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Sample records for neotenen axolotl revue

  1. The Mexican Axolotl in Schools

    Science.gov (United States)

    Thomas, R. M.

    1976-01-01

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

  2. Generation of axolotl hematopoietic chimeras

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    David Lopez

    2015-02-01

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

  3. Transgenesis in axolotl (Ambystoma mexicanum).

    Science.gov (United States)

    Khattak, Shahryar; Tanaka, Elly M

    2015-01-01

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

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

    Science.gov (United States)

    Gresens, Jill

    2004-10-01

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

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

    African Journals Online (AJOL)

    African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 18, No 2 (2014) >. Log in or Register to get access to full text downloads.

  6. African Sociological Review / Revue Africaine de Sociologie

    African Journals Online (AJOL)

    African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 20, No 1 (2016) >. Log in or Register to get access to full text downloads.

  7. African Sociological Review / Revue Africaine de Sociologie

    African Journals Online (AJOL)

    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.

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

    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 1 (2008) >. Log in or Register to get access to full text downloads.

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

    African Journals Online (AJOL)

    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.

  10. African Sociological Review / Revue Africaine de Sociologie

    African Journals Online (AJOL)

    African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 19, No 1 (2015) >. Log in or Register to get access to full text downloads.

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

    African Journals Online (AJOL)

    African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 19, No 2 (2015) >. Log in or Register to get access to full text downloads.

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

    African Journals Online (AJOL)

    African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 7, No 1 (2003) >. Log in or Register to get access to full text downloads.

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

    African Journals Online (AJOL)

    African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 19, No 1 (2015) >. Log in or Register to get access to full text downloads.

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

    Science.gov (United States)

    Coots, Peggy S; Seifert, Ashley W

    2015-01-01

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

  15. African Sociological Review / Revue Africaine de Sociologie: About ...

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    African Sociological Review / Revue Africaine de Sociologie: About this journal. Journal Home > African Sociological Review / Revue Africaine de Sociologie: About this journal. Log in or Register to get access to full text downloads.

  16. Archives: Afrique Science: Revue Internationale des Sciences et ...

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    Items 1 - 31 of 31 ... Archives: Afrique Science: Revue Internationale des Sciences et Technologie. Journal Home > Archives: Afrique Science: Revue Internationale des Sciences et Technologie. Log in or Register to get access to full text downloads.

  17. Limb Regeneration in Axolotl: Is It Superhealing?

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    Stéphane Roy

    2006-01-01

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

  18. Transcriptional landscapes of Axolotl (Ambystoma mexicanum).

    Science.gov (United States)

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

    2018-01-15

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

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

    Science.gov (United States)

    Farkas, Johanna E; Monaghan, James R

    2015-01-01

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

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

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    Suetsugu-Maki Rinako

    2012-12-01

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

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

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    Pedro Gomes Sanches

    Full Text Available The salamander axolotl is capable of complete regeneration of amputated heart tissue. However, non-invasive imaging tools for assessing its cardiac function were so far not employed. In this study, cardiac magnetic resonance imaging is introduced as a non-invasive technique to image heart function of axolotls. Three axolotls were imaged with magnetic resonance imaging using a retrospectively gated Fast Low Angle Shot cine sequence. Within one scanning session the axolotl heart was imaged three times in all planes, consecutively. Heart rate, ejection fraction, stroke volume and cardiac output were calculated using three techniques: (1 combined long-axis, (2 short-axis series, and (3 ultrasound (control for heart rate only. All values are presented as mean ± standard deviation. Heart rate (beats per minute among different animals was 32.2±6.0 (long axis, 30.4±5.5 (short axis and 32.7±4.9 (ultrasound and statistically similar regardless of the imaging method (p > 0.05. Ejection fraction (% was 59.6±10.8 (long axis and 48.1±11.3 (short axis and it differed significantly (p = 0.019. Stroke volume (μl/beat was 133.7±33.7 (long axis and 93.2±31.2 (short axis, also differed significantly (p = 0.015. Calculations were consistent among the animals and over three repeated measurements. The heart rate varied depending on depth of anaesthesia. We described a new method for defining and imaging the anatomical planes of the axolotl heart and propose one of our techniques (long axis analysis may prove useful in defining cardiac function in regenerating axolotl hearts.

  2. 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.

  3. 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.

  4. Continuous growth of the motor system in the axolotl

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  5. 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

  6. 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

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

    Science.gov (United States)

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

    2009-01-01

    Retinoic acid, a key morphogen in early vertebrate development and tissue regeneration, mediates its effects through the binding of receptors that act as ligand-induced transcription factors. These binding events function to recruit an array of transcription co-regulatory proteins to specific gene promoters. One such co-regulatory protein, neuronal proliferation and differentiation control-1 (NPDC-1), is broadly expressed during mammalian development and functions as an in vitro repressor of retinoic acid receptor (RAR)-mediated transcription. To obtain comparative and developmental insights about NPDC-1 function, we cloned the axolotl (Ambystoma mexicanum) orthologue and measured transcript abundances among tissues sampled during the embryonic and juvenile phases of development, and also during spinal cord regeneration. Structurally, the axolotl orthologue of NPDC-1 retained sequence identity to mammalian sequences in all functional domains. Functionally, we observed that axolotl NPDC-1 mRNA expression peaked late in embryogenesis, with highest levels of expression occurring during the time of limb development, a process regulated by retinoic acid signaling. Also similar to what has been observed in mammals, axolotl NPDC-1 directly interacts with axolotl RAR, modulates axolotl RAR DNA binding, and represses cell proliferation and axolotl RAR-mediated gene transcription. These data justify axolotl as a model to further investigate NPDC-1 and its role in regulating retinoic acid signaling. PMID:17331771

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

    Science.gov (United States)

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

    2015-04-10

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

  9. Axolotl cells and tissues enhances cutaneous wound healing in mice

    OpenAIRE

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

    2017-01-01

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

  10. Diffusion tensor tractography reveals muscle reconnection during axolotl limb regeneration.

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2014-01-01

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

  12. 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

  13. Revue de Médecine et de Pharmacie

    African Journals Online (AJOL)

    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 ...

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

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    Revue d'Information Scientifique et Technique. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 2, No 2 (1992) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. DOWNLOAD FULL TEXT Open Access ...

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

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

    Science.gov (United States)

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

    2004-02-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2018-05-16

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

  19. 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 ...

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

    Directory of Open Access Journals (Sweden)

    Donald M. Bryant

    2017-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Montoro, Rodrigo; Dickie, Renee

    2017-01-01

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

  7. Software Agents for Workflows Support | Zakaria | Revue d ...

    African Journals Online (AJOL)

    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 ...

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

    Science.gov (United States)

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

    2016-09-01

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

  9. [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.

  10. 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.

  11. Network based transcription factor analysis of regenerating axolotl limbs

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    Mathieu Lévesque

    2007-11-01

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

  13. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2014-03-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

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

    Science.gov (United States)

    Eisthen, Heather L; Krause, Brianne Chung

    2012-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Ellen A. G. Chernoff

    2018-02-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

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

    Science.gov (United States)

    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

  3. Axolotl/Bichos Raros Crónica

    Directory of Open Access Journals (Sweden)

    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.

  4. Nový časopis "Revue pro právo a technologie"

    Czech Academy of Sciences Publication Activity Database

    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

  5. Le stress professionnel au Cameroun | Manga | Revue de Médecine ...

    African Journals Online (AJOL)

    Revue de Médecine et de Pharmacie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 1 (2011) >. Log in or Register to get access to full text downloads.

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

    Science.gov (United States)

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

    2009-02-01

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

  7. 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...

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2002-09-01

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

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

    Science.gov (United States)

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

    2007-01-01

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

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

    NARCIS (Netherlands)

    Carlson, Bruce M.

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

  12. 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.

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

    Science.gov (United States)

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

    2016-02-04

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

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

    Directory of Open Access Journals (Sweden)

    Micah D. Gearhart

    2015-09-01

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

  15. 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.

  16. 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...

  17. Proteomic analysis of blastema formation in regenerating axolotl limbs

    Directory of Open Access Journals (Sweden)

    Nye Holly LD

    2009-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Zullian C

    2016-01-01

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

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

    Science.gov (United States)

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

    1998-12-15

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

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

    Directory of Open Access Journals (Sweden)

    Kazumasa Mitogawa

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

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

    International Nuclear Information System (INIS)

    Charlemagne, J.

    1981-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Charlemagne, J.

    1981-09-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  4. 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...

  5. 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...

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hans-Henning Epperlein

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

  8. 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.

  9. 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...

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

    Science.gov (United States)

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

    1998-12-15

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

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

    Directory of Open Access Journals (Sweden)

    Lemanski Sharon L

    2009-09-01

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

  12. 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.

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

    Science.gov (United States)

    Ackerly, Kerri L; Ward, Andrea B

    2015-12-01

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

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

    Science.gov (United States)

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

    2007-06-01

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

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. Synthèse: Revue des Sciences et de la Technologie: Submissions

    African Journals Online (AJOL)

    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 ...

  20. 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 ...

  1. 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 ...

  2. La neurosyphilis chez 3 patients VIH négatifs | Fode Cisse | Revue ...

    African Journals Online (AJOL)

    Revue de Médecine et de Pharmacie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 4, No 2 (2014) >. Log in or Register to get access to full text downloads.

  3. Synthèse: Revue des Sciences et de la Technologie

    African Journals Online (AJOL)

    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 ...

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

    Science.gov (United States)

    2013-01-01

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

  5. 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

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

    Science.gov (United States)

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

    2002-01-01

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

  7. 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.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ron Stewart

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

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

    Science.gov (United States)

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

    2007-01-01

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

  11. 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...

  12. [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.

  13. 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

  14. 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...

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

    Science.gov (United States)

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

    2007-01-01

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

  16. 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.

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

    Science.gov (United States)

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

    2016-11-21

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

  18. 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

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

    Directory of Open Access Journals (Sweden)

    Chiara Zullian

    2015-01-01

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

  20. 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

  1. 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.

  2. 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.

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    Hélène Pelczar

    2010-12-01

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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    Maden Malcolm

    2013-01-01

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

  12. 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.

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Catalina Villalobos Díaz

    2017-07-01

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

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

    Science.gov (United States)

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

    2013-08-01

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

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

    Science.gov (United States)

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

    2013-11-01

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

  17. 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...

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

    Directory of Open Access Journals (Sweden)

    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

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

    OpenAIRE

    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. ...

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2008-07-15

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

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

    Science.gov (United States)

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

    2010-10-01

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

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

    Science.gov (United States)

    Ericsson, Rolf; Olsson, Lennart

    2004-08-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2010-01-15

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

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

    Science.gov (United States)

    Davidian, Asya; Malashichev, Yegor

    2013-01-01

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

  8. 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.

  9. Première analyse du lectorat de la revue ALSIC

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Samuels Amy K

    2008-02-01

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

  11. 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.

  12. 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.

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

    Science.gov (United States)

    Jarial, M S

    1989-01-01

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

  14. 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

  15. 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.

  16. 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.

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

    Science.gov (United States)

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

    2017-08-01

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

  18. 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.

  19. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Suzuki, Hirohumi; Yamamoto, Toshiharu

    2014-02-01

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

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

    Science.gov (United States)

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

    2004-10-01

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

  2. [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.

  3. 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 ...

  4. 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.

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

    OpenAIRE

    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, ...

  6. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 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...

  9. 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

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

    Lehrberg, Jeffrey; Gardiner, David M

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jeffrey Lehrberg

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

  13. 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.

  14. 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.

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

    Science.gov (United States)

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

    2006-07-01

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

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

    Science.gov (United States)

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

    2018-04-07

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

  17. 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. 

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

    Science.gov (United States)

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

    2013-01-23

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

  19. 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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2005-08-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ji-Feng Fei

    2014-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Xiaoping Chen

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

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

    Science.gov (United States)

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

    2011-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Carlos Díaz-Castillo

    2017-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Prehn Lea R

    2010-05-01

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

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

    Science.gov (United States)

    2017-01-01

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

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

    International Nuclear Information System (INIS)

    Teplits, N.A.

    1975-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1975-01-01

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

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

    Science.gov (United States)

    Badawy, Gamal; Reinecke, Manfred

    2003-03-01

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

  12. 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.

  13. 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...

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

    OpenAIRE

    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.

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

    OpenAIRE

    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 ...

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

    Directory of Open Access Journals (Sweden)

    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...

  17. 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.)

  18. 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

  19. 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.

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

    OpenAIRE

    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.

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  3. 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 ?

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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

    Directory of Open Access Journals (Sweden)

    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

  6. 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.

  7. 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.

  8. 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 ...

  9. 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...

  10. 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

    Directory of Open Access Journals (Sweden)

    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.

  11. « 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...

  12. 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

  13. 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

  14. 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

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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.

  18. 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 ...

  19. Revue d'Information Scientifique et Technique

    African Journals Online (AJOL)

    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 ...

  20. 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.

  1. 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?

  2. 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 ...

  3. 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 ...

  4. 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

  5. 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...

  6. 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.

  7. 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

  8. Buoyancy disorders in pet axolotls Ambystoma mexicanum: three cases.

    Science.gov (United States)

    Takami, Yoshinori; Une, Yumi

    2018-01-31

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

  9. entre la pirámide y el axolotl

    Directory of Open Access Journals (Sweden)

    Paula Andrea Marín Colorado

    2006-01-01

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

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

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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 ...

  12. African Sociological Review / Revue Africaine de Sociologie - Vol 19 ...

    African Journals Online (AJOL)

    Les Jeux Video en Negroculture : Contribution a Une Anthropologie de La Solidarite Chez Les Jeunes du Cameroun · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Paul Ulrich Otye Elom, 77-87 ...

  13. African Sociological Review / Revue Africaine de Sociologie - Vol 14 ...

    African Journals Online (AJOL)

    Stratégie de survie et culture de jeunes dans les marchés urbains de Dakar : cas des adolescentes travailleuses (Sénégal). EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. RA Diop, 67-83. http://dx.doi.org/10.4314/asr.v14i1.70229 ...

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

    African Journals Online (AJOL)

    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., ...

  15. Revue de Médecine et de Pharmacie: Editorial Policies

    African Journals Online (AJOL)

    Editorial Board & Scientific Committee 2012. Directeur de Publication/Editorial director : Pr EBANA MVOGO Côme Rédacteurs en Chef/Editorial board : André OMGBWA EBALLE, William NGATCHOU, Théodore SALA BEYEME. Comité Scientifique/Scientific committee: Pr MOUELLE SONE Albert, Pr SAME EKOBO Albert,

  16. Revue d'Information Scientifique et Technique: Advanced Search

    African Journals Online (AJOL)

    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., ...

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

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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, ...

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

    African Journals Online (AJOL)

    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 ...

  20. Revue de Médecine et de Pharmacie: Advanced Search

    African Journals Online (AJOL)

    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., ...

  1. African Sociological Review / Revue Africaine de Sociologie - Vol 9 ...

    African Journals Online (AJOL)

    Putting oil first? Some ethnographic aspects of petroleum-related land use controversies in Nigeria · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT ... Reclaiming The Land - The Resurgence of Rural Movements in Africa, Asia and Latin America, Zed Books, London, 2005 · EMAIL FREE FULL TEXT EMAIL FREE FULL ...

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

    African Journals Online (AJOL)

    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 ...

  3. revue generale sur les rhinolithiases : a propos de 20 cas

    African Journals Online (AJOL)

    18 juin 2007 ... facial sont fréquemment cités dans la littérature (10, 11,. 12). Plus rarement on note des .... J. Oral maxillo fac surg; 1997; 55 : 1339-1341. 30) - ALI. DS ... Post traumatic rhinolith AM J Neuro radiol 1993 14 ; (5) : 1181-1182.

  4. Nuclear safety in France: Extracts from 'Revue Generale Nucleaire'

    International Nuclear Information System (INIS)

    1979-07-01

    Translations of 3 articles are included in this report. The first covers briefly the tasks and organisation of the Institute of Nuclear Protection and Safety (IPSN) in France. In the second article the principles of cost effectiveness are described and the applications of the general methodology to radiation protection is outlined. A study by the US Environmental Protection Agency is summarised. Methods for risk estimation in nuclear energy are presented in the final article

  5. African Sociological Review / Revue Africaine de Sociologie - Vol 17 ...

    African Journals Online (AJOL)

    The phenomenon of social conversion among farmers in France: From traditional agriculture to the Spirulina superfood · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. P Stéfanini, S Ravatua-Smith, 43-54 ...

  6. La hernie ombilicale africaine : nouvelle classification et revue de 30 ...

    African Journals Online (AJOL)

    L'objectif de ce travail était de proposer une nouvelle classification de la hernie ombilicale de l'enfant africain et d'évaluer les résultats du traitement chirurgical.Il s'agit d'une étude prospective portant sur 30 patients porteurs de hernie ombilicale, qui s'est déroulée sur une période de un an et demi dans les services de ...

  7. Afrique Science: Revue Internationale des Sciences et Technologie

    African Journals Online (AJOL)

    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/ ...

  8. Thyroid autoantibodies and differentiated thyroid cancer: revue of 662 cases

    International Nuclear Information System (INIS)

    Izembart, M.; Dagousset, F.; Chevalier, A.; Hassid, V.; Leger, A.; Barritault, L.; Clerc, J.

    1999-01-01

    The incidence of thyroid autoantibodies is clearly increased in patients with differentiated thyroid cancer. The aim of this study was to re-evaluate frequency and evolution of anti-thyroglobulin and anti-microsomal (anti-peroxidase) autoantibodies in 662 patients with thyroid carcinoma treated with 131 radioiodine. Ours results obtained with 'classical' methods confirmed others earlier reports. When using more sensitive methods to detect thyroglobulin antibodies we obtained an increase in positive results and a more frequent association with anti-microsomal antibodies. Antibodies became undetectable with a variable period, ranging from a few months to 13 years in one case. If we suppose that the disappearance of antibodies is linked to the thyroid tissue disappearance, thyroid cancer follow up ought to include anti-thyroglobulin and anti-peroxidase antibodies, both directed against thyroid antigens. A decrease of both antibodies seems to indicate a favorable prognostic factor whereas an increase may suggest relapse. (author)

  9. MIMETISME ET IMITATION : UNE REVUE DE LA LITTERATURE

    African Journals Online (AJOL)

    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.

  10. African Sociological Review / Revue Africaine de Sociologie - Vol 8 ...

    African Journals Online (AJOL)

    Pull factors in the political economy of international commercial sex work in Nigeria · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ... Zimbabwe\\'s unfinished business - rethinking land, state and nation in the context of crisis. By Amanda Hammar, Brian Raftopoulos and ...

  11. African Sociological Review / Revue Africaine de Sociologie - Vol 9 ...

    African Journals Online (AJOL)

    Speaking Truth to Power: A Personal Journey through the Politics of Boycott and Engagement at Rhodes University during the 1980s · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. D Pillay, 184-190 ...

  12. African Sociological Review / Revue Africaine de Sociologie - Vol 7 ...

    African Journals Online (AJOL)

    ? EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT ... Book Review: Louise Meintjes. South of Africa Making Music Zulu in a South African Studio. Durham. Duke University Press. 2003. Michael Drewett.

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

    African Journals Online (AJOL)

    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 ...

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

    African Journals Online (AJOL)

    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 ...

  15. Os periódicos acadêmicos de geografia francesa de 1940-1945. Entre a pobreza material e a resistência intelectual Les revues universitaires de géographie française de 1940 à 1945. Entre pénurie matérielle et résistance intellectuelle French Geographical Journals facing World War II. Between material scarcity and intellectual resistance

    Directory of Open Access Journals (Sweden)

    Laurent Beauguitte

    2010-06-01

    Full Text Available Apesar da guerra e da escassez decorrente dela, apesar da ocupação e dos censores do governo de Vichy e alemaes, os geógrafos franceses cuidaram, entre 1940 e 1945 de continuar seus trabalhos científicos. Este artigo tem como objetivo destacar as condições de produção dos seis jornais da geografia francesa durante a Segunda Guerra Mundial e as atitudes dos geógrafos frente às notícias deste momento difícil. O impacto da escassez é facilmente quantificável, e também é possível encontrar sinais claros de resistência à ocupação e ao regime de Vichy. Falando da censura como dos prisioneiros de guerra ou das dificuldades diárias relacionadas à Segunda Guerra Mundial, os geógrafos aqui estudados escreviam sobre uma geografia do presente.Malgré la guerre et les pénuries qu’elle entraîne, malgré l’occupation et les censures tant vichystes qu’allemandes, les géographes français veillent de 1940 à 1945 à poursuivre leur activité scientifique. Cet article vise à mettre en lumière tant les conditions de production des six revues de géographie françaises durant la Seconde guerre mondiale que l’attitude des géographes vis à vis de l’actualité difficile de cette époque. Si l’impact des pénuries est aisément quantifiable, il est également possible de trouver des signes nets de résistance à l’Occupation et au régime de Vichy. Evoquant tant la censure que les prisonniers de guerre ou les difficultés quotidiennes liées à la Seconde guerre mondiale, les géographes étudiés ici écrivent une géographie au présent.Despite the war and the shortages it causes, despite the Occupation and both Vichy and German censorships, French geographers achieved, from 1940 to 1945, to continue their scientific work. This article aims to highlight both the production of French geographical journals during the World War II and the behaviour of geographers in this difficult time.If the impact of shortages can be

  16. 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

  17. Positional information is reprogrammed in blastema cells of the regenerating limb of the axolotl (Ambystoma mexicanum).

