIS (Netherlands)

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

1982-01-01

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

Globalisation and Social Sciences in Africa | Sawyerr | African ...

African Journals Online (AJOL)

African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 3, No 1 (1999) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file ...

Research

African Journals Online (AJOL)

abp

28 janv. 2013 ... Cameroun, 3Faculté de médecine et des sciences biomédicales de l'université de .... plus représentés que les femmes), en situation de précarité sociale .... Noah : analyses statistiques, revue de la littérature et rédaction du.

O Quebra-Cabeça do Método Científico

Directory of Open Access Journals (Sweden)

Susan Haack

1997-12-01

Full Text Available Translated by Luiz Henrique de A. Dutra, UFSC. This is a translation of 'The Puzzle of "Scientific Method"', published in Revue Internationale de Philosophie (Issue on Quine, vol. 51 (1997, pp. 495–505. We thank the author and the editors for their kind permission to publish the present translation.

Droits d'auteur et accès au savoir en Afrique | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

Legislative review : review of IPR Act and regulations : Intellectual Property Rights from Publically Financed Research and Development Act, Act No. 51 of 2008, Republic of South Africa. Téléchargez le PDF. Articles de revue. Copyright and education : lessons on African copyright and access to knowledge. Téléchargez le ...

Arbejdshypotesen om en menneskehed

DEFF Research Database (Denmark)

Jelsbak, Torben

2011-01-01

, such as the aesthetics of advertising and shop window design, jazz music, film and revue songs. Thus, nearly all areas of popular urban culture were embraced as part of the journal’s critical strategy of promoting a modern ‘democratic’ or ‘classless’ culture to replace traditional styles and genres of bourgeois culture...

The Challenges of Studying the African Diasporas | Zeleza | African ...

African Journals Online (AJOL)

African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 12, No 2 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file ...

L'otite moyenne chronique cholestéatomateuse de l'enfant: à propos ...

African Journals Online (AJOL)

Le but de notre travail est d'analyser à travers une revue bibliographique les particularités des otites moyennes chroniques cholestèatomateuses chez 30 enfants pris en charge dans le service d'oto-rhino-laryngologie de l'hôpital militaire Avicenne de Marrakech. Le traitement est exclusivement chirurgical, actuellement, ...

Globalisation, Equity and Social Development | Mkandawire ...

African Journals Online (AJOL)

African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 6, No 1 (2002) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file ...

Globalisation and Migration in Africa | Akokpari | African Sociological ...

African Journals Online (AJOL)

African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 4, No 2 (2000) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file ...

Nietzsche l'islam et la globalisation | Monia | African Sociological ...

African Journals Online (AJOL)

African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 17, No 1 (2013) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file ...

Professions et métiers interdits : un aspect de l'histoire de la révocation de l'Édit de Nantes

NARCIS (Netherlands)

Deursen, Arie Theodorus van

1960-01-01

Si nous passons en revue une fois de plus l'ensemble de la situation, il se confirmera en premier lieu que l'Edit de Nantes reconnaissait nettement l'egalite des droits des catholiques et des protestants pour toutes les charges, tous les offices et tous les metiers, dans plusieurs de ses articles,

Maladie de kimura: À propos d'un cas | Dib | Journal Tunisien d'ORL ...

African Journals Online (AJOL)

Introduction : Mots-clés : Maladie de Kimura, parotide, chirurgie.La maladie de Kimura ou lymphogranulome éosinophile est une pathologie inflammatoire chronique très rare, d'étiologie inconnue. Nous rapportons un cas de maladie de Kimura à localisation parotidienne et à travers une revue de la littérature, rappelons les ...

Evaluation de Ia pratique transfusionnelle en urgence obstetricale et ...

African Journals Online (AJOL)

La collecte des donnees a ere faite par une technique d' observation directe et de revue documentaire. Sur cette periode, la frequence de la transfusion dans le service etait de 11,08 % par rapport a 1' ensemble des malades hospitalisees. Le delai moyen d' obtention des produits sanguins labiles etait de 2 h 46 minutes.

Recours aux cultures céréalières traditionnelles pour améliorer la ...

International Development Research Centre (IDRC) Digital Library (Canada)

Urging policy formulation on millets : an indispensable source of nutrition for Poraja, Kandha and Penthia tribal communities in Kundra Block, Odisha, India. Téléchargez le PDF. Articles de revue. Newspaper cuttings [appendix 9 of the joint technical final report (October 2010 - March 2013)]. Téléchargez le PDF. Articles de ...

Case series

African Journals Online (AJOL)

abp

4 déc. 2017 ... Cancer du sein chez l'homme: à propos de 40 cas et revue de la ... age was 62 years, the mean consultation time was 12 months, self-exam of a peri- ... 7,5%) et la maladie de Paget a été retrouvé dans 1 cas (soit 2,5%).

African Journal of Neurological Sciences - 2009 Vol. 28 No 1

African Journals Online (AJOL)

African Journal of Neurological Sciences .... Pour la majorité des sujets enquêtés, l'épileptique pouvait mener une vie sociale normale: être scolarisé, se .... Dans une revue de la littérature, sur la décennie de 2000 à 2010, réalisée par Lua et ...

African Journal of Drug & Alcohol Studies, 12(1), 2013 Copyright ...

