We have studied the effect of the administration of two doses of melatonin (melatonin 100 and melatonin 200 microg/kg bw) on diabetes and oxidative stress experimentally induced by the injection of streptozotocin (STZ) in female Wistar rats. STZ was injected as a single dose (60 mg/kg i.p. in buffered citrate solution, pH 4.0) and melatonin (melatonin 100, 100 microg/kg/day i.p.; melatonin 200, 200 microg/kg/day i.p.) beginning 3 days before diabetes induction and continuing until the end of the study (8 weeks). The parameters analysed to evaluate oxidative stress and the diabetic state were a) for oxidative stress, changes of lipoperoxides (i.e., malondialdehyde, MDA) in plasma and erythrocytes and the changes in reduced glutathione (GSH) in erythrocytes and b) for diabetes, changes in glycemia, lipids (triglycerides: TG; total cholesterol: TC; HDL-cholesterol, HDL-c), percentage of glycosylated hemoglobin (Hb%), and plasma fructosamine. The injection of STZ caused significant increases in the levels of glycemia, percentage of glycosylated hemoglobin, fructosamine, cholesterol, triglycerides, and lipoperoxides in plasma and erythrocytes, whereas it decreased the levels of HDL-c and the GSH content in erythrocytes. The melatonin 100 dose reduced significantly all these increases, except the percentage of glycosylated hemoglobin. With regard to the decreases of plasma HDL-c and GSH content in erythrocytes, this melatonin dose returned them to normal levels. The melatonin 200 dose produced similar changes, though the effects were especially noticeable in the decrease of glycemia (55% vs. diabetes), percentage of hemoglobin (P < 0.001 vs diabetes), and fructosamine (31% vs. diabetes). This dose also reversed the decreases of HDL-c and GSH in erythrocytes. Both doses of melatonin caused significant reduction of the percentage of glycosylated hemoglobin in those groups that were non-diabetic. These illustrate the protective effect of melatonin against oxidative stress and the severity of diabetes induced by STZ. In particular, this study confirms two facts: 1) the powerful antioxidant action of this pineal indole and 2) the importance of the severity of oxidative stress to maintain hyperglycemia and protein glycosylation, two pathogenetic cornerstones indicative of diabetic complications. Melatonin reduces remarkably the degree of lipoperoxidation, hyperglycemia, and protein glycosylation, which gives hope to a promising perspective of this product, together with other biological antioxidants, in the treatment of diabetic complications where oxidative stress, either in a high or in a low degree, is present.

A 11-week feeding trial was carried out to determine the effects of the probiotic bacteria Lactobacillus casei from the commercial product Yakult Ò on the growth performance, proximal composition, protein content of skin mucus and stress resistance of juvenile Porthole livebearer Poeciliopsis gracilis. Triplicate groups of 15 juveniles per tank with an initial weight of 47 ± 9 mg (mean ± standard deviation) were fed with Artemia nauplii enriched with the probiotic, by using the bacteria cells plus the fermented milk (group ProN) and the other (group ProC) by using only the bacterial cells, eliminating the fermented milk by centrifugation. A control of fish was set up, by feeding non-enriched Artemia nauplii. Growth performance and survival rates did not show significantly differences among the treatments and control group, but a slightly tendency of higher values for body weight, weight gain and specific growth rate was observed in the juveniles of ProC treatment. Whole body proximate composition did not show significant differences among the groups, but higher values of protein and lipid contents were observed in the groups fed with the probiotic. Content of protein in the skin mucus were significantly higher in the ProC treatment than control group. Recovery rates after an air-dive test were significantly higher on the fish fed with the probiotic cells than the control group. These results show that L. casei might be used as a probiotic for fish and would help during the culture of juvenile of the Porthole livebearer P. gracilis. KEY WORDS

Gráfico 1.1. Argumentos para la consideración del arte contemporáneo como patrimonio cultural. Gráfico 1.2. El sistema de transmisión del patrimonio. Gráfico 1.3. El valor como vínculo de continuidad en el proceso de transmisión. Gráfico 1.4. Aportaciones desde la experiencia personal al imaginario colectivo. Gráfico 2.1. Relación de los impulsos vigotskyanos con el entorno y el tiempo. Gráfico 2.2. Proceso de objetivación de significados. Gráfico 2.3. Pirámide cognitiva de Eiser. Gráfico 2.4. Esquema de identidad cultural como rol vs. Identidad cultural como elemento suspensorio. Gráfico 2.5. Patrimonio como fuerza trans-orbital, en el átomo identitario. Gráfico 2.6. El contexto patrimonial para el contexto patrimonial. Gráfico 2.7. El contexto patrimonial sobre el contexto patrimonial. Gráfico 2.8. El entorno a través/en el contexto patrimonial. Gráfico 3.1. El proceso de patrimonialización como feed-back de la enculturación. Gráfico 4. 1. La educación museal como ámbito entre ámbitos. Gráfico 5.1. El patrimonio institucionalizado. Gráfico 5.2. El patrimonio enculturizado. Gráfico 5.3. El patrimonio como estructura. Gráfico 5.4. El proceso de patrimonialización como sustrato de la identización. Gráfico 5.5. Secuencia procedimental enunciada por Fontal (Fontal, 2003 y 2007a).Gráfico 5.6. Secuencia procedimental del proceso de identización. Gráfico 7.1. Estructura de la investigación.Gráfico 7.2. Esquema de los procesos que conforman la fase denominada acciones.Gráfico 7.3. Fase denominada objetos: gestión y tratamiento de los

The COVID-19 pandemic is increasing negative emotions and decreasing positive emotions globally. Left unchecked, these emotional changes may have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we will examine the impact of reappraisal, a widely studied and highly effective form of emotion regulation. Participants from 55 countries (expected N = 25,448) will be randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing), an active control condition, or a passive control condition. We predict that both reappraisal interventions will reduce negative emotions and increase positive emotions relative to the control conditions. We further predict that reconstrual will decrease negative emotions more than repurposing, and that repurposing will increase positive emotions more than reconstrual. We hope to inform efforts to create a scalable intervention for use around the world to build resilience during the pandemic and beyond.

Diabetes mellitus (DM) is a group of metabolic disorders characterized by hyperglycemia. In particular, type 2 diabetes (T2D) represents one of the main causes of death in the world, and those suffering from it have a lower quality of life. Although there are multiple hypotheses about the pathophysiological mechanisms that lead to the development of T2D, the effects of this pathology on pancreatic β-cells are often ignored. We now know that in addition to genetic defects, β-cell organellar dysfunction participates in the earliest stages of the disease; other factors also contribute to this dysfunction, such as excessive production of reactive oxygen species and a decrease in cellular volume and mass. These features usually result from increased apoptosis, which is not adequately compensated for by the characteristic regeneration mechanisms of these cells. In this study, we specifically examine the genetic, epigenetic and metabolic defects that contribute to β-cell dysfunction and lead to the establishment of T2D, particularly the dysregulated insulin synthesis and secretion in these cells.