Time Course of Metabolic Capacities in Paralarvae of the Common Octopus, Octopus vulgaris, in the First Stages of Life. Searching Biomarkers of Nutritional Imbalance.

The culture of the common octopus (Octopus vulgaris) is promising since the species has a relatively short lifecycle, rapid growth, and high food conversion ratios. However, recent attempts at successful paralarvae culture have failed due to slow growth and high mortality rates. Establishing an optimal nutritional regime for the paralarvae seems to be the impeding step in successful culture methods. Gaining a thorough knowledge of food regulation and assimilation is essential for paralarvae survival and longevity under culture conditions. The aim of this study, then, was to elucidate the characteristic metabolic organization of octopus paralarvae throughout an ontogenic period of 12 days post-hatching, as well as assess the effect of diet enrichment with live prey containing abundant marine phospholipids. Our results showed that throughout the ontogenic period studied, an increase in anaerobic metabolism took place largely due to an increased dependence of paralarvae on exogenous food. Our studies showed that this activity was supported by octopine dehydrogenase activity, with a less significant contribution of lactate dehydrogenase activity. Regarding aerobic metabolism, the use of amino acids was maintained for the duration of the experiment. Our studies also showed a significant increase in the rate of oxidation of fatty acids from 6 days after-hatching. A low, although sustained, capacity for de novo synthesis of glucose from amino acids and glycerol was also observed. Regardless of the composition of the food, glycerol kinase activity significantly increased a few days prior to a massive mortality event. This could be related to a metabolic imbalance in the redox state responsible for the high mortality. Thus, glycerol kinase might be used as an effective nutritional and welfare biomarker. The studies in this report also revealed the important finding that feeding larvae with phospholipid-enriched Artemia improved animal viability and welfare, significantly increasing the rate of survival and growth of paralarvae.

Regional asymmetry of metabolic and antioxidant profile in the sciaenid fish shi drum (Umbrina cirrosa) white muscle. Response to starvation and refeeding.

The objective of the present study is to characterize the metabolic and antioxidant profile of white muscle of shi drum in two sites of the body, anterior dorsal (AM) and posterior dorsal (PM) portions. In addition, it will be analyzed the possible effect of starvation and a subsequent refeeding, with two different protocols, pair feeding and ad libitum. Activities of key enzymes of intermediary metabolism and of antioxidant enzymes, as well as lipid peroxidation, as an index of oxidative stress, were evaluated. The results indicate the existence of a regional asymmetry of the metabolic capacities of the white muscle of shi drum, which is likely related to the different contribution to swimming of the body regions examined. Starvation induces a metabolic depression that is more marked in those activities that support burst swimming in PM, while those activities supporting maintenance requirements are conserved. The greatest energy demands during starvation appear to lie in AM, which showed the highest oxidative metabolism rate. The increased use of fatty acids as energy source for AM leads to oxidative stress. A period of more than four weeks of refeeding for full restoration of metabolic capacities in AM is needed, probably related to the higher muscle mass located in this region. On the contrary, all enzyme activities in PM returned to control levels in both refeeding protocols, but pair feeding seems to be advantageous since compensatory growth has been taking place without signs of oxidative stress. This work was addressed to gain knowledge on the physiology of a promising fish species in aquaculture like shi drum. The results displayed here show how the starving and further re-feeding events could generate oxidative stress situations characterized by high lipid peroxidation levels which may influence negatively on the quality of the edible part of the fish. This study opens an interesting field on this fish species which deserves being investigated in the future.

Dietary carbohydrates improve oxidative status of common dentex (Dentex dentex) juveniles, a carnivorous fish species.

