766 research outputs found
Effects of polymerase, template dilution and cycle number on PCR based 16 S rRNA diversity analysis using the deep sequencing method
ENU-Induced Mutagenesis in Grass Carp (Ctenopharyngodon idellus) by Treating Mature Sperm
N-ethyl-N-nitrosourea (ENU) mutagenesis is a useful approach for genetic improvement of plants, as well as for inducing functional mutants in animal models including mice and zebrafish. In the present study, mature sperm of grass carp (Ctenopharyngodon idellus) were treated with a range of ENU concentrations for 45 min, and then wild-type eggs were fertilized. The results indicated that the proportion of embryos with morphological abnormalities at segmentation stage or dead fry at hatching stage increased with increasing ENU dose up to 10 mM. Choosing a dose that was mutagenic, but provided adequate numbers of viable fry, an F1 population was generated from 1 mM ENU-treated sperm for screening purposes. The ENU-treated F1 population showed large variations in growth during the first year. A few bigger mutants with morphologically normal were generated, as compared to the controls. Analysis of DNA from 15 F1 ENU-treated individuals for mutations in partial coding regions of igf-2a, igf-2b, mstn-1, mstn-2, fst-1and fst-2 loci revealed that most ENU-treated point mutations were GC to AT or AT to GC substitution, which led to nonsense, nonsynonymous and synonymous mutations. The average mutation rate at the examined loci was 0.41%. These results indicate that ENU treatment of mature sperm can efficiently induce point mutations in grass carp, which is a potentially useful approach for genetic improvement of these fish
Discovery of gamma-ray emission from a strongly lobe-dominated quasar 3C 275.1
We systematically analyze the 6-year {\it Fermi}/LAT data of the
lobe-dominated quasars (LDQs) in the complete LDQ sample from 3CRR survey and
report the discovery of high-energy -ray emission from 3C 275.1. The
-ray emission of 3C 207 is confirmed and significant variability of the
lightcurve is identified. We do not find statistically significant -ray
emission from other LDQs. 3C 275.1 is the known -ray quasar with the
lowest core dominance parameter (i.e., ). We also show that both the
northern radio hotspot and parsec jet models can reasonably reproduce the
-ray data. The parsec jet model, however, is favored by the potential
-ray variability at the timescale of months. We suggest that some
dimmer -ray LDQs will be detected in the future and LDQs could
contribute non-negligibly to the extragalactic -ray background.Comment: 26 pages, 10 figures, 3 tables; ApJ in pres
Factors associated with one year retention to methadone maintenance treatment program among patients with heroin dependence in China
Abstract
Objective
The aim of this study was to evaluate the risk factors associated with dropout from Methadone Maintenance Treatment (MMT) clinics within a 1 year follow-up cohort study in China.
Methods
A data analysis is to explore the adherence of MMT during one year from three hundred and twenty patients with heroin dependence at five clinics (3 in Shanghai, 2 in Kunming) in China. All participants were from the part of China-United States cooperation project entitled “Research about improving the compliance and efficacy of methadone maintenance treatment in China”. Our data analysis includes the patients’ attendance in the 6 months clinical study and the data in another 6 months afterward. The data of patients at baseline were collected with the Addiction Severity Index (ASI) which is a semi-structured questionnaire covering socio-demographic characteristics and drug use history. The one year attendance after recruitment at the clinics and daily dose were abstracted from the MMT clinic register system. The Cox proportional hazards model were used to explore the risk factor of dropout, defined as seven consecutive days without methadone.
Results
By the end of 1 year of treatment 86 patients still remained in MMT without dropout (87% in Shanghai and 13% patients in Kunming). Over the entire 1-year period the median days of remaining in the program were 84 days (in Shanghai and Kunming were 317 days and 22 days).The factors associated with retention included age (HR = 0.98, 95%C.I.:0.96-0.99, P = 0.0062) and ASI alcohol scores (HR = 5.72, 95%C.I.:1.49-21.92, P = 0.0109) at baseline.