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1 avr. 2013 ... rePreSentAtionS SociAleS De lA conSoMMAtion De trAMADol Au niger,. PERCEPTIONS ET ... 1Faculté des Sciences de la Santé de Niamey, Niamey, Niger. 2Service de ..... féine : à propos de 8 cas et revue de la littérature.

Adaptation aux changements climatiques et équité en Colombie rurale

International Development Research Centre (IDRC) Digital Library (Canada)

Articles de revue. Recent waves of water governance : constitutional reform and resistance to neoliberalization in Latin America (1990-2012); GEOFORUM (50: 20-30) - final version. Téléchargez le PDF. Documents. Equidad, eficiencia y escala en la asignación de agua en los países Andinos : sinergia o conflicto? 52993 ...

Les avancees en chirurgie du cancer colo-rectal | Mouafo Tambo ...

African Journals Online (AJOL)

Revue Africaine de Chirurgie et Spécialités. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 10, No 3 (2016) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. DOWNLOAD FULL TEXT Open Access ...

Rupture Uterine Par Accident De La Voie Publique: A propos d'un cas.

African Journals Online (AJOL)

Abstract. Un cas de rupture utérine par accident de la voie publique associée à une fracture de l'humérus droit et du bassin est décrit. Les pronostics maternels et foetal sont discutés à la lumière de la revue de la littérature.

Euclinostomum heterostomum (Rudolphi, 1809)

African Journals Online (AJOL)

J. Morph. 15: 697-710. MANTER, H.W. & PRITCHARD, M.H. 1969. Some digenetic trematodes of Central Africa, chiefly from fishes. Revue Zool. Bot. afro 80: 51 - 61. MONNIG, H.O. 1926. Helminthological Notes. 11th and 12th Report of the Director of Veterinary Education and Resparch. Department of Agriculture, Union of ...

On additive preservers of semi-Browder operators

Czech Academy of Sciences Publication Activity Database

Mbekhta, M.; Müller, Vladimír; Oudghiri, M.

2014-01-01

Roč. 59, č. 2 (2014), s. 237-244 ISSN 0035-3965 R&D Projects: GA ČR GA201/09/0473; GA AV ČR IAA100190903 Institutional support: RVO:67985840 Keywords : additive preservers * semi-Browder operators Subject RIV: BA - General Mathematics http://imar.ro/journals/Revue_Mathematique/pdfs/2014/2/6.pdf

La communication des sciences sur Internet stratégies et pratiques

CERN Document Server

Pignard-Cheynel, Nathalie; Miège, Bernard; Pailliart, Isabelle; Picchioli, Ingrid; Salaün, Jean Michel

2004-01-01

Parmi les outils dont disposent les scientifiques pour communiquer et échanger leurs connaissances, la revue apparaît comme le média de référence, le support officiel et légitime des publications formelles. La revue scientifique cristallise, dans ses modes de conception, de production, de diffusion et de vente, des logiques opposées (logiques scientifique, symbolique et marchande). L’émergence d’Internet conduit à une redéfinition des rôles et des logiques qui prévalaient jusqu’alors. Nous avons envisagé cette évolution selon une double perspective : 1) l’offre et les stratégies des acteurs de l’édition scientifique, 2) les usages, et plus largement les pratiques des scientifiques, mis en évidence par l’analyse d’une communauté particulière, celle de la physique des particules. Les mouvements qui orientent le développement de la communication des sciences sur Internet se traduisent par une réorganisation du paysage de l’édition scientifique (à travers la consolidation de...

Spectrochemical analysis of impurities in plutonium and its compounds; L'analyse spectrochimique des impuretes dans le plutonium et ses composes

Energy Technology Data Exchange (ETDEWEB)

Buffereau, M; Crehange, G; Deniaud, S; Leclainche, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

After a review of previous works, various powdered or wet analytical methods are studied. One tries to give an explanation for some phenomena. A detailed know-how of studied methods is given. Validity of results is discussed. Problem of impurities in alloys analysis and non spectroscopic elements determination is quickly reviewed. One concludes to the interest of the use of some particular methods and the necessity of basic studies in order to obtain best information. (author) [French] Apres une revue des travaux precedents on etudie les differentes methodes d'analyse soit sur poudre (oxyde), soit sur solution. On tente de donner une interpretation de certains phenomenes. On donne un mode d'emploi detaille des methodes etudiees, on envisage la validite des resultats. On passe en revue rapidement le probleme de l'analyse des impuretes dans les alliages et de la determination des elements non spectroscopiques. On conclut a l'interet de l'emploi de certaines methodes, et a la necessite d'etudes fondamentales en vue d'aboutir a une meilleure obtention des informations. (auteur)

Spectrochemical analysis of impurities in plutonium and its compounds; L'analyse spectrochimique des impuretes dans le plutonium et ses composes

Energy Technology Data Exchange (ETDEWEB)

Buffereau, M.; Crehange, G.; Deniaud, S.; Leclainche, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

