Does Müller cell differentiation occur prior to the emergence of synapses in embryonic turtle retina?

Müller cells are the main glial cells in the retina, and are related to plexiform layer activity. Recent studies have demonstrated that Müller cells are involved in the synaptic conservation, plasticity, development and metabolism of glutamate. During turtle retinal development, layers, cells and synapses appear at different times. The aim of this research is to study the emergence of Müller cells during embryonic development and their relationship with the synaptogenesis. The authors used retinas from Trachemys scripta elegans embryos at stages S14, 18, 20, 23, and 26. Some retinas were processed with immunocytochemistry in order to detect the presence of glutamine synthetase in Müller cells, which was used as a marker of these cells. Other retinas from the same stages were processed for ultrastructural studies. Samples were observed in confocal and transmission electron microscopes, respectively. The present results show that glutamine synthetase expression in Müller cells occurs at S18, before the emergence of the retinal layers and the early synapses.

Evidence for endothermic ancestors of crocodiles at the stem of archosaur evolution

Physiological, anatomical, and developmental features of the crocodilian heart support the paleontological evidence that the ancestors of living crocodilians were active and endothermic, but the lineage reverted to ectothermy when it invaded the aquatic, ambush predator niche. In endotherms, there is a functional nexus between high metabolic rates, high blood flow rates, and complete separation of high systemic blood pressure from low pulmonary blood pressure in a four-chambered heart. Ectotherms generally lack all of these characteristics, but crocodilians retain a four-chambered heart. However, crocodilians have a neurally controlled, pulmonary bypass shunt that is functional in diving. Shunting occurs outside of the heart and involves the left aortic arch that originates from the right ventricle, the foramen of Panizza between the left and right aortic arches, and the cog-tooth valve at the base of the pulmonary artery. Developmental studies show that all of these uniquely crocodilian features are secondarily derived, indicating a shift from the complete separation of blood flow of endotherms to the controlled shunting of ectotherms. We present other evidence for endothermy in stem archosaurs and suggest that some dinosaurs may have inherited the trait.

Sox8 is expressed at similar levels in gonads of both sexes during the sex determining period in turtles

A critical gene involved in mammalian sex determination and differentiation is the Sty-related gene Sox9. In reptiles, Sox9 resembles that of mammals in both structure and expression pattern in the developing gonad, but a causal role in male sex determination has not been established. A closely related gene, Sox8, is conserved in human, mouse, and trout and is expressed in developing testes and not developing ovaries in mouse. In this study, we tested the possibility of Sox8 being important for sex determination or sex differentiation in the red-eared slider turtle Trachemys scripta, in which sex is determined by egg incubation temperature between stages 15 and 20. We cloned partial turtle Sox8 and anti-Mullerian hormone (Amh) cDNAs, and analyzed the expression patterns of these genes in developing gonads by reverse transcriptase-polymerase chain reaction and whole-mount in situ hybridization. While Amh is expressed more strongly in males than in females at stage 17, Sox8 is expressed at similar levels in males and females throughout the sex-determining period. These observations suggest that differential transcription of Sill is not responsible for regulation of Amh, nor responsible for sex determination in turtle. (C) 2004 Wiley-Liss, Inc.

