5,914 research outputs found

    Full-length enriched multistage cDNA library construction covering floral bud development in Populus tomentosa

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    Flowering involves expression of a suite of genes associated with floral development. The genome of the Chinese white poplar (Populus trichocarpa) was sequenced because of its importance as a model tree for genetic studies as well as being an economically important woody plant. However, information on expressed genes involved in poplar floral bud development is insufficient to allow annotation of genes and use of the genomic information. To isolate and characterize genes involved in flowering of Populus tomentosa, floral bud samples were collected at different developmental stages from floral bud initiation to flower maturity, and full-length enriched cDNA libraries from both male and female floral buds were constructed. The results of titer analysis showed that the titer of the female and male primary libraries were 8.00 × 105 and 7.20 × 105 pfu/ml, respectively, and the titer of the amplified libraries were 2.60 × 108 and 2.56 × 108 pfu/ml, respectively. The combination ratio reached 90% and the insert size was 400 to 2000 bp. The results indicated that cDNA libraries were successfully constructed.Keywords: cDNA library, floral bud, flowering, Populus tomentosaAfrican Journal of Biotechnology Vol. 11(29), pp. 7373-7377, 10 April, 201

    Phylogeographic analyses of an epiphytic foliose lichen show multiple dispersal events westward from the Hengduan Mountains of Yunnan into the Himalayas.

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    Lobaria pindarensis is an endemic species of the Himalayas and the Hengduan Mountains. Little information is available on the phylogeography genetics and colonization history of this species or how its distribution patterns changed in response to the orographic history of the Himalayas and Hengduan Mountains. Based on samples covering a major part of the species' distribution range, we used 443 newly generated sequences of nine loci for molecular coalescent analyses in order to reconstruct the evolutionary history of L. pindarensis, and to reconstruct the species' ancestral phylogeographic distributions using Bayesian binary MCMC analyses. The results suggest that current populations originated from the Yunnan region of the Hengduan Mountains in the middle Pliocene, and that the Himalayas of Bhutan were colonized by a lineage that diverged from Yunnan ca. 2.72 Ma. The analysis additionally indicates that the Nepal and Xizang areas of the Himalayas were colonized from Yunnan as well, and that there was later a second dispersal event from Yunnan to Bhutan. We conclude that the change in climate and habitat related to the continuous uplift of the Himalayas and the Hengduan Mountains in the late Pliocene and middle Pleistocene influenced the geographic distribution pattern of L. pindarensis

    Quasi-periodic Variations of Coronal Mass Ejections with Different Angular Widths

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    Coronal mass ejections (CMEs) are energetic expulsions of organized magnetic features from the Sun. The study of CME quasi-periodicity helps establish a possible relationship between CMEs, solar flares, and geomagnetic disturbances. We used the angular width of CMEs as a criterion for classifying the CMEs in the study. Based on 25 years of observational data, we systematically analyzed the quasi-periodic variations corresponding to the CME occurrence rate of different angular widths in the northern and southern hemispheres, using frequency and time-frequency analysis methods. There are various periods for CMEs of different angular widths: 9 months, 1.7 years, and 3.3-4.3 years. Compared with previous studies based on the occurrence rate of CMEs, we obtained the same periods of 1.2(+-0.01) months, 3.1(+-0.04) months, ~6.1(+-0.4) months, 1.2(+-0.1) years, and 2.4(+-0.4) years. We also found additional periods of all CMEs that appear only in one hemisphere or during a specific solar cycle. For example, 7.1(+-0.2) months and 4.1(+-0.2) years in the northern hemisphere, 1(+-0.004) months, 5.9(+-0.2) months, 1(+-0.1) years, 1.4(+-0.1) years, and 2.4(+-0.4) years in the southern hemisphere, 6.1(+-0.4) months in solar cycle 23 (SC23) and 6.1(+-0.4) months, 1.2(+-0.1) years, and 3.7(+-0.2) years in solar cycle 24 (SC24). The analysis shows that quasi-periodic variations of the CMEs are a link among oscillations in coronal magnetic activity, solar flare eruptions, and interplanetary space.Comment: 18 pages, 8 figures, 4 tables, Accepted by AP

    Hybrid exciton-polaritons in a bad microcavity containing the organic and inorganic quantum wells

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    We study the hybrid exciton-polaritons in a bad microcavity containing the organic and inorganic quantum wells. The corresponding polariton states are given. The analytical solution and the numerical result of the stationary spectrum for the cavity field are finishedComment: 3 pages, 1 figure. appear in Communications in Theoretical Physic

    Assessment of Long-Term Watershed Management on Reservoir Phosphorus Concentrations and Export Fluxes.