After a review of previous works, various powdered or wet analytical methods are studied. One tries to give an explanation for some phenomena. A detailed know-how of studied methods is given. Validity of results is discussed. Problem of impurities in alloys analysis and non spectroscopic elements determination is quickly reviewed. One concludes to the interest of the use of some particular methods and the necessity of basic studies in order to obtain best information. (author) [French] Apres une revue des travaux precedents on etudie les differentes methodes d'analyse soit sur poudre (oxyde), soit sur solution. On tente de donner une interpretation de certains phenomenes. On donne un mode d'emploi detaille des methodes etudiees, on envisage la validite des resultats. On passe en revue rapidement le probleme de l'analyse des impuretes dans les alliages et de la determination des elements non spectroscopiques. On conclut a l'interet de l'emploi de certaines methodes, et a la necessite d'etudes fondamentales en vue d'aboutir a une meilleure obtention des informations. (auteur)

Les premiers pas d’Agnon à Jaffa (1908-1912 First Steps of S.Y. Agnon in Jaffa (1908-1912 ראשית דרכו של עגנון ביפו (1908 עד 1912

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Masha Itzhaki

2012-11-01

Full Text Available Les premiers pas du célèbre auteur S. Y. Agnon lors de son premier séjour à Jaffa (1908-1912 sont liés aux deux revues hébraïques : Ha-Omer, histoire d’un échec, et Ha-po‘el ha-tsa‘ir, histoire d’une réussite, et aux rédacteurs en chef de ces revues, les écrivains et pères spirituels du jeune Agnon, Sh. Ben Tzion, un écrivain esthétique, bourgeois, et Y. H. Brenner, un penseur tourmenté, un véritable intellectuel socialiste.The first period of the famous writer S. Y. Agnon in Jaffa (1908-1912 has a lot to do with two literary Hebrew periodicals: Ha-Omer, a story of a failure, and Ha-po‘el ha-tsa‘ir, a successful one, as well as  with two major figures in Hebrew literary milieu at that time, the editors, Sh. Ben Tzion and Y. H. Brenner.

Case report

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ebutamanya

26 nov. 2015 ... PubMed | Google Scholar. 2. Caignard A, Milea D. Complications ophtalmologiques de la maladie de Horton: La Revue du Praticien Médecine Générale. Tome 27. N° 899, Avril 2013. Google Scholar. 3. Kassen H, ElGharbi T, Hamadi K, Dresco E, Turner L. Toux chronique relevant une maladie de Horton.

Mécanismes de reddition de comptes dans le contexte de la ruée ...

International Development Research Centre (IDRC) Digital Library (Canada)

Corey Piccioni

l'aide des Directives volontaires de la FAO, pour une gou- vernance responsable des régimes fonciers applicables aux terres. Les résultats de la revue documentaire alimentent les débats participatifs, au niveau des sites sélectionnés, sur la protec- tion juridique des droits fonciers locaux. Les consultations tenues avec de ...

1857-IJBCS-Article-Maman Maârouchi Inoussa

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JW, Stroosnijder L, Bond WJ, Prins HHT,. Rietkerk M. 2003. Effects of fire and herbivory on the stability of Savanna ecosystems. Ecology, 84(2): 337–350. Villecourt P, Schmidt W, Cesar J. 1980. Pertes d'un écosystème à l' occasion du feu de brousse (Savane tropicale de. Lamto, Cote d'Ivoire). Revue d'Ecologie et.

Programme de troisième cycle interuniversitaire en économie ...

International Development Research Centre (IDRC) Digital Library (Canada)

La troisième phase cherche à consolider ces acquis à travers quatre programmes, soit la formation DEA (programme qui équivaut à un programme de maîtrise au Canada), le développement des activités de recherche (doctorat), les publications notamment dans la Revue africaine d'économie et le renforcement de la ...

2576-IJBCS-Article-Ehoulé Krao

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2Laboratoire de Biologie et de Recherche Médicale, Institut National de Santé Publique, BP V 47 Abidjan, ... djalonensis ont été collectées au marché de ..... Bengoumi M. 1999. Etude comparative de l'effet hypoglycémiant de six plantes de la pharmacopée traditionnelle marocaine. Revue Médecine et Pharmacie. Afrique ...

AS_643_A4 OK

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AKA BOKO

Évaluation des rejets d'eaux usées de la ville de Niamey dans le fleuve Niger. Haoua AMADOU* .... Problématique de la gestion des eaux usées dans la communauté urbaine de. Niamey ..... MALAVOI et Y. SOUCHON, Hydrologie et dynamique hydro écologique des cours d'eau ; Revue ... control Eichornia crassipes Mart.

The second golden age of theosophy in Denmark

DEFF Research Database (Denmark)

Pedersen, René Dybdal

2009-01-01

en une foi vibrante sur un plan national, faisant ainsi, de nouveau, de la théosophie une source d’inspiration agissant au coeur du nouveau paysage religieux danois. En m’appuyant sur des théories portant sur les rapports sociaux dans la société contemporaine, sur une analyse de revues théosophiques...

Pratiques de publicité au point de vente dans l'industrie du tabac ...

International Development Research Centre (IDRC) Digital Library (Canada)

Des études menées dans des pays comme le Canada démontrent que la publicité au point de vente exerce une influence importante sur les écoliers et peut les prédisposer à devenir fumeurs. De plus, les ... Articles de revue. Tobacco point-of-sale advertising in Guatemala city, Guatemala and Buenos Aires, Argentina.

African Journal of Neurological Sciences - 2009 Vol. 28 No 1

African Journals Online (AJOL)

été rapportés dans la littérature (4,13), mais ces données restent différentes de celles de Badiane (3) qui ... son coût élevé et de l'absence de sécurité sociale publique, cet examen n'est accessible qu'à un nombre .... Revue de le literature.

