Fatigue behavior of as-built L-PBF A357.0 parts

Laser-based powder bed fusion (L-PBF) is nowadays the preeminent additive manufacturing (AM) technique to produce metal parts. Nonetheless, relatively few metal powders are currently available for industrial L-PBF, especially if aluminum-based feedstocks are involved. In order to fill the existing gap, A357.0 (also known as A357 or A13570) powders are here processed by L-PBF and, for the first time, the fatigue behavior is investigated in the as-built state to verify the net-shaping potentiality of AM. Both the low-cycle and high-cycle fatigue areas are analyzed to draw the complete Wohler diagram. The infinite lifetime limit is set to 2 7 106stress cycles and the staircase method is applied to calculate a mean fatigue strength of 60 MPa. This value is slightly lower but still comparable to the published data for AlSi10Mg parts manufactured by L-PBF, even if the A357.0 samples considered here have not received any post-processing treatment

Cortisol in hair: a comparison between wild and feral cats in the north-eastern Alps

The quantification of glucocorticoid metabolites in hair is a non-invasive tool that provides important information regarding the endocrine status and represents a valuable method for studying potential stressors that may affect carnivores under both natural and non-natural conditions. Cortisol is the main glucocorticoid hormone of the hypothalamic-pituitary-adrenal gland axis and is considered a standard stress indicator for animal welfare. The current study aimed to compare cortisol levels extracted from hair of both dead, frozen European wildcats (Felis silvestris silvestris) and living feral individuals (Felis silvestris catus) living in different environmental conditions. The results obtained revealed that wild individuals exhibited a significantly (p < 0.001) higher cortisol concentration (n = 15, mean \ub1 SD = 8.91 \ub1 4.48 pg/mg) than feral ones (n = 10, mean \ub1 SD = 3.57 \ub1 1.25 pg/mg), probably as a result of both the physiological and/or environmental factors to which each subspecies was subject. This is the first study in which cortisol concentrations have been compared within the Felis silvestris subspecies, thus enriching the scarce information available for the Felidae. Nevertheless, further research is needed to better understand the various physiological and ecological factors affecting the adrenocortical activity of species or populations living in different environmental contexts

Influence of lipoproteins at dry-off on metabolism of dairy cows during transition period and on postpartum reproductive outcomes

High-yielding dairy cows are metabolically challenged during transition, when intense mobilization and hepatic oxidation of lipids is achieved, thus leading to fatty infiltration, ketosis and generalized inflammation. The condition is associated to periparturient diseases and poor fertility. The aim of this study was to assess whether serum lipoprotein concentrations in the dry period could influence the occurrence of postpartum diseases and reproductive performance in dairy cows. The study was carried out on 30 multiparous Holstein Friesian cows. Blood samples were collected at dry-off ( 1260 days), 30 days after dry-off and within 12 h after parturition for biochemical and serum lipoprotein assays. From 10 to 60 days after parturition milk was collected twice weekly after feeding, for milk whey progesterone assay. The Optimal Cutpoint package identified a threshold of 89% for serum High Density Lipoprotein (HDL) concentration at the beginning of the dry period with 95% of confidence interval. Cows with serum HDL greater than 89% (High group, n = 10) showed better reproductive performance when compared to those with low values (Low group, n = 18). The odds ratio for reproductive disorders in High group was 0.6875, however, differences were not significant probably due to both the reduced number of animals per group and overall low incidence of postpartum reproductive disease. First postpartum luteal activity occurred around day 23, while the second one between days 40 and 48. The average calving to first AI interval was 64.00 \ub1 3.95 days and 94.50 \ub1 12.32 days in High and Low group, respectively (P 89% at dry-off could be suggestive of improved liver adaptation to the transition, and probably of enhanced fertility in High group

Hair cortisol and testosterone concentrations and semen production of Bos taurus bulls