    Science.gov (United States)

    McCusker, Catherine D; Gardiner, David M

    2013-01-01

    The regenerating region of an amputated salamander limb, known as the blastema, has the amazing capacity to replace exactly the missing structures. By grafting cells from different stages and regions of blastemas induced to form on donor animals expressing Green Fluorescent Protein (GFP), to non-GFP host animals, we have determined that the cells from early stage blastemas, as well as cells at the tip of late stage blastemas are developmentally labile such that their positional identity is reprogrammed by interactions with more proximal cells with stable positional information. In contrast, cells from the adjacent, more proximal stump tissues as well as the basal region of late bud blastemas are positionally stable, and thus form ectopic limb structures when grafted. Finally, we have found that a nerve is required to maintain the blastema cells in a positionally labile state, thus indicating a role for reprogramming cues in the blastema microenvironment.

  18. Positional information is reprogrammed in blastema cells of the regenerating limb of the axolotl (Ambystoma mexicanum.

    Directory of Open Access Journals (Sweden)

    Catherine D McCusker

    Full Text Available The regenerating region of an amputated salamander limb, known as the blastema, has the amazing capacity to replace exactly the missing structures. By grafting cells from different stages and regions of blastemas induced to form on donor animals expressing Green Fluorescent Protein (GFP, to non-GFP host animals, we have determined that the cells from early stage blastemas, as well as cells at the tip of late stage blastemas are developmentally labile such that their positional identity is reprogrammed by interactions with more proximal cells with stable positional information. In contrast, cells from the adjacent, more proximal stump tissues as well as the basal region of late bud blastemas are positionally stable, and thus form ectopic limb structures when grafted. Finally, we have found that a nerve is required to maintain the blastema cells in a positionally labile state, thus indicating a role for reprogramming cues in the blastema microenvironment.

  19. Electrogenic glutamate uptake is a major current carrier in the membrane of axolotl retinal glial cells

    Science.gov (United States)

    Brew, Helen; Attwell, David

    1987-06-01

    Glutamate is taken up avidly by glial cells in the central nervous system1. Glutamate uptake may terminate the transmitter action of glutamate released from neurons1, and keep extracellular glutamate at concentrations below those which are neurotoxic. We report here that glutamate evokes a large inward current in retinal glial cells which have their membrane potential and intracellular ion concentrations controlled by the whole-cell patch-clamp technique2. This current seems to be due to an electrogenic glutamate uptake carrier, which transports at least two sodium ions with every glutamate anion carried into the cell. Glutamate uptake is strongly voltage-dependent, decreasing at depolarized potentials: when fully activated, it contributes almost half of the conductance in the part of the glial cell membrane facing the retinal neurons. The spatial localization, glutamate affinity and magnitude of the uptake are appropriate for terminating the synaptic action of glutamate released from photoreceptors and bipolar cells. These data challenge present explanations of how the b-wave of the electroretinogram is generated, and suggest a mechanism for non-vesicular voltage-dependent release of glutamate from neurons.

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

    Directory of Open Access Journals (Sweden)

    James R. Monaghan

    2012-07-01

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

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

    Science.gov (United States)

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

    2010-12-01

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

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

    OpenAIRE

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

    2007-01-01

    Retinoic acid, a key morphogen in early vertebrate development and tissue regeneration, mediates its effects through the binding of receptors that act as ligand-induced transcription factors. These binding events function to recruit an array of transcription co-regulatory proteins to specific gene promoters. One such co-regulatory protein, neuronal proliferation and differentiation control-1 (NPDC-1), is broadly expressed during mammalian development and functions as an in vitro repressor of ...

  3. Functional and structural regeneration in the axolotl heart (Ambystoma mexicanum) after partial ventricular amputation.

    Science.gov (United States)

    Cano-Martínez, Agustina; Vargas-González, Alvaro; Guarner-Lans, Verónica; Prado-Zayago, Esteban; León-Oleda, Martha; Nieto-Lima, Betzabé

    2010-01-01

    "In the present study we evaluated the effect of partial ventricular amputation (PVA) in the heart of the adult urodele amphibian (Ambystoma mexicanum) in vivo on spontaneous heart contractile activity recorded in vitro in association to the structural recovery at one, five, 30 and 90 days after injury. One day after PVA, ventricular-tension (VT) (16 ± 3%), atrium-tension (AT) (46 ± 4%) and heart rate (HR) (58+10%) resulted lower in comparison to control hearts. On days five, 30 and 90 after damage, values achieved a 61 ± 5, 93 ± 3, and 98 ± 5% (VT), 60 ± 4, 96 ± 3 and 99 ± 5% (AT) and 74 ± 5, 84 ± 10 and 95 ± 10% (HR) of the control values, respectively. Associated to contractile activity recovery we corroborated a gradual tissue restoration by cardiomyocyte proliferation. Our results represent the first quantitative evidence about the recovery of heart of A. mexicanum restores its functional capacity concomitantly to the structural recovery of the myocardium by proliferation of cardiomyocytes after PVA. These properties make the heart of A. mexicanum a potential model to study the mechanisms underlying heart regeneration in adult vertebrates in vivo.

  4. Characterization of glycosaminoglycans during tooth development and mineralization in the axolotl, Ambystoma mexicanum.

    Science.gov (United States)

    Wistuba, J; Völker, W; Ehmcke, J; Clemen, G

    2003-10-01

    Glycosaminoglycans (GAGs) involved in the formation of the teeth of Ambystoma mexicanum were located and characterized with the cuprolinic blue (CB) staining method and transmission electron microscopy (TEM). Glycosaminoglycan-cuprolinic blue precipitates (GAGCB) were found in different compartments of the mineralizing tissue. Various populations of elongated GAGCB could be discriminated both according to their size and their preferential distribution in the extracellular matrix (ECM). GAGCB populations that differ in their composition could be attributed not only to the compartments of the ECM but also to different zones and to different tooth types (early-larval and transformed). Larger precipitates were only observed within the dentine matrix of the shaft of the early-larval tooth. The composition of the populations differed significantly between the regions of the transformed tooth: pedicel, shaft and dividing zone. In later stages of tooth formation, small-sized GAGCBs were seen as intracellular deposits in the ameloblasts. It is concluded that the composition of GAGCB populations seems to play a role in the mineralization processes during tooth development in A. mexicanum and influence qualitative characteristics of the mineral in different tooth types and zones, and it is suggested that GAGs might be resorbed by the enamel epithelium during the late phase of enamel formation.

  5. Revue de Médecine et de Pharmacie - Vol 4, No 2 (2014)

    African Journals Online (AJOL)

    ... users of the Anti rabies centre Douala, Cameroon : a descriptive cross sectional study · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. AA Bita Fouda, G Etapelong Sume, N Essomba, E Nguemne, C Anani, D Mbida, E Ekosso, A Feuhgouo, G Noufack Zambou, J Owona Manga ...

  6. Jules Verne, la géogenèse des diamants et la revue Nature

    OpenAIRE

    Bollinger , Jean-Claude

    2015-01-01

    International audience; Browsing through recent issues of the respected scientific journal Nature, the author has found a number of explicit references to Jules Verne’s famous novel "Journey to the Center of the Earth". For example, in a paper about the analysis of a solid inclusion within a diamond, diamond formation from a solution is mentioned. But this is in fact a main topic within another and lesser known novel, "The Southern Star". Then a discussion concerning diamond formation is pres...

  7. Syndrome de fatigue chronique: Revue de la littérature

    OpenAIRE

    Turgeon, Sue A.

    1991-01-01

    Chronic fatigue syndrome, previously known as chronic mononucleosis or post-infectious faligue, is a poorly understood illness characterized by chronic debilitating fatigue, recurrent flu-like symptoms, and few clinical or laboratory abnormalities. While a significant incidence of psychiatric illness has been demonstrated among patients with the chronic fatigue syndrome, there is also evidence of subtle immune system abnormalities, leading some researchers to postulate a multi-fatorial psycho...

  8. Revue des sciences humaines, Université de Constantine.n° 12, 1999

    OpenAIRE

    Soufi, Fouad

    2013-01-01

    Par le nombre élevé d’études réunies, vingt quatre dont dix huit en arabe, quatre en français et deux en anglais, ce numéro a le mérite de donner une vision assez complète des centres d’intérêt des chercheurs de l’université de Constantine (trois contributions extérieures seulement). Thème premier, l’économie : La mondialisation (Belkacem Slatnia), la conservation des monuments historiques en milieu urbain (Ahmed Boudraa), L’échec des politiques industrielles (N. Boumahrat), La fuite des cerv...

  9. Synthèse: Revue des Sciences et de la Technologie - Vol 17 (2008)

    African Journals Online (AJOL)

    Modélisation numérique d'un phénomène mécanique (TRIP) induit par une transformation martensitique dans l'acier 16MND5 · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. S Mefta, L Taleb, F Barbe, F Sidoroff, 73-84 ...

  10. Synthèse: Revue des Sciences et de la Technologie - Vol 16 (2007)

    African Journals Online (AJOL)

    Etude des efforts et de la température de coupe lors de tournage dur de l'acier AISI 52100 par un outil CBN · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. MA Yallese, L Boulanouar, N Zeghib, S Belhadi, J Rigal, 74-86 ...

  11. Comité Scientifique de la Revue des Sciences et de la Technologie ...

    African Journals Online (AJOL)

    MICROSIM

    procédure d'analyse inverse basée sur l'utilisation conjointe d'un code de calcul par éléments finis et .... Espace de recherche : Soit Np le nombre de paramètres à identifier pour le problème posé. ( sat rel. KSkK) ..... basés sur la reproduction des mesures inclinomériques des déplacements horizontaux, montrent la bonne.

  12. Le Pseudomonas: Experience du Centre des Brules D’Annaba et Revue de la Litterature

    Science.gov (United States)

    Chaibdraa, A.; Medjellekh, M.S.; Saouli, A.; Bentakouk, M.C.

    2008-01-01

    Summary Le Pseudomonasest un agent pathogène à l'origine d'infections nosocomiales graves dans les centres des brûlés. Son opportunisme et sa virulence en font une préoccupation majeure. Ce travail se propose d'évaluer la place de cette bactérie dans l'écologie bactérienne locale et d'en apprécier la sensibilité aux antibiotiques. Cette étude rétrospective préliminaire porte sur la période de juin 2003 à décembre 2005. Elle intéresse l'ensemble des prélèvements bactériologiques ayant pu être réalisés au centre des brûlés d'Annaba. L'effectif est de 633 micro-organismes isolés dont 128 Pseudomonas (20,2%): 127 aeruginosa (99,2%), 1 fluorescens (0,8%); distribution selon le site de prélèvement: écouvillon (87,5%), prélèvement trachéobronchique (4,6%), hémoculture (3,1%), cathéters (1,6%), urine (1,6%) et sonde urinaire (1,6%). Le pyocyanique se situe après le staphylocoque pour les prélèvements précoces et repasse en tête après un séjour supérieur à une semaine, où 89% des pyocyaniques sont identifiés. Il est en première position dans les pneumopathies sous ventilation assistée invasive. Il se classe troisième dans les hémocultures et les cultures de cathéters. Dans les infections urinaires il est devancé par Candida et la flore périnéale. Les 128 antibiogrammes regroupent 314 réponses sensibles. La sensibilité à plus de deux antibiotiques est de 68%, à deux antibiotiques 24% et à un antibiotique 8%. Seules quatre molécules restent actives: ciprofloxacine > péfloxacine > pipéracilline > ceftazidime. Une résistance absolue est retrouvée pour trois Pseudomonas (2,4%). Le pronostic sévère des infections nosocomiales à pyocyanique et les risques d'options thérapeutiques très limitées font toute leur gravité, d'où l'intérêt de respecter des règles strictes de prescription des antibiotiques et des mesures de prévention. PMID:21991140

  13. Le lymphome primitif de la prostate : à propos d'un cas avec revue ...

    African Journals Online (AJOL)

    ra

    Linfoma no-Hodgkin primitivo de glandula prostatica. [Primary non-Hodgkin's lymphoma of the prostate gland]. Arch.Esp.Urol. 1989; Oct;42(8):733-7. Braslis KG, Lee N, Machet D, Peters J. Primary prostatic. 28. lymphoma: A rare prostatic malignancy. Aust.N.Z.J.Surg. 1994; Jan;64(1):58-9. Singh I, Joshi M, Agarwal S, Singh ...

  14. Comité Scientifique de la Revue des Sciences et de la Technologie ...

    African Journals Online (AJOL)

    MICROSIM

    For each bee, 19 morphological characters were measured. Appropriate .... Tableau 1. Sites et ruchers, coordonnées géographiques, nombre d'abeilles ouvrières mesurées par rucher ..... classification. In: Bee Genetics and Breeding T.E..

  15. Revue d'Information Scientifique et Technique - Vol 10, No 1 (2000)

    African Journals Online (AJOL)

    Le Système Algérien d'Information documentaire agricole: quell appui à la formation et la Recherche Nationales? EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. R Issolah, JF Giovannetti, 109-121. http://dx.doi.org/10.4314/rist.v10i1.26732 ...

  16. Revue d'Information Scientifique et Technique - Vol 9, No 2 (1999)

    African Journals Online (AJOL)

    L'image comme outil documentaire: exemple de SONATRACH production · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. S Menassel, 133-147. http://dx.doi.org/10.4314/rist.v9i2.26714 ...

  17. Revue d'Information Scientifique et Technique - Vol 1, No 2 (1992)

    African Journals Online (AJOL)

    La Lexicometrie Documentaire: Contribution a l'utilisation des Techniques Documentaires comme Methodologie d'Etude en Sciences Sociales · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Abdelkrim Abdoun ...

  18. Sarcome prostatique : rapport d'un cas et revue de la littérature ...

    African Journals Online (AJOL)

    Prostatic sarcoma is a rare pathologic feature accounting for 0.1-0.2% of prostatic neoplasms. This condition can occur at different ages and there is no clear consensus regarding the treatment. The authors report a case of a giant prostatic sarcoma in a patient aged 62 years old who complains of voiding symptoms and a ...

  19. Pneumoblastome de l'adulte: rapport d'un nouveau cas et revue de ...

    African Journals Online (AJOL)

    Le blastome pulmonaire décrit surtout chez les enfants, est une tumeur rare. Elle représente 0.25 à 0.5% de toutes les tumeurs pulmonaires avec un pronostic très grave. Sur le plan histologique, il s'agit d'une tumeur à double composante: une composante épithéliale et une composante mésenchymateuse. Cliniquement ...

  20. Le carcinome parathyroïdien: à propos d'un cas et revue de la ...

    African Journals Online (AJOL)

    Le traitement est basé sur la chirurgie. Femme âgée de 59 ans, aux antécédents d'hypertension artérielle, et de lithiases rénales récidivantes, consultait pour des douleurs osseuses diffuses avec asthénie. L'examen du cou a trouvé une tuméfaction basi-cervicale dure et à bord inférieur non palpable. A la biologie: ...

  1. Synthèse: Revue des Sciences et de la Technologie: Editorial Policies

    African Journals Online (AJOL)

    The manuscripts are scanned through an anti-plagiarism software. - The instructions to authors must be respected. Once the submitted manuscript has met these requirements, it is assigned to a member of the editorial board to conduct the double-blind peer-reviewing process. The anonymous submitted manuscript is send ...

  2. Revue de Médecine et de Pharmacie - Vol 2, No 1 (2012)

    African Journals Online (AJOL)

    Epidémie de choléra à Douala en 2011 épidémiologie, clinique et bactériologie · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. AAB Fouda, B Kollo, A Ngomba, JII Dissongo, LJO Manga, N Essomba, GE Sume, V Deli, MK Ngambi, 113-120 ...

  3. Revue de Médecine et de Pharmacie - Vol 1 (2011)

    African Journals Online (AJOL)

    Intérêt des procedures radiologiques interventionnelles percutanees dans le traitement des collections abdomino pelviennes · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. LTM Minkala, DN Noah, PO Zogo, C Ateba, EGA Mougnol, M Plat, 11-20 ...

  4. Revue de Médecine et de Pharmacie - Vol 1, No 1 (2011)

    African Journals Online (AJOL)

    Faciès épidemiologique de la carie dentaire en milieu scolaire à Douala, Cameroun · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. AA Bita Fouda, JII Dissongo, M-M Limagnack Miko, G Etapelong Sum, M Massama, B Kollo, 57-62 ...

  5. Revue de Médecine et de Pharmacie - Vol 4, No 1 (2014)

    African Journals Online (AJOL)

    Changements de protocoles antirétroviraux de première ligne chez des PVVIH : cas de la file active de l'Hôpital Régional d'Edéa. EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. E N Essomba, M Nida, M Kouo Ngambi, I Mbogle, I G Lehman, 372-378 ...

  6. Revue de Médecine et de Pharmacie - Vol 3, No 2 (2013)

    African Journals Online (AJOL)

    Prévalence de la sensibilisation aux pneumallergènes chez des patients asthmatiques. Etude préliminaire à Douala, Cameroun. EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. NH Mbatchou, G Agodokpessi, NY Mapoure, AC Akazong, V Fonyam, E Barla, RL Njock ...

  7. Revue de Médecine et de Pharmacie - Vol 5, No 1 (2015)

    African Journals Online (AJOL)

    Coloscopie des patients de 75 ans et plus : faisabilité, indications et rentabilité : Expérience du centre hospitalier universitaire de Cocody (Abidjan) · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. AJB Okon, AS Thot'o, D Soro, A Ouattara, M Diakite, A Kone, S Kone, BSAF ...

  8. Revue de Médecine et de Pharmacie - Vol 3, No 1 (2013)

    African Journals Online (AJOL)

    La corticothérapie dans la prise en charge hospitalière de l'asthme à Yaoundé : Connaissances, Attitudes et Pratiques · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. EA Ze, AAM Kamgueng, G Nguefack-Tsague, J-B Bogne, 254-261 ...

  9. Revue de Médecine et de Pharmacie - Vol 6, No 1 (2016)

    African Journals Online (AJOL)

    Prévalence du carcinome Hépatocellulaire chez les porteurs d'hépatopathie chronique à Yaoundé - Cameroun · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Dominique Noah Noah, Firmin Ankouane Andoulo, Aimé Bonny Bonny, Blandine Deliota Doungé, Servais Albert ...

  10. Revue de Médecine et de Pharmacie - Vol 2, No 2 (2012)

    African Journals Online (AJOL)

    Syndrome thoracique aigu chez le drépanocytaire adulte: expérience de l'Hôpital Central de Yaoundé · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. AG Etoundi-Mballa, M Azabji-Kenfack, A Chiabi, JM Obama-Nyaga, MT Obama-Abena, 177-184 ...

  11. Revue d'Information Scientifique et Technique - Vol 9, No 1 (1999)

    African Journals Online (AJOL)

    Conception et réalisation d'un système d'aide à la décision pour la gestion des ressources naturelles · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. F Admane, A El Maouheb, F Benamara, FZ Djezzar, 11-23. http://dx.doi.org/10.4314/rist.v9i1.26717 ...

  12. Revue d'Information Scientifique et Technique - Vol 5, No 1 (1995)

    African Journals Online (AJOL)

    COCACOM : environnement de développement d'applications coopérantes et multimédia · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. J-M. Inglebert, L Courtrai, S Sadou ...

  13. Comité Scientifique de la Revue des Sciences et de la Technologie ...

    African Journals Online (AJOL)

    MICROSIM

    Les escargots terrestres du genre Helix Linnaeus (1758), considérés comme ..... transport des acides aminés, la synthèse des ..... du Maroc. 32 pp. [41] Gomot A., 1997. Dose-dependent effects of cadmium on the growth of snails in toxicity.

  14. Comité Scientifique de la Revue des Sciences et de la Technologie ...

    African Journals Online (AJOL)

    MICROSIM

    croissance du mollusque Cerastoderma glaucum dans trois stations sur les berges (profondeur < 1.50 m) de la lagune Mellah. .... biométriques, peut être ramenée à la loi d'allométrie ..... Ces densités élevées dans ce secteur seraient en.