2516-IJBCS-Article-Pascal Bazongo

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développement au Burkina Faso s'est intéressé au Jatropha curcas L. comme source d'énergie et de durabilité des productions. ... Faso became interested in Jatropha curcas L. as a source of energy and sustainability of production. To assess the influence of ..... Revue des Energies Renouvelables,. 12(2):. 269. -. 278.

1513-IJBCS-Article - Malik Leye

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3Sénégalaise d'Energies Vertes S.A. (SEV) BP : 440, Louga, Sénégal. *Auteur correspondant, E-mail: elhadjmalickleye@yahoo.fr, Tel: +221 77 556 82 96. RESUME ...... la mycorhization sur la croissance et le développement de Jatropha curcas L. Revue des Energies Renouvelables, 12(2):. 269–278. Manga AGB. 2005.

Author Details

African Journals Online (AJOL)

Farikou, I. Vol 4, No 7 (2010) - Articles Aspects diagnostiques et thérapeutiques des déformations d'axe des membres inférieurs de l'enfant africain. Revue de 43 cas. Abstract · Vol 4, No 9 (2010) - Articles The management of pelvic pressure ulcers by myocutaneous flaps: a 10 years experience in Yaoundé - Cameroon.

(256-IJBCS-Article-H Yédomonhan)

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RHUMSIKI

Apicultura, 22(3): 156-158. Nacoulma O, Millogo-Rasolodimby J. 1995. Les produits de la ruche et leurs utilisations au Burkina Faso. Revue de. Médecines et Pharmacopées Africaines,. 9(2): 63-70. Nombré I. 2003. Etudes des potentialités mellifères de deux zones du Burkina. Faso : Garango (Province du Bouglou) et.

Concilier cantine bio et agriculture locale, les voies possibles

OpenAIRE

Aubry, Christine

2012-01-01

revue en ligne; Les cantines bio peinent souvent à concilier produits bio et circuits courts. Face au risque de « dilution de l’esprit pionnier », des expériences récentes montrent que le recours à des intermédiaires dans la chaîne agroalimentaire peut constituer une voie de diffusion du bio dans les cantines.

707-IJBCS-Article-Emile Fiogbe

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DR GATSING

écosystème par des modes de régulation qui garantissent peu la « santé » écologique de ce plan ... Ouest entre Tokpa- Domè et Guézin, puis une .... du lac Ahémé, 25 pêcheurs professionnels, 25 ...... 46-47, revue de la coopération française.

Templet for V° 6 N°2

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PNLC

décrit. Les pronostics maternels et foetal sont discutés à la lumière de la revue de la littérature. MOTS CLES: Rupture utérine - Grossesse - Traumatisme abdominal - Accident de la voie publique. UTERINE RUPTURE FOLLOWING A ROAD TRAFFIC ACCIDENT: A case report. ABSTRACT: A case of a ruptured gravid uterus ...

Case Report - Thrombasthénie de Glanzmann et grossesse: à ...

African Journals Online (AJOL)

'à présent, sont décrits. A travers cette observation, et à la lumière d'une revue de la littérature, nous allons essayer surtout, de mettre le point sur la prise en charge de cette association délicate, qui met en jeu, à chaque fois, le pronostic vital ...

Case report

African Journals Online (AJOL)

abp

1. Voie antérieure transversale dans l'ostéosynthèse d'une fracture type III du processus coronoïde chez un adolescent: à propos d'un cas et revue de literature ... Received: 05/01/2015 - Accepted: 10/02/2015 - Published: 23/02/2015. Abstract. Les auteurs .... de Mayo Elbow Performance Index (MEPI), étudiant douleur,.

Kas te tantsiksite? / Christel Karits

Index Scriptorium Estoniae

Karits, Christel, 1966-

2005-01-01

Tantsuüritustest: 17. märtsil Rahvusooperis Estonia esietendunud balletist "Shannon Rose". Belgia koreograaf-lavastaja Hugo Fanari tantsulavastusest "Suveöö unenägu" 18. märtsil Vanemuise suures majas. Eesti kaasaegse tantsu koreograafide ülevaatefestivalist "Uus tants 7" 18.-20. märtsini Tallinnas. Moskva Music Halli Grand Revue Tallinna Linnahallis. Jazzkaare kevadballist Mustpeade majas Tallinnas

(RODENTIA: SCIURIDAE).

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DOBRORUKA, L J 1970. Behaviour in the bush squirrel, Paraxerus cepapi (A Smith, 1836). Revue Zoo I. Bot. afro 82: 131-141. GUNTER, G cl ELEUTERIUS, L 1971. Bark-eating by the common gray squirrel following a hurricane. Am. Midi. Nat. 85:23S. NIXON, C M 1970. Insects as food for juvenile gray squirrels. Am. Midi.

entre la pirámide y el axolotl

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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.

