Search results for "Biochemistry"
showing 10 items of 20172 documents
Diverse societies are more productive: a lesson from ants
2012
The fitness consequences of animal personalities (also known as behavioural syndromes) have recently been studied in several solitary species. However, the adaptive significance of collective personalities in social insects and especially of behavioural variation among group members remains largely unexplored. Although intracolonial behavioural variation is an important component of division of labour, and as such a key feature for the success of societies, empirical links between behavioural variation and fitness are scarce. We investigated aggression, exploration and brood care behaviour in Temnothorax longispinosus ant colonies. We focused on two distinct aspects: intercolonial variabil…
Even violins can cry: specifically vocal emotional behaviours also drive the perception of emotions in non-vocal music.
2021
A wealth of theoretical and empirical arguments have suggested that music triggers emotional responses by resembling the inflections of expressive vocalizations, but have done so using low-level acoustic parameters (pitch, loudness, speed) that, in fact, may not be processed by the listener in reference to human voice. Here, we take the opportunity of the recent availability of computational models that allow the simulation of three specifically vocal emotional behaviours: smiling, vocal tremor and vocal roughness. When applied to musical material, we find that these three acoustic manipulations trigger emotional perceptions that are remarkably similar to those observed on speech and scream…
�ber den Einflu� der Verarbeitung und Konservierung auf Bek�mmlichkeit und N�hrwert der Nahrungsmittel
1951
Des haushaltsubliche Zubereiten der Nahrungsmittel wie Kochen, Braten usw. beeintrachtigt Nahrwert und Ausnutzbarkeit der Nahrung nur unwesentlich, verbessert sie vielmehr haufig sogar. Durch Masnahmen der Konservierung, vor allem Erhitzen unter Druck, kann es aber zu weitgehender Zerstorung von Nahrstoffen oder zu chemischen Verenderungen der Art kommen, das Nahrwert oder Verdaulichkeit wesentlich herabgesetzt werden. Dies wird an Hand von Beispielen in erster Linie bei Vitaminen und Eiweiskorpern gezeigt. Aus diesen Beispielen ergibt sich die grose Bedeutung, die einer schonenden und zweckmasigen Nahrungsmittelkonservierung zukommt. Optimale Methoden fur Zubereitung und Konservierung von …
Relative expression of cholesterol transport-related proteins and inflammation markers through the induction of 7-ketosterol-mediated stress in Caco-…
2013
Human diets contain sterol oxidation products that can induce cytotoxic effects, mainly caused by cholesterol oxides. However, phytosterol oxides effects have been less extensively investigated. This study evaluates the production of inflammatory biomarkers (IL-1β, IL-8, IL-10, TNFα) and the influence of gene expression transporters and enzymes related to cholesterol absorption and metabolism (NPC1L1, ABCG5/8, HMGCoA, ACAT) produced by 7-ketosterols (stigmasterol/cholesterol) in Caco-2 cells. These effects were linked to intracellular signaling pathways by using several inhibitors. Results showed 7-ketostigmasterol to have a greater proinflammatory potential than 7-ketocholesterol. In non-p…
Über enzymatische Spaltung und Stoffwechsel von Umsetzungsprodukten des Pyrokohlensäurediäthylesters mit Bestandteilen von Lebensmitteln
1966
Die Umsatzprodukte von Pflanzenphenolen, Hydroxysauren, Aminosauren und Athanol mit Pyrokohlensaurediathylester werden von den Verdauungsenzymen so rasch und so ergiebig gespalten, das mit einer Resorption derselben nicht zu rechnen ist. Die Umsatzprodukte mit Ascorbinsaure (Mono- und Dicarbathoxyascorbinsaure) werden durch die Verdauungsenzyme nicht gespalten. Untersuchungen mit den mit14C markierten Carbathoxyverbindungen der Ascorbinsaure ergaben: Die Verwendung von Pyrokohlensaurediathylester zur Behandlung von Fruchtsaften und Wein wirft daher keine toxikologischen Probleme auf und ist von der gesundheitlichen Seite aus betrachtet duldbar. Eine ausfuhrliche Publikation der erhaltenen B…
Low cholesterol stimulates the nonamyloidogenic pathway by its effect on the α-secretase ADAM 10
2001
Biochemical, epidemiological, and genetic findings demonstrate a link between cholesterol levels, processing of the amyloid precursor protein (APP), and Alzheimer's disease. In the present report, we identify the α-secretase ADAM 10 ( a d isintegrin a nd m etalloprotease) as a major target of the cholesterol effects on APP metabolism. Treatment of various peripheral and neural cell lines with either the cholesterol-extracting agent methyl-β-cyclodextrin or the hydroxymethyl glutaryl-CoA reductase inhibitor lovastatin resulted in a drastic increase of secreted α-secretase cleaved soluble APP. This strong stimulatory effect was in the range obtained with phorbol esters and was further increa…
N-Methyl-β-carboline alkaloids: structure-dependent photosensitizing properties and localization in subcellular domains
2020
N-Methyl-β-carboline (βC) alkaloids, including normelinonine F (1b) and melinonine F (2b), have been found in a vast range of living species playing different biological, biomedical and/or pharmacological roles. Despite this, molecular bases of the mechanisms through which these alkaloids would exert their effect still remain unknown. Fundamental aspects including the photosensitizing properties and intracellular internalization of a selected group of N-methyl-βC alkaloids were investigated herein. Data reveal that methylation of the βC main ring enhances its photosensitizing properties either by increasing its binding affinity with DNA as a biomolecular target and/or by increasing its oxid…
The relationship between vigilance capacity and physical exercise: a mixed-effects multistudy analysis
2019
We thank to all the participants who took part in the experiment.
Exclusion of Saccharomyces kudriavzevii from a wine model system mediated by Saccharomyces cerevisiae.
2010
This study investigated the competition and potential hybrid generation between the species Saccharomyces cerevisiae and S. kudriavzevii in a wine-model environment. Our main goal was to understand why S. kudriavzevii has not been found in wine fermentations whilst their hybrids are present. Auxotrophic mutants (Ura(-) and Lys(-)) were used to favour the selection of hybrids and to specifically differentiate the two species in mixed fermentations carried out at different temperatures (17 °C, 24 °C and 31 °C). Both yeasts showed a reduction in their maximum specific growth rates in mixed fermentations, indicating a clear antagonistic effect between the two microorganisms. Temperature played …
Anomalous time decay of transient nutations in S = 1/2 spin systems
1994
La decroissance temporelle des signaux de nutation transitoire a ete etudiee experimentalement a la frequence micro-onde sur des systemes de spin 1/2 (centres E' dans la silice and [AlO 4 ] o dans le quartz). Ces signaux decroissent exponentiellement mais avec une vitesse plus grande que la valeur habituellement donnee par les equations de Bloch. On trouve une dependence lineaire de cette vitesse avec la frequence de Rabi. Aucun interpretation pour le moment n'explique veritablement ce comportement anormal