  15. Canadian Journal of Physics. Volume 69, Number 2 (Revue Canadienne de Physique. Volume 69, Numero 2

    Science.gov (United States)

    1991-02-01

    polycristallines et ne sont pas les memes pour le CdSe d~posE sur une surface chaude et pour celui ddposE sur une surface froide et recuit A la meme haute...dolvent e dactylographits. Si une admist %~ seulement si elles sont absolument essentiellos et doivent 8tre cities machine A dcrire avec los caracttres

  16. Catamenial pneumothorax revealing diaphragmatic endometriosis: a case report and revue of literature.

    Science.gov (United States)

    Aissa, Sana; Benzarti, Wafa; Alimi, Faouzi; Gargouri, Imen; Salem, Halima Ben; Aissa, Amène; Fathallah, Khadija; Abdelkade, Atef Ben; Alouini, Rafika; Garrouche, Abdelhamid; Hayoun, Abdelaziz; Abdelghani, Ahmed; Benzarti, Mohamed

    2017-01-01

    Catamenial pneumothorax (CP) is a rare entity of spontaneous, recurring pneumothorax in women. We aim to discuss the etiology, clinical course, and surgical treatment of a 42-year-old woman with CP. This patient had a right-sided spontaneous pneumothoraces occurred one week after menses. She had under-gone video-assisted thoracoscopic surgery (VATS) because of a persistent air leak under chest tube. VATS revealed multiple diaphragmatic fenestrations with an upper right nodule. Defects were removed and a large part of the diaphragm was resected. Pleural abrasion was then performed over the diaphragm. Diaphragmatic endometriosis was confirmed by microscopic examination. Medical treatment with GnRH agonists was prescribed, and after recovery, the patient has been symptoms free for 20 months.

  17. Internal contamination measurements conducted in Europe after the Chernobyl accident, bibliographical revue

    International Nuclear Information System (INIS)

    Despres, A.

    1990-01-01

    When the radioactivity levels actually ingested by the populations of various European countries were being assessed, it was decided to conduct many in vivo measurements and measurements on excreta. The data acquired in this way for a wide range of different populations are reviewed in this report. Caesium ( 137 Cs and 134 Cs) and iodine-131, were the only radionuclides to be studied systematically. It is shown in this report that the levels of radioactivity ingested, calculated on the basis of measurements in the food chain, were constantly overestimated by up to one order of magnitude. It is also shown that there is a good correlation between the geographical distribution of the quantities ingested and the charted radionuclide deposits

  18. Synthèse: Revue des Sciences et de la Technologie - Vol 28 (2014)

    African Journals Online (AJOL)

    Les nouvelles formes de l'habitat rural de l'îlot domestique à la maison en lotissement cas de la vallée du Saf-Saf - wilaya de Skikda · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. K Messaoudi, 16-24 ...

  19. Synthèse: Revue des Sciences et de la Technologie - Vol 26 (2013)

    African Journals Online (AJOL)

    The modeling of response indicators of integrated water resources management with artificial neural networks in the Saf-Saf river basin (N-E of Algeria) · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. B Sakaa, H Chaffai, BA Sebaiti, A Hani, 75-85 ...

  20. Synthèse: Revue des Sciences et de la Technologie - Vol 18 (2008)

    African Journals Online (AJOL)

    Etude de l'action du phosphate dipotassique sur la Dolomite: formation et évaluation des phosphates doubles de Potassium et Magnésium · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. H Bouziane, A Zeghdaoui, B Dibbe, 5-11 ...

  1. Comité Scientifique de la Revue des Sciences et de la Technologie ...

    African Journals Online (AJOL)

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    الفلاحين في بعض الدول العربية، كما هو الحال في منطقة. الأحساء بالعربية السعودية. العربية المتحدة لكن ورغم أهمية هذه العملية الزراعية. في بعض المناطق، إلا أنها لم تحض ...

  2. An efficient symbolic model checker | Ferdenache | Synthèse: Revue ...

    African Journals Online (AJOL)

    The main of this paper is to design and implement a powerful new tool to check important properties in critical systems based on the concept of symbolic state and DBM data structures (Difference Bound Matrices). The specifications are expressed using timed automata system and realtime logic for properties. The obtained ...

  3. Revue d'Information Scientifique et Technique - Vol 11, No 1 (2001)

    African Journals Online (AJOL)

    Un Modèle de conception d'applications Web basées sur XML · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. M Lo, H Amrane, P Raffinat, 115-132. http://dx.doi.org/10.4314/rist.v11i1.26704 ...

  4. Comité Scientifique de la Revue des Sciences et de la Technologie ...

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    The proximity of steel pollution industry is a factor limiting the growth of Helix aspersa in the area of Sidi Amar. Keywords: Helix aspersa - Bio indicator – Biometry – Growth – Glutathione ..... lichens) et des animaux (Gastéropodes terrestres) [39-43]. H.aspersa est considéré comme l'un des bio-accumulateurs de métaux.

  5. Comité Scientifique de la Revue des Sciences et de la Technologie ...

    African Journals Online (AJOL)

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    2 mai 2014 ... U.S. Department of Agriculture, 40p. [24] Wilcox. L.V., 1955. “Classification and use of irrigation waters”. Circular 969. Washington, U.S.. Department of Agriculture, 19p. [25] ADE (Algérien Des Eaux),. 2010. Compte- rendu d'enquête sur les exploitations et les demandes d'AEP dans la Wilaya d'El-Oued, 4p.

  6. La matière grasse du lait de dromadaire : composition, microstructure et polymorphisme. Une revue

    Directory of Open Access Journals (Sweden)

    Karray Nadia

    2005-09-01

    Full Text Available In camel milk, fat, that represents about 3.6% of the composition, is dispersed in the form of globules, enveloped in a membrane, derived from the secreting cell and constituted by phospholipidprotein complexes. This review examines the present state of knowledge of the dromedary milk fat. The topics dealt with are : composition (fatty acids and triacylglycerols, microstructure, fat globule size distribution and polymorphism (thermal and structural properties.

  7. Revue Africaine de Chirurgie et Spécialités - Vol 11, No 1 (2017)

    African Journals Online (AJOL)

    Cas Clinique:Emasculation totale : à propos d'un cas · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. M.I.I. Barry, M. Keita, D. Kante, T.M.O. Diallo, M.D. Bah, A.B. Diallo, I. Bah, O.R. Bah, S. Guirassy, K.B. Sow, M.B. Diallo, 29-32 ...

  8. Revue Africaine de Chirurgie et Spécialités - Vol 7, No 3 (2013)

    African Journals Online (AJOL)

    Complications du traitement traditionnel des fractures : aspects épidémiologiques et cliniques. EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. L Lamah, D Handy, ML Bah, D Onivogui, K Keita, S Sidime, IG Diallo, A Barry, MM Diallo, B Koivogui, ML Kaba, D Keita, AP Aboud, 31-35 ...

  9. Revue Africaine de Chirurgie et Spécialités

    African Journals Online (AJOL)

    Rupture traumatique du diaphragme au CHU Gabriel Touré de Bamako, Mali · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. B T Dembélé, A Togo, A Traoré, Y Sidibé, M Konaté, A A Traoré, A Bah, T Koné, I Tounkara, L Kanté, I Diakité, B Karembé, A Koné, M.I Mangane, G Diallo ...

  10. Revue Africaine de Chirurgie et Spécialités - Vol 11, No 2 (2017)

    African Journals Online (AJOL)

    Rupture traumatique du diaphragme au CHU Gabriel Touré de Bamako, Mali · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. B T Dembélé, A Togo, A Traoré, Y Sidibé, M Konaté, A A Traoré, A Bah, T Koné, I Tounkara, L Kanté, I Diakité, B Karembé, A Koné, M.I Mangane, G Diallo ...

  11. Revue d'Information Scientifique et Technique - Vol 12, No 1 (2002)

    African Journals Online (AJOL)

    Towards the management of the databases founded on descriptions logic. H. Kherbachi, Z. Bouzidi, A. Hocine. http://dx.doi.org/10.4314/rist.v12i1.26674 · Digital images segmentation: a state of art of the different methods. A. Meziane. http://dx.doi.org/10.4314/rist.v12i1.26675 · Realtime validation of treatment programs on ...

  12. Fatigue and radiotherapy. A literature review; Fatigue et radiotherapie. Revue de la litterature

    Energy Technology Data Exchange (ETDEWEB)

    Dilhuydy, J.M.; Ouhtatou, F.; Laporte, C.; Nguyen, T.V.F.; Vendrely, V. [Institut Bergonie Centre Regional de Lutte Contre le Cancer, 33 - Bordeaux (France); Dilhuydy, J.M. [Federation Nationale des Centres de Lutte Contre le Cancer, FNCLCC, Groupe Rehabilitation, 75 - Paris (France); Dilhuydy, M.S. [Hopital Saint-Andre, Service de Medecine Interne, 33 - Bordeaux (France)

    2001-11-01

    Fatigue is a common complaint for the cancer patient during and after radiotherapy, according to the published studies. Fatigue is a subjective symptom mostly underestimated by oncologists and other care givers. Etiology is complex, poorly understood in spite of obvious causes like insomnia, nausea, pain, depression, psychological distress, anemia, hypothyroidism, menopause disturbances, treatment adverse effects. Fatigue presents multi-factorial and multidimensional aspects. To evaluate it, many tools can be used as single-item, unidimensional and multidimensional instruments. Practically, the open discussion with the patient throughout radiotherapy is essential to define it. Taking charge fatigue requires its acknowledgement by radiotherapist, treatment of associated symptoms with a multidisciplinary approach. (authors)

  13. Comité Scientifique de la Revue des Sciences et de la Technologie ...

    African Journals Online (AJOL)

    MICROSIM

    de rendre évidente une référence culturelle citadine par excellence. Ainsi, le propriétaire d'une maison (Fig.7) dans un des lotissements enquêté, au village de. Ramdane Djamel, un émigré originaire de la région, trouve dans l'emploi de la pierre et de la brique, une distinction qu'il a voulu intégrer à la façade de sa maison.

  14. Comité Scientifique de la Revue des Sciences et de la Technologie ...

    African Journals Online (AJOL)

    MICROSIM

    Ecological Indicators,1, 261 – 270. [11] Wekbeker G. & Cory G., 1988. Robo nucleotide reductase activity and growth of glutathione depleted mouse leukemia 1210 cells in vitro. Cancer letters, 40, 257 – 264. [12] Bradford M., 1976. A rapid and sensitive method for the quantification of microgram quantities of protein utilizing ...

  15. Revue bibliographique: les méthodes chimiques d'identification et de classification des champignons

    Directory of Open Access Journals (Sweden)

    Verscheure M.

    2002-01-01

    Full Text Available Chemotaxonomy of fungi : a review. For few years, advancements of molecular methods and analytical techniques enabled scientists to realise a classification of microorganisms based on biochemical characteristics. This classification, called chemotaxonomy, includes molecular methods and chemical methods which provide additional data and lead to a better identification and/or classification.

  16. Comité Scientifique de la Revue des Sciences et de la Technologie ...

    African Journals Online (AJOL)

    MICROSIM

    du Turonien enregistrent les variations lithologiques et microfaunistique relatives à l'événement anoxique océanique 2 (EAO-2). Les calcaires ... depuis des bassins océaniques profonds à des mers peu profondes [2, 3]. Cette crise résulte ..... tectonique, de la subsidence: une mise au point- Bulletin de la société géologique ...

  17. Synthèse: Revue des Sciences et de la Technologie - Vol 35 (2017)

    African Journals Online (AJOL)

    Geochemistry of dark coastal heavy-mineral beaches sand (Annaba, Northeast Algeria) · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Asma Chemam, Soraya Hadj Zobir, Menana Daif, Uwe Altenberger, Christina Günter, 154-165 ...

  18. Synthèse: Revue des Sciences et de la Technologie

    African Journals Online (AJOL)

    Geochemistry of dark coastal heavy-mineral beaches sand (Annaba, Northeast Algeria) · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Asma Chemam, Soraya Hadj Zobir, Menana Daif, Uwe Altenberger, Christina Günter, 154-165 ...

  19. Synthèse: Revue des Sciences et de la Technologie - Vol 19 (2008)

    African Journals Online (AJOL)

    Confining pressure effects on stress intensity factors: A 3D finite element analysis · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. MRM Aliha, MR Ayatollahi, MMS Mousavi, 33-39 ...

  20. Introduction aux études sur le genre. - 2e éd. revue et augm.

    NARCIS (Netherlands)

    Bereni, L.; Chauvin, S.; Jaunait, A.; Revillard, A.

    2012-01-01

    Pourquoi offre-t-on des poupées aux filles et des voitures aux garçons ? Pourquoi les femmes gagnent-elles moins que les hommes ? Comment expliquer qu’elles effectuent les deux tiers du travail domestique ? Pourquoi est-ce si mal vu pour un homme d’être efféminé ? Le pouvoir est-il intrinsèquement

  1. Leiomyome agressif naso-sinusien : a propos d'un cas et revue de ...

    African Journals Online (AJOL)

    Introduction : Les léiomyomes sont des tumeurs bénignes issues des fibres musculaires lisses. La localisation au niveau des cavités nasosinusiennes est très rare. Cas clinique : Il s'agit d'une patiente âgée de 59 ans, qui a consulté pour obstruction nasale et épistaxis gauches. L'endoscopie nasale a montré une formation ...

  2. Emissions gazeuses en élevage porcin et mode de réduction : revue bibliographique

    Directory of Open Access Journals (Sweden)

    Degre A.

    2001-01-01

    Full Text Available Gaseous emissions in pig husbandry and measures of reduction : a review. Atmospheric emissions of pig husbandry are studied at the level of the farm building, storage area and land used for spreading. The process leading to formation of NH3,N2O, CH4 and various smelling gases, the parameters controlling their level of emission, and their effects are described. Emission of molecular nitrogen is also addressed. Measures for reducing atmospheric emissions are detailed. They rely on animal feeding, design of farm building and storage area, air treatments, effluent management and disposal. The sub-products of the effluents are also considered. The costs of the techniques used to reduce gas emissions are detailed in BEF per weight of carcass. This document gives evidence that the most effective measures to reduce the emissions are linked to the design of the farm buildings and the storage of the effluents.

  3. Syndrome de Silver Russell: à propos de 3 cas et revue de la ...

    African Journals Online (AJOL)

    Abstract Le syndrome de Silver Russell (SSR) est une maladie génétique rare. Sa prévalence est estimée à 1/100.000. Il s'agit d'une pathologie de l'empreinte parentale, caractérisée par une grande diversité phénotypique. Ses signes cliniques majeurs sont: un retard de croissance intra-utérin sévère, un retard ...

  4. Le world wide web: l'hypermedià sur internet | Houmel | Revue d ...

    African Journals Online (AJOL)

    The telecommunication's networks technology linked to the electronic document has changed abroad the information specialists' methods of work. The Internet network did a lot in thèse big changes and especially after the World Wide Web intégration wich is a high hypermedia distributed information System. In Algeria lots ...

  5. Revue d'Information Scientifique et Technique - Vol 2, No 1 (1992)

    African Journals Online (AJOL)

    Société d'lnformation Innovations Technologiques et système d'information et de communication scientifique · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. L Ydroudj ...

  6. Synthèse: Revue des Sciences et de la Technologie - Vol 33 (2016)

    African Journals Online (AJOL)

    The effect of surface roughness on the performances of liner-piston ring contact in internal combustion engine · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Amar Ayad, Amar Skendraoui, Ammar Haiahem, 175 -184 ...

  7. Revue Africaine de Chirurgie et Spécialités: Submissions

    African Journals Online (AJOL)

    Any typescript that is declared unpublishable by at least two experts shall be returned via electronic mail to the corresponding author with the two anonymous reports bearing the mention «refused» In case of a single unfavourable opinion, another expertise may be solicited. In the other cases, the necessary corrections are ...

  8. Revue Africaine de Chirurgie et Spécialités - Vol 9, No 3 (2015)

    African Journals Online (AJOL)

    Les séquelles de brûlures en chirurgie pédiatrique au CHU Gabriel Touré de Bamako · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. O Coulibaly, Y Coulibaly, I Toure, M Keita, Y Coulibaly, A Togo, I Diakite, L Kante, A Traore, BT Dembele, M Konate, G Diallo, 29-34 ...

  9. L'adénocarcinome papillaire digital agressif: un cas rare et revue de ...

    African Journals Online (AJOL)

    Aggressive digital papillary adenocarcinoma is a rare variant of sweat gland carcinoma. These tumors have a high rate of local recurrence and can metastasize. The authors report a case of aggressive digital papillary adenocarcinoma and discuss the characteristics of these tumors through a literature review.A 32 year old ...

  10. Comité Scientifique de la Revue des Sciences et de la Technologie ...

    African Journals Online (AJOL)

    MICROSIM

    berges ou dans l'eau libre, soit par basculement du corps, ou par immersion du bec ou de la tête de l'oiseau. Mots clés : Fulica atra - El-Kala .... de l'avant du corps dans l'eau et alimentation à pied dans les vasières et les berges. .... moyens matériels et humains nécessaires à la réalisation de ce travail sur le terrain.

  11. Influence of Clays on Borehole Stability : a Literature Survey Part One: Occurence of Drilling Problems. Physico-Chemical Description of Clays and of Their Interaction with Fluids Influence des argiles sur la stabilité des parois de puits : revue bibliographique. Première partie : les problèmes rencontrés lors du forage dans les argiles. Description physico-chimique des argiles et de leur interaction avec les fluides

    Directory of Open Access Journals (Sweden)

    Forsans T.

    2006-11-01

    . Taking into account physico-chemistry has been done generally using an osmoticpressure, with the assumption that the shales behave as a semi-permeable membrane. Even if this assumption is too simplistic, it is still used, but more refined models are being studied, which take into account variations in pore pressures and salinities. The fourth section deals with what actually occurs on application to real wellbore. Improvement of mud formulation tries to prevent any problem occurring during drilling. Evolution of formulation is described, from lime, oil, KCI to polymers additions, and to nowadays constraints brought by environment concerns : requirements may be opposite, and thus compromises must be found. Mud monitoring seems a good prospect. In a second part, availability of representative samples, artefacts related to the recovery and storage of samples as well as choice of experimental conditions are reviewed. It is recalled that downhole conditions are rarely taken into account, and problems like drying of the samples, which induces a suction pressure, anisotropy and cohesion of the samples are rarely considered. The conclusion emphasises that if swelling pressures can now be more precisely defined in hydration domains, the effects of physicochemistry on mechanical properties are still to be investigated more thoroughly. Further experiments should be set in conditions closer to downhole ones, and teams must work together to get all the data needed. This will allow proper stability modelling, with coupling of physico-chemistry and mechanics, to become a predictive tool. Cette revue bibliographique a été réalisée dans le cadre du programme STAR (STabilité des ARgiles entrepris par l'ARTEP (Association de Recherche sur les Techniques d'Exploitation du Pétrole. Elle se divise en quatre sections: La première section rappelle les problèmes spécifiques rencontrés lors du forage des argiles, qui représentent environ 70 % des formations traversées, et sont r

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

    OpenAIRE

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

    2006-01-01

    The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the o...

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

    OpenAIRE

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

    2016-01-01

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

  14. Nerve signaling regulates basal keratinocyte proliferation in the blastema apical epithelial cap in the axolotl (Ambystoma mexicanum).

    Science.gov (United States)

    Satoh, Akira; Bryant, Susan V; Gardiner, David M

    2012-06-15

    The ability of adult vertebrates to repair tissue damage is widespread and impressive; however, the ability to regenerate structurally complex organs such as the limb is limited largely to the salamanders. The fact that most of the tissues of the limb can regenerate has led investigators to question and identify the barriers to organ regeneration. From studies in the salamander, it is known that one of the earliest steps required for successful regeneration involves signaling between nerves and the wound epithelium/apical epithelial cap (AEC). In this study we confirm an earlier report that the keratinocytes of the AEC acquire their function coincident with exiting the cell cycle. We have discovered that this unique, coordinated behavior is regulated by nerve signaling and is associated with the presence of gap junctions between the basal keratinocytes of the AEC. Disruption of nerve signaling results in a loss of gap junction protein, the reentry of the cells into the cell cycle, and regenerative failure. Finally, coordinated exit from the cell cycle appears to be a conserved behavior of populations of cells that function as signaling centers during both development and regeneration. Copyright © 2012 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    Lee, Jangwoo; Aguilar, Cristian; Gardiner, David

    2013-01-01

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

  16. Inhibition of the Processes of Growth and Differentiation in the Embryonic Development of the Axolotl (Ambystma mexicanum)

    NARCIS (Netherlands)

    Stolk, Anth.