Comment « construire » une littérature nationale ? À propos des deux premières « Revue belge » (1830 et 1835-1843

Directory of Open Access Journals (Sweden)

Lieven D’hulst

2008-10-01

Full Text Available La construction de la nation belge à partir de 1830 mobilise l’ensemble des pratiques culturelles, la littérature comprise. Mais celle-ci doit composer avec une double attente : s’inféoder aux programmes culturels émanant d’instances nationales qui la privent d’autonomie au moment où sa consœur française cherche à se libérer de la tutelle politique ; vaincre les résistances, dues notamment à la diversité des langues en Belgique, qui s’opposent au projet d’une littérature nationale homogène. L’étude de deux revues belges fondées au début des années 1830 vise à identifier et à analyser les principales procédures de construction littéraires, qui sont pour l’essentiel le fruit de transferts de modèles français. L’article se penche en particulier sur des procédures discursives qui portent sur l’énonciation (postures critiques et historiques, sur l’énoncé (dispositifs narratifs, traductifs, historiques, etc. et sur la langue (français, wallon, flamand.The construction of the Belgian nation from 1830 on makes a strong use of most cultural practices available, including literature. However, Belgian literature has to face at that time two major constraints: the need to subject itself to the larger cultural programs elaborated by national instances that hold back its autonomy at a moment when French literature tries to free itself of political meddlings; the need to supersede internal resistances, caused a.o. by language diversity, against a homogenous national literature. The article identifies and analyzes a number of construction procedures as they appear in two Belgian periodicals issued at the beginnings of the 1830s. More specifically, it concentrates on the most important discursive procedures, that make a dominant use of French models: procedures affecting enunciation, genre and language.De constructie van de Belgische natie vanaf 1830 doet in sterke mate een beroep op de verschillende

Prediction of Surfactants’ Properties using Multiscale Molecular Modeling Tools: A Review Prédiction de propriétés des tensioactifs à l’aide d’outils de modélisation moléculaire : une revue

Directory of Open Access Journals (Sweden)

Creton B.

2013-01-01

Full Text Available During one of the existing Enhanced Oil Recovery (EOR procedures, a mixture of Alkaline/Surfactant/Polymer (ASP is injected into wells in order to move the trapped oil from the reservoir to the wellbores. The conception and/or the tuning of new ASP combinations, structures of surfactants and/or mixtures of surfactants is of primary interest to improve the efficiency of a such procedure. Molecular modeling tools can be used to understand microscopic effects, predict surfactants’ properties and finally to optimize structures and mixtures of surfactants. We propose in this article a review of the literature on the ability of molecular simulation techniques such as Molecular Dynamics (MD, Monte Carlo (MC simulations, Dissipative Particle Dynamics (DPD and upper scale modeling methods such as Quantitative Structure-Property Relationship (QSPR approaches to predict thermo-physical and structural properties of surfactants. Une des voies possibles de récupération assistée du pétrole, l’EOR (Enhanced Oil Recovery, consiste en l’injection d’un fluide ASP (Alkaline/Surfactant/Polymer dans le réservoir dans le but de déplacer le pétrole piégé vers le puits de production. La conception et/ou l’optimisation de mélanges ASP, de tensioactifs ou de mélanges de tensioactifs est donc d’un intérêt premier pour améliorer l’efficacité d’un tel procédé. Les codes de simulation moléculaire développés et largement validés durant ces dernières décennies apparaissent comme des outils incontournables pour la compréhension des effets microscopiques, la prédiction de propriétés de tensioactifs complexes ou encore l’optimisation des structures voire de la composition de mélanges de tensioactifs. Dans cet article, nous présentons une revue des travaux de la littérature sur le potentiel de diverses techniques de simulation moléculaire pour la prédiction de propriétés structurales ou thermophysiques des tensioactifs. Les

Afrique Science: Revue Internationale des Sciences et Technologie ...

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Formulation d'un mortier de terre-ciment pour les murs mis en oeuvre selon la technique du pisé · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. M Mamba, R Nzengwa, I Tsomgme ...

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Situation du criquet marocain "Dociostaurus maroccanusThunb., 1815" par rapport aux différentes espèces acridiennes : morphométrie et capacités de déplacements · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. L El Ghadraoui, D Petit, R Mokhles, A Azouzi, ...

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Search tips: Search terms are case-insensitive; Common words are ignored; By default only articles containing all terms in the query are returned (i.e., AND is implied); Combine multiple words with OR to find articles containing either term; e.g., education OR research; Use parentheses to create more complex queries; e.g., ...

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cyclohexe-1-enyl)-formamidine avec les 9H-carbazole 1,4-dione substitués et activés par le brome · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. T Beguemsi, D Sissouma, L Bede, RB ...

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Degré d'impact des aménagements hydrauliques sur le ruissellement et le transport solide dans une région semi aride : cas des micro-bassins dans le haut Isser, Algérie · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. A Keddar, B Touaïbia, M Arabi ...

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OFDM codée pour le haut débit en fibre optique avec les codes correcteurs convolutifs, BCH, RS et LDPC · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. S R Sanou, F Zougmoré, Z Koalaga, M Kebré, 1-16 ...

Revue d'Information Scientifique et Technique: Advanced Search

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Influence de la phosphatation au zinc sur la résistance a la corrosion d'un acier au carbone en milieu maring · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. A Ettaqi, A Irhzo, RD Daoudi, B Chaker. http://dx.doi.org/10.4314/afsci.v1i2.61127 ...

Afrique Science: Revue Internationale des Sciences et Technologie

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Afrique Science publishes experimental, theoretical and applied results in mathematics, physics, chemistry, biology, geology and engineering. It aims to serve all scientists except medicine and pharmacology. Other websites related to this journal: http://www.afriquescience.info/ ...