Common dentex (Dentex dentex) is an appreciated carnivorous fish with high growth rate and life cycle adaptable to existing farming techniques. Since the use of carbohydrates is an economic and sustainable alternative for a protein-sparing effect, the study of how this macronutrient affects the welfare of carnivorous species must be studied. The aim of the present study was to evaluate the effects of different types and levels of carbohydrates on common dentex oxidative status. Nine isonitrogenous (43%) and isoenergetic (22MJkg-1) diets were formulated combining three types (pregelatinized starch-PS, dextrin-Dx and maltodextrin-Mx) and three levels (12, 18 and 24%) of carbohydrates. The activities of catalase-CAT, superoxide dismutase-SOD, glutathione peroxidase-GPX, glutathione reductase-GR and glucose 6-phosphate dehydrogenase-G6PDH, SOD isoenzymatic profile, lipid peroxidation-LPO and protein oxidation-PO were determined in liver and white muscle. SOD and CAT were not affected. GPX in liver and white muscle and GR in liver increased at higher inclusion carbohydrates levels. The lowest levels of GR and G6PDH in both tissues and LPO in liver were observed in maltodextrin groups. No significant effects by carbohydrate source were observed in liver PO and white muscle LPO. Regarding carbohydrate level effect, 18% and 24% dietary inclusion level decreased LPO in white muscle and PO in liver. LPO in liver was also decreased at 24% inclusion level. Altogether, results indicate the use of carbohydrates as an alternative energy source does not produce negative effects on oxidative status of common dentex, on the contrary, even contribute to their oxidative protection.

Nutritional and metabolic responses in common dentex (Dentex dentex) fed on different types and levels of carbohydrates.

The present study was aimed to evaluate the capacity of common dentex (Dentex dentex) to efficiently use dietary carbohydrates. So, the effects of different type and levels of carbohydrates on growth performance, feed utilization, fish composition, plasma metabolites and key metabolic pathways in liver and white muscle of common dentex are presented. Nine isonitrogenous (43%) and isoenergetic (22 MJ kg(-1)) diets were formulated combining three types, pregelatinized starch (PS), dextrin (Dx) and maltodextrin (Mx), and three levels (12, 18 and 24%) of carbohydrates. Growth performance was not significantly influenced by treatments. The best feed utilization was observed in 18% Mx group. Higher hepatic lipid content was found in fish fed lower dietary carbohydrate levels. PS induced higher liver and white muscle hexokinase and pyruvate kinase activities compared to the lower values observed for Mx. Malic enzyme and glucose 6-phosphate dehydrogenase in liver and white muscle were lower in Mx group. The influence of dietary carbohydrates source was more noticeable than those induced by the carbohydrate level, when glycolysis and lipogenesis pathways were considered. Common dentex is able to use properly dietary carbohydrates, although optimal dietary inclusion levels are below 24%. The greater protein-sparing effect was promoted by the less complex carbohydrate (maltodextrin) and the best feed utilization indices were obtained at intermediate levels of inclusion (18%).

Medición y predicción de la satisfacción con la vida en inmigrantes empleados en España. Diferencias según su situación administrativa / Measurement and prediction of satisfaction with life in immigrant workers in Spain. Differences according to their administrative status

Este trabajo se plantea conocer el nivel de satisfacción vital y mostrar algunos factores que predicen la satisfacción de los inmigrantes en España, así como las diferencias en función de su situación administrativa. La muestra está compuesta por 277 empleados inmigrantes (25.4% en situación irregular). Las variables independientes consideradas han sido: satisfacción con la vida en el país de origen, el apoyo social actual y satisfacción laboral. Los resultados muestran que los inmigrantes manifiestan escaso aumento de la satisfacción vital en el nuevo país, no se sienten más felices y hay una clara diferencia en la satisfacción con la vida en función de su situación administrativa (mayor en los inmigrantes con situación regularizada). El análisis de regresión muestra que para el grupo con situación administrativa irregular el 50.9% de la varianza de la satisfacción vital actual se predice por la manifestada respecto a su país de origen. Para los inmigrantes con permiso de residencia, la satisfacción vital en su país de origen, el apoyo social y la satisfacción laboral intrínseca explican el 47.2% de la satisfacción actual (AU)

This study aims to describe characteristics and job conditions in a sample of 277 immigrants of different nationalities in Spain (25.4% in unregulated situation), to know their degree of life satisfaction, to show some of the factors that predict their satisfaction with life, and to reveal possible differences between immigrants with varying legal status. The independent variables that have been considered are: life satisfaction in their country of origin, current social support and job satisfaction (both extrinsic and intrinsic). The results show that the immigrants experience meagre increases in life satisfaction in the new country, no increase in their feeling of happiness, and that there is a clear different degree of life satisfaction among immigrants with different legal statuses (higher in status regularized immigrants). The regression analysis shows that 50.9% of the variance of present life satisfaction for immigrants in an irregular legal status is predicted by the life satisfaction related to their own country. However, for those immigrants with residence permit, 47.2% of the pre-sent life satisfaction is explained by life satisfaction in their own country, social support and intrinsic job satisfaction (AU)

Antioxidant enzymatic defenses and oxidative damage in Dentex dentex fed on different dietary macronutrient levels.