Comércio de répteis exóticos: as suas implicações para a conservação da natureza

O comércio de espécies selvagens tem crescido bastante ao longo das últimas décadas. Atualmente é considerado o quarto maior tráfico ilegal no mundo, logo seguido da transação de drogas, de armas e de humanos. Estima-se que o comércio de espécies selvagens pode ultrapassar os 12 milhões de euros por ano na UE. Abrange tanto as plantas como os animais vivos; mas, nestes últimos, incluem-se também os seus derivados, tais como sejam as peles, os ossos, alimento, entre outros. O uso das espécies selvagens é bastante vastos, as espécies são utilizadas para alimentação, uso medicinal, investigação científica, comércio de peles, alimentação e o mais comum é para animais de estimação. As espécies exóticas muitas vezes tornam-se espécies exóticas invasoras, começam a ser um perigo para a biodiversidade e para as espécies nativas. O processo de invasão apresenta-se por quatro fases: dispersão ou transporte, estabelecimento, naturalização e por fim dispersão geográfica e/ou invasão. Vários são os mecanismos para combater as espécies exóticas invasoras, sendo que o mecanismo mais radical a erradicação de espécimes. Em Lisboa, estão descritas três espécies exóticas invasoras: a tartaruga da Florida Trachemys scripta, a tartaruga de Nelson Pseudemys nelsoni e a tartaruga corcunda do Mississipi Graptemys pseudogeographica; ABSTRACT: The wildlife trade is growing fast over the last decades. It is now considered the fourth largest illegal trade in the world, followed by the drugs, weapons and humans. It is estimated that trade with species can exceed 12 million € per year in the EU. This trade comprises plants or live animals; but also is derivatives, such as skins, bones, food, and others. The use of wildlife is diverse, can be for food, medical, scientific research, trade of skins, but the most common is for pets. Alien species can become invasive alien species and so they become a threat to biodiversity and for native species. The process of invasion has four phases: dispersion or transport, establishment, naturalization and geographic dispersion and/or invasion. There are several mechanisms to combat such invasive alien species: the most radical mechanism is eradication of specimens. In Lisbon, are described three invasive alien species: the red-eared slider turtle Trachemys Florida, the Florida red-bellied turtle Pseudemys nelsoni and the false map turtle Graptemys psedogeographica.

Thesaurus litteraturae mycologicae et lichenologicae ratione habita praecipue omnium quae adhuc scripta sunt de mycologia applicata quem congesserunt G. Lindau et P. Sydow.

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Thesaurus litteraturae mycologicae et lichenologicae ratione habita praecipue omnium quae adhuc scripta sunt de mycologia applicata quem congesserunt G. Lindau et P. Sydow.

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1.° Opus cujus titulus est : quadripartitum numerorum, sive de arithmetica libri quatuor ; authore Magistro Joanne de Muris, Canonico Parisiensi. — 2.° Ejusdem epistola versibus scripta ad Philippum de Vitriaco, Episcopum Meldensem, de numerorum fractionibus.

Colbertinus

1.° Valerii Catulli, Veronensis, epigrammatum variorumque carminum liber. — 2.° Priapeia. — 3.° Galli, Forliviensis, carmen de senectute. — 3.° Probae Falconiae centones Virgiliani. — 4.° Arati phaenomena, graecè, manu Joannis Rosi, Cretensis, anno 1488. scripta.

Puteanus

Ratherii,... Opera omnia, juxta editionem Veronensem, anno 1765, curantibus Petro et Hieronymo fratribus Balleriniis,... datam, ad prelum revocata, Accedunt Liutprandi Cremonensis necnon Folquini S. Bertini monachi, Gunzonis diaconi Novariensis, Richardi abbatis Floriacensis, Adalberti Metensis Scholastici Scripta vel scriptorum fragmenta quae exstant. Accurante J.-P. Migne,...

Comprend : Scripta quae extant

Scripta varia

Ordonnances et pièces diverses relatives au gouvernement du royaume, aux rapports de Philippe le Bel avec le Saint Siège, au grand schisme etc. F. 1, De origine singularum gentium,F. 104v, Notes sur divers événements du règne de Charles VI,F. 120, Glosa abbatis Joachim super libro Cirilli, F. 131v, Visio Johannis heremite, F. 137, Pavo, F. 140, Vincentii Ferrarii epistola de Antichristo, F. 167, Ordre de procéder en la ville et viconté de Paris, F. 194, Stilus curie parlamenti, editus per G. de Brolio, F. 255, Divers arrêts du Parlement,

