Impacto de las acumulaciones de macroalgas en la comunidad biológica intermareal

Los efectos de la acumulación de macroalgas verdes en la comunidad biológica intermareal del caño Sancti Petri se siguieron a lo largo de un ciclo anual. La medida con microelectrodos selectivos de O2 y H2S permitió obtener perfiles detallados de la distribución vertical de estos parámetros. Los cambios en la microflora bentónica se estudiaron en la zona superficial del sedimento mediante microscopia óptica. Los cambios en la meiofauna se estudiaron tanto en la capa de macroalgas como en el interior del sedimento. La acumulación de macroalgas produce fenómenos de hipoxia/anoxia tanto en el sedimento como en el interior de la capa de macroalgas, que se acentúan en periodos de oscuridad, favoreciendo la acumulación de H2S en zonas cercanas a la superficie del sedimento. En estas condiciones se produce una reducción del 96.7% en la población de microalgas bentónicas y un cambio en la comunidad, pasando de estar dominada por diatomeas a estarlo por cianobacterias. La meiofauna incrementa su densidad de población en un 845 ± 535%. El grupo con mayor crecimiento fueron los nematodos, cuya población es 9 veces superior al control, pasando a dominar completamente la meiofauna con un 92 ± 1% del número total de individuos, lo que produce una gran reducción de la diversidad.Ministerio de Educacion y Ciencia, proyectos: REN2002-01281/MAR y CTM2006-04015Acciones Marie Curie: HPMF-CT-2000-0099

Effects of calcium carbonate inclusion in low fishmeal diets on growth, gastrointestinal pH, digestive enzyme activity and gut bacterial community of European sea bass (Dicentrarchus labrax L.) juveniles

Fishmeal (FM) possesses one of the highest buffering capacities in comparison to most alternative vegetable aquafeed ingredients and its decreasing content in current formulations might affect the ideal gastrointestinal environment for digestive enzyme action and gut bacterial community of carnivorous fish species. A study was undertaken, therefore, to assess growth response, gastrointestinal pH, digestive enzyme activity and gut bacterial community of European sea bass (Dicentrarchus labrax L.) juveniles fed low FM diets (10% FM) with or without a feed buffering additive, calcium carbonate (FM10 + B and FM10, respectively) in comparison to a standard FM diet (20% FM, FM20). Three isonitrogenous and isolipidic extruded diets were fed to triplicate fish groups of 80 individuals (initial weight: 23 g) to overfeeding over 64 days. No significant differences due to low FM dietary levels were observed in final body weight, specific growth rate, feed intake, feed and protein efficiency. Low FM diet did not affect gastrointestinal pH in the stomach, anterior intestine, mid-intestine and hindgut at 0, 4, 8 and 12 hours post meal (hpm) while the inclusion of calcium carbonate in low FM diet seems to slightly increase the pH in the hindgut at 12 hpm. The absence of significant differences of pepsin, chymotrypsin, amylase and lipase activity suggests a comparable digestive efficiency among treatments although trypsin activity was slightly reduced in low FM diets after 4 hpm. Decreasing FM content seems to exert an effect on the overall gut bacterial community analysed by next-generation sequencing even if no significant effects on specific bacterial component were detected. The gut bacterial community in all the treatments was particularly rich in lactic acid bacteria such as Lactobacillus spp. which may provide important beneficial functions for the host and be associated with a healthy intestinal epithelium. According to the results, increasing the feed buffering capacity does not seem to improve digestive conditions while it is feasible to include 10% FM dietary level in practical formulation for European sea bass juveniles without negatively affecting growth, feed efficiency and digestive luminal conditions.info:eu-repo/semantics/publishedVersio

Impact of deoxynivalenol on rainbow trout: Growth performance, digestibility, key gene expression regulation and metabolism

The impact of deoxynivalenol (DON) on rainbow trout, Oncorhynchus mykiss, is mainly characterised by impaired growth performance and reduced feed intake, usually with the total absence of any visible clinical signs. Despite the high concentrations of DON in the present study (up to 11,412 ± 1141 μg kg−1), no clinical signs (except anorexia at the higher DON dosage) were observed, which confirms the difficulties of diagnosing DON ingestion. Compared to the control group, the proteolytic enzyme activities (pepsin, trypsin and chymotrypsin) in trout were altered by DON ingestion. However, it was not clear if the observed impact on digestive enzymes was due to the direct action of DON, or a consequence of the lower feed intake determined for DON-treated animals. The impact of DON on the abundance of specific measured mRNA transcripts was unexpected with higher expression levels for insulin-like growth factors, igf1 and igf2, which are directly related to elevated insulin levels in plasma. This can also in part be influenced by the trypsin activity and by npy, given its higher mRNA expression levels. The apparent digestibility of dry matter, protein and energy was not affected by dietary levels of DON, however, nutrient retention, protein, fat and energy retention were significantly affected in animals fed DON. Adenylate cyclase-activating polypeptide (PACAP) expression seems to play an important role in controlling feed intake in DON fed trout. In the present study, we have shown for the first time that DON is metabolized to DON-3-sulfate in trout. DON-3-sulfate is much less toxic than DON, which helps to explain the lack of clinical signs in fish fed DON. Being a novel metabolite identified in trout makes it a potential biomarker of DON exposure. Suppression of appetite due to DON contamination in feeds might be a defense mechanism in order to decrease the exposure of the animal to DON, therefore reducing the potential negative impacts of DON

