83 research outputs found

    Accessing a not for profit organizational brand from the volunteers perspectives- the case of refood

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    This exploratory qualitative research developed through in-depth interviews with a not for profit organization (Refood) volunteers in order to determine its volunteers’ perception about the organization's brand and whether that perception impacts on volunteer relationship with Refood. Results showed that Refood is perceived to have strong brand elements and it is defined not only by its cause (end food wastage and feed the needed) but also by its volunteers' performance. Since volunteers’ commitment depends on many factors, it may cause some difficulties on their relationship with the organizational brand. The research suggests recommendations to brand managers on how to make the brand more meaningful to their current volunteers

    Stepwise dehydration of thomsonite (THO) with disordered Si/Al distribution: a new partially hydrated phase

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    The structural transformations occurring as a function of increasing temperature in zeolites are of interest because the porous structure, and therefore the physical properties, can significantly change. Zeolites with THO framework type are small-pore materials, which received attention because of their applications in catalytic processes. The majority of THO zeolites (synthetic and natural) are characterized by an ordered distribution of the cations at the tetrahedral sites. To date, few cases of disordered thomsonite have been reported. In this study, we investigated the dehydration behavior of a natural thomsonite with disordered Si/Al distribution and chemical composition Ca3.34Na2.66Si11Al9O40∙12H2O. The structure was determined from room temperature (RT) to 698 K in order to compare the thermal behavior with that reported for the ordered variety. Accurate structural analysis was performed by in situ single crystal X-ray diffraction. The dehydration starts at 348 K. Up to 498 K, thomsonite gradually releases four H2O. From 498 to 573 K, additional four H2O are lost and the space group changes from orthorhombic (Pbmn) to monoclinic (P21/n). This partially hydrated phase is characterized by a unit-cell volume contraction of -3% with respect to the RT phase and by a rearrangement of the extraframework cations in the zeolitic pores. The thermally treated thomsonite is able to reabsorb 50% of the lost H2O and transform to the orthorhombic phase, equivalent to that observed at lower temperatures. However, the diffraction pattern analysis indicated a high degree of mosaicity, most probably due to the residual stress accumulated during the phase transformation

    High Stocking Density and Food Deprivation Increase Brain Monoaminergic Activity in Gilthead Sea Bream (Sparus aurata)

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    Simple Summary Farmed fish must cope with different stressors during aquaculture procedures, such as high densities, fasting, transport, or air exposure during handling. The severity and timing of these stressors can produce important imbalances in the overall status of the animals, triggering several endocrine and physiological players. In this study, gilthead sea bream (Sparus aurata) juveniles were assigned to four experimental conditions: (1) fed at a low stocking density (LSD-F, 4 kg center dot m(-3)); (2) fed at a high stocking density (HSD-F, 40 kg center dot m(-3)); (3) food-deprived at LSD (LSD-FD); and (4) food-deprived at HSD (HSD-FD). This served to evaluate, both at the plasma and central (brain) levels, the role of several hormonal (cortisol and catecholamines) and monoamine (dopaminergic and serotonergic neurotransmitters) functionalities. Our results evidenced chronic stress exposure (i.e., a high stocking density and food deprivation) fallouts in the enhancement of the parameters related to the stress response, where monoaminergic activities in different brain regions served to reorganize the physiological response depending on the challenge applied. In teleosts, brain monoamines (dopamine and serotonin) participate in the early response to different acute stressors. However, little is known regarding their role during chronic stress. In a 2 x 2 factorial design, the influence of a high stocking density (HSD) and/or food deprivation (FD) on the brain monoaminergic activity in gilthead sea bream (Sparus aurata) was evaluated. Following a 21-day experimental design, samples from the plasma and brain regions (telencephalon, hypothalamus, and optic tectum) were collected. The dopamine (DA), serotonin (5HT), and their main metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and 5 hydroxyindoleacetic acid (5HIAA), contents were HPLC-assessed in brain tissues, and the ratios DOPAC/DA and 5HIAA/5HT were calculated as indicators of enhanced monoaminergic activity. The plasma levels of cortisol and catecholamine were also evaluated. The cortisol levels increased in fish exposed to HSD and normally fed but, also, in all FD groups, whereas the NA levels decreased in LSD-FD animals. Within the brain, the dopaminergic and serotonergic activities in telencephalon and hypothalamus increased in fish subjected to HSD and in the telencephalon of LSD-FD fish. While DA (hypothalamus) and 5HT (telencephalon) increased in the animals submitted to a HSD, food-deprived fish did not show such an increase. Taken together, our results supported the hypothesis of brain monoaminergic activity participating in maintaining and orchestrating the endocrine response to chronic stress in fish.This study was partially funded by the Spanish Agencia Estatal de Investigacion and European Fund of Regional Development (PID2019-103969RB-C31). J.A.M.-S. and J.M.M. (Juan Miguel Mancera) belong to the Fish Welfare and Stress Network (AGL2016-81808-REDT) supported by the Spanish Ministry of Economy, Industry and Competitiveness. Besides, we acknowledge support of the publication fee by the Instituto Universitario de Investigacion Marina (INMAR, University of Cadiz) Open Access Publication Support Initiative through its Special Action