    1954-01-01

    The problem of the retardation of the processes of growth and differentiation is certainly as important as the processes of growth and differentiation themselves. It is striking, therefore, that whereas the analysis of growth has been carried out for a considerable period of time already, the

  17. Le carcinome parathyroïdien: à propos d’un cas et revue de la literature

    Science.gov (United States)

    kolsi, Naourez; Jellali, Sondos; Koubaa, Jamel

    2017-01-01

    Le carcinome parathyroïdien est une tumeur maligne, très rare, de la glande parathyroïde. Cliniquement, ce cancer se présente souvent par un tableau d'hyperparathyroïdie primaire sévère. Le diagnostic est histologique mais n'est pas toujours aisé. Le traitement est basé sur la chirurgie. Femme âgée de 59 ans, aux antécédents d'hypertension artérielle, et de lithiases rénales récidivantes, consultait pour des douleurs osseuses diffuses avec asthénie. L'examen du cou a trouvé une tuméfaction basi-cervicale dure et à bord inférieur non palpable. A la biologie: hypercalcémie à 4,1 mmol/l, une hyperparathyroïdie avec valeur de parathormone (PTH) très élevée à 1088 pg/ml soit 13 fois la normale. La scintigraphie au Technétium-99m-sestamibi a montré une plage de fixation anormale de MIBI en projection de la parathyroïde inférieure gauche. Une parathyroïdectomie inférieure gauche, avec évidement médiastino-récurrentiel homolatéral ont été réalisés. Les suites opératoires étaient marquées par la normalisation de la calcémie et de la PTH. L'anatomopathologie était en faveur d'un carcinome parathyroïdien. Le diagnostic de carcinome parathyroïdien est généralement établi sur la conjonction de signes radiologiques biologiques et histologiques. La gravité de cette pathologie est due à l'hypercalcémie sévère et au risque de récidive et de métastases à distance justifiant la surveillance prolongée. PMID:28819506

  18. Carcinome neuroendocrine thymique: à propos d’un cas et revue de la littérature

    Science.gov (United States)

    Ramahandrisoa, Andriatsihoarana Voahary Nasandratriniavo; Hasiniatsy, Nomeharisoa Rodrigue Emile; Refeno, Valéry; Vololonantenaina, Clairette Raharisolo; Rakotoarisoa, Andriamihaja Jean Claude; Rakotovao, Hanitrala Jean Louis; Rafaramino, Florine

    2017-01-01

    Les tumeurs neuroendocrines thymiques (TNET) sont rares, de pronostic mal connu. L'objectif est de rapporter un cas de TNET et discuter la difficulté diagnostique et thérapeutique en milieu à faibles ressources. Un homme de 60 ans présentait une douleur thoracique, une toux grasse et un amaigrissement récent. Le scanner thoracique révélait une masse tissulaire médiastinale antérieure. L'histologie définitive obtenue quatre mois après la biopsie par médiastinotomie antérieure montrait une TNET bien différenciée, avec marquage intense à la chromogranine et à la synaptophysine. La recherche d'autres tumeurs neuroendocrines et le bilan d'extension étaient négatifs. La tumeur était inextirpable d'emblée et la radiothérapie indisponible. Le patient a reçu deux lignes de chimiothérapie première. Avec un recul de 16 mois, le patient était asymptomatique, mais en progression tumorale. Le diagnostic de TNET peut être retardé quand l'examen immunohistochimique n'est pas réalisé en routine. La chimiothérapie apporte une amélioration des symptômes en situation palliative. PMID:28451004

  19. Les hémorragies post coïtales: à propos de 68 cas et revue de ...

    African Journals Online (AJOL)

    % des cas, associé à une transfusion sanguine chez deux patientes et une abstinence sexuelle pendant minimum deux semaines chez toutes nous patientes. Le contexte social ainsi que le manque d'éducation sexuelle sont souvent incriminé ...

  20. German Literature and Culture under "Revue": Learner Autonomy and Creativity through the Theme-Based Theater Practicum

    Science.gov (United States)

    Koerner, Morgan

    2012-01-01

    This article proposes a theatrically oriented, thematically structured course model for the upper level undergraduate German curriculum. The traditional focus on staging a single play in the German foreign language theater practicum neglects theater's potential to explore other literary genres and cultural texts and runs the danger of…

  1. Les interactions entre la reproduction et la biologie des populations chez les Monogènes Gyrodactylidae : revue

    Directory of Open Access Journals (Sweden)

    HARRIS P. D.

    1993-01-01

    Full Text Available Les Gyrodactylidae sont des Monogènes vivipares, les embryons se développent de manière emboitée dans l'utérus maternel. Les premier et deuxième individus fils se développent sans auto, ni fécondation croisée ; seuls les troisième et suivants peuvent se développer sexuellement. L'importance relative de la reproduction sexuée, dépend de la structure d'âge de la population et de la mortalité. Chez Macrogyrodactylus polypteri, le développement postnatal de l'appareil génital femelle facilite la fécondation croisée chez tous les individus suivant la seconde naissance. La reproduction asexuée maximise la croissance de la population mais la sexualité intervient régulièrement. Gyrdicotylus gallieni, qui parasite la bouche de Xenopus laevis, présente une croissance exceptionnellement lente de la population et les populations parasites sont surtout composées d'individus âgés et sexuellement matures. Isancistrum subulatae, parasite du Calmar Alloteuthis subulata, forme d'importantes populations, mais leur croissance est probablement lente, et la structure d'âge suggère que la sexualité est courante. Chez Gyrodactylus, plusieurs stratégies existent. Gyrodactylus turnbulli, chez les Guppis, a une courte durée de vie et manifeste une mortalité spécifique croissant exponentiellement avec l'âge, de telle sorte que moins d'un pour cent survivent assez longtemps pour donner une troisième naissance. La reproduction est principalement asexuée mais le sexe intervient dans les populations de très fortes densités. Dans la nature la reproduction asexuée prédomine sans doute et cette espèce peut être considérée comme cycliquement parthénogénétique. Chez le saumon, Gyrodactylus salaris, présente des mortalités faibles et 10-15% des survivants se reproduisent sexuellement. Des individus fécondés sont trouvés même dans les faibles infestations et la sexualité est habituelle dans la biologie de cette espèce. Chez Gasterosteus aculeatus, G. gasterostei présente à 15° une mortalité semblable à celle de G. turnbulli, mais à 10° la mortalité augmente moins vite avec l'âge. Les données, en populations naturelles, suggèrent que la sexualité est rare chez cette espèce. La sexualité peut être rare chez plusieurs espèces de Gyrodactylus, mais dans les populations naturelles de G. arcuatus une phase de croissance des populations a été observée à la suite d'une intervention probable de la sexualité. Ceci était très localisé, sur moins d'un mois, et n'a pas eu lieu, en un second site, trois kilomètres en aval. Les stratégies de la reproduction sexuée peuvent être correlées avec les variations morphologiques et la spécificité parasitaire. Les espèces sexuées peuvent être plus variables et montrent moins d'hétérogénéité entre les populations que les espèces à reproduction asexuée. Les formes sexuées apparaissent aussi plus tolérantes quant au choix de leur hôte. La double barrière de la spécificité parasitaire et de la reproduction asexuée peut être importante dans la prévention de l'hybridation entre populations génétiquement distinctes de Gyrodactylidae, ce qui maintient la diversité. L'impact potentiel de l'homme sur la biologie de la reproduction et l'évolution des Gyrodactylidae est discuté.

  2. Introduction à l 'Analyse de citations : Brève revue de la littérature ...

    African Journals Online (AJOL)

    Introduction to The Citation Analysis: A Short Review of The Literature The citation analysis, that was born in order to resolve library problems, was widely used , mainly to evaluate the quality of scientific journals. Through our short review of the literature we aim to emphasise on the fact that this method arising from ...

  3. Impact of wind turbines on bats : literature review; Impacts des eoliennes sur les chauves-souris : revue de litterature

    Energy Technology Data Exchange (ETDEWEB)

    Cote, F.

    2006-09-15

    As wind power development intensifies around the world, concerns are being raised regarding the impact on birds and chiroptera. Studies have been conducted to explore the possible causes of bat morality associated with wind power development in Quebec and to determine possible mitigation strategies. It is expected that wind energy development will increase in the province from 100 MW in 2003 to more than 3,500 MW by 2013. The regions that have high potential for wind energy development in Quebec include the Appalachian corridor, the Lower North Shore, the Magdelaine Islands, Anticosti Island, the Gaspe Peninsula and northern Quebec. The migration patterns of bats have been examined through visual and auditory observations during the springtime reproductive and nesting season as well as in the autumn. Possible causes for bat mortality by wind turbines include seasonal migration routes, light, food and ultrasonic attraction. It was concluded that it is imperative to understand the causes of bat mortality in order to develop possible mitigation measures. 40 refs.

  4. Le ganglioneurome rétropéritonéal: À propos de 5 cas et revue de la ...

    African Journals Online (AJOL)

    Le ganglioneurome est une tumeur neurogène bénigne, rare, qui se développe à partir des cellules ganglionnaires sympathiques et qui se localise essentiellement dans la région rétropéritonéale. Nous rapportons cinq cas de ganglioneuromes rétropéritonéaux, ayant eu une exérèse complète de la tumeur avec évolution ...

  5. Le ganglioneurome rétropéritonéal: À propos de 5 cas et revue de la ...

    African Journals Online (AJOL)

    N. Rebai

    Résumé. Le ganglioneurome est une tumeur neurogène bénigne, rare, qui se développe à partir des cellules ganglion- naires sympathiques et qui se localise essentiellement dans la région rétropéritonéale. Nous rapportons cinq cas de ganglioneuromes rétropéritonéaux, ayant eu une exérèse complète de la tumeur avec ...

  6. Journal of the two worlds. Energies of the future; Revue des deux mondes. Les energies du futur

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Confusion and irrationality are the two master-words of today's debates about energies and their impact on safety, environment, ethic and society. On the other hand, reports about urgent decisions to be taken are piling up (wastes reprocessing, future of nuclear energy, European policy etc..). This book analyzes the possible scenarios and the energy challenges at the year 2030 and 2050 vistas. (J.S.)

  7. Revue de la médication par le pharmacien d’officine en Belgique : pourquoi, comment et situation actuelle

    OpenAIRE

    Tommelein, Eline; Mehuys, Els; Van Tongelen, Inge; Petrovic, Mirko; Somers, Annemie; KYMPERS, CELINE; Van Hees, Thierry; Christiaens, Thierry; Demarche, Sophie; Colin, Pieter; Boussery, Koen

    2016-01-01

    Des statistiques récentes montrent qu’environ 20% de la population de l’Union européenne a plus de 65 ans. En raison de la multimorbidité (présence de plusieurs affections chroniques chez un même patient), plusieurs médicaments (polymédication) sont souvent prescrits aux personnes âgées. Tant l’âge avancé que la polymédication augmentent considérablement le risque d’effets indésirables. Des études internationales montrent qu’environ 5% de toutes les hospitalisations aiguës sont liées à l’util...

  8. Thyroid gland irradiations and thyroid cancers; Critical bibliographic journal; Irradiations de la thyroide et cancers thyroidiens. Revue bibliographique critique

    Energy Technology Data Exchange (ETDEWEB)

    Vitauxa, F. [CHI Le Raincy-Montfermeil, Faculte X. Bichat, Lab. de Biophysique, Service de Medecine Nucleaire, 93 - Le Raincy-Montfermeil (France)

    2007-07-15

    The large increase in the incidence of thyroid cancer among children who were mainly less than five years old at the time of the Chernobyl accident is still a major concern for endocrinologists and nuclear medicine physicians. Epidemiological studies have focused solely on iodine-131. However, past knowledge on thyroid irradiation (medical use of iodine-131, radioactive fallout on Marshall islands and the Nevada and Hanford site releases) as well as number of recent works (about low-dose irradiation) raise question on the role of other factors. It is here shown that post-Chernobyl thyroid irradiation is complex and that all factors (iodine-131, but also short lived isotopes of iodine and external irradiation) should be considered. Finally, one needs to think about some of the present medical uses of iodine-131 and especially to the treatment of hyperthyroidism in young subjects. (author)

  9. Les tumeurs malignes naso-sinusiennes: à propos de 32 cas et revues de la littérature

    Science.gov (United States)

    Darouassi, Youssef; Touati, Mohamed Mliha; Chihani, Mehdi; El Alami, Jihane; Bouaity, Brahim; Ammar, Haddou

    2015-01-01

    Sous l’appellation tumeurs malignes naso-sinusiennes est regroupé un vaste éventail de tumeurs, aux histologies et localisations variées, mais aux tableaux cliniques souvent similaires. Le diagnostic de ces tumeurs est difficile, nécessitant une approche multidisciplinaire, à savoir oto-rhino-laryngologique, radiologique et anatomopathologique. Notre étude rétrospective concerne 32 cas de tumeurs malignes naso-sinusiennes, colligées au service d’ORL de l’hôpital militaire Avicenne de Marrakech, entre Janvier 2004 et Décembre 2014. L’analyse des données a noté que la fréquence des tumeurs épithéliales (75% des cas) était supérieure à celle des tumeurs non épithéliales (25% des cas), avec en tête de file l’adénocarcinome de l’ethmoïde (31,25%) et le carcinome épidermoïde du sinus maxillaire (18,75%). Ces tumeurs surviennent le plus souvent chez le sujet âgé avec une moyenne d’âge de 52 ans et une répartition équitable entre les deux sexes. Le délai de consultation moyen était de 12 mois avec une symptomatologie dominée par un syndrome nasosinusien (71,8%), associé dans certains cas à des signes ophtalmologiques (12,5%) ou neurologiques (15,6%). Tous nos patients ont bénéficié d’un examen clinique notamment endoscopique, d’une exploration radiologique des tumeurs et de leurs extensions, et d’une confirmation diagnostique par un examen anatomopathologique. Le traitement a consisté en une exérèse chirurgicale de la tumeur dès que cela était possible, soit dans 81,3% des cas (26 patients), généralement complété par un traitement adjuvant radio-chimiothérapique (77%). Le suivi à un an de nos patients a permis de noter une bonne évolution pour 08 d’entre eux (25%), une récidive dans 6 cas (18,75%), le décès de neuf patients (28,1%), et l’absence d’information concernant les autres cas (28,1%). PMID:26985260

  10. Les tuméfactions sous mandibulaires: à propos de 42 cas et revue de la literature

    Science.gov (United States)

    Darouassi, Youssef; Mliha Touati, Mohamed; Chihani, Mehdi; Nadour, Karim; Ammar, Haddou; Bouaity, Brahim

    2014-01-01

    Les tuméfactions de la région sous mandibulaire sont une entité pathologique fréquente, caractérisées par un tableau clinique et une démarche diagnostique stéréotypée, et une unicité presque constante au plan chirurgical. Notre travail est une étude rétrospective sur une période de 5 an d'une série consécutive de 42 cas de tuméfactions sous mandibulaires qui ont été colligés au service d'oto-rhino-laryngologie et de chirurgie cervico-faciale de l'hôpital militaire Avicenne de Marrakech. L’âge moyen des patients était de 41 ans. Une prédominance masculine a été retrouvée. Le tableau clinique a été dominé par la tuméfaction sous mandibulaire. Tous les patients ont bénéficié d'une échographie cervicale. La tomodensitométrie cervicale a été réalisée chez 7 patients. La première étiologie était la sous maxillite chronique lithiasique dans 39,02% des cas. Le traitement était chirurgical dans tous les cas. En comparant les résultats avec ceux rapportés dans la littérature, nous allons discuter les différents aspects diagnostiques et thérapeutiques des étiologies les plus fréquentes. Les tuméfactions de la région sous mandibulaire sont fréquentes, nécessitant une démarche diagnostique rigoureuse et une prise en charge thérapeutique adaptée. PMID:25469195

  11. Abrégés Numéro spécial de la revue Regional Environmental ...

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

    Hayley Price

    En revanche, les études portant sur les deltas étaient axées sur les dangers, principalement sur les inondations côtières, qui ont une incidence ... l'Asie du Sud, soit le Gange, le Brahmapoutre et l'Indus, afin de comprendre les mécanismes de.

  12. Les carcinomes epidermoïdes du scrotum: à propos de 7 cas avec revue de la litterature

    Science.gov (United States)

    Halfya, Ayoub; Elmortaji, Khalid; Redouane, Rabii; fethi, Meziane; Rafik, Amine; Mohamed, Ezzoubi; Abdessamad, Chlihi

    2015-01-01

    Quoique rare le carcinome épidermoïde du scrotum a un mauvais pronostic. Les Carcinomes du scrotum induite et - liées au travail sont moins fréquentes en raison d'une meilleure hygiène, vêtements de protection, et la sensibilisation de la cancérogénicité des huiles industrielles. L’épidémie à l'HPV a induit une augmentation de l'incidence. Le traitement de dépend toujours exérèse locale de la lésion primaire. La radiothérapie a peu de bénéfice thérapeutique dans le traitement d'un carcinome épidermoïde du scrotum. La bléomycine peut être utile comme traitement adjuvant pour les maladies ilio-inguinal généralisée avant la tentative exérèse, même si cela n'a pas encore été prouvé. Entre janvier 2011 au 1er janvier 2013, 7 patients atteints de carcinome épidermoïde ont été pris en charge, Trois patients ont présenté une localisation ganglionnaire. Les sept patients ont eu un traitement chirurgical par exérèse large avec reconstruction, Deux patients ont été adressé pour chimiothérapie.2 patients ont présenté une récidive, dont un est décédé. PMID:26113906

  13. Les besoins en oxygène des poissons marins et leur comportement en conditions hypoxiques (revue bibliographique)

    OpenAIRE

    Person-le Ruyet, Jeanine

    1986-01-01

    Les données expérimentales relatives aux besoins en oxygène des poissons marins (pélagiques et démersaux) sont rappelées. Les variations de la consommation d'oxygène en fonction du poids (w) sont généralement décrites par l'équation : M02 (ml/h) = 0,33 W0. 80 Le comportement général des poissons en conditions hypoxiques et leurs limites de tolérance sont de même considérés en fonction du stade de développement.

  14. 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

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    Julian Sosnik

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

  17. A Fraction of Political Science: Behind the Masks of the Discipline’s Status Revue, an Unexpected (Primordial Question Has Arisen: A Faculty or a Political School?

    Directory of Open Access Journals (Sweden)

    Dag Strpić

    2008-01-01

    Full Text Available The world academic literature shows that political science (in singular has been in such status for centuries, within (the plural of political sciences preceding today’s social sciences, within which political science has also been in a permanent synergetic “duality”, as a political science among other social sciences, with close collaboration with humanistic and even all other disciplines. For political science, then, “the way out of the plural” is possible only as a way out of social sciences, which is essentially argued for by Kasapović. This is not a trend anywhere in the world – because this would imply a way out of science in general. This is suggested by the academic literature which was not analysed by Kasapović or was not analysed against established academic rules, just as she did not analyse the “status of the discipline” against the conventional rules of profession and non--fiction genre – in the full scope of standard branches of political science. Without such a scope, what we get is in fact a “fractional” instead of “singular” political science. A review of the discipline cannot be replaced by a comparative analysis of political science educational institutions, particularly not at their undergraduate level, and especially not when it is pulled out of its complex academic, historical and social contexts and the context of “the building of institutions”. It can neither be replaced by the ideological and political accusations used by the author instead of a scientific argument. The orientation of the author’s and editor’s project as a political science ideal consequently suggests the establishment of a de facto political school of some sect instead of a faculty of political science which she allegedly seeks. The Faculty at which the author works can further develop successfully only through a more intensive development of national political science which is better embedded in global political science and of mutually critical political science academic community, and not through “liberation” from purported “colonisers” and “occupiers” from other social and some humanistic sciences. It is possible only through a development that should at least maintain the Croatian and global relative academic level which the Faculty has had since its very beginning and which Croatian political science has had since its beginnings in the 17th and 18th centuries; surely not through such a designed decline under that level and the way out of the scientific community, even from the entirety of political science. In this way, the author, wittingly or not, falsely presents her discipline, her professors and fellow-scholars and her Faculty, their history, current problems and perspectives, and is misleading her and our students.

  18. One year of Italian press review in the energy domain; Une annee de revue de presse italienne dans le domaine de l'energie

    Energy Technology Data Exchange (ETDEWEB)

    Augier, L.; Perna, N.; Carles, R.

    2004-03-01

    In terms of energy, 2003 has been an important and key year for Italy with a highlight: the black-out of September 28, 2003 which has paralyzed part of Italy. This event has led to think about the necessity for Italy to diversify its energy sources. This requires a reinforcement of energy efficiency, a rational use of energy, a policy of construction of new facilities, the use of biomass fuels and the promotion of renewable energy sources. This report groups together the overall brief news written by the scientific service of the French Embassy in Italy about this topic and spread to the readers of electronic bulletins. (J.S.)

  19. Un numéro spécial de la revue met en lumière les conclusions d'une ...

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

    8 mars 2018 ... S'attaquer à ces lacunes ne constitue pas seulement un impératif moral, c'est aussi une chance, car il est de plus en plus évident que l'égalité des sexes peut stimuler directement la croissance économique et ... Cover of the Policy in Focus special issue showing photos of women working in different work.

  20. Protest, styl a sociální identita. Diskurzivní analýza anarchistické revue Existence

    OpenAIRE

    Svobodová, Tereza

    2016-01-01

    The diploma thesis focuses on representation of protest in the official periodical of Czech Anarchist federation. It looks into the protest strategies which influence the level of personal lifestyle of an individual. This practice is connected to the issue of devaluation of the anarchist programme and more prominent emphasis on the form of the activities rather than the content. On the example of anarchist review Existence the thesis investigates how the practice is treated at the discursive ...

  1. Abcès thyroïdien révélant un basedow: à propos d'un cas et revue ...

    African Journals Online (AJOL)

    Une radiographie thoracique a été demandée montrant un foyer alvéolaire pulmonaire apical droit. L'étude cytobactériologique des crachats ont isolé le bacille de koch. Le bilan biologique thyroïdien était en faveur d'un Basedow. La prise en charge était médicale comprenait une tri-antibiothérapie par voie parentérale, ...

