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31.
Paternal behaviour presumably evolved because male care of young was critical for offspring survival. We report field evidence indicating that paternal behaviour enhances offspring survival in a monogamous mammal, the biparental California mouse, Peromyscus californicus. Male removal resulted in lower offspring survival in father-absent than in father-present families. New males took up residence with widowed females, but usually after females had stopped lactating, suggesting that the importance of the father is not primarily protection against infanticidal intruders but rather direct care of young. 相似文献
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The twigs of Dorstenia prorepens furnished the digeranylated chalcone, 5,3'-(3,7-dimethyl-2,6-octadienyl)-3,4, 2',4'-tetrahydroxychalcone while Dorstenia zenkeri yielded the 3',4'-(3-hydroxy-2,2-dimethyldihydropyrano)-4,2'-dihydroxychalcone and a bichalcone. 4-Hydroxylonchocarpin was found in both plants. D. prorepens also yielded the known compounds: psoralen, bergapten, beta-sitosterol and its D-glucopyranosyl derivative. D. zenkeri yielded p-hydroxybenzaldehyde, dorsmanin A, 4,2',4'-trihydroxychalcone and 4,2',4'-trihydroxy-3'-prenylchalcone. Structures of the new compounds were established by UV, IR, MS and 2-D NMR analysis. 相似文献
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In low and middle income countries road traffic injuries are commonly under-reported. This problem is significantly higher among those less severely injured road users. The objective of this study was to determine the incidence and the level of ascertainment of road traffic injuries and deaths by traffic police and hospital registry. In this study two-sample capture-recapture method was applied using data from traffic police and hospital injury surveillance, through June 2012 to May 2013. The study was conducted on one of the busiest highways in Ethiopia, the Addis Ababa – Hawassa highway. Primary data were collected by accident investigators and hospital emergency nurses using a structured checklist. Four matching variables; name of the victim, sex, place and time of the accidents was used to get the matched cases. During the study period the police independently reported 224 deaths and 446 injuries/billion vehicle kilometer while hospitals reported 123 deaths and 1,046 injuries/billion vehicle kilometer. Both sources in common captured 73 deaths and 248 injuries/billion vehicle kilometer. Taking the two data sources into consideration, the capture-recapture model estimated the incidence of deaths and injuries ranged 368–390 and 1,869–1,895 per billion vehicle kilometer, respectively. The police source captured 57.4%–60.9% of deaths and 23.5%–23.9% of injuries while the hospital sources captured 31.5%–33.4% of deaths and 55.2%–56% of injuries. Deaths and injuries among females, younger age victims, cyclists/motorcyclists and pedestrians were under-reported by traffic police. In conclusion neither of the two sources independently provided accurate coverage of road traffic incident related deaths and injuries. Strengthening both systems is necessary to obtain accurate information on road accidents and human causalities. 相似文献
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The composition of the essential oil of A. rehan has been studied. A total of 22 components were identified, the major components being davanone and camphor, and the occurrence of eudalene is noted for the first time. The characteristic blue colour of the oil is due to chamazulene. 相似文献
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Chi G. Fru Louis P. Sandjo Victor Kuete Johannes C. Liermann Dieter Schollmeyer Samuel O. Yeboah Renameditswe Mapitse Berhanu M. Abegaz Bonaventure T. Ngadjui Till Opatz 《Phytochemistry letters》2013,6(4):676-680
Phytochemical studies of the wood and the stem bark of Tridesmostemon omphalocarpoides Engl. (Sapotaceae) led to the isolation of omphalocarpoidone (1), a new lanostane-type furano-spiro-γ-lactone together with β-amyrin acetate (2), taraxerol (3), spinasterol (4), lichexanthone (5), epi-catechin (6), spinasterol 3-O-β-d-glucopyranoside (7), tormentic acid (8), and 1,2,3,4-tetrahydronorharman-1-one (9). Their structures were established on the basis of extensive NMR studies, mass spectrometry, and by comparison of the data with those previously reported in the literature. The structure of the new secondary metabolite was later confirmed by X-ray crystallography. Except for spinasterol, the antimicrobial activities of these secondary metabolites were investigated on ten bacterial strains and the alkaloid 9 showed a significant activity against Escherichia coli with a MIC at 16 μg/mL. 相似文献
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Victor Muleya Rose Hayeshi Hilary Ranson Berhanu Abegaz Merha-Tibeb Bezabih Metuno Robert 《Journal of enzyme inhibition and medicinal chemistry》2013,28(3):391-399
Elevated glutathione transferase (GST) E2 activity is associated with DDT resistance in the mosquito Anopheles gambiae. The search for chemomodulators that inhibit the function of AgGSTE2 would enhance the insecticidal activity of DDT. Therefore, we examined the interaction of novel natural plant products with heterologously expressed An. gambiae GSTE 2 in vitro. Five of the ten compounds, epiphyllocoumarin (Tral-1), knipholone anthrone, isofuranonaphthoquinones (Mr 13/2, Mr13/4) and the polyprenylated benzophenone (GG1) were shown to be potent inhibitors of AgGSTE2 with IC50 values of 1.5 μM, 3.5 μM, 4 μM, 4.3 μM and 4.8 μM respectively. Non-competitive inhibition was obtained for Tral 1 and GG1 with regards to GSH (Ki of 0.24 μM and 0.14 μM respectively). Competitive inhibition for Tral1 was obtained with CDNB (Ki = 0.4 μM) whilst GG1 produced mixed type of inhibition. The Ki and Ki' for GSH for Tral-1 and GG1 were 0.2 μM and 0.1 μM respectively. These results suggest that the novel natural plant products, particularly Tral-1, represent potent AgGSTE2 in vitro inhibitors. 相似文献
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Shetonde O. Mihigo Wendimagegn Mammo Merhatibeb Bezabih Kerstin Andrae-Marobela Berhanu M. Abegaz 《Bioorganic & medicinal chemistry》2010,18(7):2464-2473
The total synthesis of a potent antiplasmodial natural bichalcone, rhuschalcone VI, is described starting from simple and available resorcinol and 4-hydroxybenzaldehyde. Key steps include the solvent-free Aldol syntheses of chalcones, and the successful application of the Suzuki–Miyaura coupling reaction in the synthesis of bichalcones. The present work constitutes a general method for the rapid syntheses of a number of bichalcones related to rhuschalcone VI. Some of the bichalcones showed moderate antiprotozoal activities against Bodo caudatus, a preliminary screening system for antitrypanosomal activities, most of them with little or no cytotoxicity. 相似文献
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Raffaella Bucciardini Vincenzo Fragola Teshome Abegaz Stefano Lucattini Atakilt Halifom Eskedar Tadesse Micheal Berhe Katherina Pugliese Andrea Binelli Paola De Castro Roberta Terlizzi Luca Fucili Massimiliano Di Gregorio Marco Mirra Erika Olivieri Tsigemariam Teklu Teame Zegeye Amanuel Haile Stefano Vella Loko Abraham Hagos Godefay CASA-project Health Facilities 《PloS one》2015,10(9)