A wide range of antioxidant mechanisms are present in fish maintaining an adequate "oxidative balance". When this balance tilts in favor of the oxidant agents "oxidative stress" arises with detrimental effects in molecules of great biological importance. Little has been reported about the influence of different dietary energy sources on antioxidant defenses in fish. The influence of different dietary macronutrient combinations on the key antioxidant enzyme activity, the oxidative damage to lipids and proteins and the possible modifications in the SOD isoenzymatic pattern were evaluated in liver, white muscle, heart and erythrocytes of common dentex (Dentex dentex). Four experimental diets with different protein:lipid:carbohydrate ratios (43/16/28; 43/24/4; 38/19/28 and 38/24/13) were formulated. In general, neither different dietary macronutrient levels nor the interaction among them induces substantial modifications in enzymatic antioxidant defense mechanisms. Two constitutive SOD isoforms, CuZn-SOD I and Mn-SOD, were detected in the tissues analyzed in all experimental groups, independently of diet formulation, but, a third SOD isoenzyme, CuZn-SOD II seems to be induced in white muscle by higher dietary protein levels. Densitometric analyses of western blotting membranes revealed higher CuZn-SOD expression in the heart of dentex fed on lower dietary protein levels, although these differences did not correlate with the SOD activity. Finally, a direct relation exists between the lipid or protein intake level and occurrence of oxidative damage in different tissue components.

Digestive enzymatic profile of Dentex dentex and response to different dietary formulations.

Digestive physiology of on-growing common dentex (Dentex dentex), including protease, amylase and lipase activity in stomach, pyloric caeca, anterior and posterior intestine, was evaluated. The influence of dietary macronutrient balance on these digestive processes was also assessed. Four experimental diets with different protein:lipid:carbohydrate ratios (43/16/28; 43/24/4; 38/19/28 and 38/24/13) were formulated. The highest activity for acid proteases was located in the stomach at pH 1.5. Alkaline proteolytic activities showed the highest values in the pyloric caeca and posterior intestine at pH 8.5-9.0. Dentex showed substantial amylase activity in the pyloric caeca and posterior intestine. Lipase activity was higher in the pyloric caeca, anterior and posterior intestine and was not detected in the stomach. Feed composition influenced alkaline protease activity in the anterior and posterior intestine and was higher for the diet with less protein and more carbohydrates. Enhanced amylase activity was observed in the pyloric caeca and posterior intestine in those groups fed on higher carbohydrate and lower lipid level diets. High dietary carbohydrate levels produced the highest lipase activity but this only occurred in the anterior intestine. We can conclude that the digestive tract of dentex adapts well to protein digestion and possesses a high potential for digesting the other dietary macronutrients, too. Dietary carbohydrate content seems to induce changes in protease, amylase and lipase activity.

Use of different combinations of macronutrients in diets for dentex (Dentex dentex): effects on intermediary metabolism.

The influence of the dietary macronutrient balance on the intermediary metabolism of common dentex (Dentex dentex L.) was evaluated. Four experimental diets combining high and low levels of macronutrients were formulated. Dentex fed on 43% protein had higher liver and muscle lipid content, corresponding with an increased hepatic G6PDH activity. This "excess" of hepatic lipids at higher protein levels could be used to obtain energy as would be reflected by hepatic HOAD. In the liver, 43% of dietary protein induced higher AlaAT and FBPase activities. Similarly, dentex fed on the P(43)C(28) and P(38)C(28) diets showed an increased hepatic and muscular gluconeogenic pathways (higher FBPase activity) from amino acids (elevated AlaAT) and/or glycerol (elevated GK). However, changes in glycemia were not observed among dietary treatments. At coronary level, the use of lower dietary protein induced an increase in the activity of glycolytic (PK and HK-IV) and lipolytic (HOAD) enzymes. Considering the overall results and the experimental conditions, it could be suggested that dietary protein could be reduced until 38% without affecting negatively the normal physiology of dentex. Moreover, high dietary carbohydrate levels could not be used efficiently by dentex given that gluconeogenesis occurs.

Effect of starvation and refeeding on digestive enzyme activities in sturgeon (Acipenser naccarii) and trout (Oncorhynchus mykiss).

