The graptolite Rhabdopleura recondita tube composition, development and morphological invariance (Hemichordata, Pterobranchia)

Le phylum Hemichordata est composé exclusivement d'organismes marins et, avec les embranchement Echinodermata et chordata, il forme le groupe des Deutérostomes sur l'arbre de la vie des animaux. Dans les chapitres d'introduction et le deuxième, je donne un aperçu des hémichordés, y compris les enteropneustes solitaires et les pterobranches coloniaux et je les défini dans un contexte évolutif ou phylogénétique. Les enteropneustes sont souvent considérés comme le meilleur proxy vivant de l'ancêtre des deutérostomes. Les ptérobranches comprennent les Cephalodiscida et les Graptolithina. Les graptolites (graptos = écrit, lithos = roche) sont principalement représentés par des espèces fossiles remontant à la Période Cambrienne, il y a plus de 500 millions d'années. Ces «écritures dans la roche» sont largement connues et étudiées par les paléontologues et sont si abondantes qu'elles sont utilisées comme fossiles indicateurs pour identifier les couches sédimentaires. Les graptolites sont éteints sauf pour cinq espèces benthiques appartenant au genre Rhabdopleura, membres de la famille Rhabdopleuridae, que j'examine en détail dans le chapitre trois. Rhabdopleura recondita de la mer Méditerranée fait l'objet de cette thèse. Il est courant le long des côtes sud de l'Italie d'où je l’ai échantillonné en plongée sous- marine. Il est inhabituel que des colonies résident cachées à l'intérieur de la zoaria des bryozoaires morts. Seuls les tubes érigés font saillie à partir de la matrice de l'hôte. Les chapitres quatre et cinq sont les contributions les plus significatives de cette thèse, avec un accent sur les tubes de R. recondita. Le chapitre quatre fournit des observations de la construction de tubes par R. recondita gardé en captivité. J'ai observé la capacité des larves, des zooïdes et des colonies à sécréter de nouveaux tubes en présence et en l'absence du matériel hôte du zoarium bryozoaire. Nous avons découvert que la colonisation larvaire et la sécrétion du dôme peuvent se produire sans l'hôte bryozoaire, mais la croissance continue de la colonie nécessite le substrat de l'hôte. Les zooïdes adultes ne peuvent reformer de nouveaux tubes que s'ils sont capables de s'abriter à l'intérieur du matériel hôte. Un résultat surprenant des observations des zooïdes a été la sécrétion d'un opercule et d'un tube évasé. Les colonies qui avaient des tubes érigés enlevés ont pu fabriquer de nouveaux tubes, mais à un faible nombre. Une étude parallèle a été réalisée sur des colonies dont les tubes avaient été retirés, puis cultivées dans des canaux à quatre vitesses d'écoulement. Cette expérience a été conçue pour induire une réponse plastique phénotypique à l'écoulement. Au lieu de cela, je n'ai trouvé aucune différence significative dans la longueur du tube ou le nombre de tubes en réponse à quatre vitesses d'écoulement. Ce résultat suggère que le développement du tube de R. recondita peut être canalisé ou fixé. Il est significatif car il suggère que de petites différences qui distinguent les espèces primitives de graptolites encroûtantes sont bonnes. Le chapitre cinq porte sur la composition des tubes de R. recondita. Plusieurs hypothèses et de nombreuses analyses ont été faites sur ce sujet, mais aucune n'a été concluante. J'utilise ici la génomique et la bioinformatique, l'immunochimie et la spectroscopie et rejette les hypothèses selon lesquelles les tubes sont de la kératine ou de la cellulose. Au lieu de cela, j'ai trouvé huit gènes de chitine synthase dans le génome et le trascriptome, un complexe composé d'un polysaccharide semblable à la chitine, d'une protéine, d'un acide gras et