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1.
The phylogeny of the fungus gnat family Mycetophilidae (Diptera) is reconstructed with a focus on the species‐rich and taxonomically difficult subfamilies Gnoristinae and Mycomyinae. The multigene phylogenetic analyses are based on five nuclear (18S, 28S, CAD, MCS, ITS2) and four mitochondrial (12S, 16S, COI, CytB) gene markers. The analyses strongly support the monophyly of Mycetophilidae and the subfamilies Manotinae, Sciophilinae, Leiinae, and Mycomyinae, although Gnoristinae is paraphyletic with respect to Mycetophilinae. All the genera and groups of genera included are supported as monophyletic, except for Acomoptera Vockeroth, Boletina Staeger, Dziedzickia Johannsen, Ectrepesthoneura Enderlein, and Neoempheria Osten Sacken. Ancestral character state reconstructions were applied to two morphological features present in Gnoristinae and Mycomyinae (i.e. presence of setae on wing membrane and wing vein R4) in order to assess their evolution. The wing vein R4 appears as an unstable character, spread throughout different clades. A dated phylogeny of the family Mycetophilidae showed that most of the subfamilies of Mycetophilidae originated and diversified during the Cretaceous. The youngest subfamilies, originated in the Paleogene, appear to be Mycomyinae and Mycetophilinae. 相似文献
2.
Identifying common prognostic factors in genomic cancer studies: A novel index for censored outcomes
Background
With the growing number of public repositories for high-throughput genomic data, it is of great interest to combine the results produced by independent research groups. Such a combination allows the identification of common genomic factors across multiple cancer types and provides new insights into the disease process. In the framework of the proportional hazards model, classical procedures, which consist of ranking genes according to the estimated hazard ratio or the p-value obtained from a test statistic of no association between survival and gene expression level, are not suitable for gene selection across multiple genomic datasets with different sample sizes. We propose a novel index for identifying genes with a common effect across heterogeneous genomic studies designed to remain stable whatever the sample size and which has a straightforward interpretation in terms of the percentage of separability between patients according to their survival times and gene expression measurements. 相似文献3.
L Chrobák D Radochová K Smetana F Mat?ja M Kout J Polák P Dít? J Pribrosky I Dvorácková 《Folia haematologica (Leipzig, Germany : 1928)》1980,107(4):628-640
These siblings of a Czech family aged 21, 19 and 6 years, respectively, with congenital dyserythropoietic anemia, type II, (HEMPAS) are reported. In two elder siblings ferrokinetic studies revealed a rapid plasma 59Fe clearance, markedly decreased erythrocyte incorporation and shortened 51Cr red-cell survival. Direct anti-globulin test was found positive in one of them. Further investigations revealed low values of blood plasma cholesterol, total lipids, beta-lipoproteins, beta-carotine and vitamin E and A as well as low values of the prothrombin complex. Liver biopsy demonstrated siderosis and disseminated intravascular coagulation in the liver in both patients. The possible reasons for these humoral aberrations are discussed. 相似文献
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RegB is involved in the control of the phage T4 life cycle. It inactivates the phage early mRNAs when their translation is
no more required. We determined its structure and identified residues involved in substrate binding. For this, all backbone
and 90% of side-chain resonance frequencies were assigned. 相似文献
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The stem barks and the leaves from Bridelia ferruginea (BF, Euphorbiaceae), a medicinal plant, are used in traditional medicine for the treatment of several ailments including male impotency. The present study was aimed at investigating the effects of the dried stem bark of BF on the sexual behaviour of normal and castrated sexually inexperienced male Wistar rats. Animals were orally administered with 100 mg/kg of either the aqueous or the ethanol extracts of BF whilst the neutral control group received in the same way 10 ml/kg of distilled water. The positive control group was treated with a subcutaneous injection of testosterone propionate (20 mg/kg/day/3days) prior to the experiment. The sexual behaviour of all rats was monitored on days 0, 1 and 7 by measuring frequencies of penile erection, mount, intromission and ejaculation. In a separate group of normal sexually inexperienced rats, the pro-sexual effects induced by a single dose of the aqueous extract (100 mg/kg) were measured after pre-treatment with either haloperidol (10 mg/kg), atropine (10 mg/kg) or L-omega-nitro-arginine methyl ester (Lω-NAME, 10 mg/kg). Results obtained showed a significant influence of the duration of treatment on the frequencies of penile erection, mount and intromission of both normal and castrated rats. An increase in all sexual performance parameters was observed when compared to respective controls. The intromission frequency of normal animals was significantly increased (P < 0.05–0.01) on day 1 of treatment and the effect was more expressed in rats receiving the aqueous extract. In castrated animals, a statistical increase was noticed on day 7 for rats treated with testosterone. The sexual effects induced by the aqueous extract of BF were completely abolished after pre-treatment of rats with atropine or haloperidol while pre-administration of Lω-NAME did not produce any significant effects. Flavonoids and sterols revealed in the aqueous and ethanolic extracts from the barks of BF may account for the enhancement of sexual activity in naive rats which could be expressed through dopaminergic and/or cholinergic receptor(s). Results of this work also give value to the traditional use of the plant for the improvement of male sexual behaviour. 相似文献
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P de Taxis du Po?t Y Arcand R Bernier J N Barbotin D Thomas 《Applied and environmental microbiology》1987,53(7):1548-1555
Stability of the plasmid pKK223-200 in Escherichia coli JM105 was studied for both free and immobilized cells during continuous culture. The relationship between plasmid copy number, xylanase activity, which was coded for by the plasmid, and growth rate and culture conditions involved complex interactions which determined the plasmid stability. Generally, the plasmid stability was enhanced in cultured immobilized cells compared with free-cell cultures. This stability was associated with modified plasmid copy number, depending on the media used. Hypotheses are presented concerning the different plasmid instability kinetics observed in free-cell cultures which involve the antagonistic effects of plasmid copy number and plasmid presence on the plasmid-bearing/plasmid-free cell growth rate ratio. Both diffusional limitation in carrageenan gel beads, which is described in Theoretical Analysis of Immobilized-Cell Growth, and compartmentalized growth of immobilized cells are proposed to explain plasmid stability in immobilized cells. 相似文献
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