1,721,051 research outputs found
Maternal influences on food preferences in weanling mice (Mus domesticus)
No full textThis study has been designed to evaluate the role of social (maternal) influences on the development of feeding behaviour in mice. A large enclosure, allowing direct observation, was divided into three separate areas: a central area for the nest and two side feeding areas at opposite ends. In one the young could feed with their mother, in the other one the young had to feed on their own. Three different groups were studied: one had the same food in the two feeding areas: the second had a less palatable food in the mother feeding area: the third had two different kinds of food with similar palatability in the feeding areas. The development of infants' behaviour expressed as: a) order of exit from the nest; b) first direction taken on leaving the nest; c) first food consumed: d) frequency of contacts with mother or pup food was electronically recorded and analysed. The results clearly show that weanlingmice strongly prefer to follow their mother at her feeding sites even when the mother's food is less palatable than their own. Furthermore infants of one group, in a following binary choice test, preferred to eat the food they experienced in the mum's feeding area instead of what they experienced in their own feeding area. The fitness of such behaviour in more natural situations is discusse
Quantitative structure-activity relationship modeling of polycyclic aromatic hydrocarbon mutagenicity by classification methods based on holistic theoretical molecular descriptors
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Diels-Alder reactions of cycloalkenones. 8. A one-step preparation of 4,4-dimetyl-1-octalones, useful intermediate in the terpene synthesis.
No full textTecnologie di estrazione, conservazione, packaging e loro riflessi sulla qualità dell'olio vergine di oliva
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Synthesis and mutagenicity of some cyclopenta[c]phenanthrenes and indeno[c]phenanthrenes.
No full textAn efficient two-step synthesis of 8(H)-9,10,11,12-tetrahydrodicyclopenta[a, c]phenanthren-7-one, based on the high pressure Diels-Alder cycloaddition of 4-acetoxy-2-cyclopenten-1-one with 1-(1-naphthyl)cyclopentene and a subsequent dehydrogenation-aromatization reaction, is reported. Further, the synthesis of two cyclopenta[c]phenanthrenes and indeno[c]phenanthrenes is described. Structural analysis of the new products by 1H and 13C NMR spectroscopy is presented. The mutagenic activity of the compounds in Salmonella typhimurium was estimated by Ames' test. Three compounds were shown to be mutagenic for the strain TA 100. The mutagenic activities exhibited by cyclopenta[c]phenanthrenes are compared with those shown by the related cyclopenta[a]phenanthrenes and then discussed with respect to the effect of the cyclopentane ring facing the bay region. Indeno[c]phenanthrenes are mostly inactive. The effect of benzoannulation on the mutagenic activities of cyclopenta[e]phenanthrenes is discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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