    The prevalence of autoimmune thyroiditis in adolescent girls with polycystic ovary syndrome

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    Objectives: Both polycystic ovary syndrome (PCOS) and autoimmune thyroiditis (AT) are reported to be common endocrinopathies. In recent years the number of publications assessing the coexistence of these two disease entities in adult women has been growing. There are many suggestions regarding pathophysiological mechanisms that can cause the relationship between AT and PCOS. However, there is still a lack of research among adolescent girls. The aim of the study was to analyze the occurrence of autoimmune thyroiditis in adolescent girls with PCOS. Material and methods: The study group included 80 girls diagnosed with PCOS (chronological age: 16.54 ± 1.00 years, BMI: 22.80 ± 3.27 kg/m2), and the control group — 64 regularly menstruating girls (chronological age: 16.71 ± 0.63 years, BMI: 24.8 ± 5.2 kg/m2). The thyroid function and morphology were assessed based on the concentration of thyroid stimulating hormone (TSH), free thyroxine (fT4), anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin (anti-TG) antibodies and ultrasound scan of the thyroid gland. Results: AT was diagnosed in 18 (22.5%) girls from the study group and nine (14.06%) from the control group (p > 0.05). Positive anti-TPO titer was observed more often in the study group [21 patients (26.25%)] than in the control group [9 girls (14.06%)] (p = 0.054). Moreover, an abnormal ultrasound scan of the thyroid gland characteristic for AT was found in 18 girls from the study group (22.50%) and 8 girls from the control group (12.50%) (p > 0.05). Conclusions: The results of the analyzed studies do not confirm a significant relationship between PCOS and AT in adolescent girls. However, in the group of girls with PCOS, autoimmune process exponents were more frequent (anti-TPO), reaching the borderline level of statistical significance

    Roles of neuropeptides arginine vasotocin and isotocin in endocrine regulation of physiological process in the gilthead sea bream (Sparus aurata)

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    International Symposium in Marine Science (ISMS) 2012 (Cádiz, 24-26 enero de 2012). III Simposio Internacional de Ciencias del MarLos neuropéptidos arginina-vasotocina (AVT) e isotocina (IT) de teleósteos, análogos respectivamente de la arginina-vasopresina (AVP) y oxitocina (OXY) de mamíferos, participan en diversos procesos fisiológicos de los organismos.Estudio financiado por los proyectos AGL2010-14876 otorgado por el MICINN (España) a JMM y 498/N-HISZP-JPR/2009/0 (Polonia) a EK. JAM-S está financiado por una beca predoctoral (FPU, Referencia AP2008-01194) del Ministerio de Educación (España).Peer Reviewe

    Dietary Arachidonic Acid (20:4n-6) Levels and Its Effect on Growth Performance, Fatty Acid Profile, Gene Expression for Lipid Metabolism, and Health Status of Juvenile California Yellowtail (Seriola dorsalis)