Conclusion
One year retention of newly recruited patients with heroin dependence was related to age and ASI alcohol scores at baseline. The adherence is poorer for the patients who are young and having more serious alcohol problems.http://deepblue.lib.umich.edu/bitstream/2027.42/109460/1/13011_2013_Article_286.pd
A Practical Infrastructure for Real-Time Simulation across Timing Domains
A real-time infrastructure, called MLRTI, is proposed in this paper to fulfill the requirement of real-time simulation in distributed environment. There are two novel contributions in this work. Firstly, a flexible timing mechanism is proposed to integrate external time source and local timer utility, enabling the distributed nodes to advance their timeline simultaneously at different speeds with high precision. A data transmission solution is also presented in which the reflective memory card (VMIC) is employed to provide fast data transmission with minimum delay. Secondly, a system partition schema is proposed in MLRTI to reduce the solution errors introduced by transforming a continuous system into distribution system, which is common in a class of control applications where the system is designed in centralized model but simulated in distributed environment for constrains on system structure or the need to balance computation load. Experiments are conducted and the results show this schema effectively reduces the possible errors by properly partitioning the system into parts that are suitable to be deployed in distributed environment
Effect of estradiol on proliferation and differentiation of side population stem/progenitor cells from murine endometrium
<p>Abstract</p> <p>Background</p> <p>In our previous study, endometrium side population cells (SP cells) were isolated from postpartum murine uterus, and characterized by a heterogeneous population of stem/progenitor cells. In this study, we investigated the effect of estrogen on the proliferation and differentiation of SP cells.</p> <p>Methods</p> <p>SP and non-SP cells of postpartum murine endometrium were isolated by DNA dye Hoechst 33342. The expression of estrogen receptor 1 (ESR1) was measured by reverse transcription polymerase chain reaction (RT-PCR), Real-time PCR, Western blot, immunofluorescence and immunohistochemistry. The proliferation and differentiation of SP cells treated with different concentrations [10(-8) M-10(-6) M] of estradiol (E2) and E2+ ICI182780 (Faslodex, inhibitor of ESR1) were measured by 3-(4, 5-dimethylthiazoly1-2)-2,5-diphenyltetrazolium bromide(MTT) and clonogenic assays.</p> <p>Results</p> <p>(1) SP cells expressed ESR1 at a higher level than non-SP cells. (2) The level of E2 in the serum and the expression of ESR1 in the uterus of postpartum murine changed in the same manner with the ratio of SP cells to total uterus cells at a different postpartum time point. ESR1, as ABCG2 is also predominantly located in the stroma and the glandular epithelium of the uterus. (3) 10(-6) M E2 notably promoted the proliferation of SP cells after treatment for 24 h. This effect could be inhibited by ICI182780. E2 at the concentration of 10(-7) M or 10(-8) M was sent to impair the large cloning efficiency (CE) of SP cells.</p> <p>Conclusions</p> <p>The effect of estrogen on the proliferation and differentiation of endometrium SP cells via ESR1 was observed and it was in a concentration dependent fashion. Clearly, more work is needed to understand the <it>in vivo </it>effect of E2 at the physiological concentration on the differentiation of SP cells.</p
Community of endophytic fungi from the medicinal and edible plant Fagopyrum tataricum and their antimicrobial activity
Purpose: To isolate and identify the fungal endophytes of Fagopyrum tataricum and assess their antimicrobial activity.Methods: The fungal isolates were identified according to their morphological characters and internal transcribed spacer (ITS) sequence analysis. Both broth-dilution-colorimetric assay and spore germination test were employed to assess the antimicrobial activity of fungal mycelia extracts.Results: A total of 72 endophytic fungal isolates were successfully obtained from the healthy tissues of F. tataricum. On the basis of their morphological and molecular characteristics, thirteen distinct fungal isolates were identified, and belonged to Alternaria, Bionectria, Botryosphaeria, Fusarium, Guignardia, Nectria, Neonectria, Phomopsis, Pseudocercospora and Verticillium spp. Of these, Pseudocercospora owned the maximum colonization frequency (15.3 %), next for Alternaria (12.5 %) and Neonectria (11.1 %). Through antimicrobial screening assays, six endophytes (Fataf-4, 6, 9, 11, 12 and 15) were active against Bacillus subtilis, Staphylococcus aureus, Agrobacterium tumefaciens, Escherichia coli and Pseudomonas lachrymans, and their minimal inhibitory concentration (MIC) ranged from 0.125 to 2.00 mg/mL. Furthermore, the endophytes, Fataf-9 and Fataf-11, also displayed strong inhibitory activity on the spore germination of F. oxysporum f. sp. vasinfectum and F. oxysporum f. sp. cucumerinum, and their median effective inhibitory concentration (IC50) was 0.356, 0.463, 0.451 and 0.489 mg/mL, respectively.Conclusion: The endophytic fungi of F. tataricum appear to be diverse and promising in their antimicrobial activity, and may represent a potential source of antibiotics for agriculture and/or pharmaceutical applications.Keywords: Endophytic fungi, Fagopyrum tataricum, Diversity, Antimicrobial activity, Antibiotics, Pseudocercospor
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