de composants élémentaires inattendus. Cette étude est significative car elle ferme la porte sur une ancienne hypothèse de composition de tube de graptolite et révèle qu'il s'agit d'une structure complexe comprenant de la chitine. Le chapitre de conclusion est un bref résumé des résultats et une réflexion sur les aveenues potentiellement fructueuse pour des recherches futures.The phylum Hemichordata is comprised of exclusively marine organisms, and together with the Echinodermata and Chordata forms the Deuterostomia branch on the animal tree of life. In the introductory and second chapters I provide a background on Hemichordata including the solitary Enteropneusta and the colonial Pterobranchia and define them in an evolutionary or phylogenetic context. The enteropneusts are often regarded as the best living proxy of the deuterostome ancestor. Pterobranchs, include the Cephalodiscida and Graptolithina. Graptolites (graptos=written, lithos=rock) are mostly represented by fossil species dating back to the Cambrian Period, more than 500 million years ago. These “writings in the rock” are widely known and studied by paleontologists and are so abundant that they are used as index fossils to identify sedimentary layers. Graptolites are extinct but for five benthic species belonging to the genus Rhabdopleura, members of the Rhabdopleurida, which I extensively review in chapter three. Rhabdopleura recondita from the Mediterranean Sea is the subject of this thesis. It is common along the south coasts of Italy from where I sample it by SCUBA diving. It is unusual in that colonies reside hidden inside of the zoaria of dead bryozoans. Only erect tubes project from the host matrix. Chapters four and five are the most significant contributions of this thesis, with a focus on R. recondita tubes. Chapter four provides observations of tube building by R. recondita kept in captivity. I observed larvae, zooids and colonies abilities to secrete new tubes in the presence and absence of the bryozoan zoarium host material. We discovered that larval settlement and dome secretion can occur without the bryozoan host, but the continued growth of the colony requires the host substrate. Adult zooids can reform new tubes only if they are able to shelter inside of host material. A surprising result from the zooid observations was the secretion of an operculum and a flared tube. Colonies that had erect tubes removed were able to make new tubes, but fewer in number. A parallel study was done on colonies that had tubes removed and then were cultured in channels at four flow velocities. This experiment was designed to induce a phenotypic plastic response to flow. Instead, I found no significant difference in tube length or tube number in response to four flow velocities. This result suggests that the tube development of R. recondita may be canalized, or fixed. It is significant because it suggests that small differences that distinguish primitive, encrusting graptolite species, are good. Chapter five is on the composition of R. recondita tubes. Several hypotheses and numerous analysis have been done on this topic, but none were conclusive. Here I use genomics and bioinformatics, immunochemistry and spectroscopy and reject the hypotheses that the tubes contain keratin or cellulose. Instead I found eight chitin synthase genes in the genome and transcriptome, a complex made of a chitin-like polysaccharide, protein, fatty acid and unexpected elemental components. This study is significant because it closes the door on old hypothesis of graptolite tube composition and reveals that it is a complex structure including chitin. The conclusion chapter is a brief summary of the results and a reflection on fruitful avenues of future research

