Search results for "Philosophy of Science"
showing 10 items of 808 documents
Inhibition of herpesvirus DNA synthesis by 9-beta-D-arabinofuranosyladenine in cellular and cell-free systems.
1977
9-beta-D-Arabinofuranosyladenine 5'-triphosphate (ara-ATP) is an inhibitor both of DNA polymerase-alpha and -beta from noninfected rabbit kidney cells and of the DNA-dependent DNA polymerase induced by herpes simplex virus Type 1 (strain IES). The studies were performed with partially purified enzymes, and each of the different polymerase preparations contained only one DNA-dependent DNA polymerase species. These enzymes were inhibited in a competitive manner. The HSV-induced DNA-dependent DNA polymerase was 39-fold more sensitive to ara-ATP than was cellular DNA polymerase-beta and 116-fold more sensitive than cellular DNA polymerase-alpha. The affinity of the HSV-induced enzyme for ara-AT…
Fragments of β-thymosin from the sea urchinParacentrotus lividusas potential antimicrobial peptides against staphylococcal biofilms
2012
The immune mediators in echinoderms can be a potential source of novel antimicrobial peptides (AMPs) applied toward controlling pathogenic staphylococcal biofilms that are intrinsically resistant to conventional antibiotics. The peptide fraction <5 kDa from the cytosol of coelomocytes of the sea urchin Paracentrotus lividus (5-CC) was tested against a group of Gram-positive and Gram-negative pathogen reference strains. The 5-CC of P. lividus was active against all planktonic-tested strains but also showed antibiofilm properties against staphylococcal strains. Additionally, we demonstrated the presence of three small peptides in the 5-CC belonging to segment 9-41 of a P. lividusβ-thymosin. T…
Zinc and inflammatory/immune response in aging
2007
Life-long antigenic burden determines a condition of chronic inflammation, with increased lymphocyte activation and proinflammatory cytokine production. A large number of studies have documented changes in zinc metabolism in experimental animal models of acute and chronic inflammation and in human chronic inflammatory conditions. In particular, modification of zinc plasma concentration, as well as intracellular disturbance of antioxidant intracellular pathways, has been found in aging and in some age-related diseases. Zinc deficiency is diffused in aged individuals in order to avoid meat and other high zinc content foods due to fear of cholesterol. Rather, they increase the consumption of r…
Embodied graffiti and street art research
2021
Graffiti and street art research (GSAR) has become more acknowledged within the academic discourse; however, it has much to gain from theorising its methodological aspects. As a multidisciplinary field, GSAR has mostly used qualitative research methods, exploring urban space through methods that range from visual recordings to ethnography, emphasising the researchers’ reflexivity. This qualitative approach has, however, paid little attention to the role of embodied practices. In this paper we discuss how embodied methodologies provide multisensory research results where the experienced moments, the participant’s and researcher’s senses, cognition and mobility in urban spaces are connected.…
La conquesta del lector. Reptes evolutius del periodisme científic en un ambient extrem
2014
La gran responsabilidad de los medios de comunicacion radica en que la ciudadania tiene derecho a tener una informacion cientifica de calidad. Que le sirva para tomar mejores decisiones, con espiritu critico, y para crear su propia opinion; que reactualice sus conocimientos y le haga participe de la cultura de su tiempo. En la actualidad, el entorno es cambiante y competitivo para la prensa escrita y las condiciones ambientales amenazan la supervivencia de la divulgacion. Profesionalmente, es momento de evolucionar pero tambien de conservar lo imprescindible: la esencia del buen periodismo, para diferenciarnos, con calidad y audacia, y ser asi elegidos por el publico. Debe seguir habiendo s…
La genètica de les migracions humanes: Seguint el rastre de les migracions a través del nostre genoma
2014
La reconstruccio de les migracions humanes es possible gracies a la informacio aportada per diverses disciplines. L’estudi de la diversitat genetica de les poblacions humanes actuals ens revela quins han estat els esdeveniments demografics i moviments migratoris passats que han deixat una empremta en el nostre genoma. El coneixement dels moviments migratoris en temps prehistorics ens permet comprovar hipotesis proposades des d’altres disciplines cientifiques. De la mateixa manera, la distribucio de la diversitat genetica en el futur dependra, en gran part, de les intenses migracions humanes actuals facilitades pels avencos tecnologics.
Longitudinal and situational associations between math anxiety and performance among early adolescents
2022
Studies have found math anxiety and achievement to be related from the beginning of formal schooling, but the knowledge regarding the direction of the relationship is vague. The purpose of the present study was to study this relationship. We investigated math anxiety from two points of view: trait and state anxiety. In the first substudy, we investigated the longitudinal relationship between math anxiety and performance from sixth to seventh grade (n = 848) with cross-lagged modeling. In the second substudy, we investigated the situational relationship of anxiety and performance by giving the participants (n = 149) challenging and nonchallenging math tasks adapted to their skill level, and …
Els viatges de la física: perseguint ombres, mesurant meridians
2013
A partir del segle XVII l’estudi acurat i resolució de diversos problemes de la física, principalment relacionats amb l’astronomia i la forma de la Terra, però no sols, ha passat per realitzar mesures a diferents llocs i, per tant, per l’organització de viatges científics amb aquests objectius específics. Presentarem alguns d’aquests problemes i les solucions adoptades a l’època.
Human recombinant vasostatin-1 may interfere with cell-extracellular matrix interactions
2006
Vasostatin-1 (VS-1), the N-terminal fragment derived from the cleavage of chromogranin A (CgA), has been shown to exert several biological activities on several tissues and organs. Recently, it has been reported that human recombinant VS-1 (STA-CGA(1-78)) may alter myocardial contractility in eel, frog., and rat hearts. In this article we have explored if STA-CGA(1-78) can induce intracellular cascades interacting both with adhesion molecules and/or extracellular matrix (ECM), components, that is, involvement of the heat shock protein 90 (HSP90) and the endothelial NOS (eNOS), known to be implicated in signal transduction mechanisms affecting myocardial contractility. We used 3D cultured ad…
Pharmacological Characterization of Melanocortin Receptors in Fish Suggests an Important Role for ACTH
2005
The melanocortin (MC) receptor subtypes have distinctive characteristic binding profiles. We found that the trout and Fugu MC4 receptors have similar affinity for alpha-MSH and beta-MSH and a much higher affinity for ACTH than does the human MC4 receptor. The Fugu MC1 and the trout and Fugu MC5 receptors also have higher affinity for ACTH-derived peptides than alpha-, beta-, or gamma-MSH. It is tempting to speculate that ACTH-derived peptides may have played an important role as "original" ligands at the MC receptors, while the specificity of the different subtypes for the alpha-, beta-, and gamma-MSH peptides may have appeared at later stages during vertebrate evolution.