Experimental investigation of the mooring system of a wave energy converter in operating and extreme wave conditions

A proper design of the mooring systems for Wave Energy Converters (WECs) requires an accurate investigation of both operating and extreme wave conditions. A careful analysis of these systems is required to design a mooring configuration that ensures station keeping, reliability, maintainability, and low costs, without affecting the WEC dynamics. In this context, an experimental campaign on a 1:20 scaled prototype of the ISWEC (Inertial Sea Wave Energy Converter), focusing on the influence of the mooring layout on loads in extreme wave conditions, is presented and discussed. Two mooring configurations composed of multiple slack catenaries with sub-surface buoys, with or without clump-weights, have been designed and investigated experimentally. Tests in regular, irregular, and extreme waves for a moored model of the ISWEC device have been performed at the University of Naples Federico II. The aim is to identify a mooring solution that could guarantee both correct operation of the device and load carrying in extreme sea conditions. Pitch motion and loads in the rotational joint have been considered as indicators of the device hydrodynamic behavior and mooring configuration impact on the WEC

Alexithymia in anorexia and bulimia: Ubiquitous and primary trait?

Background: Alexithymia is associated to Eating Disorders (ED) and relevant for their prognosis but it is uncertain if it is ubiquitous, primary, and necessary for ED outburst. Methods: 124 ED outpatients and 80 healthy controls were compared with the Toronto Alexithymia Scale, personality, and psychopathology measures. Alexithymia and the other features are compared between anorexia nervosa (AN), bulimia nervosa (BN) and control groups. Alexithymia-based clusters were explored and compared with controls. Alexithymia traits are correlated with the other features. Results: Difficulty in identifying feelings was ubiquitous in ED subjects. A Non-Alexithymic Cluster (NAC) and an Alexithymic Cluster (ALC) were found with no difference in AN/BN distribution. ALC displays disordered personality and high psychopathology. Self-directiveness and interoceptive awareness were independently related to alexithymia and to depressive feelings. These two features along with depressive features completely accounted for alexithymia variance. Conclusion: Even though the difficulty in identifying feelings is ubiquitous in ED subjects, Alexithymia may not represent a primary trait but a complex dysfunction consequent to co-occurring character immaturity, altered interoceptive awareness, and depressive traits

Determinación del neuropéptido Y en la corteza adrenal de ratas gestantes estresadas

Chronic stress during pregnancy can alter many factors and mechanisms that maintain the homeostasis\nof the organism. Neuropeptide Y has anxiolytic functions and is involved in modulating the stress\nresponse. The aim was to determine the effects of chronic stress on the plasmatic corticosterone and\nestrogen levels and the immunolabeling of the neuropeptide Y in the adrenal cortex of pregnant\nrats. The immobilization stress was applied from the fourth day of gestation until the sacrifice at\ndays 12, 17 and 21 of the gestation. Immunostaining techniques, radioimmunoassay, stereological\nanalysis and quantification of images were used. In the stressed pregnant rats significant increase in\nthe plasmatic corticosterone levels at 12, 17 and 21 days and in the plasmatic estrogen levels at 12\nand 17 days were observed. On the other hand, a decrease in the neuropeptide Y index at 12 and\n17 were observed. We can conclude that the increase in the plasmatic corticosterone and estrogen\nlevels exerts an inhibitory effect on the adrenal neuropeptide Y immunostaining at 12 and 17 days\nof gestation.Fil: Bertorello Cuenca, M. Universidad Nacional de Rio Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Anatomía Animal; ArgentinaFil: Bozzo, A. Universidad Nacional de Rio Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Anatomía Animal; ArgentinaFil: Cots, D. Universidad Nacional de Rio Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Anatomía Animal; ArgentinaFil: Rolando, A. Universidad Nacional de Rio Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Anatomía Animal; ArgentinaFil: Diaz, T. Universidad Nacional de Rio Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Anatomía Animal; ArgentinaFil: Romanini, M.C. Universidad Nacional de Rio Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Anatomía Animal; ArgentinaEl estrés crónico durante la gestación puede alterar diversos factores y mecanismos que mantienen\nla homeostasis del organismo. El neuropéptido Y tiene una función ansiolítica y participa en la\nmodulación de la respuesta al estrés. El objetivo fue determinar los efectos del estrés crónico sobre\nlos niveles plasmáticos de corticosterona y estrógenos, y sobre la inmumarcación del neuropéptido\nY en la corteza adrenal de ratas gestantes. El estrés por inmovilización fue aplicado desde el cuarto\ndía de la gestación hasta el sacrificio a los 12, 17 y 21 días de la gestación. Se combinaron técnicas\nde inmunomarcación, radioinmunoanálisis, análisis estereológico y cuantificación de imágenes.\nEn las ratas estresadas gestantes se presentó un incremento significativo en los niveles plasmáticos\nde corticosterona a los 12, 17 y 21 días, de estrógenos a los 12 y 17 días y una disminución del\níndice de neuropéptido Y en los días 12 y 17. Se puede concluir que el incremento de los niveles\nplasmáticos de corticosterona y estrógenos ejerce un efecto inhibitorio sobre la inmunomarcación\ndel neuropéptido Y adrenal a los 12 y 17 días de la gestación