Scripta diversa super scientiam mathematicam et physicam

1.° Practica geometriae, ordinata per Magistrum Dominicum de Mastinario Clanaxio. — 2.° Tractatus brevis et utilis de proportionalitate motuum coelestium : authore Nicolao Oresme, Normanno. — 3.° Anonymi fragmentum de quadratura circuli. — 4.° Euclidis liber de speculis : initium desideratur. — 5.° Ejusdem perspectiva. — 6.° Anonymi liber de crepusculis. — 7.° Liber Jordanis de triangulis. — 8.° Ejusdem liber de ponderibus. — 9.° Libri duo de musica. — 10.° Joannis de Lineriis canones primi mobilis. — 11.° Canones minutiarum, sive fractionum arithmetica. — 12.° Magistri Leonis, Hebraei, tractatus de harmonicis numeris. — 13.° Ars novae musicae. — 14.° Ars cujusvis compositionis de motetis, compilata à Philippo de Vitry, Magistro in musica. — 15.° Magister Leo, Judaeus, Prognosticatio super conjunctione Saturni, Jovis et Martis. — 16.° Johannes de Muris Prognosticatio super eodem argumento. — 17.° Firminus de Bellavalle Prognosticatio de eodem argumento. — 18.° Planisphaerium Nicolai Jude. — 19.° Tractatus brevis de compositione et usu cylindri. — 20.° Epistola Petri Peregrini de Maricourt ad Sigermum de Foucaucourt, de magnete : ibi reperias delineationem veteris pyxidis nauticae. — 21.° Compositio tabulae quae saphea dicitur, sive astrolabium Arzachelis. — 22.° Tractatus de optica, dioptrica et catoptrica. — 23.° Canones astrolabii. — 24.° Variae receptae medicinales. — 25.° Plantarum usitatarum nomina, ordine alphabetico disposita. — 26.° Anonymi fragmentum de visione. — 27.° Propositiones notabiles octo librorum Aristotelis de physica auscultatione. — 28.° Dicta super libros de coelo et mundo Aristotelis. Decimo quarto saeculo videtur exaratus.

Scripta diversa super rhetoricam et grammaticam. Carmina.

Catalogus codicum manuscriptorum Bibliothecae regiae. Pars tertia. Tomus tertius (-quartus), Parisiis : ex typographia regia, 1744 : "1.° Anonymi grammatica, in qua de verborum conjugatione. — 2.° Bedae, Presbyteri, de arte metrica liber ad Gutbertum. — 3.° Ejusdem de schematibus et tropis liber ad eundem. — 4.° Claudii Marii Victoris Massiliensis, de Genesi libri tres : carmine heroïco ; porro hi libri iidem prorsus cum illis qui commentariorum in Genesim in editis titulum prae se ferunt : praemittitur Victoris precatio ad Deum, oratione soluta. — 5.° Sancti Paulini carmina ad Ausonium. — 6.° Ausonii, qui in hoc codice sanctus appellatur, carmina ad Paulinum. — 7.° Anonymi carmen in laudem sancti Joannis Baptistae. — 8.° Anonymi carmen cujus is est titulus : laudes Domini cum miraculo quod accidit in Aedrico. — 9.° Anonymi carmen in laudem Christi Domini ; incipit : Jam mihi polliceor. — 10.° Bebiani carmen de uxore sua morti proxima, è variis versuum generibus contextum ; incipit : ô vir beatus cui remissa iniquitas. — 11.° Drepanii Flori Diaconi Lugdunensis, carmen de cereo paschali. — 12.° Hymnus in solemnitate S. Michaëlis, Archangeli. — 13.° Drepanii Flori, Diaconi Lugdunensis, epistola ad Modoinum, Episcopum Augustodunensem. — 14.° Servii Honorati de ultimarum syllabarum natura liber ad Aquilinum. — 15.° Anonymi grammatica. — 16.° Epigrammata quorumdam psalmorum, sive potiùs, psalmi XXII. XXVI. XXVII. versibus haeroïcis expositi ; authore Drepanio Floro. — 17.° Canticum trium puerorum, versibus heroïcis : eodem authore. — 18.° Anonymi cohortatio ad Wlfinum, Aurelianensem Grammaticum. — 19.° Sedulii carmen elegiacum de incarnatione Christi. Saeculo nono videtur exaratus."

Scripta varia

Fragment d'une chronique rédigée en partie d'après Sigebert, de 991 à 1099 ; -- F. 97, Collection de lettres du XIIe siècle dont plusieurs se rattachent à l'histoire de Saint-Victor ; -- F. 159, Sur Otton, évêque de Padoue ; -- F. 164, Sur les maires du Palais ; -- F. 165, Chronique des rois de France de 985 à 1437 ; -- F. 172, Lettres du XIIIe siècle dont beaucoup sont de Clément IV, avec des statuas synodaux ; -- F. 266, Liste des évêques ayant siégé au concile de Latran en 1179 ; -- F. 270, Raimundus arbor philosophie amoris ; -- F. 297, Epitome super cognitione sui auctore Petro Seguier ; -- F. 368, Chronique de Normandie. Copiés sur le ms. Latin 14663, f. 168v.F. 392, Fragment de la chronique de Girard de Frachet.