Herramienta software para la enseñanza del paralelismo a nivel de instrucciones (ILP)

Resumen—La arquitectura de computadores es una asignatura de gran importancia en las titulaciones de Informática. Debido a la dificultad de poder acceder directamente a los componentes internos de un procesador, es común en la enseñanza hacer uso de una o varias herramientas software que simulen el comportamiento interno del mismo. Sin embargo, suelen ser herramientas limitadas u obsoletas. Esto provoca una gran dificultad a la hora de transmitir los conocimientos en este tipo de asignaturas. Este caso se puede aplicar directamente al paralelismo a nivel de instrucciones (ILP), que precisa poder visualizar el comportamiento a nivel interno del camino de datos del procesador. Para ello, en este trabajo se presenta una herramienta software desarrollada íntegramente a medida para la enseñanza de arquitectura de computadores, que permite la visualización detallada del pipeline del procesador, permitiendo modificaciones sobre su ejecución y aplicar optimizaciones en tiempo de ejecución para poder obtener medidas de rendimiento. Seguidamente, tras tres años de uso en docencia, se presenta un estudio sobre la bondad del uso de la herramienta atendiendo a la evolución de las calificaciones y a encuestas realizadas sobre el alumnado.TEP-108: Robótica y Tecnología de Computadores de la Universidad de Sevill

Teleost fish larvae adapt to dietary arachidonic acid supply through modulation of the expression of lipid metabolism and stress response genes

Dietary fatty acid supply can affect stress response in fish during early development. Although knowledge on the mechanisms involved in fatty acid regulation of stress tolerance is scarce, it has often been hypothesised that eicosanoid profiles can influence cortisol production. Genomic cortisol actions are mediated by cytosolic receptors which may respond to cellular fatty acid signalling. An experiment was designed to test the effects of feeding gilthead sea-bream larvae with four microdiets, containing graded arachidonic acid (ARA) levels (0·4, 0·8, 1·5 and 3·0 %), on the expression of genes involved in stress response (steroidogenic acute regulatory protein, glucocorticoid receptor and phosphoenolpyruvate carboxykinase), lipid and, particularly, eicosanoid metabolism (hormone-sensitive lipase, PPARα, phospholipase A2, cyclo-oxygenase-2 and 5-lipoxygenase), as determined by real-time quantitative PCR. Fish fatty acid phenotypes reflected dietary fatty acid profiles. Growth performance, survival after acute stress and similar whole-body basal cortisol levels suggested that sea-bream larvae could tolerate a wide range of dietary ARA levels. Transcription of all genes analysed was significantly reduced at dietary ARA levels above 0·4 %. Nonetheless, despite practical suppression of phospholipase A2 transcription, higher leukotriene B4 levels were detected in larvae fed 3·0 % ARA, whereas a similar trend was observed regarding PGE2 production. The present study demonstrates that adaptation to a wide range of dietary ARA levels in gilthead sea-bream larvae involves the modulation of the expression of genes related to eicosanoid synthesis, lipid metabolism and stress response. The roles of ARA, other polyunsaturates and eicosanoids as signals in this process are discussed

Dentex dentex larvalari ve canlı gıdaların proteaz aktiviteleri üzerine ticari yemlerin potansiyel inhibitör etkileri

