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981.
The National Aeronautics and Space Administration (NASA) Astrobiology Institute (NAI) conducted two "Workshops Without Walls" during 2010 that enabled global scientific exchange--with no travel required. The second of these was on the topic "Molecular Paleontology and Resurrection: Rewinding the Tape of Life." Scientists from diverse disciplines and locations around the world were joined through an integrated suite of collaborative technologies to exchange information on the latest developments in this area of origin of life research. Through social media outlets and popular science blogs, participation in the workshop was broadened to include educators, science writers, and members of the general public. In total, over 560 people from 31 US states and 30 other nations were registered. Among the scientific disciplines represented were geochemistry, biochemistry, molecular biology and evolution, and microbial ecology. We present this workshop as a case study in how interdisciplinary collaborative research may be fostered, with substantial public engagement, without sustaining the deleterious environmental and economic impacts of travel. 相似文献
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983.
984.
Paulo Corti Aaron B. A. Shafer David W. Coltman Marco Festa-Bianchet 《Conservation Genetics》2011,12(1):119-128
Small populations in fragmented habitats can lose genetic variation through drift and inbreeding. The huemul (Hippocamelus bisulcus) is an endangered deer endemic to the southern Andes of Chile and Argentina. Huemul numbers have declined by 99% and its
distribution by 50% since European settlement. The total population is estimated at less than 2,000 individuals and is highly
fragmented. At one isolated population in Chilean Patagonia we sampled 56 individuals between 2005 and 2007 and genotyped
them at 14 microsatellite loci. Despite low genetic variability (average 2.071 alleles/locus and average H
O of 0.341), a low inbreeding coefficient (F
IS) of 0.009 suggests nearly random mating. Population genetic bottleneck tests suggest both historical and contemporary reductions
in population size. Simulations indicated that the population must be maintained at 75% of the current size of 120 individuals
to maintain 90% of its current genetic diversity over the next 100 years. Potential management strategies to maintain genetic
variability and limit future inbreeding include the conservation and establishment of habitat corridors to facilitate gene
flow and the enlargement of protected areas to increase effective population size. 相似文献
985.
In the course of recent efforts to identify new potential antiproliferative active principles, Salvia leriifolia extracts and isolated constituents were evaluated for their cytotoxic activity against a panel of human cancer cell lines, including renal adenocarcinoma (ACHN), amelanotic melanoma (C32), colorectal adenocarcinoma (Caco‐2), lung large cell carcinoma (COR‐L23), malignant melanoma (A375), lung carcinoma (A549), and hepatocellular carcinoma (Huh‐7D12) cells. The hexane and CH2Cl2 extracts showed the strongest cytotoxic activity against the C32 cell line with IC50 values of 11.2 and 13.6 μg/ml, respectively, and the AcOEt extract was the most active extract against the COR‐L23 cell line (IC50 of 20.9 μg/ml). Buchariol, a sesquiterpene obtained by biofractionation of the CH2Cl2 extract, exhibited a higher activity than the positive control vinblastine against the C32 and A549 cell lines (IC50 values of 2.1 and 12.6 μM , resp.). Interesting results were also obtained for naringenin, a flavonoid isolated from the AcOEt extract, which exhibited a strong cytotoxic activity against the C32, LNCaP, and COR‐L23 cell lines (IC50 values of 2.2, 7.7, and 33.4 μM , resp.), compared to vinblastine (IC50 values of 3.3, 32.2, 50.0 μM , resp.). None of the tested compounds affected the proliferation of skin fibroblasts (142BR), suggesting a selective activity against tumor cells. 相似文献
986.
Scandura Massimo Iacolina Laura Capitani Claudia Gazzola Andrea Mattioli Luca Apollonio Marco 《European Journal of Wildlife Research》2011,57(4):949-958
We investigated local gene flow in a high-density wolf (Canis lupus) population of the Italian Apennines, where no effective barrier to wolf dispersal was present. From 1998 to 2004 we examined
wolf carcasses and non-invasively collected samples, focusing on three mountain districts, separated by two valleys, where
wolf packs showed high spatial stability. Using nine autosomal microsatellites we successfully genotyped 177 samples, achieving
the identification of 74 wolves. Genetic relatedness steeply decreased with increasing distance between sampling areas, thus
suggesting that short-distance interpack migration is infrequent in this population. In addition, no individual from a central
pack under intensive monitoring was sampled in the range of the surrounding packs over a 4-year period. The limited short-distance
gene flow resulted in a cryptic genetic structure, which was revealed by Bayesian analysis. A different genetic cluster was
found in each of the three mountain areas, and a small proportion of first-generation immigrants was detected. Overall, the
present study suggests that local genetic differentiation in Italian wolves might arise from high spatial stability of packs
and can be favoured by a combination of long-range dispersal, the attitude to mate between unrelated individuals and a high
young mortality rate. 相似文献
987.