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    Source water nutrient management to prevent eutrophication requires critical strategies to reduce watershed phosphorus (P) loadings. Shanxi Drinking-Water Source Area (SDWSA) in eastern China experienced severe water quality deterioration before 2010, but showed considerable improvement following application of several watershed management actions to reduce P. This paper assessed the changes in total phosphorus (TP) concentrations and fluxes at the SDWSA outlet relative to watershed anthropogenic P sources during 2005⁻2016. Overall anthropogenic P inputs decreased by 21.5% over the study period. Domestic sewage, livestock, and fertilizer accounted for (mean ± SD) 18.4 ± 0.6%, 30.1 ± 1.9%, and 51.5 ± 1.5% of total anthropogenic P inputs during 2005⁻2010, compared to 24.3 ± 2.7%, 8.8 ± 10.7%, and 66.9 ± 8.0% for the 2011⁻2016 period, respectively. Annual average TP concentrations in SDWSA decreased from 0.041 ± 0.019 mg/L in 2009 to 0.025 ± 0.013 mg/L in 2016, a total decrease of 38.2%. Annual P flux exported from SDWSA decreased from 0.46 ± 0.04 kg P/(ha·a) in 2010 to 0.25 ± 0.02 kg P/(ha·a) in 2016, a decrease of 44.9%. The success in reducing TP concentrations was mainly due to the development of domestic sewage/refuse collection/treatment and improved livestock management. These P management practices have prevented harmful algal blooms, providing for safe drinking water

    Active Hypothermic Growth: A Novel Means For Increasing Total Interferon-γ Production by Chinese Hamster Ovary Cells

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    When grown under hypothermic conditions, Chinese Hamster Ovary (CHO) cells become growth arrested in the G₀/G₁ phase of the cell cycle and also often exhibit increased recombinant protein production. In this study, we have validated this hypothesis by stimulating hypothermic growth using basic fibroblast growth factor and fetal bovine serum supplementation. This method led to 7.7- and 4.9-fold increase in total production compared to the 37°C and 32°C control cultures, respectively. This proof-of-concept study will motivate the creation of cell lines capable of growing at low temperatures for use in industrial processes.Singapore-MIT Alliance (SMA

    Mobility Census for the analysis of rapid urban development

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    Traditionally urban structure and development are monitored using infrequent high-quality datasets such as censuses. However, human culture is accelerating and aggregating, leading to ever-larger cities and an increased pace of urban development. Our modern interconnected world also provides us with new data sources that can be leveraged in the study of cities. However, these often noisy and unstructured sources of big data pose new challenges. Here we propose a method to extract meaningful explanatory variables and classifications from such data. Using movement data from Beijing, which is produced as a byproduct of mobile communication, we show that meaningful features can be extracted, revealing for example the emergence and absorption of subcenters. In the future this method will allow the analysis of urban dynamics at a high spatial resolution (here, 500m) and near real-time frequency

    Photodynamic therapy combined with the Sanqi Panax Notoginseng for patients with age-related macular degeneration and choroidal neovascularization

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    AIM: To investigate the clinical effect of photodynamic therapy(PDT)combined with Traditional Chinese medicine Sanqi Panax Notoginseng therapy for age-related macular degeneration(AMD)and choroidal neovascularization(CNV). <p>METHODS: Seventeen patients(17 eyes)with AMD and CNV were diagnosed by visual acuity, ocular pressure, fundus fluorescein angiography(FFA), idocyanine green angiography(ICGA)and optic coherence tomography(OCT), and male 7 cases, female 10 cases, age 53-72 years old. PDT was performed using the recommended standard procedure. The patients were treated with PDT for 5 days, and Sanqi Panax Notoginseng 500mg injection by intravenous drip for 10 days, once a day, 15 days as one course. One month, 3, 6 months of follow-up after treatment. <p>RESULTS: Of 17 patients after 6 months treatment, visual acuity improved in 8 cases(47%, 8/17), remained stable in 6 cases(35%), and decreased in 3 cases(18%); and 12 cases(71%)with CNV closure and leakage stopped completely, 5 cases(29%)with most of the CNV's closure, 1 patient experienced blurred vision. <p>CONCLUSION: The results show that PDT combined with traditional Chinese medicine Sanqi Panax Notoginseng in treatment of ADM-CNV is simple and has reliable effect, it can be used in clinical application
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