4,618 research outputs found

    Colossendeis species (Pycnogonida: Colossendeidae) collected during the Italica XIX cruise to Victoria Land (Antarctica), with remarks on some taxonomic characters of the ovigers

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    The pycnogonid fauna of the genus Colossendeis collected during the Italica XIX cruise to Victoria Land (Ross Sea, Antarctica) was studied. A total of 19 specimens of six species were collected: Colossendeis australis (6), C. wilsoni (3), C. scotti (2), C. robusta (3), C. lilliei (2) and C. megalonyx (3). In the present contribution the observed variability of all collected Colossendeis species is described and illustrated. The previously synonymised C. lilliei is considered a different species from C. robusta. The observations made in this study lead us to discuss a controversy about the total number of oviger segments in this genus. Despite the currently established 10-segmented status, a short basal element is here considered to be a possible 11th segment. A detailed SEM study of the last oviger segment is carried out in all collected species, showing some intraspecific and the interspecific variability in the structures examined (shape and number of rows of compound spines, morphology of terminal claw, etc.). Finally, we discuss the taxonomic value of these characters of the last strigilis segment for distinguishing the Colossendeis species, and their possible utility in establishing internal phylogenetic relationships in future contributions

    New findings and a new species of the genus Ammothea (Pycnogonida, Ammotheidae), with an updated identification key to all Antarctic and sub-Antarctic species

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    Specimens of the pycnogonid genus Ammothea collected during the Polarstern cruise XXIII/8 (23 November 2006–30 January 2007) were studied. Nine species were recognized in this collection: Ammothea bentartica, A. bicorniculata, A. carolinensis, A. clausi, A. longispina, A. minor, A. spinosa, A. striata and A. tibialis. Three of them (A. bentartica, A. bicorniculata and A. tibialis) are reported for the second time, enlarging their known geographical and bathymetric range. In the present contribution, the observed morphological variability of all collected Ammothea species is described and discussed. For the identification and description of the material, different museum specimens were consulted. Among them, we have consulted part of the Discovery collection housed at the Natural History Museum in London. That material was initially identified by Isabella Gordon, a reputed author in the field of pycnogonid taxonomy. A new species, based on a museum specimen previously highly confused in the literature, is proposed in the present contribution as Ammothea isabellae n. sp. The new taxon is compared with its closest congeners, especially with A. longispina and A. stylirostris. Finally, we propose an updated dichotomous key to species covering all currently known Antarctic and sub-Antarctic Ammothea specie

    Two new species of Ammothea (Pycnogonida, Ammotheidae) from Antarctic waters

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    Two new species of the genus Ammothea are described from Elephant Island and the South Shetlands Islands, Antarctica. The material was captured during the Polarstern cruise XXIII/8 to the Antarctic Peninsula area. The main features of Ammothea pseudospinosa n. sp. are a proboscis distinctly trilobulated distally with a constriction at 2/3 of its length and dimorphism between the propodi of the anterior (first and second) and posterior (third and fourth) legs, and a trunk: proboscis length ratio of about 1.5. The main features of Ammothea childi n. sp. are a cylindrical proboscis, longer than trunk length, and adults with functional chelifores. These species are compared with their closest congeners from the Southern Ocean: A. pseudospinosa n. sp. with Ammothea spinosa and Ammothea allopodes;A. childi n. sp. withAmmothea gigantea, Ammothea bicorniculata and Ammothea hesperidensis

    Nuevo modo de desarrollo postembrionario en el género Ammothea (Pycnogonida: Ammotheidae) procedente de aguas Antárticas

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    In this paper the postembryonic development of Ammothea glacialis (family ammotheidae) is described. The studied material was collected during the Italica XIX cruise to Victoria land, ross sea, antarctica. The external morphology of three larval instars is described and illustrated. The development of A. glacialis has the following characteristics: (1) protonymphon hatch from the eggs; (2) the larvae have yolk reserves and relatively large size (0.7 mm in length); (3) the larvae remain on the ovigerous legs of males during several moults; (4) the larvae have reduced larval II-III appendages and the spinning apparatus is absent; (5) the development of walking legs is sequential. This development is compared with those previously known, especially with Propallene longiceps and Nymphon grossipes.Nuevo modo de desarrollo postembrionario en el género AmmotheA (Pycnogonida: Ammotheidae) procedente de aguas Antárticas. – En este trabajo se describe el desarrollo postembrionario de Ammothea glacialis (familia ammotheidae). El material estudiado fue recolectado durante el crucero Itálica XIX a Tierra Victoria, en el mar de ross, antártida. se describe e ilustra la morfología externa de tres estadios larvarios. El desarrollo de A. glacialis se caracteriza por: (1) la larva eclosiona como protonymphon; (2) la larva es de tamaño relativo grande (0.7 mm de longitud) y con reservas de vitelo; (3) la larva permanece en los ovígeros del macho durante varias mudas; (4) la larva presenta los apéndices larvarios II y III reducidos y el “spinning apparatus” está ausente; (5) el desarrollo de las patas es secuencial. Este desarrollo es comparado con otros desarrollos postembrionarios previamente conocidos, especialmente con los de Propallene longiceps and Nymphon grossipes

    Fiabilidad y validez del instrumento RSTPQ y su relación con las ideas de referencia en una muestra de estudiantes universitarios

