Función de la NAT en la regulación de la síntesis rítmica de melatonina en la retina de anfibios : influencia de factores ambientales y endógenos

La arilaquilamina n-acetiltransferasa ha sido considerada la enzima limitante en la ruta de síntesis de melatonina en los vertebrados. El objetivo de la tesis doctoral es el conocimiento del papel que juega esta enzima en la síntesis de melatonina en la retina de los anfibios anuros, su regulación por factores ambientales correlacionándose con los mecanismos endógenos del animal. La nat muestra un ritmo diario en su actividad mostrando apareciendo los valores máximos durante la noche, la exposición a la luz reduce los niveles de la nat hasta valores equivalentes a los basales diurnos. La aparición del ritmo ocular de la actividad nat durante la ontogenia de los anuros coincide con el comienzo de la función visual. Las variaciones estacionales del fotoperiodo y la temperatura determinan el perfil diario de la melatonina y nat ocular. La temperatura regula la amplitud de la oscilación diaria de melatonina, y el fotoperiodo la duración del máximo nocturno. La cinética de la nat muestra una modulación térmica positiva, y una inhibición por exceso de serotonina dependiente de la temperatura, la regulación endogena del ritmo de melatonina y nat se lleva a cabo por medio de la dopamina a través de receptores d2 los mensajeros intracelulares responsables del ritmo de melatonina son el ampc y el calci

Retrieval of bilingual Spanish-English information by means of a standard automatic translation system

This paper describes our participation in bilingual retrieval (queries in Spanish on documents in English), by means of an information retrieval system based on the vector model. The queries, formulated in Spanish, were translated into English by means of a commercial automatic translation system; the terms extracted from the resulting translations were filtered in order to get rid of empty words and then they were normalised by stemming. Results are poorer than those obtained through monolingual retrieval with the original queries in English slightly above 15%

Performance of Catalan-Spanish bilinguals on the Bilingual Aphasia Test of Michel Paradis: Influence of age and educational level

El Test de la Afasia para Bilingües (TAB) fue diseñado para valorar las capacidades lingüísticas residuales de individuos bilingües o plurilingües con afasia. En la actualidad, el test está disponible en más de 60 idiomas. Aunque su aparición data de finales de los 80, los estudios destinados a valorar sus propiedades psicométricas son todavía escasos. El objetivo del presente trabajo fue doble: (1) comparar el rendimiento verbal en catalán y en castellano de 56 bilingües sanos con las versiones en catalán (TAB-Cat) y en castellano (TAB-Cast) del test, y (2) determinar si la edad y el nivel educativo influyen en los resultados obtenidos en cada lengua. En general, el rendimiento obtenido en catalán y en castellano fue más similar que diferente. Las diferencias a favor del castellano pueden interpretarse en términos sociolingüísticos. Los análisis de regresión efectuados mostraron que el nivel educativo por sí mismo tuvo una mayor influencia en el rendimiento lingüístico que la edad. Esta influencia también se refleja en la puntuación total de cada versión del TAB. Salvo excepciones, los participantes del estudio alcanzaron el criterio de éxito marcado por el manual para cada subtest. Finalmente, creemos que las versiones en catalán y en castellano del TAB son comparables y adecuadas para su utilización en nuestro entorno. No obstante, es necesario realizar más estudios que permitan profundizar en sus características y propiedades.The Bilingual Aphasia Test (BAT) was designed to assess the residual language capacities of bilingual or multilingual individuals with aphasia. At the present time, the test is available in more than 60 languages. Although its appearance dates from the late 80’s, studies to evaluate its psychometric properties are still scarce. The aim of this study was double: (1) to compare language performance in Catalan and Spanish of 56 healthy bilinguals with the Catalan (BAT-Cat) and Spanish (BAT-Spa) versions of the test, and (2) to determine the influence of age and educational level in each language. In general, language performance in Catalan and Spanish was more similar than different. The differences in favour of Spanish can be interpreted in sociolinguistic terms. In general, the regression analysis performed showed that the educational level itself had a greater influence on language performance than age. Except for some cases, the participants of the study achieved the success criteria set by the test manual for each subtest. Finally, the Catalan and Spanish versions of the BAT are comparable and appropriate for their use in our environment; nevertheless, more studies are needed to deepen in their characteristics and properties

Rendimiento de bilingües catalán-castellano en el test de Afasia para Bilingües de Michel Paradís: influencia de la edad y del nivel educativo

The Bilingual Aphasia Test (BAT) was designed to assess the residual language capacities of bilingual or multilingual individuals with aphasia. At the present time, the test is available in more than 60 languages. Although its appearance dates from the late 80's, studies to evaluate its psychometric properties are still scarce. The aim of this study was double: (1) to compare language performance in Catalan and Spanish of 56 healthy bilinguals with the Catalan (BAT-Cat) and Spanish (BAT-Spa) versions of the test, and (2) to determine the influence of age and educational level in each language. In general, language performance in Catalan and Spanish was more similar than different. The differences in favour of Spanish can be interpreted in sociolinguistic terms. In general, the regression analysis performed showed that the educational level itself had a greater influence on language performance than age. Except for some cases, the participants of the study achieved the success criteria set by the test manual for each subtest. Finally, the Catalan and Spanish versions of the BAT are comparable and appropriate for their use in our environment; nevertheless, more studies are needed to deepen in their characteristics and properties