  2. Défaut de lainure et fermentation secondaire des fromages à pâte pressée cuite - une revue

    OpenAIRE

    Daly , David F.M.; McSweeney , Paul L.H.; Sheehan , Jeremiah J.

    2010-01-01

    International audience; Split and secondary fermentation defects in Swiss-type cheese varieties are manifested as undesirable slits or cracks that may lead to downgrading of the cheese. Split defect is associated with an excessive production of gas or an unsuitable cheese body that cannot accommodate gas produced, or a combination of both factors. Secondary fermentation is the apparent production of gas after the desired propionic fermentation of the warm room has taken place. No consensus ex...

  3. « Les usages sociaux de la Bible ». Numéro de la revue Médiévales

    Directory of Open Access Journals (Sweden)

    Dominique Iogna-Prat

    2007-08-01

    Full Text Available L’ambition de ce numéro de Médiévales, qui donnera d’abord lieu à un Atelier à Auxerre les 16 et 17 novembre 2007, consiste à rendre compte des recherches actuelles sur la Bible et l’exégèse au Moyen Âge, dans une double direction : Les exploitations sociales et « politiques » de la Bible, telles qu’on peut les saisir à travers les commentaires et l’utilisation des figures bibliques au fil des siècles. Ce type d’étude s’inscrit dans la lignée d’un certain nombre de travaux anglo-saxons et ita...

  4. Exposure to uranium and cancer risk: a review of epidemiological studies; Exposition a l'uranium et risque de cancer: une revue des etudes epidemiologiques

    Energy Technology Data Exchange (ETDEWEB)

    Tirmarche, M.; Baysson, H.; Telle-Lamberton, M. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Service de Radiobiologie et d' Epidemiologie, Dir. de la Radioprotection de l' Homme, 92 - Clamart (France)

    2004-02-01

    Objective: At the end of 2000, certain diseases including leukemia were reported among soldiers who participated in the Balkan and in the Gulf wars. Depleted uranium used during these conflicts was considered as a possible cause. Its radiotoxicity is close to that of natural uranium. This paper reviews the epidemiological knowledge of uranium, the means of exposure and the associated risk of cancer. Methods: The only available epidemiological data concerns nuclear workers exposed to uranium. A review of the international literature is proposed by distinguishing between uranium miners and other workers of the nuclear industry. French studies are described in details. Results: In ionizing radiation epidemiology, contamination by uranium is often cited as a risk factor, but the dose-effect relationship is rarely studied. Retrospective assessment of individual exposure is generally insufficient. Moreover, it is difficult to distinguish between uranium radiotoxicity, its chemical toxicity and the radiotoxicity of its progeny. A causal relation between lung cancer and radon exposure, a gas derived from the decay of uranium, has been demonstrated in epidemiological studies of miners. Among other nuclear workers exposed to uranium, there is a mortality deficit from all causes (healthy worker effect). No cancer site appears systematically in excess compared to the national population; very few studies describe a dose-response relationship. Conclusion: Only studies with a precise reconstruction of doses and sufficient numbers of workers will allow a better assessment of risks associated with uranium exposure at levels encountered in industry or during conflicts using depleted uranium weapons. (author)

  5. Scientometrical approach of the definition of a research domain using scientific journals; Approche scientometrique de la definition d`un domaine de recherche par des revues scientifiques

    Energy Technology Data Exchange (ETDEWEB)

    Signogneau, A

    1995-11-22

    The goal of this thesis is to analyse how the academic domain of a research entity can be defined by a panel of scientific journals. The aim of this work is to contribute to the creation of information tools as a help in research management. The first part gives an analysis of the scientific journals as markers of the scientific development: the production and diffusion of scientific journals and their ``scientometrical`` analysis (references, citation reports, citation indexes etc..). In the second part, a research unit is analyzed according to its related scientific journals and to its research domain. The SPAM (Photons, Atoms and Molecules Service) of the CEA was chosen for this task (main journals and co-publications network, specialization, main topics, collaborations and competition). The OST (Observatory of Sciences and Techniques) has in charge the production of scientific and technical indicators for research operators. The third part evaluates the methods used by the OST (analyses of reviews and journals) to provide a documentary corpus, taking the topic of the environment as an example. Finally the relevance of the information products obtained is evaluated. (J.S.).

  6. The deep inspection of the energy policy in France by the IEA; La revue en profondeur de la politique energetique de la France par l'AIE

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-11-01

    The members of the International Energy Agency present every four years an inspection concerning their energy policy. This document deals with the french inspection and covers the following subjects: the french energy statement, the french energy policy, the energy and nuclear independence, the nuclear competitiveness, the french electric power production facing the the increase of the petroleum prices, the renewable energies statement, the energy mastership, the greenhouse effect, the Charpin-Dessus-Pellat report, the directive transposition on the internal electric power market in France, the european directive transposition on the internal natural gas market in France, the energy policy audit by the IEA. (A.L.B.)

  7. The deep inspection of the energy policy in France by the IEA; La revue en profondeur de la politique energetique de la France par l'AIE

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-11-01

    The members of the International Energy Agency present every four years an inspection concerning their energy policy. This document deals with the french inspection and covers the following subjects: the french energy statement, the french energy policy, the energy and nuclear independence, the nuclear competitiveness, the french electric power production facing the the increase of the petroleum prices, the renewable energies statement, the energy mastership, the greenhouse effect, the Charpin-Dessus-Pellat report, the directive transposition on the internal electric power market in France, the european directive transposition on the internal natural gas market in France, the energy policy audit by the IEA. (A.L.B.)

  8. Review of the analytical techniques used in the hydrogeochemical prospecting of uranium; Revue des techniques analytiques utilisees dans la prospection hydrogeochimique de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Grimbert, A; Berthollet, P [Commissariat a l' Energie Atomique, Section de Geochimie de la Dir. des Recherches et Exploitations Minieres, Fontenay aux Roses (France)

    1959-07-01

    This report examines the methods recommended for the estimation of uranium in water. The advantages and disadvantages of these methods are studied with respect to the qualities necessary for the hydrogeochemical prospecting of uranium sensitivity of the order of 1/5 ppb with an accuracy of 15 to 20 per cent, high fidelity, rapidity, simplicity and low cost. (author) [French] Ce rapport examine les methodes preconisees pour le dosage de l'uranium dans les eaux; les avantages et les inconvenients de ces methodes sont etudies en fonction des qualites necessitees par la prospection hydrogeochimique de l'uranium: sensibilite de l'ordre de 1/5 de ppb avec une precision de 15 a 20 pour cent, grande fidelite, rapidite, simplicite, et bas prix de revient. (auteur)

  9. Review and comparison of bi-fluid interpenetration mixing models; Revue et comparaison de modeles bifluides bivitesses d'interpenetration

    Energy Technology Data Exchange (ETDEWEB)

    Enaux, C

    2006-07-01

    Today, there is a lot of bi-fluid models with two different speeds: Baer-Nunziato models; Godunov-Romensky models. coupled Euler's equations, and so on. In this report, one compares the most used models in the fields of physics and mathematics while basing this study on the literature. From the point of view of physics. for each model. one reviews: -) the type of mixture considered and modeling assumptions, -) the technique of construction, -) some properties like the respect of thermodynamical principles, the respect of the Galilean invariance principle, or the equilibrium conservation. From the point of view of mathematics, for each model, one looks at: -) the possibility of writing the equations in conservative form, -) hyperbolicity, -) the existence of a mathematical entropy. Finally, a unified review of the models is proposed. It is shown that under certain closing assumptions or for certain flow types. some of the models become equivalent. (author)

  10. Le soi et l’estime de soi chez l’enfant: Une revue systématique de la littérature

    OpenAIRE

    Pinto, Alexandra Maria Pereira Inácio Sequeira; Gatinho, Ana Rita dos Santos; Tereno, Susana; Veríssimo, Manuela

    2016-01-01

    Cette étude vise : a) à analyser les différentes méthodes utilisées pour l’étude du Soi et chez les enfants, en ce que concerne sa qualité et son potentiel et b) à synthétiser les résultats déjà obtenus en termes de Soi/d’estime de soi/d’autoconcept, pour les enfants en âge préscolaire. Après avoir établi des critères rigoureux d’inclusion et d’exclusion, 33 articles ont été sélectionnés, dans plusieurs bases de données, nationales et international...

  11. Environmental Modeling Packages for the MSTDCL TDP: Review and Recommendations (Trousses de Modelisation Environnementale Pour le PDT DCLTCM: Revue et Recommendations)

    Science.gov (United States)

    2009-09-01

    frequency shallow water scenarios, and DRDC has ready access to a well-established PE model ( PECan ). In those spectral areas below 1 kHz, where the PE...Ocean, LaSpezia, Italy , 2002. 26 DRDC Atlantic CR 2009-004 List of acronyms and initialisms ARP Address Resolution Protocol BLUG Bottom...PCs Personnel Computers PE Parabolic Equation PECan PE Model developed by DRDC SPADES/ICE Sensor Performance and Acoustic Detection Evaluation

  12. Une revue systématique des cibles de tension artérielle sous vasopresseurs chez des adultes gravement malades atteints d’hypotension

    DEFF Research Database (Denmark)

    Hylands, Mathieu; Moller, Morten Hylander; Asfar, Pierre

    2017-01-01

    pressure targets for vasopressor therapy in critically ill hypotensive adult patients. Two reviewers independently assessed trial eligibility based on titles and abstracts, and they then selected full-text reports. Outcomes, subgroups, and analyses were prespecified. We used GRADE (Grading...... of Recommendations Assessment, Development and Evaluation) to rate the overall confidence in the estimates of intervention effects. Results: Of 8001 citations, we retrieved 57 full-text articles and ultimately included two randomized-controlled trials (894 patients). Higher blood pressure targets were not associated...

  13. L’insuffisance mitrale chez le cheval : revue de la littérature et comparaison avec la pathologie chez l’homme et chez le chien

    OpenAIRE

    Al Haidar, Ali; Leroux, Aurélia; Amory, Hélène

    2013-01-01

    L’insuffisance mitrale (IM) est l’une des pathologies cardiaques les plus fréquemment rencontrées dans l’espèce équine. C’est, en outre, la pathologie valvulaire qui présente le plus de risque d’entraver les performances sportives, d’évoluer en insuffisance cardiaque congestive (ICC) et donc de mettre en jeu la vie de l’animal affecté. Le diagnostic clinique de l’IM dépend beaucoup l’expertise du vétérinaire en cardiologie et repose en grande partie sur l’auscultation cardiaque. Dans tous ...

  14. Fracture panfaciale: un challenge thérapeutique: à propos d'une observation et revue de la littérature

    Science.gov (United States)

    Fassih, Malika; Nassik, Hicham; Abada, Mourad Nafaa Redallah; Rouadi, Sami; Mahta, Mohamed; Roubal, Mohamed; Essaadi, Mustapha; El Kadiri, Mohamed Fatmi

    2015-01-01

    La gestion des traumatismes de la face a subi plusieurs progrès dans la dernière décennie. Avec l'avènement de la tomodensitométrie bi- et tridimensionnelle, qui permet de dresser une cartographie précise des lésions osseuses, le développement du matériel d'ostéosynthèse, et les procédés de réduction des fractures. L'objectif est la restauration totale de la forme et la fonction de la face, seul garant pour empêcher la survenue de préjudices esthétiques et fonctionnels. Nous rapportons l'observation de Mme assal khadija, âgée de 38 ans, admise le 25 Aout 2010, au service des urgences d'ORL et maxillo-faciales, à l'hôpital 20 aout de Casablanca, victime d'un AVP, occasionnant un traumatisme facial grave, avec un important délabrement de la face, et asphyxie. Une trachéotomie a été réalisée en urgence. Le bilan lésionnel a objectivé un important fracas du massif facial intéressant l’étage supérieure, moyen et inférieur. Dans l'immédiat, un parage a été réalisé sous anesthésie générale, la réparation des parties molles délabrées a été effectuée en endobuccale (vestibules, langue et plancher buccal) et pour les téguments de la face. Une semaine après, la patiente a été reprise pour la reconstruction du massif facial, nous avons opté pour le «inside-out, de bas en haut" pour la réduction des fractures. Nous avons procédé à la fixation de la mandibule qui a précédé la reconstruction du maxillaire, de la pyramide nasale, et de l'orbite. L’évolution a été marquée par l'apparition d'un orostome, qui fera l'objet après tarissement de l'infection, d'une réparation grâce à un lambeau myocutané, et une nécrose cutanée de la région zygomatique laissée à la cicatrisation dirigée. Toutes les lésions traumatiques de la face ont des répercussions esthétiques et fonctionnelles à moyen et long termes, dont le degré dépend de la qualité de la prise en charge, qui étant la plus précoce et la plus complète possible avant la consolidation des fractures est le meilleur garant d'un résultat satisfaisant à long terme. PMID:27386025

  15. Spécification des besoins de performabilité dans les modèles BPMN Une revue de la littérature

    Directory of Open Access Journals (Sweden)

    Fatima-Zahra Belouadha

    2015-11-01

    Full Text Available The information system performance depends on the operational efficiency of the implemented business processes, but also on their ability to meet the non-functional requirements, especially those of performability (performance and reliability. Indeed, the modelling phase of business processes is a critical phase within the BPM (Business Process Management lifecycle. Nevertheless, the notation BPMN (Business Process Model and Notation which is the de facto standard for business process modelling, is limited to the contemplative modelling of their behavior enabling developers to capture their functional requirements. As part of a productive modelling approach, integrating performability requirements of business processes at design-time is essential to enable their automatic analysis and to predict their quality of service. This article classifies and compares contributions among the most recent or referenced in this field. The aim is to highlight their limitations and to identify the criteria of an efficient approach

  16. Aerothermodynamic Design, Review on Ground Testing and CFD (Conception aerothermodynamique, revue sur les essais au sol et dynamique des fluides informatisee)

    Science.gov (United States)

    2010-04-01

    Aerothermodynamic Design, Review on Ground Testing and CFD (RTO-EN-AVT-186) Executive Summary The Lecture Series focus on the presentation of...impulsions ITAM et les tubes à choc DLR HEG. Les sondes à réponse rapide et les techniques de mesures instables ont été présentées ainsi que les outils de

  17. Irradiation of unknown pregnancy: review of 17 cases; Irradiation d'une grossesse meconnue: revue a court terme de 17 cas

    Energy Technology Data Exchange (ETDEWEB)

    Chahed, N.; Mhiri, A.; Gaigi, S.; Mtimet, S. [Centre national de radioprotection, Hopital d' enfants, Tunis (Tunisia)

    2000-12-01

    The article summarizes the analysis of 47 cases of pregnant women who did not know their pregnancy and had undergone one or more diagnostic radiological examinations. We distinguished two groups. The first group G1 consisting of 12 women whose exposure to radiation had been focused under diaphragmatic region and occurred during tire critical period of organogenesis with a gonadal dose estimated to range 12 to 52 mGy. A therapeutic abortion had been recommended to these women. The second group G2 consisting of 35 women whose exposure to radiation interested directly or indirectly tire above diaphragmatic region with dose lower than 10 mGy. To these women, a recommendation to continue their pregnancy had been given. We investigated only 17 pregnant women issues; 7 from G1 et 10 from G2, We noted that there were no spontaneous abortion or major abnormalities or malignant diseases. However, 4 minor abnormalities were identified among tire examined children sample: facial dysmorphy. anus atresia. hypospadias and harelip. These anomalies could not be attributed to the irradiation effects because the conceptus received very low doses during tire minimal risk gestation period. We believe that the malformations observed may be attributed to congenital malformation risk. (authors)

  18. Le réseau céramique infiltré de polymères, revue de littérature

    OpenAIRE

    Chue , Yohann

    2017-01-01

    La Conception et la Fabrication Assistées par Ordinateur (CFAO) a été introduite en odontologie au début des années 1980. Du fait de la demande croissante en esthétique et en degré de précision, les indications de la CFAO se sont étendues, avec l’apparition de nouveaux matériaux. Les matériaux de restauration les plus utilisés à l’heure actuelle sont la céramique et la résine composite, mais ils présentent encore des inconvénients, notamment mécaniques. C’est pourquoi les recherches s’oriente...

  19. Le carcinome neuro-endocrine cutané primitif: à propos d'un nouveau cas et revue de la littérature

    Science.gov (United States)

    Boukind, Samira; Elatiqi, Oumkeltoum; Dlimi, Meriem; Elamrani, Driss; Benchamkha, Yassine; Ettalbi, Saloua

    2015-01-01

    Le carcinome neuro- endocrine cutané primitif (CNEC) est une tumeur cutanée rare et agressive du sujet âgé, favorisée par le soleil et l'immunodépression. Elle est caractérisée par une évolution agressive avec un fort taux de récidive, une évolution ganglionnaire régionale et un risque de métastases à distance. Nous rapportons un cas de cette tumeur chez un patient âgé de 67 ans sous forme d'un placard nodulaire hémorragique mesurant 16 /14 cm. Le patient a bénéficié d'une exérèse chirurgicale large avec couverture de la perte de substance par un lambeau musculo-cutané du muscle grand dorsal, un curage ganglionnaire axillaire et une radiothérapie adjuvante. Après un recul de 2 ans et 2 mois, le patient est toujours vivant sans métastase ni récidive. La littérature étant pauvre, la prise en charge diagnostique et thérapeutique est controversée et donc hétérogène. Globalement le pronostic est mauvais, et certains paramètres corrélés au pronostic sont précisés. PMID:26185585

  20. Thermochemical Conversion of Lignin for Fuels and Chemicals: A Review Conversion thermochimique de la lignine en carburants et produits chimiques : une revue

    Directory of Open Access Journals (Sweden)

    Joffres B.

    2013-10-01

    Full Text Available Lignin is one of the biomass components potentially usable as renewable resource to produce fuels or chemicals. After separation from the lignocellulosic matrix, this macromolecule is nowadays essentially valorized by combustion in paper mills. If second generation ethanol is produced in the future from lignocellulosic biomass, some increasing reserves of lignin will be available in addition to the ones coming from the paper industry. The main thermochemical ways such as pyrolysis, solvolysis, hydrothermal conversion and hydroconversion considered for the valorization of the lignin are reviewed in this article. La lignine est une des composantes de la biomasse lignocellulosique potentiellement valorisable comme ressource renouvelable pour la production de carburants ou de produits chimiques. Après séparation de la matrice lignocellulosique, cette macromolécule est de nos jours essentiellement utilisée comme combustible dans l’industrie papetière. Outre cette filière papetière, la production d’éthanol de seconde génération à partir de la cellulose aura comme conséquence la mise à disponibilité d’encore plus grandes quantités de lignine. De nouvelles applications pourront donc être proposées pour l’utilisation de cette bio-ressource. Les différentes voies thermochimiques : pyrolyse, solvolyse, conversion hydrothermale et hydroconversion envisagées pour la valorisation de la lignine sont décrites dans cet article.

  1. Techniques de débitmétrie polyphasique non intrusive. Revue bibliographique Non Intrusive Multiphase Flow Measurement Techniques. Bibliographic Review

    Directory of Open Access Journals (Sweden)

    Lynch J.

    2006-11-01

    Full Text Available Cet article présente les différentes techniques de débitmétrie polyphasique non intrusive décrites dans la littérature du domaine public. Ces techniques sont considérées du point de vue de leur application dans le cadre de la production pétrolière sous-marine (mélange eau/huile/gaz. A partir d'une analyse des différentes méthodes physiques qui peuvent être utilisées, des perspectives d'avenir sont proposées. Several operations in the oil reservoir exploitation industry call for flowmeters capable of delivering information on the quantity and rate of flow of the different phases (gas, oil, water, solids . . . present in a pipeline. Amongst these are the estimation of remaining reserves and of well performance, control of production units such as multiphase pumping systems and fiscal monitoring in the case of pipeline networking. Existing methods, based on phase separation, require separate test lines and thus tend to be cumbersome, give only intermittent values of flow parameters and need to be calibrated due to the intrusive nature of the measurements. These drawbacks are seen to be all the more critical in subsea production where the ideal flowmeter would be compact, require little maintenance and supply precise real time data for network and multiphase pump control. In recent years flow measurement in two or more phase systems has received increasing attention both in laboratory studies and for applications in a variety of industries (for example : nuclear power production and food processing as well as of course oil production. We review here the many methods considered for non-intrusive flow metering with two or more components from the point of view of an industrial (in particular subsea oil production application. The situation is rendered delicate, in particular for density measurement, by the uncontrolled nature of the flow which may occur in any of several regimes with differing spatial distributions of the components. Parameters permitting the various phases to be discriminated are identified in order to evaluate the various techniques. The latter are classified in two major families of interaction for which a range of frequencies are explored : mechanical interactions from ultrasound to simple pressure and noisemeasurement and electromagnetic interactions from the use of gamma rays to the measurement of static electrical properties. Consideration is also given to two techniques of special interest falling outside this classification : the use of neutron bombardment and that of nuclear magnetic resonance (NMR. Most of the techniques considered give only partial responses to the question of measuring the quantites and velocities of each of the three major components : oil water and gas. Some, such as visible light or infrared spectroscopy, are eliminated entirely due to the local nature of the measurements in the system considered. Methods such as acoustic or pressure measurement, providing a rapid and simple means of detecting major events such as the passage of slugs and gas pockets and of measuring their velocity in favorable cases, may be incorporated into the final system. Little information is however furnished as to the flow rates of individual components. Four types of measurement have been selected as presenting particular advantages in all or part of the range of parameters for which information is required. Neutron based methods, particularly when coupled to induced gamma ray spectroscopy, promise to provide useful information on water/oil ratios and on salinity although the development of practical sources is as yet only in its earliest stage. NMR is potentially capable of providing independant measurements of both the quantity and velocity of the two liquid phases although the size of such a flowmeter would be prohibitive in the application envisaged. A restricted application (both in terms of size and in the number of measured parameters may however be advantageous in combination with other techniques. Two regions of the electromagnetic spectrum are identified as of particular interest. The first is the hard X-ray to gamma ray region where the use of two energies would allow evaluation of three phases : oil water and gas. Velocity measurement is however intrinsically difficult and, for industrial applications, detector technology still has to be improved. In the microwave region (including high frequency capacitance and resistivity measurements most of the necessary parameters appear to be attainable by combining absorption and reflection measurements with the easy tunability of sources. Although this technology is already used in a wide variety of applications from food processing to traffic control, the range of conditions for which it will be applicable in multiphase oil production is not yet clear. A successful industrial flowmeter may imply a combination of several of these techniques incorporating intelligent use of more classical measurements such as temperature and pressure for auto calibration. Further work on evaluating the range of attainable measurements in a compact, reliable and economic system is likely to further stimulate the development of subsea multiphase production systems.