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    Este estudio analiza las propiedades psicométricas del cuestionario RSTPQ, el cual proporciona una serie de factores relacionados con los sistemas de aproximación conductual, inhibición conductual y lucha-huida-inmovilidad propuestos por la Teoría revisada de la Sensibilidad al Refuerzo (Gray, 1987), y las relaciones existentes entre sus factores con las ideas de referencia en una muestra de 465 estudiantes universitarios. Los resultados mostraron un alfa de Cronbach para la escala global de .88 y una fiabilidad test-retest de .86. La validez de constructo, mediante un análisis factorial exploratorio, evidenció siete factores similares a los propuestos por Corr (2008). En cuanto a la validez concurrente se hallaron correlaciones estadísticamente significativas entre los distintos factores con la sensibilidad al castigo y sensibilidad a la recompensa (SPSRQ). Se obtuvieron correlaciones positivas y estadísticamente significativas entre los factores del RSTPQ y las ideas de referencia del GTPS, lo que muestra la presencia de actividad predelirante en la población general relacionada con estructuras de organización de la personalidad. Se concluye que la escala posee adecuadas propiedades de fiabilidad y validez, lo que sugiere que es apta en su estructura global.This study analyzes the psychometric properties of the RSTPQ, which provides a lot of factors related to the behavior approach system, behavior inhibition system and fight-flight-freezing system posited by Revised Reinforcement Sensitivity (Gray, 1987), and the relations among its factors with ideas of reference in a sample of 465 college students. The results showed a Cronbach's alpha for the overall scale of .88 and test-retest reliability of .86. Construct validity by exploratory factor analysis showed seven similar factors to those proposed by Corr (2008). Regarding concurrent validity statistically significant correlations among the various factors of RSTPQ with sensitivity to punishment and reward sensitivity (SPSRQ) were reached. Correlations among factors of RSTPQ and ideas of reference of GTPS were positive and statistically significant, which shows the presence of pre delirious activity in the general population related to structures of organization of the personality. It was concluded that the RSTPQ has adequate reliability and validity properties, suggesting that is suitable in its overall structureUniversidad de Sevilla. Grado en Psicologí

    Observaciones sobre la distinción entre procesos sistémicos y estructurales en la adquisición del componente fonológico

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    El objetivo del presente trabajo es el de analizar la distinción entre procesos sistémicos y estructurales, que suele manejarse al describir la adquisición del componente fonológico. Para llevar a cabo este análisis se tomará como punto de partida la propuesta analítica de Laura Bosch (2004), que goza de gran difusión entre los investigadores españoles. Nuestra atención se centrará, en primer lugar, en las dificultades que pueden surgir al tratar de distinguir con nitidez las peculiaridades etiquetadas como “sistémicas” y “estructurales”. A continuación, señalaremos la posible presencia de influencias contextuales o sintagmáticas en algunos de los procesos etiquetados habitualmente como fenómenos sistémicos.The purpose of this paper is to discuss the distinction between systemic processes and structural processes, which is well-known and frequently applied in studies on children’s phonological development. As a basis for reflection, we have selected Laura Bosch’s proposal (2004), because of its diffusion and influence among Spanish researchers. First of all, our attention will focus on the difficulties which may arise when trying to draw a perfectly neat line between the two types of processes. Secondly, and lastly, we will try to uncover the syntagmatic factors which lay behind some processes which are usually described as systemic

    Hume and the Conception of Passions in Four Dissertations

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    Hume publicó Four Dissertations en 1757, una obra que incluía un extenso ensayo sobre Religión, una Disertación sobre las Pasiones y dos ensayos breves sobre Estética. Aunque la crítica ha solido interpretar el libro como un conjunto de ensayos independientes, recientemente John Immerwahr y Amyas Marivale han propuesto “The Unite Thesis”, según la cual, Hume concibió la obra como un texto unitario, que tenía como eje principal las “pasiones”. Siguiendo la posición de estos autores, el presente trabajo pretende comprobar cómo una interpretación unitaria de Four Dissertations muestra el profundo espíritu de la ilustración presente en el pensamiento de David Hume.Hume published Four Dissertations in 1757, a book that included an extensive essay on Religion, a Dissertation on the Passions and two short essays on Aesthetics. Although the critics have usually interpreted the book as a set of independent essays, recently John Immerwahr and Amyas Marivale have proposed “The Unite Thesis”, according to which, Hume conceived the work like a book with a unit, which had as its main axis the “passions”. Following the position of these authors, this paper aims to verify how a unitary interpretation of Four Dissertations shows the deep spirit of the Enlightenment, present in the thought of David Hume

    Las reflexiones de Antoine Meillet sobre la lingüística descriptiva

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    The role of aversiveness in the relationship between intolerance of uncertainty and inflexible avoidance

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    The study of avoidance behaviour is considered relevant to improve our understanding of anxiety disorders, which are commonly characterized by the presence of undue avoidance behaviours. Flores et al. (2018) found evidence that Prospective Intolerance of Uncertainty (P-IU) is associated with inflexible avoidance behaviour. Specifically, healthy participants learned in a free-operant discriminative task to avoid an aversive sound, and were tested in extinction to measure the sensitivity of avoidance responses to the devaluation of the sound aversiveness. The results showed that an increase in P-IU was positively associated with insensitivity to outcome devaluation. This association was still significant even when trait anxiety was controlled for. These results suggested that PIU may be a vulnerability factor for inflexible avoidance. However, in a recent replication, we found that the relationship between P-IU and inflexible avoidance was moderated by the participants ratings of outcome aversiveness. Specifically, the significant association between PIU and insensitivity to outcome devaluation was found to be conditional upon high aversiveness ratings.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Ministerio de Economía y Competitividad, proyecto I+D+i PSI2014-56061. Marie Curie International Outgoing Fellowship within the 7th European Community Framework Programme. Plan Propio de Investigación de la Universidad de Málaga, Programa de Fortalecimiento de las Capacidades en I+D+I en las Universidades 2014-20150, Fondos FEDER
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