Industrial Resources - Fulton County - Hickman

Resources for Economic Development: Hickman, Kentucky” prepared by the Kentucky Department of Economic Development, Division of Research and Planning, and the Purchase Area Development District, 1985. The report includes, but is not limited to, information about: population, labor market, local manufacturing, transportation, utilities, fuel, water, sewage, industrial sites, local government and services, taxes, educational and health facilities, housing, communication, recreation, natural resources, markets, and climate

Revisitando el cine documental: de Flaherty al webdoc

En los últimos tiempos, y propiciado por el auge de la imagen digital, el género documental ha liderado una importante renovación en sus formas cinematográficas indagando en nuevos lenguajes para la imagen contemporánea. Desdibujando por completo los límites entre la ficción y la no ficción, el documental contemporáneo ha fraccionado algunas de las convenciones asociadas al género, encontrando fácil acomodo entre lo narrativo, lo observacional, lo etnográfico, lo ensayístico, la videocreación, lo autobiográfico y, obviamente, lo experimental. Tras décadas de constante mutación, el cine documental se nos presenta como un fascinante territorio de exploración fílmica, aportando una reflexión sobre las fronteras actuales del lenguaje cinematográfico y que requiere a su vez un nuevo tipo de mirada desde el ámbito académico. Dispuestas así las cosas, el presente libro se propone revisitar el género documental y recoger experiencias e investigaciones que, desde diferentes planteamientos, buscan reflexionar sobre la evolución del propio género desde un enfoque multidisciplinar. De este modo, se pretende establecer un estado de la cuestión con textos vinculados a los disímiles modos de abordar el documental a lo largo de su dilatada historia: estudios historiográficos, análisis fílmicos sustentados en ejemplos concretos de películas o directores de especial interés, investigaciones que ponen en relieve la influencia y consecuencia de la evolución de la tecnología digital e Internet, así como la evolución e innovación en los modos de producción, exhibición y/o distribución por los que el documental ha transitado.Este Libro se ha realizado dentro del Grupo de Investigación GIU 13/21 (2013-2016), MAC (Mutaciones del Audiovisual Contemporáneo) de la Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU).La redacción del capítulo "Un lugar ético para las imágenes documentales (en el contexto de las ciencias sociales) / Josetxo Cerdán Los Arcos" fue posible gracias al proyecto de investigación CSO2010/15798 (TRANSCINE), financiado por el Ministerio de Ciencia e Innovación del Gobierno de España. -- La redacción del capítulo "Documentalidad. Cine sin autoría, pedagogías visuales colectivas y valor afectivo / Virginia Villaplana Ruiz" fue posible gracias al proyecto de investigación eDCINEMA: "Hacia el Espacio Digital Europeo", financiado por el Plan Nacional de I+D+i del Ministerio de Economía y Competitividad. Ref. CSO2012-35784. -- La redacción del capítulo "Cosas que hacen crack. Emociones y cinefilia en Color perro que huye (Andrés Duque, 2011) / Miguel Fernández Labayen y Elena Oroz" se ha realizado en el marco del proyecto de investigación CSO2010-15798 (TRANSCINE), "El audiovisual español contemporáneo en el contexto transnacional: aproximaciones cualitativas a sus relaciones transfronterizas", financiado por el Ministerio de Economía y Competitividad del Gobierno de España. -- El capítulo "Aproximación a la no ficción interactiva: panorámica del webdocumental español en la era digital / Robert Arnau Roselló" ha sido financiado con la ayuda del Proyecto de Investigación de la convocatoria Universitat Jaume I-Bancaja, con el título "Análisis de los flujos de transferencia de conocimiento entre los sistemas educativos superiores y la industria del videojuego", código 11I301.01/1, bajo la dirección del Dr. Javier Marzal Felici.Prólogo / J.M. Català Domènech (pp. 9-14). -- Un lugar ético para las imágenes documentales (en el contexto de las ciencias sociales) / Josetxo Cerdán Los Arcos (pp. 17-32). -- Documentalidad. Cine sin autoría, pedagogías visuales colectivas y valor afectivo / Virginia Villaplana Ruiz (pp. 33-54). -- Diseño de títulos en documental: cuestión de etiqueta / Koldo Atxaga Arnedo (pp. 55-65). -- La creación del documental: archivo, recreaciones y entrevistas / Mónica del Sagrario Medina Cuevas y Alejandro Jiménez Arrazquito (pp. 67-76). -- Desterritorialización, modulación y puntos de inflexión en el documental contemporáneo español / Vanesa Fernández Guerra y Estibaliz Alonso Ruiz de Erentzun (pp. 79-103). -- La propuesta de vertebración del Novo Cine Galego: lo procesual y la marca documental / Fernando Redondo Neira y Xurxo González Rodríguez (pp. 105-126). -- Revisión de la etiqueta "Novo Cinema Galego". Testimonios de autor / Beli Martínez Martínez (pp. 127-152). -- El cine de no ficción en los cortometrajes de Kimuak: evoluación, tendencias y nuevas propuestas creativas / Ainhoa Fernández de Arroyabe Olaorut, Nekane E. Zubiaur Gorozika y Iñaki Lazkano Arrillaga (pp. 153-179). -- Cosas que hacen "crack". Emociones y cinefilia en Color perro que huye (Andrés Duque, 2011) / Miguel Fernández Labayen y Elena Oroz (pp. 181- 204). -- Estudio evolutivo del lenguaje narrativo, desde los primeros documentales a las transmedia / Begoña Gutiérrez San Miguel (pp. 207-244). -- La participación ciudadana en el documental colaborativo: hacia nuevas narrativas audiovisuales / Gloria Rosique Cedillo (pp. 245-263). -- Del documental lineal al webdocumental: enunciación y experiencia espectatorial en Gare du Nord de Claire Simon / Amanda Rueda (pp. 265-274). -- El documental multimedia interactivo. Un estudio de caso: En el reino del plomo (En Portada y Lab de RTVE.es, 2013) / Irene Liberia Vayá y Cristina Pérez de Algaba Chicano (pp. 275-299). -- Aproximación a la no ficción interactiva: panorámica del webdocumental español en la era digital / Robert Arnau Roselló (pp. 301-323)

