Aim A New Caledonian insect group was studied in a world‐wide phylogenetic context to test: (1) whether local or regional island clades are older than 37 Ma, the postulated re‐emergence time of New Caledonia; (2) whether these clades show evidence for local radiations or multiple colonizations; and (3) whether there is evidence for relict taxa with long branches in phylogenetic trees that relate New Caledonian species to geographically distant taxa. Location New Caledonia, south‐west Pacific. Methods We sampled 43 cricket species representing all tribes of the subfamily Eneopterinae and 15 of the 17 described genera, focusing on taxa distributed in the South Pacific and around New Caledonia. One nuclear and three mitochondrial genes were analysed using Bayesian and parsimony methods. Phylogenetic divergence times were estimated using a relaxed clock method and several calibration criteria. Results The analyses indicate that, under the most conservative dating scenario, New Caledonian eneopterines are 5–16 million years old. The largest group in the Pacific region dates to 18–29 Ma. New Caledonia has been colonized in two phases: the first around 10.6 Ma, with the subsequent diversification of the endemic genus Agnotecous, and the second with more recent events around 1–4 Ma. The distribution of the sister group of Agnotecous and the lack of phylogenetic long branches in the genus refute an assumption of major extinction events in this clade and the hypothesis of local relicts. Main conclusions Our phylogenetic studies invalidate a simple scenario of local persistence of this group in New Caledonia since 80 Ma, either by survival on the New Caledonian island since its rift from Australia, or, if one accepts the submergence of New Caledonia, by local island‐hopping among other subaerial islands, now drowned, in the region during periods of New Caledonian submergence. 相似文献
In everyday life, people often make decisions on behalf of others. The current study investigates whether risk preferences of decision-makers differ when the reference point is no longer their own money but somebody else money. Thirty four healthy participants performed three different monetary risky choices tasks by making decisions for oneself and for another unknown person. Results showed that loss aversion bias was significantly reduced when participants were choosing on behalf of another person compared to when choosing for themselves. The influence of emotions like regret on decision-making may explain these results. We discuss the importance of the sense of responsibility embodied in the emotion of regret in modulating economic decisions for self but not for others. Moreover, our findings are consistent with the Risk-as-feelings hypothesis, suggesting that self-other asymmetrical behavior is due to the extent the decision-maker is affected by the real and emotional consequences of his/her decision. 相似文献
Abstract Plasmid pIP501 was transferred by conjugation from Lactococcus lactis to Lactobacillus delbrückii subsp. bulgaricus and Lactobacillus helveticus . Only Lb. delbrückii subsp. bulgaricus transconjugants could act as a donor in crosses with Lc. lactis . No Lactobacillus transconjugants were detected after inter- or intra-species Lactobacillus crosses. Plasmid pIP501 has undergone no detectable deletion or rearrangement during transfer from Lc. lactis to Lactobacillus strains. 相似文献
Systematics and taxonomy of Usnea cornuta, U. flammea and U. fragilescens are discussed. The morphology, chemistry and distribution of these species in Europe are described and a first attempt is made to provide a key for the erect-bushy to subpendant and sorediate species in Scandinavia. Compounds reported in this aggregate include lobaric acid (new to the genus). U. flammea is new for Scandinavia. U. constrictula, U. inflate, U. intexla and U. subpectinata are reduced to synonymy with U. cornuta, U. dalmatica and U. rupestris to synonymy with U. flammea, U. glaucescens to synonymy with U. hirta and the new combination U. fragilescens var. mollis is proposed. 相似文献
Adult mouse liver nuclei and their subfractions corresponding to heterochromatin, nucleoli, membranes, and euchromatin were studied for DNA-polymerase activity. The intact nuclei and the two heavy nuclear fractions contained rather low activity while the two light fractions (membranes and euchromatin) had no activity at all. In the two heavy fractions, the activity was stimulated by β-mercaptoethanol and depressed by p-hydroxymercuribenzoate and by omission of one or more nucleotides. A nuclease activity, detected in the intact nuclei, may also be present in the nuclear subfractions. DNA-polymerase activity in the heavy fractions of mouse liver nuclei is discussed in relation to other published results. 相似文献
The efficiency of ethyleneglycol-bis (β-amino-ethyl ether) N,N′-tetra-acetic acid (EGTA) in removing possible contamination from myelin was tested. Myelin fractions were isolated in the presence or absence of EGTA. An axolemma-enriched fraction was also prepared. Gel electrophoresis showed no important alteration of the protein pattern of myelin treated with EGTA. Only a minor band of about 41,000 daltons was selectively removed when EGTA was used during the two density gradient and differential centrifugation steps. EGTA, when used in the final washes, did not remove this band. It was absent from axolemma-enriched fractions. Different hypotheses are considered to explain these findings. 相似文献
Plant natural products (PNP) (e.g., secondary vegetal metabolites and their derivatives) have been a productive source of active ingredients for the pharmaceutical industry. The High Throughput Screening of Plant Natural Products (PNP-HTS) with extracts or isolated compounds has shown to be time consuming, expensive, and not as successful as expected. Recently building upon the innovative fragment-based drug discovery (FBDD) a disruptive approach was developed based on PNP. The fragment approach involves elaboration and/or isolation of weakly binding small molecules with molecular weights between 150 and 250 Da. This method is fundamentally different from HTS in almost every aspect (i.e., size of the compound library, screening methods, and optimization steps from hit to lead). Due to their nature, vegetal natural fragments have unique three-dimensional (3D) properties, high Fsp3, low aromaticity, and large chemo-diversities which represent potential opportunities for developing novel drugs. Preliminary results using vegetal natural fragments appear to be a promising and emerging field which offers valuable prospects for developing new drugs.