Paolo De Franceschi Luca Pierantoni Luca Dondini Marco Grandi Silviero Sansavini Javier Sanzol 《Tree Genetics & Genomes》2011,7(4):663-683
The recent analysis of the S-locus region of apple and Japanese pear, two species of Pyrinae (Rosaceae), suggested multiple
and different F-box genes (called SFBBs) as candidates for the male determinant (pollen S) of RNase-based gametophytic self-incompatibility in these two species.
Here, we followed a phylogenetic approach to take advantage of the pattern of molecular evolution of the S-locus of Pyrinae
in characterizing SFBB homologs belonging to S-haplotypes of apple and three species of Pyrus (European, Japanese, and Chinese pears). Our results suggested that the S-locus region of Pyrinae contains no less than six
SFBB members and that its structure seems to be rather conserved between apple and pear species. In accordance with the prevailing
theory on S-haplotype evolution, the pollen S is expected to have coevolved with the S-RNase and to show some common features derived from the long-term evolution under frequency-dependent balancing selection, i.e.,
high sequence diversity, evidence of positive selection, and shared ancestral polymorphisms. Using this conceptual framework,
we present evidence that some SFBB genes may be better candidates for pollen S in Pyrinae than others. Overall, the SFBB genes analyzed exhibited much lower sequence diversity than their associated S-RNases; likewise, they showed little or no evidence of positive selection. However, evidence of coevolution with the S-RNase clearly emerged for two of them. Altogether our results suggested different evolutionary histories for different SFBBs putatively derived from their distinct involvement in self-incompatibility. 相似文献
988.
Marco Barbero Roberto Gatti Loredana Lo Conte Fiona Macmillan Fiona Coutts Roberto MerlettiAuthor vitae 《Journal of electromyography and kinesiology》2011,21(5):827-833
The identification of the motor unit (MU) innervation zone (IZ) using surface electromyographic (sEMG) signals detected on the skin with a linear array or a matrix of electrodes has been recently proposed in the literature. However, an analysis of the reliability of this procedure and, therefore, of the suitability of the sEMG signals for this purpose has not been reported.The purpose of this work is to describe the intra and inter-rater reliability and the suitability of surface EMG in locating the innervation zone of the upper trapezius muscle.Two operators were trained on electrode matrix positioning and sEMG signal analysis. Ten healthy subjects, instructed to perform a series of isometric contractions of the upper trapezius muscle participated in the study. The two operators collected sEMG signals and then independently estimated the IZ location through visual analysis.Results showed an almost perfect agreement for intra-rater and inter-rater reliability. The constancy of IZ location could be affected by the factors reflecting the population of active MUs and their IZs, including: the contraction intensity, the acquisition period analyzed, the contraction repetition. In almost all cases the IZ location shift due to these factors did not exceed 4 mm. Results generalization to other muscles should be made with caution. 相似文献
989.
Miehlke S Krasz S Schneider-Brachert W Kuhlisch E Berning M Madisch A Laass MW Neumeyer M Jebens C Zekorn C Knoth H Vieth M Stolte M Lehn N Morgner A 《Helicobacter》2011,16(6):420-426
Background: Triple therapy with a proton pump inhibitor, moxifloxacin, and amoxicillin has been proven effective in first‐line treatment of Helicobacter pylori infection. Aim: To explore 1, the value of triple therapy with esomeprazole, moxifloxacin, and amoxicillin in second‐line or rescue treatment of Caucasian patients and 2, the impact of treatment duration on eradication success. Methods: H. pylori‐infected patients with at least one previous treatment failure were randomized to oral esomeprazole 20 mg b.i.d., moxifloxacin 400 mg o.d., and amoxicillin 1000 mg b.i.d. for either 7 (EMA‐7) or 14 days (EMA‐14). Eradication was confirmed by 13C urea breath test. Antimicrobial susceptibility testing was performed in all patients at baseline and in patients who failed treatment. Results: Eighty patients were randomized, and 60% had ≥2 previous treatment failures. Pretreatment resistance against clarithromycin and metronidazole was found in 70.5 and 61.5% of cases, respectively. The intention‐to‐treat eradication rate was significantly higher after EMA‐14 compared with EMA‐7 (95.0 vs 78.9%, p = .036). No independent risk factor for treatment failure could be identified. There were no serious adverse events. Five of the EMA‐14 patients (12.5%) compared with none of the EMA‐7 patients discontinued prematurely because of adverse events (p = .031). Post‐treatment resistance against moxifloxacin was found in one of seven patients with isolated organisms (14.3%). Conclusion: Second‐line/rescue H. pylori eradication therapy with esomeprazole, moxifloxacin, and amoxicillin is very effective and well tolerated. Fourteen days of treatment significantly increase the eradication rate but also the rate of adverse events. 相似文献
990.
Molecular cloning of IGF-1 and IGF-1 receptor and their expression pattern in the Chilean flounder (Paralichthys adspersus) 总被引:1,自引:0,他引:1