MIMETISME ET IMITATION : UNE REVUE DE LA LITTERATURE

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l‟imitation «des idées pures», mais aussi l‟existence d‟un type de protection de .... gion qui diffuse les caractéristiques de la mode d‟une organisation à une autre. ... d‟amélioration des performances mais par besoin de légitimité. La.

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Etude cinétique de la dégradation de l'Endosufane en solution · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. S Traore, K Mamadou, A Dembele, V Yao, Y Bekro, P Mazellier, B Legube, P Houenou, 362-3771. http://dx.doi.org/10.4314/afsci.v3i3.61620 ...

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Etude technico-économique d'un système hybride (aérogénérateur et moteur diesel) pour la production d'électricité. EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. L Merad, B Benyoucef, JP Charles. http://dx.doi.org/10.4314/afsci.v2i2.61156 ...

Un think tank de l'Amérique latine contribue à rationaliser les ...

International Development Research Centre (IDRC) Digital Library (Canada)

23 mai 2012 ... Mme Peixoto explique que, partout dans la région, le LATN a ouvert les débats sur des questions économiques pointues au grand public afin de s'éloigner des dogmes rigides propres aux jeux à somme nulle. Le réseau a également revu sa mission. Ses chercheurs sont non seulement des producteurs de ...

Symbolisme et gestion endogène de l'eau en milieu Shabè dans la ...

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SARAH

31 déc. 2015 ... Armand Colin, 127p. Durkheim E, 1898. Représentations individuelles et représentations Collectives. In : Revue de métaphysique et de morale. Page). Durkheim E, 2008. Les formes élémentaires de la vie religieuse. Paris, Presse Universitaire de. France. Eliade M, 2009. Le mythe de l'éternel retour. Paris,.

Browse Title Index

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Vol 9, No 1 (1999), Conception et réalisation d'un système d'aide à la décision pour la gestion des ressources naturelles, Abstract ... Vol 11, No 1 (2001), Contrat de Lecture et Revue Electronique : Quel paradigme éditorial, Abstract ... Vol 12, No 2 (2002), Le Document Web, Lisibilité, Structure et Oculométrie, Abstract.

Application de la théorie mathématique de l'information pour l ...

African Journals Online (AJOL)

Revue Synthèse N° 21, Janvier 2010. F.L. Rahmani et A. Chibat. 5. Application de la théorie mathématique de l'information pour l'élaboration de questionnaires. Fouad Lazhar Rahmani et Ahmed Chibat. Laboratoire des mathématiques appliquées et modélisation,. Université Frères Mentouri, Constantine 25000, Algérie.

Des atomes d'antihydrogene produits en quantites substantielles au CERN

CERN Multimedia

Sevestre, G

2002-01-01

"Des quantites relativement substantielles d'atomes d'antihydrogene a basse temperature ont ete produites cet ete au Laboratoire europeen de physique des particules, le CERN a Geneve, ouvrant la voie a une etude approfondie de cette antimatiere qui pourrait remettre en cause les theories actuelles, a annonce mercredi sur le site Internet de la revue Nature une equipe internationale de chercheurs" (1 page).

Entre idéal et polémique. La littérature politique dans la Bohême des Luxembourg

Czech Academy of Sciences Publication Activity Database

Vojtíšek, J.; Žůrek, Václav

-, č. 67 (2014), s. 11-30 ISSN 0751-2708 Grant - others:ERC(CZ) Origins of the Vernacular Mode. Regional Identities and European Networks in Late Medieval Europe Source of funding: R - rámcový projekt EK Keywords : allegory * Bohemia * house of Luxembourg * mirrors for princes * political literature * political society Subject RIV: AB - History http:// medieval es.revues.org/7365

Mobilité de la main-d'oeuvre féminine en Asie : migration

International Development Research Centre (IDRC) Digital Library (Canada)

Document de travail 1: Mobilité de la main-d'oeuvre féminine en Asie : migration transnationale, protection sociale et citoyenneté. 13 décembre 2010. Naila Kabeer. Ce document passe en revue l'ensemble des travaux portant sur les mouvements migratoires de la main-d'oeuvre féminine en Asie du point de vue de la ...

Právní úprava zpřístupňující informace orgánů veřejné správy ČR a EU elektronickou cestou a formou open data

Czech Academy of Sciences Publication Activity Database

Kolman, Jiří

2014-01-01

Roč. 5, č. 10 (2014), s. 23-45 ISSN 1804-5383 Institutional support: RVO:67179843 Keywords : freedom of information * open data * electronic Access * Czech public service * institutions of the European union * regulation (EC) No 1049/2001 regarding public acces to EP * council and commission documents Subject RIV: AG - Legal Sciences https://journals.muni.cz/revue/issue/viewFile/245/pdf_8

2. Serge Bernard.pmd

African Journals Online (AJOL)

chifaou.amzat

19 mai 2017 ... pas gratuit. La définition et l'histoire du concept nous en fournissent la preuve. ... principes les plus essentiels de la démocratie et de l'État de droit, le Livre ... autour d'un arbre ou simplement dans un lieu public, en Afrique, « les ...... Revue internationale des Sciences sociales, n° 155, Éditions Unesco.

