Coordinated regulation of chromatophore differentiation and melanogenesis during the ontogeny of skin pigmentation of Solea senegalensis (Kaup, 1858)

Abnormal pigmentation of Senegalese sole has been described as one problem facing the full exploitation of its commercial production. To improve our understanding of flatfish pigmentation of this commercially important species we have evaluated eleven genes related to two different processes of pigmentation: melanophore differentiation, and melanin production. The temporal distribution of gene expression peaks corresponds well with changes in pigmentation patterns and the intensity of skin melanization. Several gene ratios were also examined to put in perspective possible genetic markers for the different stages of normal pigmentation development. Further, the phenotypic changes that occur during morphogenesis correspond well with the main transitions in gene expression that occur. Given the dramatic phenotypic alterations which flatfish undergo, including the asymmetric coloration that occurs between the ocular and the blind side, and the synchrony of the two processes of morphogenesis and pigmentation ontogenesis, these species constitute an interesting model for the study of pigmentation. In this study we present a first approximation towards explaining the genetic mechanisms for regulating pigmentation ontogeny in Senegalese sole, Solea senegalensis.Ministry of Science and Innovation (MICIIN) of the Spanish Government [AGL2008-03897-C04-01/ACU]; European Community [FP7/2007-2013-222719-LIFECYCLE]; Spanish Governmentinfo:eu-repo/semantics/publishedVersio

Kvalitet jaja morskih riba u akvakulturi, pregled tehnika i rezultata

Background: Despite most of marine teleosts can produce large quantities of viable eggs in captivity, the quantity and quality of the larvae are low and variable, being the initial quality of the eggs one of the main causes of the variability. Considering that commercial hatcheries rely on good larval quality, the establishment of a series of criteria for egg quality is of paramount importance. Objectives: This review presents an overview on some of recent researches carried out in IRTA and University of Salzburg (2004‒2010) to address this bottleneck through correlating egg biochemical contents (BC) to embryo/larva success in a marine teleost considered as new species for Mediterranean aquaculture. Target species: Besides production cost reduction and market enlargement, species diversification is one of the main strategies to ensure future expansion of aquaculture industry. A series of biological and commercial characteristics make the common dentex, Dentex dentex, a highly suitable species to enter mariculture systems as a new species to supplement the intensive sparids production and to increase diversification. Applied methodologies: (i) Viable eggs were obtained from natural spawning of broodfish in captivity. (ii) Egg biometrical parameters (i.e., wet mass, dry mass, and water content) were recorded. (iii) Embryo/larva viability parameters (VPs, i.e., floating rate, hatching rate, and survival rate) were determined. (iv) Egg biochemical parameters (i.e., carbohydrate metabolites/enzymes, vitellogenin-derived proteins [VDP], non-Vtg-derived protein [non-VDP], free amino acid [FAA], proteinic amino acids [PAA], lipid classes [LC], fatty acids [FA], and morphological characteristics of lipid vesicle [LV]) were characterized and quantified. (v) A variety of statistical analyses were used to define the relationships existing between the egg BCs (as egg quality indicators) and the VPs (as criteria for embryo/larva success) that are currently used in mariculture systems. Results: Although a combination of statistical methods were used to correlate the egg BCs to embryo/larva success in common dentex, the current review was prepared based on the results of regression models. Carbohydrate (CH) metabolite contents and enzyme activity of the egg together with VDP, non-VDP, FAA, PAA, LC , and FA contents for one side and lipid vesicle (LV) morphological characteristics on the other were significantly and strongly correlated to embryo/larva success through almost 350 simple regression model (11 [r2=0.184‒0.490] for CHs and enzymes, 16 [r2=0.095‒0.634] for VDPs, 55 [r2=0.079–0.637] for non-VDPs, 49 [r2=0.605–0.875] for FAAs, 19 [r2=0.919−0.991] for PAAs, 5 [r2=0.459–0.739] for LCs, 201 [r2=0.640–0.948] for FAs, and 10 [r2=0.293–0.480] for LV). Conclusions: (i) Under a biological/physiological perspective the significant relationships found between egg BCs and embryo/larva success in common dentex highlight the importance of egg composition during the initial events of embryonic/larval development. The results obtained present a series of new relationships (either in agreement or against previous findings) that deserve further investigation to define their physiological ground. (ii) Under a more applied perspective these relationships indicate a potential use of egg BCs, as bio-markers, to predict egg quality in aquaculture. These markers can also be used as molecular probes to assess the improvements in broodstock management

Effects of dietary arachidonic and eicosapentaenoic acids on common dentex (Dentex dentex Linnaeus 1758) larval performance

Oily emulsions containing constant levels of total fatty acids (FAs) and varying eicosapentaenoic acid (EPA) and arachidonic acid (ARA) levels were used to enrich rotifers. Common dentex larval survival and growth were compared between groups fed different enriched live prey. Growth, survival rate, and lipid composition of larvae suggest that feeding common dentex in the first 15 days posthatching with 2.5–3% EPA, 6–8% docosahexaenoic acid (DHA), and DHA/EPA ratio of 2.0–2.5 is sufficient to fulfill their EPA requirements. Higher amounts of dietary EPA did not result in any significant improvement in growth or survival. EPA requirement during this period of larval development does not seem to be as critical as other FAs during the first 15 days of common dentex larval development, but it does not exclude its essentiality later in development. In the case of ARA, nutritional requirements are low compared to other marine finfish species, with the upper limit of this essential FA being around 2% of total FAs provided in the live prey composition.info:eu-repo/semantics/acceptedVersio