Conventional Industrial Robotics Applied to the Process of Tomato Grafting Using the Splicing Technique

Horticultural grafting is routinely performed manually, demanding a high degree of concentration and requiring operators to withstand extreme humidity and temperature conditions. This article presents the results derived from adapting the splicing technique for tomato grafting, characterized by the coordinated work of two conventional anthropomorphic industrial robots with the support of low-cost passive auxiliary units for the transportation, handling, and conditioning of the seedlings. This work provides a new approach to improve the efficiency of tomato grafting. Six test rates were analyzed, which allowed the system to be evaluated across 900 grafted units, with gradual increases in the speed of robots work, operating from 80 grafts/hour to over 300 grafts/hour. The results obtained show that a higher number of grafts per hour than the number manually performed by skilled workers could be reached easily, with success rates of approximately 90% for working speeds around 210–240 grafts/hour

Statistical study of combustion characteristics and optimal operation factor determination in an emulsion burner fuelled with vegetable oils

This work experimentally investigates the combustion characteristics of refined soya, sunflower and rapeseed vegetable oils and, by means of statistical techniques, determines the optimal operating factors of an emulsion burner to obtain the best combustion performance and low pollutant emissions. Given the high dimensionality of the study, the PCA provides a descriptive study of the variables involved in the combustion process and of the physicochemical properties of the vegetable oils so as to establish the correlations between them. ANOVA was then performed to identify which factors (type of vegetable oil, fuel flow, and airflow), as well as any possible interactions, have the greatest impact on the combustion results (performance as well as CO2, CO, NOx, CxHy and SOx emissions). ANOVA results showed that almost all of the factors and their interactions were significant, which makes it essential to analyse the interaction plots to see the optimal combinations of levels. This study showed that fuel flow rate was quite an important factor affecting combustion characteristics, that the type of vegetable oil influenced CxHy emissions, and that the airflow rate displayed no clear trend. Furthermore, the best combustion performance coupled with pollutant emissions that were below the lowest limits established by current legislation were achieved for a combination of maximum fuel flow and minimum airflow rates, with soya exhibiting the best performance. In general, good combustion performances were obtained with extremely low NOx emissions, and SOx emissions were not detected in any of the combustion experiments performed.Spanish Ministerio de Economía y Competitividad, grant MTM2017-86061-C2-1-P, and by Consejería de Educación de la Junta de Castilla y León and FEDER, grant VA005P17 and VA002G18

Statistical Study of Combustion Characteristics and Optimal Operation Factor Determination in an Emulsion Burner Fueled with Vegetable Oils

This work experimentally investigates the combustion characteristics of refined soya, sunflower, and rapeseed vegetable oils and, by means of statistical techniques, determines the optimal operating factors of an emulsion burner to obtain the best combustion performance and low pollutant emissions. Given the high dimensionality of the study, principal component analysis provides a descriptive study of the variables involved in the combustion process and of the physicochemical properties of the vegetable oils so as to establish the correlations between them. ANOVA was then performed to identify which factors (type of vegetable oil, fuel flow, and airflow), as well as any possible interactions, have the greatest impact on the combustion results (performance as well as CO2, CO, NOx, CxHy, and SOx emissions). The ANOVA results showed that almost all of the factors and their interactions were significant, which makes it essential to analyze the interaction plots in order to see the optimal combinations of levels. This study showed that fuel flow rate was quite an important factor affecting combustion characteristics, that the type of vegetable oil influenced CxHy emissions, and that the airflow rate displayed no clear trend. Furthermore, the best combustion performance coupled with pollutant emissions below the lowest limits established by the current legislation were achieved for a combination of maximum fuel flow and minimum airflow rates, with soya exhibiting the best performance. In general, good combustion performances were obtained with extremely low NOx emissions. SOx emissions were not detected in any of the combustion experiments performed.Spanish Ministerio de Economía y Competitividad, grant MTM2017-86061-C2-1-P, and by Consejería de Educación de la Junta de Castilla y León and FEDER, grant VA005P17 and VA002G18

Ghrelin induces clock gene expression in the liver of goldfish in vitro via protein kinase C and protein kinase A pathways