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    Arachidonic acid (ARA, 20:4n-6) fed to Seriola dorsalis juveniles at different levels was evaluated. After a seven-week feeding trial, growth performance, hepatopancreas and muscle fatty acid (FA) composition, expression of lipid-relevant genes, and blood parameters were evaluated. Four isoproteic and isolipidic experimental diets were formulated to contain 44% crude protein and 11% lipids with graded inclusion levels of ARA, 0% (Control), 0.4, 0.9, and 1.4% of the total diet. S. dorsalis juveniles (14.54 +/- 0.18 g) were randomly divided into twelve tanks with fifteen animals each. The animals were hand fed three times per day to apparent satiation. Dietary treatments did not significantly affect the growth performance, SGR, FCR, and feed intake of fish. Different levels of ARA in the experimental diets directly influenced liver and muscle FA profiles, with significant changes in ARA and EPA deposition between Control treatment and 1.4%, in both tissues. The expression of arachidonate 5-lipoxygenase (alox5), acyl-CoA dehydrogenase very long chain (acadvl), carnitine O-palmitoyltransferase 1(cpt1a) was significantly affected by dietary treatments, with an expression increasing accordingly to the increasing ARA levels. In contrast, a reduction of fatty acid synthase (fas) and proliferator-activated receptor alpha (ppara) expression was significantly reduced as ARA increased in the diet. In addition, a significant reduction in blood cortisol and glucose was found at a 0.9% ARA level compared to the other treatments. Based on the performance, cortisol levels, the gene expression for eicosanoids synthesis, and lipid metabolic pathways, the present study suggests a maximum ARA inclusion of 0.9% in diets for California yellowtail juveniles, S. dorsalis

    Arginine Vasotocin and Cortisol Co-regulate Vasotocinergic, Isotocinergic, Stress, and Thyroid Pathways in the Gilthead Sea Bream (Sparus aurata)

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    In teleosts, a complex interaction between several endocrine axes modulates physiological functions related to metabolism, stress, and osmoregulation. Although many studies in fish underline the interconnection between the hypothalamic– pituitary–interrenal (HPI) and hypothalamic–pituitary–thyroid (HPT) endocrine axes, their relationship with the vasotocinergic and isotocinergic systems remains unknown. The aim of the present study is therefore to shed light on the potential cross-regulations between HPT, HPI, and the vasotocinergic and isotocinergic axes in gilthead sea bream (Sparus aurata) at hypothalamic, hypophyseal, and plasma levels. Sea breams were administered with intraperitoneal slow-release implants containing different doses of vasotocin (the active peptide in vasotocinergic system) or cortisol (the last component of HPI axis). Plasma osmolality was higher in active neuropeptides vasotocin (Avt)- treated fish, indicating an osmoregulatory function of this hormone. Low concentrations of Avt increased hypothalamic arginine vasotocin precursor (avt) mRNA levels and increased Avt storage in the pituitary. Avt treatment down-regulated hypothalamic arginine vasotocin receptor v1a-type (avtrv1a), suggesting a negative paracrine coregulation of the HPI axis due to the close location of avtrv1a and adrenocorticotropin hormone (Acth) cells in the anterior pituitary. Furthermore, the up-regulation observed in arginine vasotocin receptor v2-type (avtrv2) suggests their involvement in metabolic and cortisol-related pathways in the hypothalamus. The decrease in isotocin (It) pituitary storage and the up-regulation of it receptor, observed in the Avt-treated group, reinforce the idea of an interconnection between the vasotocinergic and isotocinergic systems. Cortisol and Avt administration each inhibited the HPI axis, down-regulating crh gene expression in the absence of variations in corticotropin releasing hormone binding protein (crhbp). Finally, both hormonal treatments activated the HPT axis via upregulation of trh and down-regulation of thrb. Our results provide evidence for strong interactions among the Avt/It, HPI, and HPT axes of marine teleosts, particularly at the hypothalamic level

    Unique properties of alpha-helical DNA-binding KfrA protein of RA3 plasmid from IncU incompatibility group and its host-dependent role in plasmid maintenance.

