LociScan,a tool for screening genetic marker combinations for plant variety discrimination

To reduce the cost and increase the efficiency of plant genetic marker fingerprinting for variety discrimination,it is desirable to identify the optimal marker combinations.We describe a marker combination screening model based on the genetic algorithm(GA)and implemented in a software tool,Loci Scan.Ratio-based variety discrimination power provided the largest optimization space among multiple fitness functions.Among GA parameters,an increase in population size and generation number enlarged optimization depth but also calculation workload.Exhaustive algorithm afforded the same optimization depth as GA but vastly increased calculation time.In comparison with two other software tools,Loci Scan accommodated missing data,reduced calculation time,and offered more fitness functions.In large datasets,the sample size of training data exerted the strongest influence on calculation time,whereas the marker size of training data showed no effect,and target marker number had limited effect on analysis speed.

数字PCR技术及其在检测领域的应用

随着分子生物学技术的不断发展和需求的多样化,用于核酸检测的各种PCR衍生技术应运而生。数字PCR是一种单分子水平的大规模分区扩增定量核酸检测技术。该技术以微腔室/微孔或微滴作为PCR反应器,无需校准物和绘制标准曲线即可实现对样品初始浓度的绝对定量,具有高灵敏度、高特异性和高精确度的特点。本文详细介绍了数字PCR的技术发展史、作用原理以及仪器平台类型,系统阐述了数字PCR在转基因检测、疾病诊断、环境及食品监管等方面的应用概况,并对该技术的应用前景进行了展望,以期对未来数字PCR的开发利用提供参考。

Etoposide,dexamethasone,and pegaspargase with sandwiched radiotherapy in early-stage natural killer/T-cell lymphoma:A randomized phase III study

Methotrexate,etoposide,dexamethasone,and pegaspargase(MESA)with sandwiched radiotherapy is known to be effective for early-stage extranodal natural killer/T-cell lymphoma,nasal type(NKTCL).We explored the efficacy and safety of reduced-intensity,non-intravenous etoposide,dexamethasone,and pegaspargase(ESA)with sandwiched radiotherapy.This multicenter,randomized,phase III trial enrolled patients aged between 14 and 70 years with newly diagnosed early-stage nasal NKTCL from 27 centers in China.Patients were randomly assigned(1:1)to receive ESA(pegaspargase 2,500 IU/m^(2)intramuscularly on day 1,etoposide 200 mg orally,and dexamethasone 40 mg orally on days 2–4)or MESA(methotrexate 1 g/m^(2)intravenously on day 1,etoposide 200 mg orally,and dexamethasone 40 mg orally on days 2–4,and pegaspargase 2,500 IU/m^(2)intramuscularly on day 5)regimen(four cycles),combined with sandwiched radiotherapy.

Outcomes in refractory diffuse large B-cell lymphoma:results fromamulticenter real-world study in China

Background:Diffuse large B-cell lymphoma(DLBCL)patients refractory to rituximab-based immunochemotherapy have a dismal prognosis.However,the definition of refractory DLBCL remains inconsistent and no large cohort study data is available from Asian countries.To validate the definition and outcomes of refractory DLBCL in China,we conducted a multicenter,retrospective cohort study.Methods:The REtrospective AnaLysis of Treatment REspoNse of refractory DLBCL(REAL-TREND)study was performed using real-world data from 8 centers in China.DLBCL patients with curative intent were included in the REAL-TREND dataset.Overall survival(OS)was estimated using the Kaplan-Meier method and compared by the log-rank test.Due to heterogeneity in response rates among different centers,the response rates of refractory patients were pooled using random-effect models.Multivariate survival analysis was performed using the Cox regression model.Results:A total of 2778 DLBCL patients diagnosed between January,2010 and December,2015 were enrolled to this study.After validating previous definitions,the SCHOLAR-1 study was most suitable to define refractory DLBCL.The estimated 5-year cumulative incidence of refractory patients was 20%(95% confidence Interval[CI]=18%-22%).After the determination of refractory disease,overall response rate and complete remission rate were 30%(95%CI=22%-38%)and 9%(95%CI=4%-15%),respectively.Patients with either no response to immunochemotherapy or relapse within 12 months after stem-cell transplantation had inferior survival with a median OS of 5.9 months(95%CI=5.5-7.1 months)and 2-year OS rate of 16%(95%CI=12%-20%).International prognostic index score 4-5(hazard ratio[HR]=2.22;95%CI=1.47-3.35),central nervous systemrelapse(HR=1.43;95%CI=1.04-1.97),and best response status(HR=2.68;95%CI=1.42-5.03 for partial remission.HR=5.97,95%CI=3.21-11.11 for stable disease/progressive disease)were independent unfavorable prognostic factors.Conclusions:This is the first large-scale Asian cohort study focusing on outcomes of refractory DLBCL.The definition of the SCHOLAR-1 study identifies patients with homogenously inferior survival,thus is appropriate to select refractory DLBCL.Due to poor clinical outcomes in the rituximab era,patients with refractory DLBCL may be potential candidates for novel treatment modalities.