  2. Iodine kinetics and effectiveness of stable iodine prophylaxis after intake of radioiodine: a review; Pharmacocinetique de l'iode: revue des connaissances utiles en radioprotection accidentelle

    Energy Technology Data Exchange (ETDEWEB)

    Geoffroy, B.; Verger, P.; Le Guen, B. [CEA/Fontenay-aux-Roses, Inst. de Protection et de Surete Nucleaire, IPSN, 92 (France)

    2000-06-01

    Ingestion of stable iodine (potassium iodide) offers an efficient protection against the irradiation of the thyroid when an accidental exposure to radioiodine occurs. This prophylaxis aims at obtaining a rapid and maximum thyroid protection without antithyroid effects. This article reviews studies on iodine kinetics in the human and on stable iodine effectiveness to protect the thyroid. In adults with a normal thyroid function, ingestion of 100 mg of iodide just before exposure to radioiodine allows a percentage of thyroid averted dose equal or greater than 95%. If the exposure persists after iodide ingestion (100 mg), the percentage of averted dose may decrease significantly. Repeated ingestion of daily amounts of 15 mg of stable iodine would then allow to maintain a 90% effectiveness. Iodide effectiveness and antithyroid effects also depend on external and individual factors such as iodine amounts in the diet, thyroid function and age. It is recommended to adapt the amount of ingested stable iodine according to age at the time of exposure. (author)

  3. Radiotherapy in stage 1 testicular seminoma: retrospective study and review of literature; Radiotherapie des seminomes testiculaires de stade 1: etude retrospective et revue de la litterature

    Energy Technology Data Exchange (ETDEWEB)

    Bauduceau, O.; Le-Moulec, S.; Bernard, O. [Hopital des Armees du Val-de-Grace, Service de Radiotherapie et Oncologie, 75 - Paris (France); Souleau, B. [Hopital des Armees Percy, Service d' Hematologie, 92 - Clamart (France); Houlgatte, A. [Hopital des Armees du Val-de-Grace, Service d' Urologie, 75 - Paris (France)

    2003-12-01

    Introduction. - Seminoma accounts for about 40% of germ cell tumours of the testicle. In this retrospective analysis, we review literature concerning management of stage I seminoma. Materials and methods. - Between March 1987 and April 2001, 65 patients with stage I pure testicular seminoma received adjuvant radiotherapy with a 25 MV linear accelerator. Results. - Median age was 33 years. Testicular tumour has been found on the right testis in 39 patients and on the left one in 24 patients. Patients have been treated using an anterior-posterior parallel pair and have received 20-25 Gy in 10-14 fractions. The target volume consisted of paraaortic, and paraaortic + homolateral iliac lymph nodes in 17 and 46 patients, respectively. Acute toxicity was mainly digestive, 38% of patients presenting nausea and vomiting. Median follow-up time was 37 months. All patients are alive in complete remission. Discussion. - Because of good radio-sensitivity of seminoma, radiotherapy is regarded as standard adjuvant treatment (5 years relapse rate: 3-5%). Acute toxicity is dominated by moderate gastro-intestinal side effects. Secondary neoplasia represents one of the worst possible long-term complications of therapy. Waiting for ongoing randomized trials, the modern literature for seminoma reflects a trend toward lower radiation doses (20-25 Gy) and smaller treatment volumes (paraaortic field). Adjuvant chemotherapy with two courses of carbo-platin, might be equivalent to radiotherapy but must be investigated in randomized trials. A surveillance policy is one of the other management options less recommended. (author)

  4. Revue bibliographique. Ultrastructure des Monogènes : liste des espèces et des organes étudiés

    Directory of Open Access Journals (Sweden)

    JUSTINE J-L.

    1993-01-01

    Full Text Available Les données bibliographiques (plus de 180 références concernant l'ultrastructure des monogènes, en microscopie électronique à balayage (MEB et microscopie électronique à transmission (MET, sont présentées sous la forme de deux listes. La liste des espèces étudiées indique pour chaque espèce les organes qui ont été décrits en microscopie électronique et la référence; plus de 60 espèces de Monopisthocotylea et 70 espèces de Polyopisthocotylea sont citées. La liste des organes indique pour chaque organe quelles espèces ont été étudiées et la référence. Les structures sont classées en: 1. Organes externes (morphologie externe en MEB, tégument, récepteurs tégumentaires, photorécepteurs, glandes, pièces sclérifiées du hapteur. 2. Organes internes non reproducteurs (appareil digestif, protonéphridies, cellules nerveuses. 3. Organes reproducteurs (canaux génitaux mâles, canaux génitaux femelles, ovogenèse et oeufs, oeufs en MEB, vitellogenèse, spermiogenèse et sperme. 4. Hyperparasites et symbiontes (microsporidies, bactéries et autres procaryotes, virus. Les travaux concernant des oncomiracidia ou des larves sont indiqués.

  5. Blast pulmonaire primaire chez le brûlé. a propos d’un cas et revue de la littérature

    Science.gov (United States)

    Siah, S.; Emane, A.; Bertin-Maghit, M.

    2016-01-01

    Summary Le blast est à l’origine de lésions spécifiques pour lesquelles une prise en charge spécialisée est nécessaire. Après une explosion on peut observer des lésions de blast primaire, liées à l’onde de choc, secondaire par polycriblage et tertiaire par projection du patient. Les blasts secondaire et tertiaire sont plus fréquents que le blast primaire et peuvent entraîner un polytraumatisme. Dans 5% des cas, on retrouve des brûlures pouvant faire partie du blast quaternaire, qui regroupe toutes les lésions d’autres mécanismes que ceux précités. La prise en charge des lésions secondaires et tertiaires de blast est comparable à celle des traumatisés graves. Le blast pulmonaire primaire aggrave le pronostic des blessés les plus graves mais impose rarement une prise en charge spécifique. La connaissance des particularités physiopathologiques et lésionnelles permet de mieux traiter les blastés et brûlés graves survivants. Nous rapportons une observation de blast pulmonaire primaire chez un brûlé. PMID:28149247

  6. Développement des compétences interprofessionnelles de la nouvelle infirmière diplômée: revue de littérature

    OpenAIRE

    Meyer, Agnès,; Hauser, Christine,; Bulliard Verville, Danielle

    2017-01-01

    La pénurie infirmière qui touche actuellement la Suisse sera comblée en grande partie par les nouvelles diplômées infirmières1, d’ici quelques années. Cependant, un taux important de turnover dans les équipes peut mettre en péril leur encadrement. Leur processus d’insertion étant particulièrement éprouvant dans les premiers mois de pratique, il en résulte que nombre d’entre elles quittent précocement la profession. Comme stratégie pour pallier ce problème, la littérature montre les effets pos...

  7. Sécurisation alimentaire et innovations dans l’agriculture et l’agroalimentaire : vers un nouvel agenda de recherche ? : Une revue de la littérature

    OpenAIRE

    Touzard, Jean-Marc

    2012-01-01

    L'article propose d'utiliser le concept de sécurisation alimentaire pour étudier les actions et processus qui améliorent une situation alimentaire, plutôt que celui de sécurité alimentaire qui se réfère avant tout à la satisfaction de besoins alimentaires. Dans une première partie, ces deux concepts sont précisés et discutés. La sécurité alimentaire est caractérisée selon plusieurs dimensions : disponibilités, conditions d'accès, qualités des aliments, stabilité, mais aussi objectifs sociaux ...

  8. 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

  9. 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

  10. 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

  11. Section urétérale au cours d’un traumatisme pénétrant de l’abdomen: à propos d’un cas et revue de la littérature

    Directory of Open Access Journals (Sweden)

    A. Moataz

    2017-12-01

    Conclusions: Les lésions urétérales post-traumatiques non diagnostiquées à temps sont corrélées à une morbidité et une mortalité élevée. Un index de suspicion élevé permettrait un diagnostic rapide et une prise en charge à temps.

  12. Neurolymphomatosis of the sciatic nerve and F.D.G. PET: case report and review; Neurolymphomatose du nerf sciatique en TEP au FDG: a propos d'un cas et revue de la litterature

    Energy Technology Data Exchange (ETDEWEB)

    Bruna-Muraille, C.; Papathanassiou, D.; Cuif-Job, A.; Liehn, J.C. [Institut Jean-Godinot, Service de Medecine Nucleaire, 51 - Reims (France); Job, L. [CHU Robert-Debre, Service de Radiologie, 51 - Reims (France); Kolb, B.; Himberlin, C.; Delmer, A. [CHU Robert-Debre, Service d' Hematologie Clinique, 51 - Reims (France)

    2009-12-15

    We are reporting the case of a woman who has been suffering from sciatica for several months. A neurolymphomatosis of the sciatic nerve was found. In this report, we present the characteristics of this lesion in conventional imaging and in F.D.G. PET. (authors)

  13. L’Homme et la Société, revue internationale de recherche et de synthèse en sciences sociales, L’Harmattan, Parisn° 134, 1999/4

    OpenAIRE

    Daoud, Mohamed

    2013-01-01

    Numéro consacré à “La littérature et les sciences sociales”. Tout en abordant la littérature dans sa valeur épistémologique, selon des angles d’attaque méthodologiques et théoriques très variés, les coordinateurs de ce numéro (Suzanne Chazan, Nia Perivolaropoulou) ont proposé quatre grands axes thématiques : 1.La place de l’écriture dans la production des sciences sociales ; 2.L’appréhension de l’altérité dans les écrits littéraires et scientifiques ; 3.La mémoire, les “régimes de mémoire”, l...

  14. Technical Status Review Appraisal of the Suitability of Turbulence Models in Flow Calculations (Revue Technique - L’Evaluation de l’Applicabilite des Modeles de Turbulence dans de Calcul des Ecoulements)

    Science.gov (United States)

    1991-07-01

    Is 0.12- - -- often focussed on complex turbulent flows and the A -0.4y deficiencies of turbulence models in these cir- cumstances. However, turbulent...inherent deficiencies in stress discrepancies which have been traced to numer- ical errors, and as the collaboration and interac- LASHER, W.C.; TAULBEE, D.B...nIliio K I A ( tK2 .iWA Notiwcwiar Ivitit: 1kiciii. I’ stabi.in t \\MAIU(Attn: Itilioickrt DI11 :ni~h I ).Ih oItii li o I’.t ll) ’kOE 25 - \\cd Iitacispa

  15. Ingénierie des exigences de la sécurité informatique : Revue de travaux de recherche de l’élicitation à la spécification

    Directory of Open Access Journals (Sweden)

    Lamia Ben Hiba

    2012-03-01

    Full Text Available Nowadays Security plays an important role in the development of applications because of network expansion on one side and of the importance of information on the other side. However, security requirements have long been relegated to second place compared to the functional requirements which can cause some damage to the applications. One of the challenges of current research in the area of requirement engineering is to develop simple, expressive, reliable and costless methods for expressing and modelling security requirements. The purpose of this article is to review research studies related to approaches for eliciting and specifying security requirements in the context of software development process. It aims then to analyse and classify them into categories and to highlight their contribution to security requirements engineering field and their limits.

  16. L’érysipèle sur cicatrice post opératoire en traumatologie: à propos d'un cas et revue de la littérature

    Science.gov (United States)

    Abid, Hatim; El Idrissi, Mohamed; Shimi, Mohamed; El Ibrahimi, Abdelhalim; El Mrini, Abdelmajid; Amraoui, Nissrine; Mernissi, Fatima Zohra

    2015-01-01

    L’érysipèle sur cicatrice post opératoire est une entité rare, décrite principalement chez des patients présentant les facteurs de risque classiques de la maladie au niveau des sites de veinectomie pour pontage coronarien. En traumatologie orthopédie, nous n'avons que les 3 cas rapportés dans le travail de Dhrif survenus au décours d'une implantation prothétique chez des malades à risque. Nous présentons à travers cet article, le cas d'un érysipèle post opératoire sur une cicatrice d'ostéosynthèse d'une fracture fermée du pilon tibial, ayant la particularité du terrain et des circonstances de survenues, pour enfin conclure aux principes de la prévention primaire à adopter. PMID:26401204

  17. Médiastinite compliquant une cellulite cervicale à porte d’entrée dentaire: à propos d’un cas et revue de la littérature

    Directory of Open Access Journals (Sweden)

    Issam Serghini

    2011-03-01

    Full Text Available Les cellulites cervicales ou fasciites cervicales nécrosantes sont des infections des parties molles développées à partir de foyer dentaire ou pharyngé dont le risque, si elles ne sont pas reconnues précocement, est l’extension vers le médiastin. Les premiers signes cliniques sont parfois frustres et peuvent conduire à un retard diagnostique. L’examen clé est la tomodensitométrie cervicale et thoracique. Le traitement consiste en des excisions tissulaires larges et répétées associées une antibiothérapie dirigée contre les germes aréo- et anaérobies. Nous rapportons le cas d’un homme connu diabétique présentant une cellulite cervicale d’origine dentaire compliquée de médiastinite.

  18. Les tumeurs neuro ectodermiques périphériques primitives de localisation thoracique (tumeur d'Askin) chez l'adulte jeune : à propos de deux observations, revue de la littérature

    OpenAIRE

    Brugger , Catherine

    2003-01-01

    Non disponible / Not available; La tumeur d'Askin appartient à la famille des tumeurs neuro ectodermiques périphériques primitives. De localisation thoracique, elle est décrite initialement chez l'enfant, sa survenue chez l'adulte jeune demeure exceptionnelle. Elle est définie comme une tumeur maligne à petites cellules rondes exprimant le gène MIC2 et présentant une translocation chromosomique t(11,22) spécifique. Ses aspects cliniques et radiologiques ne sont pas spécifiques. L'évolution à ...

  19. Phéochromocytome et grossesse - Gestion péri opératoire et conduite à tenir obstétricale: a propos d’un cas clinique et revue de littérature

    Directory of Open Access Journals (Sweden)

    Hicham Sbai

    2010-06-01

    Full Text Available L’association phéochromocytome et grossesse est rare pouvant mettre en jeu le pronostic vital maternel et fœtal. Le diagnostic est aisé à condition d’y penser systématiquement face à une hypertension artérielle gravidique atypique, accompagnée de signes cliniques évocateurs, ou résistante au traitement. La certitude diagnostique est donnée par des tests biologiques simples et fiables. Nous rapportons le cas d’un phéochromocytome survenu au 1er trimestre, révélé par des épisodes d’hypertension artérielle. Le traitement avait consisté en une préparation médicale préopératoire suivie d’une surrénalectomie. L’évolution materno-fœtale était favorable. La survenue d’un phéochromocytome au cours de la grossesse pose un problème de diagnostic et de contrôle tensionnel. La stratégie thérapeutique dépend du terme, du retentissement materno-fœtal et de la réponse au traitement médical.

  20. Post-pneumonectomy empyema and dosimetric CT scan. Report of two cases and review of literature; Empyeme thoracique postpneumonectomie et scanographie dosimetrique. A propos de deux observations et revue de la litterature

    Energy Technology Data Exchange (ETDEWEB)

    Latorzeff, I.; Bachaud, J.M.; Aziza, R.; Arboucalot, F. [Centre Claudius-Regaud, 31 - Toulouse (France); Berjaud, J.; Dahan, M.; Giron, J. [Centre Hospitalier Universitaire Purpan, 31 - Toulouse (France)

    1999-12-01

    Following a pneumonectomy for cancer, the patients are classically observed by clinical examination and standard chest X-ray. However, torpid empyemas can be missed when they occur after the period of hospitalization and when they are not accompanied by a fever, At the time of postoperative radiotherapy, the dosimetric CT scan constitutes the first examination providing objective information of the endo-thoracic content. It is therefore necessary on this occasion to assure the normality of the post-pneumonectomy pleural space while checking that the substituted liquid is homogeneous and above all that the internal mediastinal part of the cavity has a concave appearance. If that is not the case, an empyema should be suspected. The diagnosis, confirmed by a cyto-bacteriological examination of the pleural fluid, constitutes a counter-indication of the radiotherapy. We present two cases of post-pneumonectomy pauci-symptomatic empyema which were diagnosed during the course of postoperative radiotherapy when the initial dosimetric CT scan was pathologic and could have allowed an earlier diagnosis. (author)

  1. What telomeres say about activity and health: A rapid review: Ce que les télomères révèlent au sujet de l'activité et de la santé : revue rapide.

    Science.gov (United States)

    To-Miles, Flora Y L; Backman, Catherine L

    2016-04-06

    Empirical studies on occupation as a determinant of health could be advanced with research incorporating biological measures of health. Telomere length and telomerase function are promising biomarkers of the interaction of genetics, lifestyle, and behaviour; however, they have not been used in occupational therapy research. This paper reviews current evidence on the role of physical and mindfulness activities in sustaining telomeres. The findings are applied to the study of occupation, health, and aging. A rapid review was conducted with an evidence synthesis of 23 studies published from 2008 to 2014. Mindfulness activities may preserve telomeres, slow cell senescence and death, and sustain health through mediating life stressors. Inconsistencies exist for the effect of physical activities on telomeres. Similar research examining a range of occupations may help to identify the health-promoting benefits of occupation and inform lifestyle interventions. © CAOT 2016.

  2. Radioinduced optic nerve neuropathy after treatment for nasopharynx cancer. About two cases and literature review; Neuropathie radio-induite du nerf optique apres traitement pour cancer du nasopharynx. A propos de deux cas et revue de la litterature

    Energy Technology Data Exchange (ETDEWEB)

    Mnejja, W.; Siala, W.; Daoud, J. [Centre Hospitalier Universitaire Habib-Bourguiba, Service de Radiotherapie Carcinologique, Sfax (Tunisia); Fki, J. [Centre Hospitalier Universitaire Habib-Bourguiba, Service d' Ophtalmologie, Sfax (Tunisia); Ghorbel, M. [Centre Hospitalier Universitaire Habib-Bourguiba, Service d' ORL, Sfax (Tunisia); Frikha, M. [Centre Hospitalier Universitaire Habib-Bourguiba, Service de Carcinologie Medicale, Sfax (Tunisia)

    2007-11-15

    The radioinduced neuropathy of the optic nerve is a rare and delayed complication. Its incidence is difficult to evaluate in the literature. It depends on the whole irradiation dose, fractionation and irradiated volume. Currently, it does not exist any efficient treatment, only the prevention play an important part on avoiding the high doses, and the broad irradiation volumes. The innovating techniques using conformal radiotherapy with or without modulated intensity could contribute to reduce this toxicity incidence. (N.C.)

  3. Revue des aspects hydrodynamiques des réacteurs catalytiques gaz-liquide-solide à lit fixe arrosé Hydrodynamics of Gas-Liquid-Solid Trickle-Bed Reactors: a Critical Review

    Directory of Open Access Journals (Sweden)

    Attou A.

