The sensorial function of the girdle of the Polyplacophora

The sensorial function of the girdle of the Polyplacophora Carmen Salas1, Antonio G. Checa2,3, Michael J. Vendrasco2 1Depto. Biología Animal, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; 2Departamento de Estratigrafía y Paleontología, Universidad de Granada, 18071 Granada, Spain, 3Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, 18100 Armilla, Spain. The polyplacophorans or chitons are characterized by the presence of eight dorsal overlapping shell plates that are embedded in a thick mantle tissue and surrounded by the girdle (also called perinotum). In chitons, the hard layers of plates consist of the uppermost tegmentum, the articulamentum whose projections form the sutural laminae and insertion plates, and the underlying hypostracum. The tegmentum, which is the visible layer of the chiton shell in life, is infiltrated with a complex, tissue-filled canal system that opens at the dorsal valve surface as sensory or secretory organs known as aesthetes. Structures secreted by the epidermis of the girdle have been mainly described as ornamentation or armature, such as numerous calcareous spines, scales, hairs or bristles, but other studies suggest that the girdle epidermis has other functions such as sensorial (Leise and Cloney, 1982; Leise, 1988). In chitons, epidermal sensory receptors have been mainly found around the mouth, on the subradular organ, in the buccal cavity, in the pallial grooves and in the shell. During a study of the formation of the cuticle in the mantle girdle of several species of chitons (Lepidozona pectinulata, Ischnochiton rissoi, Lepidochitona cinerea, Leptochiton algesirensis, Lepidopleurus cajetanus), we have observed several sensory structures in the mantle girdle. In the case of fully-grown scales and marginal spines, a group of cells differentiated from the papilla constitutes a stalked body or nodule, which progressively elevates and pushes the spine until it finally, pierces through the cuticle surface. The stalked nodules are more conspicuous in L. cinerea and L. pectinulata than in L. cajetanus. These projections arise from epidermal papillae and have been considered mechanoreceptors. Lens-like structures have been observed inside some stalked nodules in L. cinerea and L. algesirensis. The stalked nodules show dendritic structures underlying the lens-like structure, which point to a photoreception ability. The lens-like structure found in the nodule of L. cinerea seems to be a rigid, possibly mineralized structure. Aragonite lenses have been found in Acanthopleura granulata by Speiser et al. (2011). In L. algesirensis we have observed groups of long microvilli in the top margin of the papillae and in contact with the spines that we consider as mechanoreceptors. As in other chitons, dendritic processes are frequently found in association mainly with dorsal spicules, although not every spine is innervated.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Almería, tierra de migraciones

En número dedicado a: Almerí

Comparing phonetic difficulties by EFL learners from Spain and Japan.

XXII Jornades de Foment de la Investigació de la Facultat de Ciències Humanes i Socials (Any 2017)After decades of improving language learning methods, English as a Foreign Language (hereafter EFL) still makes Spanish and Japanese learners struggle with the correct pronunciation. Each country focused on its own lack of phonemes in relation to the target language and, despite years, of research the problem is as present as ever. This article approaches this border-crossing problem by means of the moderate version of the contrastive analysis hypothesis (henceforth CAH) and compares and analyses the phonetic problems of both languages against the target language, English. By expanding the focus, the resulting data could serve as a starting point for further studies that down the way could facilitate EFL learning all around the world

Salud y derechos sexuales y reproductivos

Fil: Checa, Susana. Universidad de Buenos Aires. Facultad de Ciencias Sociales; Argentina.La salud sexual y reproductiva y su correlato, los derechos\nsexuales y reproductivos, son problemáticas de gran complejidad\nque cuando se instalan en el debate público generan, por\nello mismo, fuertes controversias porque colocan en el escenario\nsocial y político el tratamiento de aspectos profundamente\nsilenciados, como son la inequidad de género y la de clase, el\npoder patriarcal, el poder médico, la sexualidad como fuente\nde placer independiente de sus consecuencias procreativas, los\nderechos de las minorías sexuales, la maternidad libremente\nelegida o el derecho al aborto

PBO Fibres: from saliling design towards architectural performance

p. 3013-3023PBO fibres, also called "high-performance" polymer fibres, are a group of materials known as "rigid rods". Through this work it is pretended to make some considerations about the use of these new generation fibres. Poly (p-phenylene-2.6-benzobisoxazole)(PBO) is rigid-rod isotropic crystal polymer. PBO fibre is a high performance fibre developed by TOYOBO (Japan) PBO fibre is quite flexible and has very soft handling, in spite of its extremely high mechanical properties. Over the past ten years Future Fibres Company has pioneered the use of PBO for yacht rigging and has proven it to provide remarkable performance and longevity. Their method of producing these PBO cables delivers the lightest, smallest cables available on the market today. The PBO cable is formed by combining the incredible properties of PBO (poly(p-phenylene-2,6- benzobisoxazole)) fibre with the simple yet undeniably reliable process of continuous winding. A PBO cable is dry fibre tightly compacted and does not rely on a resin matrix that, if impacted, can be compromised. The cover of the cable is a vital component and whilst PBO is an excellent material for yacht rigging purposes, due to its extreme strength, low elongation and general robustness it must be protected from sunlight and seawater. Future Fibres has perfected its cover design that comprises a consolidating film, environmental protection layer and a customizable braided cover that can be tailored to suit any specific application. PBO has great potential to be used in construction or rehabilitation applications. At the same time the fibres, following further testing, would open up several design opportunities for high quality architectural projects.Gough, CE.; Pobo Blasco, M.; Ruiz Checa, JR. (2009). PBO Fibres: from saliling design towards architectural performance. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/670

La psicología se encuentra con la antropología y el deporte

Obra ressenyada: J. DÍAZ RODRÍGUEZ, El entrenamiento mental de los jugadores de bolos Preparación para el alto rendimiento. Santander: Federación Cántabra de Bolos, 201

Quantum Dots

The purpose of this communication is to make a bibliographic review of Quantum Dots methods and their applications in the field of Biotechnology. Quantum dots (QDs) are a novel class of inorganic fluorophores, which are gaining widespread recognition as a result of their exceptional photophysical properties

La prensa napoleónica en España (1808-1814). Una perspectiva

La presse partisane du régime de José I en Espagne entre 1808 et 1814, appelée presse napoléonienne, n’a guère suscité, du moins jusqu’à il y a peu, l’attention des historiens. En effet, elle était considérée comme intruse, et ses rédacteurs étaient tenus pour des traîtres. Aujourd’hui une vision plus équilibrée s’impose. Cet article offre un tour d’horizon de cette presse, ses créateurs, ses conditions de publication, son contenu et ses obsessions. Et surtout, il décrit qui étaient ses rédacteurs et quel a été leur sort après le départ des troupes napoléoniennes de la péninsule ibérique.La prensa afín al régimen de José I en España en 1808-1814, la prensa napoleónica, ha merecido, hasta fechas recientes, escasa atención de los historiadores, considerada intrusa y traidores sus componentes. Hoy se impone una visión más equilibrada. El presente artículo ofrece un panorama de esa prensa, sus creadores, su mantenimiento, sus contenidos y obsesiones y en especial quienes la redactaron y cuál fue su suerte tras la salida de las tropas napoleónicas de la península ibérica.The press related to Joseph I’s regime in Spain in 1808-1814, the Napoleonic press, has deserved, up to recent dates, little attention from historians, being considered as an intruder and his editors as traitors. Today a more balanced vision prevails. The present article offers a big picture of this press: his creators, his maintenance, his contents and obsessions and especially those who wrote it and which was their fate after the exit of the Napoleonic troops of the Iberian peninsula