How Are Secondary Vocational Schools in China Measuring up to Government Benchmarks?

Drawing on a survey of106 secondary vocational schools and 7309 students in two provinces of China, this descriptive paper assesses whether vocational schooling is measuring up to government benchmarks for quality and whether poor students are able to access quality schools. We find that secondary vocational schools have met government benchmarks for teacher qualification and training, student opportunities forpractical training and adequate facilities. Furthermore, poor students access schools of similar quality to non-poor students, even though 34percent of poor students do not receive financial aid. We conclude that recent policies are successfully ensuring secondary vocational school quality and equity of access to school quality between poor and non-poor students. However, financial aid policies should be re-examined, such that poor students receive sufficient coverage. Moreover, given that input-based measures only proxy school quality, the government should consider holding schools accountable for outcomes such as student learning.

HTPdb and HTPtools:Exploiting maize haplotypetag polymorphisms for germplasm resource analyses and genomics-informed breeding

Along with rapid advances in high-throughput-sequencing technology,the development and application of molecular markers has been critical for the progress that has been made in crop breeding and genetic research.Desirable molecular markers should be able to rapidly genotype tens of thousands of breeding accessions with tens to hundreds of markers.In this study,we developed a multiplex molecular marker,the haplotype-tag polymorphism(HTP),that integrates Maize6H-60K array data from 3,587 maize inbred lines with 6,375 blocks from the recombination block map.After applying strict filtering criteria,we obtained 6,163 highly polymorphic HTPs,which were evenly distributed in the genome.Furthermore,we developed a genome-wide HTP analysis toolkit,HTPtools,which we used to establish an HTP database(HTPdb)covering the whole genomes of 3,587 maize inbred lines commonly used in breeding.A total of 172,921 non-redundant HTP allelic variations were obtained.Three major HTPtools modules combine seven algorithms(e.g.,chain Bayes probability and the heterotic-pattern prediction algorithm)and a new plotting engine named“BCplot”that enables rapid visualization of the background information of multiple backcross groups.HTPtools was designed for big-data analyses such as complex pedigree reconstruction and maize heterotic-pattern prediction.The HTP-based analytical strategy and the toolkit developed in this study are applicable for high-throughput genotyping and for genetic mapping,germplasm resource analyses,and genomics-informed breeding in maize.

The Impacts of Highly Resourced Vocational Schools on Student Outcomes in China

Policymakers in developing countries have prioritized the mass expansion of vocational education and training(VET).This study examines whether the quality of VET in developing countries increases by investing greater resources per student.To achieve this goal,we examine the impacts of attending model schools(which have far more resources per student)on a range of student cognitive,non-cognitive,and behavioral outcomes.Using representative data from a survey of approximately 12,000 VET students from China,multivariate regression and propensity score matching analyses show that attending model vocational high schools do not benefit student outcomes,despite their substantially greater resources.

Meeting the Health-care Needs of the Rural Elderly:The Unique Role of Village Doctors

Despite their recent deterioration, village clinics have historically been an important source of health care for the poor and elderly in rural China. In this paper, we examine the current role of village clinics, the patients who use them and some of the services they provide. We focus specifically on the role of village clinics in meeting the health-care needs of the rural poor and elderly. We find that although clinics are continuing to decline financially, they remain a source of care for the rural elderly and poor. We estimate that the elderly are 10-15 percent more likely than young individuals to seek care at a clinic. We show that clinics provide many unique services to support the rural elderly （and the elderly poor）, such as in-home patient care, the option for patients to pay on credit, and free and discounted services.