    2006-12-01

    Full Text Available Bien que les aspects hydrodynamiques soient d'une importance primordiale lors de la conception et du fonctionnement d'un réacteur gaz-liquide-solide à lit fixe arrosé, les méthodes de calcul prédictif proposées sont restées fort rudimentaires. La plupart des études portant sur ce sujet ont été menées dans des conditions quasi atmosphériques alors que les réacteurs industriels fonctionnent à des pressions élevées. C'est seulement récemment que quelques résultats expérimentaux ont été obtenus à des hautes pressions, et des corrélations ont été proposées dans ces conditions pour prédire la transition entre les régimes ruisselant et pulsé, la perte de pression et le taux de rétention de liquide. L'objectif de cet article est double. D'une part, une synthèse y est présentée ; elle fait état des connaissances acquises sur les divers aspects hydrodynamiques du réacteur triphasique à lit fixe, incluant les récents développements réalisés à hautes pressions. D'autre part, les modèles et les corrélations actuels de transitions de régimes, de la perte de pression et du taux de rétention de liquide sont soumis à une analyse critique en confrontant leurs prédictions à l'ensemble des données expérimentales obtenues pour un large intervalle de la pression de fonctionnement du réacteur. Des conclusions objectives ont pu être tirées concernant les aptitudes des corrélations et des modèles actuels à être utilisées pour les calculs de conception des réacteurs triphasiques à lit fixe industriels. Malheureusement, il apparaît qu'aucun modèle de transitions entre les régimes ruisselant et pulsé n'est satisfaisant. Seule la corrélation empirique de Larachi et al. (1993 s'avère être jusqu'à présent la méthode la plus précise pour prédire la position de la frontière entre les régimes ruisselant et pulsé dans un large domaine de la pression de fonctionnement. Par ailleurs, aucune corrélation empirique de la perte de pression et du taux de rétention de liquide ne correspond à une erreur relative moyenne de prédiction acceptable. Seul le modèle phénoménologique étendu d'Al-Dahhan et al. (1998 semble constituer une technique satisfaisante pour la prédiction des deux paramètres hydrodynamiques en régime ruisselant. Néanmoins, son principal inconvénient réside dans la nécessité de déterminer préalablement les deux coefficients du modèle au moyen d'expériences sur des écoulements monophasiques gazeux. De telles expériences restent difficiles à réaliser dans la pratique. Il est cependant regrettable de constater qu'aucune des ces méthodes, qui se distinguent par leurs résultats, n'est basée sur une approche physique des phénomènes hydrodynamiques permettant d'améliorer la connaissance de ces écoulements et de prédire leur comportement en dehors des domaines de conditions expérimentales testées. De ce travail, il ressort la nécessité d'appliquer les outils classiques de la mécanique des fluides diphasique à la description de ces écoulements, en apportant une attention particulière aux phénomènes d'interactions hydrodynamiques auxquelles sont soumises les trois phases du système (gaz, liquide et solide. While it is recognised that the hydrodynamic aspects have a considerable importance in the design and the operation of gas-liquid-solid trickle-bed reactors, the accuracy of the proposed calculation methods remains poor. Most studies in this field have been performed in atmospheric conditions in contrast of industrial reactors operating at quite high pressures. Only recently, some experimental results have been obtained at elevated pressures and correlations have been proposed in these conditions in order to predict the tricking-pulsing transition, the pressure drop and the liquid holdup. The scope of this article is twice. Firstly, the knowledge on the several hydrodynamic aspects of three-phase trickle-bed reactors, including the recent developments performed at high operating pressures, is summarised. Secondly, the models and the correlations of regimes transitions, pressure drop and liquid holdup are submitted to critical evaluations by comparing their predictions with the set of experimental data obtained in a wide range of operating pressure. Some conclusions have been deduced concerning the ability of the correlations and the models to be used in the design procedures of industrial three-phase trickle-bed reactors. Unfortunately, it is shown that there is no model of trickling-pulsing regimes transitions which gives satisfactory results. Up this time, the empirical correlation of Larachi et al. (1993 is found to be the more accurate method for the prediction of the location of the boundary between the trickle and pulsed regimes in a wide range of operating pressure. In the other hand, no empirical correlation of pressure drop and liquid holdup corresponds to an acceptable mean relative error of prediction. To now, the phenomenological extended model of Al-Dahhan et al. (1998 appears to be the more satisfactory method for the predictions of the two hydrodynamic parameters in the trickle flow regime. However, it is necessary to determine the two coefficients of the model from experiments to be performed in single-phase gas flow. Finally, it is recommended to apply the two-phase fluid mechanics tools for describing of the gas-liquid flow through flxed bed reactors by devoting a particular attention to the hydrodynamic interactions phenomena between the three phases of the system (gas, liquid and solid.

  4. [Boulduc's dynasty, apothecaries in Paris in XVIIth an XVIIIth centuries (following the article published in Revue d'histoire de la pharmacie, 2001, no. 331, p. 339-354)].

    Science.gov (United States)

    Warolin, Christian

    2002-01-01

    Like his father Simon Boulduc, Gilles-François Boulduc worked as a demonstrator in chemistry at the Jardin Royal. He was the apothecary of King Louis XIV and King Louis XV, a member of the Académie Royale des Sciences. In addition he was appointed alderman of the town of Paris. He worked in Paris rue des Boucheries and went into partnership with another apothecary, Claude Pia. He was also the drug supplier of the Duke de Saint-Simon who quoted him several times as a Royal apothecary in his Mémoires. Gilles-François Boulduc's main chemistry research work is presented in this article.

  5. Efficacy of ondansetron in the management of radiotherapy induced emesis: a review. Efficacite de l'ondansetron dans les nausees et vomissements radio-induits: revue de la litterature

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E. (Hopital Henri-Mondor, 94 - Creteil (France)); Paillarse, J.M.; Votan, B. (Laboratoires Glaxo, 75 - Paris (France))

    1994-01-01

    Radiotherapy-induced emesis depends on the site of irradiation, the field size and the dose per fraction and is generally less intense than chemotherapy-induced emesis. Established anti-emetic drugs offer only limited symptom control (50%). Ondansetron, a 5HT[sub 3] receptors antagonist, had proven a complete or a major control efficacy (0-2 emetic episodes) of 68 to 95% in three pilot studies (fractionated, single-dose and total body irradiations). In controlled studies, ondansetron efficacy was significantly higher than placebo, metoclopramide and prochlorperazine. The treatment was well tolerated in the different studies. (authors). 23 refs., 2 figs., 1 tab.

  6. Angiomyolipome rénal agressif avec extension à la veine rénale: à propos d'un cas et une revue de la littérature

    Science.gov (United States)

    Majdoub, Aziz El; Khallouk, Abdelhak; Farih, Moulay Hassan

    2017-01-01

    L'angiomyolipome rénal est une tumeur qui est reconnue bénigne. Elle présente trois composantes différentes: musculaire, vasculaire et graisseuse, dont la distribution est variable. Le diagnostic repose sur la mise en évidence de la composante graisseuse intra-tumorale en TDM ou IRM. Exceptionnellement la tumeur peut avoir un caractère agressive avec extension locorégionale et veineuse (la veine rénale et la veine cave inferieure). Nous présentons une observation d'une patiente âgée de 37 ans présentant un Angiomyolipome rénal volumineux avec extension à la veine rénale. PMID:29599888

  7. Isomérisation des paraffines de C4 à C7 sur catalyseurs zéolithiques. Revue bibliographique Isomerization of C4 to C7 Paraffins on Zeolitic Catalysts (Bibliographic Review

    Directory of Open Access Journals (Sweden)

    Belloum M.

    2006-11-01

    Full Text Available L'isomérisation des alcanes connaît un nouvel intérêt, depuis que la législation a prévu, par souci de protection de l'environnement, la suppression des alkyls de plomb dans les essences à l'horizon 1992. Cette réaction catalytique permet, en partant de n-paraffines de faible indice d'octane, issues du réformage catalytique ou de la distillation directe, d'obtenir des iso-paraffines présentant un indice d'octane beaucoup plus élevé. Elle est thermodynamiquement favorisée à basse température et nécessite par conséquent l'utilisation de catalyseurs développant une acidité importante. Deux types de catalyseurs sont actuellement utilisés industriellement : les catalyseurs à base de Pt sur lumine chlorée et les catalyseurs zéolithiques à base de Pt sur mordinite. Ces derniers sont considérés comme étant la nouvelle génération de catalyseurs. Ils présentent l'avantage d'être faciles à mettre en oeuvre et d'être beaucoup moins sensibles à la présence de poisons tels que soufre et eau dans la charge. Cependant ils conduisent à un gain d'octane considérablement plus faible que celui obtenu avec les catalyseurs Pt sur alumine chlorée. Cette étude bibliographique fait le point sur les différents mécanismes invoqués suivant le type de catalyseurs, les données cinétiques obtenues dans la littérature, et les différents procédés mis en oeuvre. Elle permet en particulier de mettre en évidence les contributions respectives des fonctions acides et métalliques pour l'isomérisation des alcanes de C4 à C7. En effet, il apparaît que suivant le type de catalyseurs utilisés, le mécanisme de la traction peut être bifonctionnel ou monofonctionnel acide. Dans certains cas, il pourrait même y avoir superposition des 2 mécanismes. L'étude de la longueur de la chaîne carbonée sur la réaction d'isomérisation ainsi que l'influence de la présence de composés cycliques, aromatiques ou non, ont également été envisagées. Il apparaît que la réactivité des alcanes augmente avec le nombre d'atomes de carbone et le degré de ramification de la molécule, et que la présence de composés aromatiques provoque une inhibition de la réaction d'isomérisation. Ce dernier point est très important pour l'industrie. There has been renewed interest in the isomerization of alkanes since legislation, with a view to environmental protection, has undertaken to eliminate lead alkyls from gasoline between now and 1992. Starting from low octane-number n-paraffins issuing from catalytic reforming or straight-run distillation, this catalytic reaction can be used to produce iso-paraffins having a much higher octane number. It is thermodynamically enhanced at low temperature and hence requires the use of catalysts developing high acidity. Two types of catalysts are currently used industrially, i. e. Pt base catalysts on chlorinated alumina and Pt base zeolitic catalysts on mordenite. These latter are considered to be the new generation of catalysts. They have the advantage of being easy to use and of being much less sensitive to the presence of poisons such as sulfur and water in the feedstock. However, they lead to a considerably lower improvement in octane than what is obtained with Pt catalysts on chlorinated alumina. This bibliographic study reviews the different mechanisms used according to the type of catalyst, the kinetic data obtained from the literature and the different processes used. In particular, it highlights the respective contributions of the acidic and metallic functions for the isomerization of C4 to C7 alkanes. Indeed, depending on the type of catalyst used, it appears the traction mechanism may be acidic bifunctional or monofunctional. In some cases two mechanisms might even be superposed. The study has also considered the effect of the length of this carbon chain on the isomerization reaction as well as the influence of the presence of ring compounds, whether aromatic or not. It seems that the reactivity of alkanes increases with the number of carbon atoms and with the degree of branching of the molecule, and that the presence of aromatic compounds inhibits the isomerization reaction. This last point is of great industrial importance.

  8. Méningiome intracrânien multiple: expérience du service de neurochirurgie CHU Avicenne Rabat - Salé, à propos de 4 cas et revue de la literature

    Science.gov (United States)

    Djoubairou, Ben Ousmanou; Karekezi, Claire; Moussé, Nabil; Doleagbenou, Agbéko Komlan; Gana, Rachid; El Abbadi, Najia; El Maaqili, Moulay Rachid

    2014-01-01

    Les méningiomes intracrâniennes multiples sont définies comme la présence d'au moins deux méningiomes sur des sites intracrâniens différents et ceci en absence de neurofibromatose. C'est une tumeur rare dont la prévalence varie entre 1-10%. Le but de notre travail était de décrire les caractéristiques cliniques, radiologiques, histologiques d'une série de 4 patients porteurs de méningiome multiple et en déduire les facteurs de risques de survenue de cette pathologie. Préciser la qualité d'exérèse chirurgicale de la lésion selon la classification de Simpson. Rapporter les suites postopératoires ainsi que le suivie à long termes des patients afin de préciser leur qualité de vie. Il s'agit d'une étude rétrospective portant sur 4 cas de Méningiomes intracrâniens multiples sur 174 patients opérés pour méningiome au CHU Avicenne entre Janvier 2000 à Décembre 2013. En s'aidant des données cliniques, imageries, chirurgicales, histologiques mentionnée dans le dossier médical de chaque patient. Notre série est constitué de 4 patients (3 femmes pour 1 homme), d'un âge allant de 42-50 ans (moyenne d’âge= 45,5 ans). Nous avons identifié 21 méningiomes (17 en sus tentoriel et 4 en sous tentoriel), aucun cas de décès ni d'infection postopératoire dans notre échantillon. Le pronostic reste bon malgré le nombre de lésion nécessitant parfois plusieurs interventions chirurgicales. PMID:25419331

  9. Les conséquences obstétricales de l'endométriose pendant la grossesse, l'accouchement et ses suitesA partir d'une revue de la littérature

    OpenAIRE

    Lauriol, Manon

    2017-01-01

    Background: endometriosis affects 10% of the general population. It’s a gynaecologic benign, estrogen-dependent disease of the woman of childbearing age. Endometriosis may have adverse effects on pregnancy.Objectif: to investigate obstetric complications of endometriosis during pregnancy, delivery and post-partum period.Methods: a literature review was conducted. 15 articles, published between 2005 and 2016, were selected from the PubMed database using the following keywords : endometriosis, ...

  10. Absence d'embryons ou embryons non transférables en ICSI : que dire aux patients ?: Une étude nancéenne et revue de la littérature

    OpenAIRE

    Tomaszewski , Cécile

    2009-01-01

    Non disponible / Not available; Depuis sa découverte, l'essor de la FIV avec micro-injection intra-cytoplasmique du spermatozoïde (FIV-ICSI) est incontestable. La FIV-ICSI a transformé la prise en charge des infertilités, notamment masculines. En outrepassant les échecs de fécondation en FIV classique, la FIV-ICSI a permis une meilleure compréhension des mécanismes de fécondation. Avec des taux de fécondation proches de 70% en ICSI, l'absence de replacement embryonnaire est peu habituelle et ...

  11. A Review of Approaches for the Design of Li-Ion BMS Estimation Functions Revue de différentes approches pour l’estimation de l’état de charge de batteries Li-ion

    Directory of Open Access Journals (Sweden)

    Di Domenico D.

    2013-02-01

    Full Text Available This paper aims at comparing different approaches for the estimation of the state of charge of lithium-ion batteries. The main advantages as well as the critical points of the considered techniques are analyzed, highlighting the impact of the cell model precision and complexity on the estimator performance. Among others, the electrical equivalent circuit based technique is selected for further development. The results of a complete procedure from the cell characterization to the online estimation are illustrated. The experimental tests based on the data collected on batteries testing facilities of IFP Energies nouvelles show that the proposed strategy allows a satisfying state of charge real time estimation. Cet article vise à comparer différentes approches pour l’estimation de l’état de charge pour les batteries Li-ion. Les principaux avantages ainsi que les points critiques des différentes techniques sont analysés, en soulignant l’impact de la complexité et de la précision du modèle sur les performances de l’estimateur. La procédure complète, allant de la caractérisation de la cellule jusqu’à l’estimation en ligne de l’état de charge, est présentée pour la modélisation par circuit électrique équivalent. Les tests expérimentaux sur la base des données acquises au laboratoire batteries d’IFP Energies nouvelles montrent que cette stratégie permet d’obtenir un estimateur en temps réel de l’état de charge présentant de bonnes performances.

  12. Le dermatofibrosarcome de Darier et Ferrand, une tumeur cutanée particulière: à propos de 32 cas et revue de la littérature

    Science.gov (United States)

    Elamrani, Driss; Droussi, Hatim; Boukind, Samira; Elatiqi, Keltoum; Dlimi, Meriem; Benchamkha, Yassine; Ettalbi, Saloua

    2014-01-01

    Le dermatofibrosarcome (DFS) est une tumeur fibreuse de la peau, de croissance lente, à très haut risque de récidive locale, mais à potentiel métastatique faible. A partir d'une étude rétrospective étalée sur une période de 5 ans (décembre 2008 - décembre 2013), nous avons analysé les caractéristiques épidémiologiques et cliniques, le délai de diagnostic, le type de thérapeutique et le devenir de 32 patients présentant des tumeurs de Darier et Ferrand histologiquement prouvées. Parmi les 32 patients, 10 se sont présentés initialement au service pour une récidive tumorale. Une discrète prédominance masculine a été notée. Les DFS touchent préférentiellement l'adulte jeune. Le délai diagnostique observé est en moyenne de 4 ans. Le tronc est la localisation préférentielle (60%), suivi par les extrémités proximales (30%). Les 32 patients ont été traités par exérèse chirurgicale avec une marge de 5cm en surface, emportant en profondeur une barrière anatomique saine. La couverture de la perte de substance (PDS) a été réalisée après confirmation anatomopathologique du caractère carcinologique de l'exérèse, et a fait appel à différents moyens allant de la greffe cutanée aux lambeaux musculo –cutanés libres. L’évolution a été marquée par la survenue d'une récidive tumorale chez 8 patients (3 cas parmi les tumeurs vues en première intention et 5 cas parmi les tumeurs vues en récidive) et les résultats ont été jugés satisfaisants sur le plan esthétique et fonctionnel. Le DFS de Darier et Ferrand est une tumeur dont le pronostic et le risque évolutif sont principalement liés au délai diagnostic et la qualité de la première exérèse. Le diagnostic tardif, rend difficile la chirurgie d'exérèse et de reconstruction Les possibilités de guérison en cas de chirurgie primaire bien conduite sont significativement supérieures à celles d'une chirurgie de rattrapage. L'amélioration du pronostic passe par une prise en charge multidisciplinaire précoce et codifiée d'où l'intérêt de la sensibilisation et de l'information du médecin généraliste pour le diagnostic précoce et l'orientation correcte de ces malades vers des centres spécialisés. PMID:25821539

  13. Review of avoidance reactions of tropical fish to a survey vessel = Revue des réactions d'évitement des poissons tropicaux au passage d'un navire de prospection

    OpenAIRE

    Gerlotto, François; Fréon, Pierre

    1990-01-01

    Les réactions des poissons pélagiques tropicaux au passage d'un navire de recherches sont décrites en fonction de l'impact qu'elles peuvent avoir sur les résultats des prospections acoustiques. Deux composantes principales sont décrites : déplacement du poisson latéralement ou en plongée, et situation dans les trois dimensions. Une description empirique des influences des divers stimuli d'un navire sur les poissons est proposée : les trois stimuli pris en compte sont le bruit, l'éclairement d...

  14. 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

  15. 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

  16. 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...

  17. 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...

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    Bryant Susan V

    2009-01-01

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

  20. 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, ...

  1. 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 ...

  2. 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?

  3. 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 ...

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. Les Archives de l’anthropologie criminelle

    Directory of Open Access Journals (Sweden)

    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.....

  9. Senescence gives insights into the morphogenetic evolution of anamniotes

    Directory of Open Access Journals (Sweden)

    Éric Villiard

    2017-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Villiard Éric

    2007-09-01

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

  11. 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

  12. 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

  13. Fiche Pratique: Pour en finir avec les histoires de modes; Faire parler les bruits; FDM Frequence Plus: La revue de presse; Construire l'absurde (Practical Ideas: Finishing the Modal Story; Making Noises Speak; FDM Frequence Plus: The Press Review; Constructing the Absurd).

    Science.gov (United States)

    Courally, Sylvie; And Others

    1993-01-01

    Four ideas for French language instruction are described, including an exercise on modals, an activity focusing on the use of noises for expression, a listening comprehension exercise, and a lesson on humorous possibilities in language using material from the theater of the absurd. (MSE)

  14. The upper to uppermost Cenomanian oceanic anoxic event: a review and an interpretation involving a seawater stratification by the CO{sub 2} of mantle origin; L`evenement oceanique anoxique du Cenomanien superieur-terminal: une revue et une interpretation mettant en jeu une stratification des eaux marines par le CO{sub 2} mantellique

    Energy Technology Data Exchange (ETDEWEB)

    Busson, G; Cornee, A [Laboratoire de Geologie du Museum, 75 - Paris (France)

    1997-12-31

    Oil exploration data have revealed the exceptional richness of the middle Cretaceous in source rocks worldwide. Oceanic drillings have shown the existence of oceanic anoxic events (OAE) well defined in time. This study analyzes the OAE 2 event dated from the upper Cenomanian-lower Turonian. This event has been recognized in numerous sites from the northern, central and southern Atlantic and punctually in the Pacific and Indian oceans. It occurs in both numerous deep oceanic sites and orogenic zones, and stable platforms covered by epeiric seas. It coincides with a sea level rise which is one of the most sudden and highest in Phanerozoic times and it stands out as a remarkable episode of massive faunal extinction which led to the deposition of organic matter of marine planktonic dominant nature. The first part of the study recalls the previous interpretations of this event (oceanic stratification, euxinic conditions, spreading of an oxygen minimum zone, greenhouse climate effect, sluggish atmospheric and oceanic circulations, high planktonic production, great oceanic overturns, marginal or general upwellings, marine transgressions on epeiric areas etc..). The second part gives the basis of the new hypothesis: connection between separated seas due to the transgression, retreat of evaporite facies, high sea-floor spreading rates, intense volcanic activity and high mantle outgassing with huge CO{sub 2} influxes. The last part describes the proposed interpretation: CO{sub 2} accumulation in deep and intermediate waters and sea overflows on marginal and continental areas which led to a rise of the CO{sub 2}-rich hypolimnion. (J.S.) 236 refs.