The digestive enzyme activities were determined in Adriatic sturgeon and rainbow trout during starvation and refeeding period. Overall, the digestive enzyme activities are affected in the same sense in both species. The protease and lipase activities were decreased later than amylase activity. Even after 1 month of starvation, both species would be prepared to digest protein and lipids in an effective way. After 72 days of starvation, the digestive machinery of the sturgeon and of the trout shows an altered capacity to digest macronutrients. The capacity to digest proteins and lipids, after 60 days of refeeding, begins to become re-established in sturgeon and trout. In contrast, in this period, the capacity to digest carbohydrates remains depressed in both species.

Effect of urban vegetation on psychological restorativeness.

The present study analyzes the contribution which natural elements in the city make to restorativeness, that is, the potential of certain environments to help recover the capacity to focus attention, reduce mental fatigue, and reduce stress. We presented photographs of 12 urban scenes (streets, industrial areas, and buildings) with and without vegetation to 214 university students, divided into 12 groups who then completed the Perceived Restorativeness Scale. The results support the hypothesis, i.e., urban environments with natural elements yield higher restorativeness than urban environments lacking these.

Oxidative stress and antioxidant defenses after prolonged starvation in Dentex dentex liver.

The aim of this work was to evaluate the effects of prolonged starvation and refeeding on antioxidant status and some metabolic-related parameters in common dentex (Dentex dentex) liver. Fish deprived of food for 5 weeks showed a significant increase in lipid peroxidation, measured as malondialdehyde (MDA) levels. The activity of the antioxidative enzymes superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX) in starved fish significantly increased (by 42%, 22%, and 52%, respectively), whereas glutathione reductase (GR) activity was significantly depressed by 53% compared to controls. No qualitative changes in the SOD isoenzymatic pattern were detected by nondenaturing PAGE analysis, but the isoforms corresponding to CuZn-SOD I and II were enhanced in starved fish. The activity of the enzymes indicative of oxidative metabolism, beta-hydroxyacyl CoA dehydrogenase (HOAD) and citrate synthase (CS), significantly increased (by 123% and 28%, respectively), and that of glucose-6-phosphate dehydrogenase (G6PDH) was inhibited by 56%. Oxidative damage under these circumstances is reversible since all biomarkers assayed returned to control values after refeeding. Our results show that prolonged starvation leads to a pro-oxidant situation and oxidative stress despite activation of antioxidant defense mechanisms, and that inhibition of G6PDH activity might be responsible for this failure in cellular antioxidant defenses.

Oxidative stress generated by dietary Zn-deficiency: studies in rainbow trout (Oncorhynchus mykiss).

To date, there is scarce information on the metabolic and biochemical repercussions of Zn-deficiency in fish. In this work, the effect of dietary Zn-deficiency on the diet utilization and the metabolism of activated oxygen species in rainbow trout (Oncorhynchus mykiss) has been studied. Fish were randomly separated in different lots according to their Zn-starvation and diet intake. In crude extracts of liver, gut and muscle, total and isoenzymatic superoxide dismutase and catalase activities were analysed. Lipid peroxidation was also determined in the same tissues. Western blotting was performed using antibodies against manganese- and copperzinc-containing superoxide dismutase. Lots fed on the Zn-deficient diet and with low intake showed significantly lower weight gain and feed-conversion efficiency indexes than control trouts. However, these parameters returned to control values when trouts were recovered by feeding them a control diet ad libitum. In control trouts, three independent copperzinc superoxide dismutase isozymes were detected in liver, whereas only one isozyme was present in the other lots. However, by Western blotting analysis the presence of a manganese superoxide dismutase was found in liver from all lots except in control trouts. Catalase activity and lipid peroxidation values were mainly detected in liver and gut, respectively, and both parameters increased in all lots with respect to the control group. Our results thus suggest that in rainbow trout an oxidative stress appears to occur as a consequence of Zn-deficiency.

Attachment to the physical dimension of places.

Social relationships had been important in explanation and prediction of attachment to places. Although some have asserted the importance of physical aspects of the environment in the formation of attachment ties to a place, the social environment is required for the formation of bonds to a place, although strong emphasis on the social aspect has been questioned and the importance of the physical environment noted. The present objective in two studies was to test whether college students (ns = 30 and 27) show a preference for a place they know, independently of the social interactions developed in them. Results confirmed the hypothesis, i.e., after a very brief stay in a certain place with nobody else there, these college students preferred that place to another with which they had not had previous contact.