Bu çalışmanın amacı, Dentex dentex larvaları ve canlı gıdaların proteaz aktiviteleri üzerine ticari yemlerin potansiyel inhibitör etkilerini belirlemektir. Larvaların en yüksek ve en düşük proteaz aktiviteleri sırasıyla 387,08 ±0,23 U/mg protein ve 54,66 ±0,15 U/mg protein olarak tespit edildi. Canlı gıdaların en yüksek ve en düşük proteaz aktiviteleri sırasıyla Artemia metanaupli (414,5 ±0,41 U/mg protein) ve rotiferde (156,25 ±0,09 U/mg protein) bulundu. Larvaların ve canlı gıdaların proteaz aktiviteleri üzerine ticari yemlerin inhibisyon miktarları arasında istatistiksel olarak önemli farklılıklar bulundu (p<0,05). Aynı zamanda, inhibisyon yüzdeleri arasında da istatistiksel olarak önemli farklılıklar gözlendi (p<0.05). Zenginleştirilmiş rotiferler üzerinde, Caviar (200- 300?), Caviar (300-500?) ve copepod’un en yüksek inhibisyon yüzdeleri sırasıyla %91.86 ±0.26, %90.72 ±0,13 ve %90.82 ±0.22 olarak bulundu. Buna ilaveten 35 günlük larvalarda, Caviar (100-200?) ve Protonun (200-400?) en yüksek inhibisyon yüzdeleri sırasıyla %93.57 ±0.18 ve %93.34 ±0.22 olarak gözlendi. Rotiferlerin proteaz aktiviteleri üzerine Caviar’ın (200-300?) etkisi en düşük seviyede oldu. Genelde, larvaların proteaz aktiviteleri üzerinde kopepod’un diğer ticari yemlerden daha düşük bir inhibitör etkisine sahip olduğu gözlendi. Kopepod, 30 günlük larvaların proteaz aktiviteleri üzerinde en düşük etkiyi gösterdi. Canlı gıdaların proteaz aktiviteleri üzerine ticari yemlerin inhibisyon etkileri rotiferler dışında yüksek oldu. Çalışmamız larvaların ve canlı gıdaların proteaz aktiviteleri üzerine sövraj dönemi boyunca kullanılan ticari yemlerin inhibitör etkilerinin dikkate alınması gerektiğini ortaya koymuştur. Sonuç olarak gelecekteki çalışmalarda, kuluçkahanelerde yaşama ve büyüme oranlarını arttırmak için deniz balık larvaları ve canlı gıdaların proteaz aktiviteleri üzerine ticari yemlerin potansiyel inhibitör etkilerinin araştırılması tavsiye edilmiştir.The aim of this study was to determine the potential inhibitory effects of commercial diets on protease activities of Dentex dentex larvae and live foods. The highest and lowest protease activity of larvae was 387.08 &plusmn;0.23 U/mg protein and 54.66 &plusmn;0.15 U/mg protein, respectively. The highest and lowest protease activities of live foods were found in Artemia metanaupli (414.5 &plusmn;0.41 U/mg protein) and rotifer (156.25 &plusmn;0.09 U/mg protein), respectively. The significant differences between inhibition amounts of commercial diets on protease activities of larvae and live foods were found (p&lt;0.05). Also, the significant differences between the inhibition percents were observed (p&lt;0.05). The highest inhibition percents of Caviar (200-300&amp;#956;), Caviar (300-500&amp;#956;) and copepod were found as 91.86 &plusmn;0.26%, 90.72 &plusmn;0.13% and 90.82 &plusmn;0.22% in enriched rotifers, respectively. In addition, the highest inhibition percents of Caviar (100-200&amp;#956;) and Proton (200-400&amp;#956;) were observed as 93.57 &plusmn;0.18% and 93.34 &plusmn;0.22% in the larvae on day 35, respectively. The effect of Caviar (200-300&amp;#956;) on protease activities of rotifer was the lowest. In general, copepod had the lower inhibitory effect than those of other commercial diets on protease activities of larvae. Copepod showed the lowest effect on protease activity of larvae on day 30. The inhibition percents of commercial diets on protease activities of live foods were high except for rotifers. Our study revealed that the inhibitory effects of commercial diets used through weaning on protease activities of larvae and live foods should be taken into account. In conclusion, the potential inhibitory effects of commercial diets on protease activities of marine fish larvae and live foods to increase the survival and growth rates in hatcheries should be investigated in future studies