SIK1/SOS2 networks: decoding sodium signals via calcium-responsive protein kinase pathways

Changes in cellular ion levels can modulate distinct signaling networks aimed at correcting major disruptions in ion balances that might otherwise threaten cell growth and development. Salt-inducible kinase 1 (SIK1) and salt overly sensitive 2 (SOS2) are key protein kinases within such networks in mammalian and plant cells, respectively. In animals, SIK1 expression and activity are regulated in response to the salt content of the diet, and in plants SOS2 activity is controlled by the salinity of the soil. The specific ionic stress (elevated intracellular sodium) is followed by changes in intracellular calcium; the calcium signals are sensed by calcium-binding proteins and lead to activation of SIK1 or SOS2. These kinases target major plasma membrane transporters such as the Na+,K+-ATPase in mammalian cells, and Na+/H+ exchangers in the plasma membrane and membranes of intracellular vacuoles of plant cells. Activation of these networks prevents abnormal increases in intracellular sodium concentration

Protein Phosphatase 2A Interacts with the Na+,K+-ATPase and Modulates Its Trafficking by Inhibition of Its Association with Arrestin

Background: The P-type ATPase family constitutes a collection of ion pumps that form phosphorylated intermediates during ion transport. One of the best known members of this family is the Na +,K +-ATPase. The catalytic subunit of the Na +,K +-ATPase includes several functional domains that determine its enzymatic and trafficking properties. Methodology/Principal Findings: Using the yeast two-hybrid system we found that protein phosphatase 2A (PP2A) catalytic C-subunit is a specific Na +,K +-ATPase interacting protein. PP-2A C-subunit interacted with the Na +,K +-ATPase, but not with the homologous sequences of the H +,K +-ATPase. We confirmed that the Na +,K +-ATPase interacts with a complex of A- and C-subunits in native rat kidney. Arrestins and G-protein coupled receptor kinases (GRKs) are important regulators of G-protein coupled receptor (GPCR) signaling, and they also regulate Na +,K +-ATPase trafficking through direct association. PP2A inhibits association between the Na +,K +-ATPase and arrestin, and diminishes the effect of arrestin on Na +,K +-ATPase trafficking. GRK phosphorylates the Na +,K +-ATPase and PP2A can at least partially reverse this phosphorylation. Conclusions/Significance: Taken together, these data demonstrate that the sodium pump belongs to a growing list of io

Primary aldosteronism and impaired natriuresis in mice underexpressing TGF 1

To uncover the potential cardiovascular effects of human polymorphisms influencing transforming growth factor β1 (TGFβ1) expression, we generated mice with Tgfb1 mRNA expression graded in five steps from 10% to 300% normal. Adrenal expression of the genes for mineralocorticoid-producing enzymes ranged from 50% normal in the hypermorphs at age 12 wk to 400% normal in the hypomorphs accompanied with proportionate changes in plasma aldosterone levels, whereas plasma volumes ranged from 50% to 150% normal accompanied by marked compensatory changes in plasma angiotensin II and renin levels. The aldosterone/renin ratio ranged from 0.3 times normal in the 300% hypermorphs to six times in the 10% hypomorphs, which have elevated blood pressure. Urinary output of water and electrolytes are markedly decreased in the 10% hypomorphs without significant change in the glomerular filtration rate. Renal activities for the Na+, K+-ATPase, and epithelial sodium channel are markedly increased in the 10% hypomorphs. The hypertension in the 10% hypomorphs is corrected by spironolactone or amiloride at doses that do not change blood pressure in wild-type mice. Thus, changes in Tgfb1 expression cause marked progressive changes in multiple systems that regulate blood pressure and fluid homeostasis, with the major effects being mediated by changes in adrenocortical function