Metáforas y analogías científicas

En el contexto de una tesis de maestría en Historia y Filosofía de las Ciencias, abordamos como problema central la ubicuidad de la metáfora, esto es la capacidad de aparecer en muy diferentes campos teóricos y marcos conceptuales. El principal objetivo de la tesis de carácter teórico fue especificar bajo qué formas se manifiesta la metáfora en el discurso científico psicológico.Eje: Estudios interdisciplinarios y nuevos desarrollosFacultad de Psicologí

Metáforas y analogías científicas

En el contexto de una tesis de maestría en Historia y Filosofía de las Ciencias, abordamos como problema central la ubicuidad de la metáfora, esto es la capacidad de aparecer en muy diferentes campos teóricos y marcos conceptuales. El principal objetivo de la tesis de carácter teórico fue especificar bajo qué formas se manifiesta la metáfora en el discurso científico psicológico.Eje: Estudios interdisciplinarios y nuevos desarrollosFacultad de Psicologí

Variations in Bacterial Community of Rearing Water and Gut of Common Dentex, Dentex dentex (Linnaeus 1758), Larvae Using Three Microalgae Management Approaches

Microorganisms present in the rearing water colonize the gut of first feeding larvae and represent the first barrier against opportunistic pathogens. The aim of the experiments presented herein was to standardize a protocol for the management of rearing water and microalgae suitable for the larval rearing of common dentex. In Experiment 1, bacteria–algae interactions were tested using a monospecific microalgal community, Tetraselmis chuii, suitable for nutritional experiments and with known antibacterial activity. In Experiment 2, the evolution of the bacterial community and larval performance (growth and survival) were monitored daily, in three conditions: (1) mature water: T. chuii was added 5 d before the rearing of common dentex larvae, (2) green water: T. chuii was added 1 d before, and (3) clear water: no T. chuii addition. The results show the influence of the presence of T. chuii on the evolution of the bacterial communities, both in terms of bacterial density and morphology, and indicate green water is the most suitable water treatment for management of larval rearing for common dentex.info:eu-repo/semantics/acceptedVersio

Concepciones de adolescencia

En este trabajo queremos destacar la importancia del análisis de las concepciones acerca de la Adolescencia porque éstas suponen un juicio que revela algo de la teoría intuitiva que se hace acerca del objeto de conocimiento. Para ser develadas requieren un trabajo de reflexión para dejar al descubierto la influencia que ejercen en las prácticas con adolescentes, por qué resultan eficaces y sobre todo, por qué perduran a pesar que han cambiado los sujetos y el contexto social. Asimismo, estas concepciones pueden operar como obstáculo para la comprensión de las teorías del desarrollo ya que se caracterizan por tener un núcleo resistente.Eje: Psicología del desarrolloFacultad de Psicologí

Concepciones de adolescencia

En este trabajo queremos destacar la importancia del análisis de las concepciones acerca de la Adolescencia porque éstas suponen un juicio que revela algo de la teoría intuitiva que se hace acerca del objeto de conocimiento. Para ser develadas requieren un trabajo de reflexión para dejar al descubierto la influencia que ejercen en las prácticas con adolescentes, por qué resultan eficaces y sobre todo, por qué perduran a pesar que han cambiado los sujetos y el contexto social. Asimismo, estas concepciones pueden operar como obstáculo para la comprensión de las teorías del desarrollo ya que se caracterizan por tener un núcleo resistente.Eje: Psicología del desarrolloFacultad de Psicologí

Desafíos y perspectivas de la formación de psicólogos en la Universidad Nacional del Comahue

A diferencia de otras Unidades Académicas de Psicología, en nuestro caso no contábamos con experiencia institucional en la formación de psicólogos y quizás, por ello mismo, en la gestación del proyecto académico de la carrera se conjugaron tanto aspectos tradicionales como innovadores pero también desafíos y obstáculos de diversa naturaleza a la hora de su implementación. En lo que hace a las prácticas profesionales de grado el análisis se realiza en dos planos: el normativo-organizativo y el específicamente formativo.Simposio autoconvocado: Las prácticas formativas en contextos interinstitucionales.Facultad de Psicologí

Desafíos y perspectivas de la formación de psicólogos en la Universidad Nacional del Comahue

A diferencia de otras Unidades Académicas de Psicología, en nuestro caso no contábamos con experiencia institucional en la formación de psicólogos y quizás, por ello mismo, en la gestación del proyecto académico de la carrera se conjugaron tanto aspectos tradicionales como innovadores pero también desafíos y obstáculos de diversa naturaleza a la hora de su implementación. En lo que hace a las prácticas profesionales de grado el análisis se realiza en dos planos: el normativo-organizativo y el específicamente formativo.Simposio autoconvocado: Las prácticas formativas en contextos interinstitucionales.Facultad de Psicologí