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    KfrA, encoded on the broad-host-range RA3 plasmid, is an alphahelical DNA-binding protein that acts as a transcriptional autoregulator. The KfrARA3 operator site overlaps the kfrA promoter and is composed of five 9-bp direct repeats (DRs). Here, the biological properties of KfrA were studied using both in vivo and in vitro approaches. Localization of the DNA-binding helix-turn-helix motif (HTH) was mapped to the N29-R52 region by protein structure modeling and confirmed by alanine scanning. KfrA repressor ability depended on the number and orientation of DRs in the operator, as well as the ability of the protein to oligomerize. The long alpha-helical tail from residues 54 to 355 was shown to be involved in self-interactions, whereas the region from residue 54 to 177 was involved in heterodimerization with KfrC, another RA3-encoded alphahelical protein. KfrA also interacted with the segrosome proteins IncC (ParA) and KorB (ParB), representatives of the class Ia active partition systems. Deletion of the kfr genes from the RA3 stability module decreased the plasmid retention in diverse hosts in a species-dependent manner. The specific interactions of KfrA with DNA are essential not only for the transcriptional regulatory function but also for the accessory role of KfrA in stable plasmid maintenance

    Procesos osmorreguladores en peces teleósteos: control mediado por diferentes sistemas endocrinos

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    A large number of fish species are defined as euryhaline, being able to withstand drastic changes in environmental salinity. Within these species we can distinguish between: i) totally euryhaline teleosts, if they are capable of inhabiting environments from fresh water to environments with high salinity; and ii) partially euryhaline teleosts, when the range of salinities in which they can live excludes completely freshwater environments. For its part, another way in which teleost fish can differentiate will depend on the environment in which they live; that is, freshwater fish or saltwater fish.Un gran número de especies de peces se definen como eurihalinas, siendo capaces de soportar cambios drásticos en la salinidad ambiental. Dentro de estas especies se pueden distinguir entre: i) teleósteos totalmente eurihalinos, si son capaces de habitar desde medios de agua dulce hasta medios con alta salinidad; y ii) teleósteos parcialmente eurihalinos, cuando el rango de salinidades en el que pueden vivir excluye los medios de agua completamente dulce. Por su parte, otra de las formas en las que los peces teleósteos pueden diferenciarse dependerá del ambiente en el que habiten; esto es, peces de agua dulce o peces de agua salada

    Tissue-Specific Orchestration of Gilthead Sea Bream Resilience to Hypoxia and High Stocking Density

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    Two different O-2 levels (normoxia: 75-85% O-2 saturation; moderate hypoxia: 42-43% O-2 saturation) and stocking densities (LD: 9.5, and HD: 19 kg/m(3)) were assessed on gilthead sea bream (Sparus aurata) in a 3-week feeding trial. Reduced O-2 availability had a negative impact on feed intake and growth rates, which was exacerbated by HD despite of the improvement in feed efficiency. Blood physiological hallmarks disclosed the enhancement in O-2-carrying capacity in fish maintained under moderate hypoxia. This feature was related to a hypo-metabolic state to cope with a chronic and widespread environmental O-2 reduction, which was accompanied by a differential regulation of circulating cortisol and growth hormone levels. Customized PCR-arrays were used for the simultaneous gene expression profiling of 34-44 selected stress and metabolic markers in liver, white skeletal muscle, heart, and blood cells. The number of differentially expressed genes ranged between 22 and 19 in liver, heart, and white skeletal muscle to 5 in total blood cells. Partial Least-Squares Discriminant Analysis (PLS-DA) explained [R2Y(cum)] and predicted [Q2Y(cum)] up to 95 and 65% of total variance, respectively. The first component (R2Y = 0.2889) gathered fish on the basis of O-2 availability, and liver and cardiac genes on the category of energy sensing and oxidative metabolism (cs, hif-1 alpha, pgc1 alpha, pgc1 beta, sirts 1-2-4-5-6-7), antioxidant defense and tissue repair (prdx5, sod2, mortalin, gpx4, gr, grp-170, and prdx3) and oxidative phosphorylation (nd2, nd5, and coxi) highly contributed to this separation. The second component (R2Y = 0.2927) differentiated normoxic fish at different stocking densities, and the white muscle clearly promoted this separation by a high over-representation of genes related to GH/IGF system (ghr-i, igfbp6b, igfbp5b, insr, igfbp3, and igf-i). The third component (R2Y = 0.2542) discriminated the effect of stocking density in fish exposed to moderate hypoxia by means of hepatic fatty acid desaturases (fads2, scd1a, and scd1b) and muscle markers of fatty acid oxidation (cpt1a). All these findings disclose the different contribution of analyzed tissues (liver >= heart > muscle > blood) and specific genes to the hypoxic- and crowding stress-mediated responses. This study will contribute to better explain and understand the different stress resilience of farmed fish across individuals and species
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