Cas Clinique Métastase d\\'un adénocarcinome du pancréas au ...

African Journals Online (AJOL)

La tomodensitométrie, puis l'anatomie pathologique ont permis d'obtenir le diagnostic de certitude. Les particularités diagnostiques et thérapeutiques sont discutées à la lumière d'une revue de la littérature. Keywords: Adénocarcinome, métastase, pancréas, cordon spermatique, chirurgie. African Journal Of Urology Vol.14 ...

Méditerranée asiatique : un modèle urbain polycentrique

OpenAIRE

Gipouloux , François

2012-01-01

Publication de la revue "Diplomatie. Affaires stratégiques et relations internationales" http://www.diplomatie-presse.com/; International audience; En Asie orientale, un corridor maritime a pris forme autour de plates-formes logistiques et portuaires, fidèles au modèle de Hong Kong. C'est là que bat le coeur de l'économie régionale.

Place de l'embrochage fasciculé selon Hackethal dans le traitement ...

African Journals Online (AJOL)

A travers cette étude rétrospective, nous avons revu 80 patients traités initialement par embrochage fasciculé centromédullaire selon Hackethal au service de traumatologie orthopédie de l'hôpital militaire Avicenne entre janvier 2000 et janvier 2012. Les fractures ont été classées selon la classification AO et selon la ...

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

Science.gov (United States)

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

2012-01-01

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

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

Directory of Open Access Journals (Sweden)

Bryant Susan V

2009-01-01

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

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

Directory of Open Access Journals (Sweden)

Juan Felipe Diaz Quiroz

2014-06-01

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

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

Science.gov (United States)

Makanae, Aki; Satoh, Akira

2018-01-01

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

Nem holismo nem individualismo metodológicos: Marcel Mauss e o paradigma da dádiva

Directory of Open Access Journals (Sweden)

Caillé Alain

1998-01-01

Full Text Available O artigo se situa no contexto da crítica ao utilitarismo que vem sendo conduzida, desde o início dos anos 80, por um grupo de intelectuais reunidos em torno do MAUSS - Movimento Antiutilitarista nas Ciências Sociais, cujas idéias são divulgadas pela La Revue du MAUSS, publicada pela Editora La Découverte, em Paris. Alain Caillé procura resgatar a importância de Marcel Mauss no interior da escola sociológica francesa, ressaltando a contribuição deste autor clássico na sistematização inicial do paradigma do dom, que subsiste na modernidade, como o demonstram, em várias oportunidades, os colaboradores deste movimento antiutilitarista. Para Caillé, o paradigma do dom constitui o fundamento necessário de criação de uma teoria paradoxal e pluridimensional da ação, capaz de resolver a dicotomia clássica entre holismo e individualismo. No entanto, ressalta o diretor da Revue du MAUSS, na constituição do novo paradigma, as imbricações entre o dom e o simbolismo ainda permanecem imprecisas e algo misteriosas.

Ecrire un article scientifique en anglais guide de rédaction dans la langue de Darwin

CERN Document Server

Forget-Dubois, Nadine

2016-01-01

C’est bien connu, les étudiants universitaires francophones préfèrent écrire dans leur langue maternelle. Voilà pourtant qu’on leur recommande de publier leurs résultats de recherche dans des revues savantes anglaises. L’effort supplémentaire en vaut-il la peine ? Absolument ! Pour rejoindre la communauté scientifique, il faut en maîtriser la langue. Et ce n’est pas tout. En plus d’être rédigé en anglais, votre article devra être clair, bien écrit et impeccablement structuré pour passer l’épreuve de la révision scientifique, puis être enfin publié dans une revue respectable. Commencez-vous à sentir la pression ? Vous vous apercevrez que l’anglais scientifique est un langage particulier que même les anglophones doivent acquérir. L’anglais des sciences n’est pas exactement la langue de Shakespeare dans sa forme et ses fonctions; je préfère l’appeler la langue de Darwin. C’est pour en apprendre le style et les codes que je vous propose ce guide de rédaction.

prise en charge des complications orbitaires et endocrâniennes

African Journals Online (AJOL)

Les complications orbitaires et endocrâniennes des sinusites aiguës infectieuses posent un problème diagnostique et thérapeutique. Le but de notre travail est de proposer un algorithme de prise en charge de ces complications à travers une revue de littérature. Les sinusites de la base du crâne (frontal, sphénoïdal et ...

African Journals Online: Congo, Republic

African Journals Online (AJOL)

Annales Aequatoria. As of 2010 Annales Aequatoria has ceased publication. Cette revue sort une fois par année (environ 600 pages par numéro), publiant des articles en français et en anglais (d'autres langues peuvent également êtres acceptées) et encourage des études sur les langues, les littératures, les sociétés et ...

Efficacité de la gestion de vaccins et qualité de vaccination à l ...

African Journals Online (AJOL)

La revue documentaire complétée par les entretiens semi-dirigés des gestionnaires et prestataires de services de vaccination ont permis d'évaluer la gestion de vaccins en se servant des modèle GEV de l'OMS, en vue de dégager les écarts. Résultats: il est observé une faible connaissance des prestataires sur les vaccins ...