The liver is the most important link between the circadian system and metabolism. As a food-entrainable oscillator, the hepatic clock needs to be entrained by food-related signals. The objective of the present study was to investigate the possible role of ghrelin (an orexigenic peptide mainly synthesized in the gastrointestinal tract) as an endogenous synchronizer of the liver oscillator in teleosts. To achieve this aim, we first examined the presence of ghrelin receptors in the liver of goldfish. Then, the ghrelin regulation of clock gene expression in the goldfish liver was studied. Finally, the possible involvement of the phospholipase C/protein kinase C (PLC/PKC) and adenylate cyclase/protein kinase A (AC/PKA) intracellular signalling pathways was investigated. Ghrelin receptor transcripts, ghs-r1a, are present in the majority of goldfish hepatic cells. Ghrelin induced the mRNA expression of the positive (gbmal1a, gclock1a) and negative (gper genes) elements of the main loop of the molecular clock machinery, as well as grev-erbα (auxiliary loop) in cultured liver. These effects were blocked, at least in part, by a ghrelin antagonist. Incubation of liver with a PLC inhibitor (U73122), a PKC activator (phorbol 12-myristate 13-acetate) and a PKC inhibitor (chelerythrine chloride) demonstrated that the PLC/PKC pathway mediates such ghrelin actions. Experiments with an AC activator (forskolin) and a PKA inhibitor (H89) showed that grev-erbα regulation could be due to activation of PKA. Taken together, the present results show for the first time in vertebrates a direct action of ghrelin on hepatic clock genes and support a role for this hormone as a temporal messenger in the entrainment of liver circadian functions

Nuclear receptors (PPARs, REV-ERBs, RORs) and clock gene rhythms in goldfish (Carassius auratus) are differently regulated in hypothalamus and liver

The circadian system is formed by a network of oscillators located in central and peripheral tissues that are tightly linked to generate rhythms in vertebrates to adapt the organism to the cyclic environmental changes. The nuclear receptors PPARs, REV-ERBs and RORs are transcription factors controlled by the circadian system that regulate, among others, a large number of genes that control metabolic processes for which they have been proposed as key genes that link metabolism and temporal homeostasis. To date it is unclear whether these nuclear receptors show circadian expression and which zeitgebers are important for their synchronization in fish. Therefore, the objective of this study was to investigate whether the two main zeitgebers (light-dark cycle and feeding time) could affect the synchronization of central (hypothalamus) and peripheral (liver) core clocks and nuclear receptors in goldfish. To this aim, three experimental groups were established: fish under a 12 h light-12 h darkness and fed at Zeitgeber Time 2; fish with the same photoperiod but randomly fed; and fish under constant darkness and fed at Circadian Time 2. After one month, clock genes and nuclear receptors expression in hypothalamus and liver and circulating glucose were studied. Clock genes displayed daily rhythms in both tissues of goldfish if the light-dark cycle was present, with shifted-acrophases of negative and positive elements, as expected for proper functioning clocks. In darkness-maintained fish hypothalamic clock genes were fully arrhythmic while the hepatic ones were still rhythmic. Among studied nuclear receptors, in the hypothalamus only nr1d1 was rhythmic and only when the light-dark cycle was present. In the liver all nuclear receptors were rhythmic when both zeitgebers were present, but only nr1d1 when one of them was removed. Plasma glucose levels showed significant rhythms in fish maintained under random fed regimen or constant darkness, with the highest levels at 1-h postprandially in all groups. Altogether these results support that hypothalamus is mainly a light-entrained-oscillator, while the liver is a food-entrained-oscillator. Moreover, nuclear receptors are revealed as clear outputs of the circadian system acting as key elements in the timekeeping of temporal homeostasis, particularly in the liver

Fatty acid sensing in the gastrointestinal tract of rainbow trout: different to mammalian model?

It is well established in mammals that the gastrointestinal tract (GIT) senses the luminal presence of nutrients and responds to such information by releasing signaling molecules that ultimately regulate feeding. However, gut nutrient sensing mechanisms are poorly known in fish. This research characterized fatty acid (FA) sensing mechanisms in the GIT of a fish species with great interest in aquaculture: the rainbow trout (Oncorhynchus mykiss). Main results showed that: (i) the trout GIT has mRNAs encoding numerous key FA transporters characterized in mammals (FA transporter CD36 -FAT/CD36-, FA transport protein 4 -FATP4-, and monocarboxylate transporter isoform-1 -MCT-1-) and receptors (several free FA receptor -Ffar- isoforms, and G protein-coupled receptors 84 and 119 -Gpr84 and Gpr119-), and (ii) intragastrically-administered FAs differing in their length and degree of unsaturation (i.e., medium-chain (octanoate), long-chain (oleate), long-chain polyunsaturated (α-linolenate), and short-chain (butyrate) FAs) exert a differential modulation of the gastrointestinal abundance of mRNAs encoding the identified transporters and receptors and intracellular signaling elements, as well as gastrointestinal appetite-regulatory hormone mRNAs and proteins. Together, results from this study offer the first set of evidence supporting the existence of FA sensing mechanisms n the fish GIT. Additionally, we detected several differences in FA sensing mechanisms of rainbow trout vs. mammals, which may suggest evolutionary divergence between fish and mammals.Xunta de Galicia | Ref. ED431B 2022/01Agencia Estatal de Investigación española | Ref. PID2019-103969RB-C31Ministerio de Educación, Cultura y Deporte | Ref. FPU19/00122Ministerio de Educación, Cultura y Deporte | Ref. FPU16/00045Ministerio de Ciencia e Innovación | Ref. IJC2019-039166-