Fossilization processes of graptolites: insights from the experimental decay of Rhabdopleura sp. (Pterobranchia)

Laboratory experiments documenting the decomposition pattern of extant organisms are used to reconstruct the anatomy and taphonomy of fossil taxa. The subclass Graptolithina (Hemichordata: Pterobranchia) is a significant fossil taxon of the Palaeozoic era, represented by just one modern genus, Rhabdopleura. The rich graptolite fossil record is characterized by an almost total absence of fossil zooids. Here we investigated the temporal decay pattern of Rhabdopleura sp. tubes, stolons and single zooids removed from the tubarium. Tubes showed decay after four days, when fuselli began to separate from the tube walls. This rapid loss may explain the absence of fuselli from some graptolite fossils. The black stolon did not show decay until day 155. One day after their removal, zooids quickly decomposed in the following temporal sequence: (1) tentacles; (2) ectoderm; (3) arms; (4) gut; (5) cephalic shield, leading to complete disappearance of recognizable body parts in the majority of experimental zooids within 64–104 h. The most resistant zooid features to decay (61 days) were black-pigmented granules. These results indicate that tubes and the black stolon would persist for weeks across death, transport and burial, whereas a complete decay of zooid features occurs in few days, providing an explanation for the overall poor record of fossil graptolite zooids and suggesting that recorded silhouettes of fossil zooids may be attributed to fossil decay-resistant pigments

Development and Phenotypic Plasticity of Tubes and Tubaria of the Living Graptolite Rhabdopleura recondita (Pterobranchia, Hemichordata)

The extant graptolite Rhabdopleura recondita has been so far recorded only as inhabiting a bryozoan skeleton. Its larval settlement and metamorphosis are possible in the absence of a bryozoan zoarium, whereas further colony development may require that the larva is hidden inside the bryozoan host. This dependence may constrain the development of R. recondita tube and tubaria compared to the other Rhabdopleura species that develop without a host. We report here on larval settlement and metamorphosis in the absence/presence of a bryozoan host skeleton. We also make the first attempt to test the phenotypical response of R. recondita tubes and tubaria under variable hydrodynamic regimes in laboratory conditions. After 40 days, no significant variation was detected in the number or length of the newly formed tubes. These findings suggest that R. recondita eventually resides in a narrow velocity range and that tube and tubarium development is largely invariable

Development and Phenotypic Plasticity of Tubes and Tubaria of the Living Graptolite <i>Rhabdopleura recondita</i> (Pterobranchia, Hemichordata)

The extant graptolite Rhabdopleura recondita has been so far recorded only as inhabiting a bryozoan skeleton. Its larval settlement and metamorphosis are possible in the absence of a bryozoan zoarium, whereas further colony development may require that the larva is hidden inside the bryozoan host. This dependence may constrain the development of R. recondita tube and tubaria compared to the other Rhabdopleura species that develop without a host. We report here on larval settlement and metamorphosis in the absence/presence of a bryozoan host skeleton. We also make the first attempt to test the phenotypical response of R. recondita tubes and tubaria under variable hydrodynamic regimes in laboratory conditions. After 40 days, no significant variation was detected in the number or length of the newly formed tubes. These findings suggest that R. recondita eventually resides in a narrow velocity range and that tube and tubarium development is largely invariable

Merged Municipalities, Higher Debt : On Free-riding and the Common Pool Problem in Politics

We use the 1952 Swedish municipal amalgamation reform to study free- riding and the common pool problem in politics. We expect municipalities that were affected by the reform to increase their debt in anticipation of a merger, and this effect to be larger if they were merged with many other populous municipalities (i.e. facing a large common pool). We use ordinary least squares and matching on the complete cross section of rural municipalities for the period 1947−1951, fixed effects when exploiting the panel features, as well as a geographical instrumental variables strategy. We find an average treatment effect close to the amount that the average merged municipality increased its debt with during this period, which corresponds to 2.8 percent of average income or 63 percent of the average increase in income. However, we do not find larger increases in municipalities that were part of a larger common pool