Christianity and Marxism

CERN Multimedia

Gaillard,A

1974-01-01

Deux conférenciers s'expriment: le pasteur Albert Gaillard qui a été sécrétaire géneral de l'église réformé de France et dirige et coordonne maintenant la recherche théologique. Roger Garaudi était membre du bureau politique du parti communiste français et dirige maintenant la revue alternative socialiste

Les infections nosocomiales néonatales: quand l'infirmière a une place centrale dans la prévention

OpenAIRE

Hayoz, Mathilde; Moser, Olivia; Thévoz, Anne-Laure

2015-01-01

L’objectif de cette revue de littérature est de répondre au questionnement clinique suivant : quelles sont les mesures de prévention que l’infirmière peut mettre en place afin de diminuer le taux d’infections nosocomiales lors de procédures invasives auprès des nouveau-nés dans un service de soins intensifs de néonatologie ?

Le lancement canadien du Rapport sur les politiques alimentaires ...

International Development Research Centre (IDRC) Digital Library (Canada)

1 mai 2018 ... Cet événement sera filmé, puis accessible en ligne sur la chaîne YouTube du CRDI. Le Rapport sur les politiques alimentaires mondiales 2018 passe en revue les principaux faits nouveaux et événements en matière de politiques alimentaires survenus au cours de l'année. D'éminents chercheurs ...

Wor(l)ds of Czech Oral History (1990-2015). A Couple of Historiographical Remarks

Czech Academy of Sciences Publication Activity Database

Mücke, Pavel

2017-01-01

Roč. 2017, č. 43 (2017), s. 28-39 ISSN 2109-9537 R&D Projects : GA ČR GA15-08130S Institutional support: RVO:68378114 Keywords : oral history * Czech Republic * contemporary history Subject RIV: AB - History OBOR OECD: History (history of science and technology to be 6.3, history of specific sciences to be under the respective headings) https://afas.revues.org/3049

Influence sur les politiques et bidonvilles en Amérique latine -Atelier ...

International Development Research Centre (IDRC) Digital Library (Canada)

Salud humana y cambios en la producción tegnológica de la papa : 11vo Congreso Mundial de Salud Publica y 8vo Congreso Brasileño de Salud Colectiva, Rio de Janeiro, Agosto 2006. Téléchargez le PDF. Articles de revue. Water quality and health in poor urban areas of Latin America. Téléchargez le PDF. Évaluations.

La guerre dans les médias, les médias dans la guerre en Côte d'Ivoire

African Journals Online (AJOL)

chifaou.amzat

12 mars 2007 ... préoccupations, à travers la parole libérée et le droit de vote. ... revue scientifique (électronique) du Groupe de Recherche sur les Enjeux de ...... trahison par rapport à la coopération militaire qui lie les deux pays, et par les .... communauté internationale et à tous les défenseurs des droits de l'homme,.

La neurotoxoplasmose congenitale du nourrisson : a propos d'une ...

African Journals Online (AJOL)

Les auteurs rapportent un cas isolé d'une Toxoplasmose cérébrale congénitale chez un enfant de 02 ans hospitalisé dans le service de neurologie du centre hospitalouniversitaire (C.H.U) Campus de Lomé. La revue de la littérature permet d'insister sur les formes cliniques, l'imagerie médicale, la biologie ainsi que les ...

L'Inde, pays des filles disparues | CRDI - Centre de recherches pour ...

International Development Research Centre (IDRC) Digital Library (Canada)

4 nov. 2010 ... En janvier 2006, dans un article traitant des résultats de leurs travaux publié dans la revue médicale The Lancet, les chercheurs signalaient que la meilleure preuve de la pression culturelle qui s'exerce pour avoir au moins un garçon était la baisse du nombre de naissances de filles dans les familles dont ...

Répercussions environnementales et sanitaires de l'exploitation ...

International Development Research Centre (IDRC) Digital Library (Canada)

Mining and Seasonal Variation of the Metals Concentration in the Puyango River Basin—Ecuador. Articles de revue. Mineria, Ambiente y Salud en la Cuenca del Rio Puyango Sur del Ecuador. Rapports. Informe técnico final : minería del oro en el Ecuador fase III; consolidación, uso de la investigación y difusión (período ...

Etat Des Lieux De La Reglementation Relative A L'homologation ...

African Journals Online (AJOL)

Notre étude a comporté d'une part une revue de textes législatifs et réglementaires sur les laits infantiles tant au plan national qu'international et une phase d'enquête transversale dans le district d'Abidjan, auprès des officines privées de pharmacie et des grossistes répartiteurs privés de produits pharmaceutiques.Il ressort ...

Les baobabs de Madagascar : Quel cadre réglementaire pour leur ...

African Journals Online (AJOL)

Abstract. Avec les lémuriens, les baobabs sont certainement reconnus dans le monde comme l'un des groupes les plus emblématiques de Madagascar. La Grande Île abrite six espèces endémiques dont trois 'En Danger' sur la liste rouge de l'UICN et trois 'Quasi - menacées'. Cet article se propose de passer en revue les ...

Qualité, portée et incidence de l'édition savante en libre accès en ...

International Development Research Centre (IDRC) Digital Library (Canada)

Une meilleure compréhension du libre accès aux recherches savantes aidera à déterminer en quoi il contribue à accroître la circulation des connaissances et la diffusion des résultats de recherche en Amérique latine. Le libre accès (le fait de pouvoir consulter, sans restriction aucune, des articles publiés dans des revues ...