  15. Reduction of the greenhouse effect by geological mineral in-situ sequestration of CO{sub 2} in basic rocks: bibliographic synthesis and possibilities in France. Final report; Reduction de l'effet de serre par sequestration geologique minerale in-situ de CO{sub 2} au sein de roches basiques: synthese bibliographique et revue des potentialites en France. Rapport final

    Energy Technology Data Exchange (ETDEWEB)

    Marechal, J.C.; Lachassagne, P

    2004-07-01

    The report constitutes a first bibliographic study defining the environments the most adapted to the geological mineral in-situ sequestration of CO{sub 2}. For each environment the lithology and the rocks permeability and porosity are analyzed. Thus the possible rocks and deposits in France are presented. (A.L.B.)

  16. Influence du taux d’acide alpha-linolénique de l’aliment sur la teneur en oméga-3 et les caractéristiques hédoniques de la viande de lapin. Revue bibliographique

    Directory of Open Access Journals (Sweden)

    Teillet Benoît

    2013-01-01

    Full Text Available Several publications are dealing with the influence of the omega 3 level in the feed, more particularly the alpha-linolenic acid level, on the rabbit meat level in this fatty acid, but only few of them deal with the use of the flaxseed. This review is a synthesis of the effects of the level of alpha-linolenic acid brought by the flaxseed on the omega 3 level of the rabbit meat. It shows a direct connection between the alpha-linolenic acid level in the feed and the omega 3 content of the rabbit meat. Besides, this enrichment decreases the saturated fatty acids level, the omega 6 level and consequently the omega 6/omega 3 ratio below 4. In consequence, the contribution of around 0.65% of alpha-linolenic acid in the feed by incorporation of flaxseed in the feed allows to bring in average 967 mg of omega 3 for 100 g of back or 459 mg for 100 kcal and 1004 mg of omega 3 for 100 g of shoulder or 483 mg for 100 kcal and consequently to claim the allegation “rich in omega 3”. This enrichment doesn’t modify the hedonic characteristics of the rabbit meat.

  17. Programme of air surveillance and health 9 towns. Synthesis review. Surveillance of effects on the health in relation with air pollution in urban area. Phase 2; Programme de surveillance Air et Sante 9 villes. Revue de synthese. Surveillance des effets sur la sante lies a la pollution atmospherique en milieu urbain. Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-06-15

    The InVS published its first results on the Nine-City Air and Health Surveillance Programme (PSAS-9) in March 1999. This phase I pointed out that it was possible for various specialists in the field of air pollution and health to gather around a common set of problems. They also found a link between the daily variations of all the urban air pollution indicators and the total, cardio-vascular and respiratory mortality which, based on French data, contributed to strengthen scientific knowledge in this field. Today's report presents the results of phase Il of the PSAS-9 programme which essentially aimed at assessing the short-term exposure-risk relationships between pollution indicators and hospital admission indicators. This second phase also allowed to confirm the results of phase I on the short-term effect of air pollution on mortality thanks to longer periods of study. Exploratory analysis using new indicators and sensitivity analysis on the pertinence of results were also conducted. Finally, methodological tools were developed in order to optimise data collection and statistical modelization. All these results enabled the quantification of the short-term health impact of air pollution on the PSAS-9 cities. PSAS-9 is now an ongoing epidemiological surveillance programme on the effects of urban air pollution on health, providing information tools to decision-makers and the general population. (author)

  18. The upper to uppermost Cenomanian oceanic anoxic event: a review and an interpretation involving a seawater stratification by the CO{sub 2} of mantle origin; L`evenement oceanique anoxique du Cenomanien superieur-terminal: une revue et une interpretation mettant en jeu une stratification des eaux marines par le CO{sub 2} mantellique

    Energy Technology Data Exchange (ETDEWEB)

    Busson, G.; Cornee, A. [Laboratoire de Geologie du Museum, 75 - Paris (France)

    1996-12-31

    Oil exploration data have revealed the exceptional richness of the middle Cretaceous in source rocks worldwide. Oceanic drillings have shown the existence of oceanic anoxic events (OAE) well defined in time. This study analyzes the OAE 2 event dated from the upper Cenomanian-lower Turonian. This event has been recognized in numerous sites from the northern, central and southern Atlantic and punctually in the Pacific and Indian oceans. It occurs in both numerous deep oceanic sites and orogenic zones, and stable platforms covered by epeiric seas. It coincides with a sea level rise which is one of the most sudden and highest in Phanerozoic times and it stands out as a remarkable episode of massive faunal extinction which led to the deposition of organic matter of marine planktonic dominant nature. The first part of the study recalls the previous interpretations of this event (oceanic stratification, euxinic conditions, spreading of an oxygen minimum zone, greenhouse climate effect, sluggish atmospheric and oceanic circulations, high planktonic production, great oceanic overturns, marginal or general upwellings, marine transgressions on epeiric areas etc..). The second part gives the basis of the new hypothesis: connection between separated seas due to the transgression, retreat of evaporite facies, high sea-floor spreading rates, intense volcanic activity and high mantle outgassing with huge CO{sub 2} influxes. The last part describes the proposed interpretation: CO{sub 2} accumulation in deep and intermediate waters and sea overflows on marginal and continental areas which led to a rise of the CO{sub 2}-rich hypolimnion. (J.S.) 236 refs.

  19. Exclusive radiotherapy and concurrent endocrine therapy for the management of elderly breast cancer patients: Case study and review of hypo-fractionated schemes; Hormonoradiotherapie exclusive dans la prise en charge du cancer du sein de la personne agee: cas clinique et revue de la litterature des schemas hypofractionnes

    Energy Technology Data Exchange (ETDEWEB)

    Auberdiac, P.; Cartier, L.; Malkoun, N.; Chauleur, C.; De Laroche, G.; Magne, N. [Departement de radiotherapie, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, BP 60008, 42271 Saint-Priest-en-Jarez cedex (France); Chargari, C. [Service d' oncologie radiotherapie, hopital d' instruction des armees du Val-de-Grace, 74, boulevard de Port-Royal, 75230 Paris cedex 5 (France); Melis, A.; Jacquin, J.P. [Departement d' oncologie medicale, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, BP 60008, 42271 Saint-Priest-en-Jarez cedex (France)

    2011-12-15

    Normo-fractionated radiotherapy is standard for adjuvant management of patients treated with breast conservative surgery for breast cancer. However, many elderly patients are not eligible to such strategy, either because of concurrent diseases, or because the tumor is inoperable. Several protocols of exclusive radiotherapy have been reported in the literature, frequently using hypo-fractionated radiotherapy and endocrine therapy. We report a case of a patient treated with exclusive endocrine and radiotherapy and address the state of the art on hypo-fractionated schemes for the management of elderly breast cancer patients. While hypo-fractionated radiotherapy does not compromise the oncologic or cosmetic outcome, there is no prospective data that assesses the place of radiotherapy for the exclusive treatment of elderly patients. This strategy should be further assessed in clinical randomized trial. (authors)

  20. Accident vasculaire cérébral hémorragique du tronc cérébral suite à une éclampsie du post partum: à propos d’un cas et revue de la littérature

    OpenAIRE

    Ennaqui, Khadija; Makayssi, Assia; Boufettal, Houssine; Samouh, Naima

    2017-01-01

    Les accidents vasculaires cérébraux sont des accidents rares mais graves durant la grossesse et le post-partum, ils sont responsable d'une mortalité et d'une morbidité élevée, la pré éclampsie, l'éclampsie et les accidents vasculaires cérébraux sont significativement liés. Le dysfonctionnement endothélial, l'altération de l'autorégulation cérébrale, et l'hypertension sévère sont, probablement, la cause de nombreux accidents vasculaires cérébraux chez la femme enceinte et durant la période du ...

  1. Science review of the Beaufort Institute of Oceanography, the Halifax Fisheries Research Laboratory, and the St. Andrews Biological Station, 1990-91. Revue des sciences de l'Institut oceanographique de Bedford, du Laboratoire de recherche halieutique de Halifax, et de la Station biologique de St. Andrews, 1990-91

    Energy Technology Data Exchange (ETDEWEB)

    Smith, T E; Cook, J [eds.

    1992-01-01

    A review is presented of the research and survey programs being undertaken in 1990-91 at the Bedford Institute of Oceanography, the Halifax Fisheries Research Laboratory, and the St. Andrews Biological Station (all in Nova Scotia). The broad objectives of these programs are to perform applied research leading to the provision of advice on the management of marine and freshwater environments, including fisheries and offshore hydrocarbon resources; to perform targeted basic research in accordance with the mandates of Canada's Department of Fisheries and Oceans, Environment Canada, and Energy, Mines and Resources; to perform surveys and cartographic work; and to respond to major marine environmental emergencies. The research and survey work encompasses the fields of marine geology and geophysics, physical oceanography, marine chemistry, biological oceanography, fisheries research, seabird research, and navigational surveys and cartography. Topics of specific projects reviewed include marine pollution detection, phytoplankton profiling, seal populations, ocean mapping, geographic information systems, fish and invertebrate nutrition, shellfish culture, lobster habitat ecology, physics and biology of the Georges Bank frontal system, water-level instrumentation, data acquisition techniques, sea ice monitoring, salmon management, nearshore sedimentary processes, and oil/gas distribution in offshore basins. Separate abstracts have been prepared for three project reports from this review.

  2. Possibilités de prise en compte des phénomènes de transferts internes aux grains lors de la modélisation du séchage en lit fixe du maïs : revue

    Directory of Open Access Journals (Sweden)

    Janas, S.

    2012-01-01

    Full Text Available Opportunity to take the grain internal transfers into account in the context of the modelization of the fixed bed drying of corn: a review. The fixed-bed drying is a preservation technique widely used in food industries. Its control and optimization require to know the distributions of temperature and water content in the bed depending on the operating conditions used. This information is obtained through modeling of the heat and mass transfers involved. Models of fixed bed drying have two components. The first one is the model at the product level. This model can predict how temperature and water content of the product change at each point of the bed according to local conditions of temperature and humidity. The second component is the model for the entire bed, which describes how heat and water are conveyed by the drying air through the bed. In this literature review, the main models of fixed bed drying are presented, with particular emphasis on the models used for corn drying. In this review, these two components are presented separately. The goal is to idendify the advantages and disadvantages of each approach, and opportunities for future research in this field.

  3. Epstein-Barr virus associated central nervous system leiomyosarcoma occurring after renal transplantation: case report and review of the literature; Leiomyosarcome primitif du systeme nerveux central associe au virus d'Epstein-Barr (EBV) et survenu apres transplantation renale: a propos d'un cas et revue de la litterature

    Energy Technology Data Exchange (ETDEWEB)

    Tahri, A.; Noel, G.; Feuvret, L.; Jauffret, E.; Brun, B.; Mazeron, J.J.; Baillet, F. [Centre des Tumeurs, Groupe Hospitalier Universitaire Pitie-Salpetriere, 75 - Paris (France); Feuvret, L. [Centre de Protontherapie d' Orsay, 91 (France); Figuerella-Branger, D. [Hopital de la Timone, Service d' Anatomopathologie, 13 - Marseille (France); Goncalves, A. [Institut Paoli-Calmettes, Service d' Oncologie Medicale, 13 - Marseille (France)

    2003-10-01

    Central nervous system leiomyosarcomas are extremely rare, however, they became more frequent among immuno-deficient patients, either in a patients infected with human immunodeficiency virus (HIV), or after organ transplantation. The data of the literature indicate that the infection by Epstein-Barr virus (EBV) plays a causal role in the development of these tumours but its precise role in the onco-genesis remains unresolved. We report a new case of EBV associated leiomyosarcoma of the left cavernous sinus occurring after renal transplantation. The epidemiological, clinical, pathological and therapeutic characteristics of these tumours are discussed. (authors)

  4. Les facteurs influançant les compétences des infirmiers et des infirmières en matière de soins spirituels dans un contexte de soins somatiques: une revue de littérature étoffée

    OpenAIRE

    Bédaton, Stéphanie; Hayoz, Marine; Schenevey Perroulaz, Eliane

    2013-01-01

    Les facteurs influençant les compétences des infirmiers et des infirmières en matière de soins spirituels dans un contexte de soins somatiques. Objectif : identifier la place de la spiritualité dans les soins et identifier les facteurs aidants et les obstacles qui influencent les compétences des infirmières dans le domaine de la spiritualité dans un contexte de soins somatiques.

  5. 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

  6. 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.

  7. 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.

  8. 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).

  9. A lunguistica pour ses quarante ans

    Directory of Open Access Journals (Sweden)

    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.

  10. 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

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

    African Journals Online (AJOL)

    Revue d'Information Scientifique et Technique. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 7, No 1 (1997) >. Log in or Register to get access to full text downloads.

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

    African Journals Online (AJOL)

    Revue de Médecine et de Pharmacie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 1 (2011) >. Log in or Register to get access to full text downloads.

  13. 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.

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

    African Journals Online (AJOL)

    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.

  15. Ambulance Services of Lagos State, Nigeria

    African Journals Online (AJOL)

    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.

  16. 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 ...

  17. 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.

  18. 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

  19. qualite des rejets industriels textiles et ses repercussions

    African Journals Online (AJOL)

    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.

  20. Crisis, Capital, Compromise: Mining and Empowerment in Zimbabwe

    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 1 (2008) >. Log in or Register to get access to full text downloads.

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

    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 2 (1999) >. Log in or Register to get access to full text downloads.

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

    African Journals Online (AJOL)

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

  3. Ju/'hoansi Adaptations to a Cash Economy | McCall | 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 4, No 1 (2000) >. Log in or Register to get access to full text downloads.

  4. Annonce du diagnostic et rupture biographique | Francine | 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 14, No 2 (2010) >. Log in or Register to get access to full text downloads.

  5. Adolescent Sexuality and Culture: South African Mothers` Perspective

    African Journals Online (AJOL)

    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.

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

    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 2 (2002) >. Log in or Register to get access to full text downloads.

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

    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 2 (2013) >. Log in or Register to get access to full text downloads.

  8. Postcolonial debates in Germany – An Overview | Pape | 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 21, No 2 (2017) >. Log in or Register to get access to full text downloads.

  9. 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.

  10. 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

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

    Science.gov (United States)

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

    2015-06-02

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

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

    NARCIS (Netherlands)

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

    1982-01-01

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

  13. The MHC molecules of nonmammalian vertebrates

    DEFF Research Database (Denmark)

    Kaufman, J; Skjoedt, K; Salomonsen, J

    1990-01-01

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

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

    Science.gov (United States)

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

    2018-01-12

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

  15. Visualisation of animal anatomy using MRI and CT

    DEFF Research Database (Denmark)

    Lauridsen, Henrik; Hansen, Kasper; Pedersen, Michael

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

  16. Development and regulation of response properties in spinal cord motoneurons

    DEFF Research Database (Denmark)

    Perrier, J F; Hounsgaard, J

    2000-01-01

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

  17. Steady-State Two-Phase Flow in Porous Media: Review of Progress in the Development of the DeProF Theory Bridging Pore to Statistical Thermodynamics Scales Écoulement diphasique stationnaire en milieu poreux : revue des avancées sur les développements de la théorie DeProF reliant l’échelle du pore à l’échelle de la thermodynamique

    Directory of Open Access Journals (Sweden)

    Valavanides M.S.

    2012-11-01

    Full Text Available Scope of present article is to present the research efforts (implementing experimental study, theoretical analysis and modeling taken towards the development of a complete theory for steady-state concurrent two-phase flow in porous media (the DeProF theory. The current state of progress is outlined and open problems are addressed. First attempts are traced back in the 1980s with the analysis, description and modeling of phenomena governing two-phase flow in pore scale. Appropriate simulators extending over hundreds and/or thousands of pores (network scale were developed in the following decade (1990s; in parallel, extensive experimental research work identified three prototype/elementary flows comprising the average macroscopic flow, namely connected-oil pathway flow, ganglion dynamics and drop traffic flow and mapped their relative contribution to the macroscopic flow in terms of the process parameters. Efforts to provide a consistent physical rationale to explain the experimental observations, i.e. the map of prototype flow regimes, laid the grounds for developing the DeProF (Decomposition in Prototype Flows theory. Amongst the main results/features of the DeProF theory was the identification of the actual operational and system parameters of the process and the introduction – according to ergodicity principles – of the domain of physically admissible internal flow arrangements of the average macroscopic flow. Use of the respective mechanistic model as a simulation tool (in the 2000s revealed many characteristic properties of the sought process. Important is the existence of optimum operating conditions in the form of a smooth and continuous locus in the domain of the process operational parameters. This characteristic remained in latency within the relative permeability curves, until recently unveiled by the DeProF theory. Research efforts continue in the present (2010s by elaborating appropriate physical considerations based on statistical thermodynamics and the introduction of the aSaPP (as Spontaneous as Physically Possible concept that corroborates the correlation of the process efficiency to the multiplicity of the internal flow arrangements. Cet article présente les efforts de recherche effectués au travers d’une étude expérimentale, d’une analyse théorique et d’une modélisation, afin de développer une théorie complète pour les écoulements diphasiques stationnaires en milieu poreux (théorie DeProF. Les dernières avancées sont mises en avant et les problématiques restées ouvertes sont exposées. Les premières tentatives dans ce domaine remontent aux années 80, avec l’analyse, la description et la modélisation des phénomènes régissant les écoulements diphasiques à l’échelle du pore. Des simulateurs appropriés à l’échelle de centaines et/ou de milliers de pores (échelle du réseau ont été développés dans les années 90. Parallèlement, des recherches expérimentales approfondies ont permis d’identifier trois mécanismes d’écoulements élémentaires pour représenter l’écoulement moyen à l’échelle macroscopique : l’écoulement à travers la fraction d’huile connectée, la dynamique des globules d’huile et l’écoulement par circulation de gouttes et d’établir leur contribution relative dans l’écoulement macroscopique. Les efforts faits pour apporter une interprétation physique cohérente aux observations expérimentales, c’est-à-dire pour réaliser la cartographie des régimes d’écoulement, ont jeté les bases de ce qui est devenu la théorie de la décomposition en écoulements élémentaires (DeProF. Parmi les principaux résultats/ caractéristiques de la théorie DeProF, on compte l’identification des paramètres du système et la définition, dans le respect des principes de l’ergodicité, du domaine des différentes combinaisons d’écoulement physiquement admissibles pouvant représenter l’écoulement macroscopique moyen. L’utilisation, comme outil de simulation, de ce modèle mécanistique (années 2000 a permis de découvrir de nombreuses propriétés caractéristiques du processus étudié. On notera l’importance de l’existence, dans le domaine des paramètres de fonctionnement du processus, d’une fenêtre d’intérêt optimale sous la forme d’une surface lisse et continue. La justification de l’existence de conditions opératoires optimales pour le transport de l’huile, dissimulées dans l’utilisation des courbes de perméabilité relatives, a récemment été apportée par la théorie DeProF. Les efforts de recherche se poursuivent actuellement (années 2010 pour élaborer une approche physique s’appuyant sur la thermodynamique statistique et sur le concept aSaPP “aussi spontané que physiquement possible” (as Spontaneous as Physically Possible, qui confirme la corrélation entre l’efficacité du transport et la multiplicité des combinaisons d’écoulements élémentaires.

  18. Presence of human papillomavirus-18 and Epstein-Barr virus in a squamous cell carcinoma of the tongue in a 20-year-old patient. Case report and review of the current literature; Presence dans un cancer epidermoide de la langue d'un papillomavirus HPV-18 et d'un virus d'Epstein-Barr chez une patiente de 20 ans. Case-report et revue de la litterature

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, R.M.; Pradier, O.; Christiansen, H.; Schmidberger, H. [Georg-August Gottingen Universitat, Dept. of Radiotherapy (Germany); Fuzesi, L. [Georg-August Gottingen Universitat, Dept. of Pathology (Germany)

    2004-08-01

    We report on a squamous cell carcinoma of the tongue in a 20-year-old woman with co-infection of the tumor with human papilloma virus type 18 and Epstein-Barr virus.To our knowledge, this is the first case of co-infection in carcinoma of the tongue to be reported. We review the present data and theories concerning viral onco-genesis of oral carcinomas. (author)

  19. Joint scientific publication by the INSERM and IRSN concerning child leukaemia about French nuclear power stations on the Internet site of the 'International Journal of Cancer' the 4 January 2012; Publication scientifique conjointe Inserm et IRSN concernant les leucemies chez l'enfant autour des centrales nucleaires francaises sur le site internet de la revue 'International Journal of Cancer' le 4 Janvier 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-01-12

    This document describes the cooperation between the INSERM and IRSN in the field of child leukaemia about nuclear power stations, and presents the published study: context and objectives, methodology (epidemiological data, geographical data), and obtained results (risks and comparison with a German study)

  20. 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://...

  1. 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...

  2. 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...

  3. 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...

  4. Éditorial

    Directory of Open Access Journals (Sweden)

    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 ...

  5. 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...

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

    Directory of Open Access Journals (Sweden)

    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...

  7. 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...

  8. 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...

  9. 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 ...

  10. 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...

  11. 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

  12. 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 ...

  13. 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 ...

  14. 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...

  15. 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...

  16. 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 ...

  17. 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.

  18. 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...

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

    Directory of Open Access Journals (Sweden)

    An Van Hecke

    2014-06-01

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

  20. 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.