The experiment was aimed to evaluate the usefulness of hair cortisol concentrations (HCC) in revealing the activation of the hypothalamic-pituitary-adrenal (HPA) axis due to the passage of young bulls from genetic rearing stations to artificial insemination (AI) centre and the influence of this passage on hair testosterone concentrations (HTC). Hair samples on 33 yearling bulls were collected at the time of arrival (ST1) to the AI centre and 3 more hair samples (ST2, ST3, ST4) were collected at monthly intervals. After the end of quarantine each animal was submitted to the standard procedures for collection and production of semen. Overall HCC were significantly affected by period of collection (p\u2009\u2009.05). The effect of breed was observed only for HTC that was higher in PRI than BS (p\u2009\u2009.05). On the contrary, the effect of breed was evident. The results of this study replicated the effects of a major environmental stressor on mean cortisol concentrations assessed in hair, and add to the growing body of evidence that HCC is an effective and simply collected marker for long-term activity of the HPA system in response to persistent environmental challenge

assessment of cortisol and dhea concentrations in griffon vulture gyps fulvus feathers to evaluate its allostatic load

AbstractThe use of a non-invasive approach to collect biological samples from natural populations represents a great means of gathering information while avoiding handling animals. Even if corticosterone is the main glucocorticoid investigated in birds, there has been observed a proportional direct link between corticosterone and cortisol concentrations. Dehydroepiandrosterone (DHEA) can be produced by the adrenal cortex and should have prominent antiglucocorticoid properties also in birds. The aim of this study was to verify if there is any difference in the cortisol and DHEA feather concentrations between clinically normal and physiologically compromised Griffon vultures (Gyps fulvus) through the non-invasive approach of collecting moulted feathers without having to pluck them from the bird. The study was carried out using 8 physiologically compromised (PC) Griffons and 9 clinically normal Griffons considered as the control (CTRL) group that were necropsied or from the wildlife rehabilitation centre. Primary and secondary covert feathers were either collected directly from the birds' cage floors, or, in the case of dead Griffons, they were plucked off the animals. The results, obtained by RIA, revealed that both cortisol (P<0.01) and DHEA (P<0.05) feather concentrations were higher in the PC than in the CTRL group. No difference was observed by comparing the cortisol/DHEA ratio between the two evaluated groups (P=0.15). Pearson's correlation coefficients showed no correlation between feather hormone concentrations in the PC group (r=0.01, P=0.96) while a positive correlation in the CTRL group (r=0.65, P=0.006) was observed. In conclusion, our study reveals that moulted feathers can be a non-invasive and an interesting tool to evaluate the allostatic load of wild birds and they allowed better understanding the relationship between hormones of the hypothalamic–pituitary–adrenal axis and the physiological status of the birds

Síntesis y caracterización de materiales de referencia certificados de impurezas de ingredientes farmacéuticos activos

A partir de la promulgación de Ley N° 19.511/1972, el Instituto Nacional de Tecnología Industrial (INTI) fue designado Instituto Nacional de Metrología. En función de la reglamentación de esta ley, el INTI es responsable de producir, mantener y diseminar los patrones nacionales de medida, y diseminar trazabilidad metrológica en todo el territorio nacional. Esta diseminación se establece principalmente al Sistema Internacional de Unidades (SI). Además, tiene un rol en el aseguramiento de la calidad de las mediciones vinculadas con la producción industrial, la equidad en el comercio, y el cuidado del ambiente, la salud, los alimentos y la seguridad pública. La necesidad de mejorar las mediciones en la actualidad es una premisa fundamental del desarrollo industrial y por ende económico, de nuestro país. Combinando las capacidades existentes en INTI de investigación y desarrollo en síntesis química, caracterización de pequeñas moléculas y en la producción de MR para distintos sectores industriales, nos planteamos como objetivo el Desarrollo de Materiales de Referencia Certificados de Sustancias Relacionadas (SR) de Ingredientes Farmacéuticos Activos (IFAs). En este trabajo describimos los principales avances en este proyecto.Fil: Gandolfi Donadío, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Hermida, Laura Graciela. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Molinari, Judith Paola. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Alberti, Cecilia. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Ciarlantini, Matias Sebastián. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Santos, Leandro. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Scravaglieri, Antonella. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Fischer, Diego Alejandro. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Heba, Julieta. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Bellomo, Ana. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Paolo, Luciano Sebastián. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Grillo, Sergio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Puelles, María Mabel. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Gatti, Patricia Alejandra. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Comin, Maria Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial; Argentin

Çédille, revista de estudios franceses

Presentació