The zoogeography of extant rhabdopleurid hemichordates (Pterobranchia: Graptolithina), with a new species from the Mediterranean Sea

The early origin and evolutionary radiation of graptolites (Hemichordata: Pterobranchia) is a story told almost entirely in the fossil record, but for four extant species of the genus Rhabdopleura. Here we report the discovery of a fifth species, Rhabdopleura recondita sp. nov., at a depth range of -2 to -70 m from the Adriatic and Ionian Seas, always associated with bryozoans in coralligenous habitats. This is the first pterobranch record in Italian waters, and the second in the Mediterranean Sea. The new species is characterized by a) tubaria with smooth creeping tubes adherent to the inside of empty bryozoan zooecia; b) erect outer tubes with a graptolite, fusellar-like organization; and c) zooids that extend from a black stolon, which is free from the creeping tube. Each of the paired feeding arms has two rows of tentacles that do not extend to the arm tip. The distal ends of the arms, the collar, and the cephalic shield are replete with black granules. Phylogenetic analyses of individual and concatenated gene sequences of mitochondrial 16S rDNA and nuclear 18S rDNA support the validity of R. recondita as a new species. Finally, we discuss the global biogeographic and habitat distributions of the extant Rhabdopleura representatives

A Transcriptomic-Phylogenomic Analysis of the Evolutionary Relationships of Flatworms

The interrelationships of the flatworms (phylum Platyhelminthes) are poorly resolved despite decades of morphological and molecular phylogenetic studies [1, 2]. The earliest-branching clades (Catenulida, Macrostomorpha, and Polycladida) share spiral cleavage and entolecithal eggs with other lophotrochozoans. Lecithoepitheliata have primitive spiral cleavage but derived ectolecithal eggs. Other orders (Rhabdocoela, Proseriata, Tricladida and relatives, and Bothrioplanida) all have derived ectolecithal eggs but have uncertain affinities to one another. The orders of parasitic Neodermata emerge from an uncertain position from within these ectolecithal classes. To tackle these problems, we have sequenced transcriptomes from 18 flatworms and 5 other metazoan groups. The addition of published data produces an alignment of >107,000 amino acids with less than 28% missing data from 27 flatworm taxa in 11 orders covering all major clades. Our phylogenetic analyses show that Platyhelminthes consist of the two clades Catenulida and Rhabditophora. Within Rhabditophora, we show the earliest-emerging branch is Macrostomorpha, not Polycladida. We show Lecithoepitheliata are not members of Neoophora but are sister group of Polycladida, implying independent origins of the ectolecithal eggs found in Lecithoepitheliata and Neoophora. We resolve Rhabdocoela as the most basally branching euneoophoran taxon. Tricladida, Bothrioplanida, and Neodermata constitute a group that appears to have lost both spiral cleavage and centrosomes. We identify Bothrioplanida as the long-sought closest free-living sister group of the parasitic Neodermata. Among parasitic orders, we show that Cestoda are closer to Trematoda than to Monogenea, rejecting the concept of the Cercomeromorpha. Our results have important implications for understanding the evolution of this major phylum.ISSN:0960-9822ISSN:1879-044

Setting thresholds is not enough: Beach litter as indicator of poor environmental status in the southern Adriatic Sea

This study deals with the issue of beach litter pollution in the context of the Descriptor 10 of the Marine Strategy Framework Directive Good Environmental Status of EU waters and Ecological objective 10, Common indicator 22 of IMAP. Analyses of the amount, distribution and categorization of beach litter were conducted on nine beaches during 108 surveys covering the area of 206.620 m2 in Albania, Italy and Montenegro. Our findings showed that the level of beach litter pollution on south Adriatic beaches is significantly above the adopted threshold values, with a median item numbers of 327, 258 and 234 per 100 m of beach stretch for Albania, Italy and Montenegro, respectively. It can be concluded that, when it comes to beach litter pollution, GES has not been achieved. Given the defined baseline and threshold values at the EU level, the process of reducing the total amount of marine litter in southern Adriatic Sea will be very challenging and needs urgent and specific actions