A Preliminary study on the biochemical compositions of Na-alginate microcapsules

Bu çalışmada, 80?-900 ? arasındaki Na-alginat mikrokapsullerinin biyokimyasal kompozisyonlarındaki değişimler belirlendi. Bu amaca ulaşmak için mikrokapsüllerin 6 grubu (80-200?; 200-250?; 250-355?; 355-500?; 500-900?; >900?) analiz edildi. Mikrokapsüllerin kuru madde, kül ve lipit miktarları arasında önemli farklılıklar bulundu (P900?) and % 21.85 ±0.85 (355-500?) gruplarda bulundu. Mikrokapsül gruplarının protein miktarları arasındaki farklılıklar istatistiksel olarak önemli oldu (P<0,05). Sonuçlar, en yüksek protein miktarının 80-200?’luk grupta % 66.24 ±0.05 olduğunu gösterdi. Çalışmamız, deniz balık larvalarında gözlenen düşük yaşama ve büyüme oranlarının larvaların beslenmesinde kullanılan mikrokapsüllerin biyokimyasal kompozisyonlarında gözlenen değişimlerin sonucuyla ilişkili olabileceğini ortaya çıkarmıştır. Sonuç olarak gelecek çalışmalarda, sürdürülebilir akuakültür için diğer üretim metotlarıyla farklı büyüklük sınıflarında üretilen mikrokapsüllerin biyokimyasal kompozisyonlarındaki değişimlerin araştırılması gerekir.In present study, the changes in the biochemical compositions of Na-alginate microcapsules with diameters between 80&amp;#956;-900 &amp;#956; were determined. To achive this purpose, six groups(80-200&amp;#956;; 200-250&amp;#956;; 250-355&amp;#956;; 355-500&amp;#956;; 500-900&amp;#956;; &gt;900&amp;#956;) of microcapsules were analyzed. The significant differences between dry matter, ash and lipid amounts of microcapsules were found (P&lt;0.05). The highest dry matter, ash and lipid amounts were 98.32&plusmn;0.02% (80-200&amp;#956;) , 3.91&plusmn;0.02% (&gt;900&amp;#956;) and 21.85&plusmn;0.85% (355-500&amp;#956;), respectively. Also, the differences between protein amounts of all microcapsule groups were statistically significant (P&lt;0.05). Results showed that the highest protein amount was 66.24&plusmn;0.05 % (80-200&amp;#956;). Our study revealed that low survival and growth rates in marine fish larvae may be related to the result of the changes in biochemical compositions of microcapsules used in the feeding of larvae. In conclusion, the changes in the biochemical compositions of microcapsules produced in the different size classes with other manufacturing methods to sustainable aquaculture should be investigated in future studies

The spatiotemporal expression pattern of trypsinogen and bile salt-activated lipase during the larval development of red porgy (Pagrus pagrus, Pisces, Sparidae)

The fish larval stage is a critical step since only those specimens that survive will reach the adult stage in future. Knowledge related to fish larval nutritional requirements and digestive enzymes capacity is still scarce, although necessary to obtain satisfactory survival and growth rates. Trypsinogen is the precursor of trypsin, the main proteolytic enzyme acting during the early larval stage. Bile salt-activated lipase (BAL) is a multi-substrate digestive enzyme that hydrolyzes carboxyl ester bonds of acylglycerols, cholesterol esters and fat-soluble vitamin esters. The goal of this study was to determine the pattern of trypsinogen and BAL expression during larval development in red porgy (Pagrus pagrus, Pisces, Sparidae), reared under standard conditions to provide the basis for future experiments testing the possible transcriptional regulation for this enzyme under different nutritional conditions. Thus, partial cDNAs for trypsinogen and BAL from red porgy were isolated. The putative aminoacid sequences obtained for both precursors showed around 80% identity to other fish sequences from GenBank database. Trypsinogen and BAL were expressed from hatching and specifically located in the exocrine pancreas, revealed by in situ hybridization. The present study shows that this species is being prepared for protein and lipid digestion before exogenous feeding starts, exhibiting an ontogenetically programmed pattern for trypsinogen and BAL expression during the yolk-sac stage.Peer reviewed: YesNRC publication: Ye

The spatiotemporal expression pattern of trypsinogen and bile salt-activated lipase during the larval development of red porgy (Pagrus pagrus, Pisces, Sparidae)

The fish larval stage is a critical step since only those specimens that survive will reach the adult stage in future. Knowledge related to fish larval nutritional requirements and digestive enzymes capacity is still scarce, although necessary to obtain satisfactory survival and growth rates. Trypsinogen is the precursor of trypsin, the main proteolytic enzyme acting during the early larval stage. Bile salt-activated lipase (BAL) is a multi-substrate digestive enzyme that hydrolyzes carboxyl ester bonds of acylglycerols, cholesterol esters and fat-soluble vitamin esters. The goal of this study was to determine the pattern of trypsinogen and BAL expression during larval development in red porgy (Pagrus pagrus, Pisces, Sparidae), reared under standard conditions to provide the basis for future experiments testing the possible transcriptional regulation for this enzyme under different nutritional conditions. Thus, partial cDNAs for trypsinogen and BAL from red porgy were isolated. The putative aminoacid sequences obtained for both precursors showed around 80% identity to other fish sequences from GenBank database. Trypsinogen and BAL were expressed from hatching and specifically located in the exocrine pancreas, revealed by in situ hybridization. The present study shows that this species is being prepared for protein and lipid digestion before exogenous feeding starts, exhibiting an ontogenetically programmed pattern for trypsinogen and BAL expression during the yolk-sac stage.Peer reviewed: YesNRC publication: Ye