经验视角下乡村日常景观的价值感知研究——以盐城八灶村为例

乡村环境中存在一类日常而平凡的景观,和专家视角下具有突出价值的景观一样,它们同样是文化和社会关系的表征空间。在新型城镇化中,这类景观对形成以人为本的、完整适宜的生产生活环境单元具有重要意义,值得我们解读。以江苏盐城普通村落八灶村为典型案例,分析八灶村村民对日常景观的价值感知及其时空分布情况,识别出具有普遍意义的场所类型,包括惯常行为空间、主题活动空间、个人所属领地,其意义产生于不同物质空间基础上村民多样的日常活动中。发现意义场所的分布存在一定边界,其热区由住宅区向周边扩散,密度级别逐渐降低。意义场所的感知具有时间特征,主要集聚在明代、人民公社时期和2000年前后,是村落集体记忆的体现。最终提出在城镇化过程中,应重视日常景观中意义场所的识别,并在村落的更新和重建中予以响应和重塑,藉此延续村落的内在活力和乡村特性。

How rice organs are colored: The genetic basis of anthocyanin biosynthesis in rice

Anthocyanins are a major subclass of flavonoids that have diverse biological functions and benefit human health.In rice(Oryza sativa),the various colors shown by organs are due mainly to the accumulation of anthocyanins and are traits associated with domestication.Elucidating the genetic basis of anthocyanin biosynthesis in rice would support the engineering of anthocyanins as well as shedding light on the evolutionary history of O.sativa.We summarize recent progress in rice anthocyanin biosynthesis research,including gene cloning,biosynthetic pathway discovery,and study of the domestication process.We discuss the application of anthocyanin biosynthesis genes in rice breeding.Our object is to broaden knowledge of the genetic basis of anthocyanin biosynthesis in rice and support the breeding of novel rice cultivars.

High-sensitivity methane monitoring based on quasi-fundamental mode matched continuous-wave cavity ring-down spectroscopy

Continuous-wave cavity ring-down spectroscopy(CW-CRDS)is an important technical means to monitor greenhouse gases in atmospheric environment.In this paper,a CW-CRDS system is built to meet the needs of atmospheric methane monitoring.The problem of mode matching is explained from the perspective of transverse mode and longitudinal mode,and the influence of laser injection efficiency on measurement precision is further analyzed.The results of cavity ring-down time measurement show that the measurement precision is higher when the laser is coupled with the fundamental mode.In the experiment,DFB laser is used to calibrate the system with standard methane concentration,and the measurement residual is less than±4×10^(-4)μs^(-1).The methane concentration in the air is monitored in real time for two days.The results show the consistency of the concentration changes over the two days,which further demonstrates the reliability of the system for the measurement of trace methane.By analyzing the influence of mode matching,it not only assists the adjustment of the optical path,but also further improves the sensitivity of the system measurement.

A QoS-aware Method for Web Services Discovery

The non-functional QoS (quality of service) information helps us to select a proper Web-service from the web applications, by using component services such as UDDI[1](Universal Description, Discovery, and Integration) and MDS(Monitoring and Discovery System). MDS is a suite of web services to monitor and discover resources and service on Grids, but MDS only based on function aspects. This paper studies on an approach to provide the QoS information and a discovery model by using MDS and gives a system deployment and implementation plan. The simulation results show that the method is effective in service discovery.

Long-term Therapeutic Outcome and Prognostic Factors of Patients with Nasopharyngeal Carcinoma Receiving Intensity-modulated Radiotherapy: An Analysis of 608 Patients from Low-endemic Regions of China

Objective To evaluate the long-term outcome and prognostic factors of patients with nasopharyngeal carcinoma(NPC)from low-endemic regions of China who received definitive intensity-modulated radiation therapy(IMRT).Methods The clinical data from 608 patients with newly-diagnosed non-metastatic NPC who have received initial treatment at our cancer center from January,2008 to December,2013 were retrospectively reviewed.All patients received definitive IMRT,and 87.7%received platinum-based chemotherapy.Results The median follow-up duration was 51 months(follow-up rate,98.5%;range,10–106 months)for the entire cohort.The 5-year overall survival rate was 79.7%.The 5-year local relapse-free survival rate,regional relapse-free survival rate,distant metastasis-free survival rate and progression-free survival rate were 92.4%,93.3%,79.2%and 74.3%,respectively.A total of 153 patients had experienced treatment failure,with distant metastasis as the primary cause in 77.1%(118/153).Patients with T4 or N3 diseases had a significantly poorer prognosis than other subcategories.Stage T4 and N3 were closely associated with distant metastasis,with the metastatic rate of 29.3%and 45.5%,respectively.Conclusion IMRT provides patients with non-metastatic NPC with satisfactory long-term survival.Both T stage and N stage are important prognostic factors for NPC patients.Patients with T4 or N3 diseases have significantly increased distant metastatic rates and poor survival time.

Effect of lens-to-sample distance on spatial uniformity and emission spectrum of flat-top laser-induced plasma

The optimal spectral excitation and acquisition scheme is explored by studying the effect of the lensto-sample distance(LTSD)on the spatial homogeneity and emission spectra of flat-top laser converging spot induced plasma.The energy distribution characteristics before and after the convergence of the laser beam with quasi flat-top intensity profile used in this study are theoretically simulated and experimentally measured.For an aspheric converging mirror with a focal length of100 mm,the LTSD(106 mm≥LTSD≥96 mm)was changed by raising the stainless-steel sample height.The plasma images acquired by ICCD show that there is air breakdown when the sample is below the focal point,and a ring-like plasma is produced when the sample is above the focal point.When the sample is located near the focal point,the plasma shape resembles a hemisphere.Since the spectral acquisition region is confined to the plasma core and the image contains all the optical information of the plasma,it has a lower relative standard deviation(RSD)than the spectral lines.When the sample surface is slightly higher than the focal plane of the lens,the converging spot has a quasi flat-top distribution,the spatial distribution of the plasma is more uniform,and the spectral signal is more stable.Simultaneously,there is little difference between the RSD of the plasma image and the laser energy.In order to further improve the stability of the spectral signal,it is necessary to expand the spectral acquisition area.

Recent advances in chemical protein synthesis:method developments and biological applications

The central dogma of modern biology underscores the pivotal roles proteins play in diverse biological processes,the study of which necessitates advanced methods to produce proteins with precision and versatility.Chemical protein synthesis,a powerful approach utilizing chemical reactions for the de novo construction of structurally accurate proteins,has emerged as a transformative tool for studying proteins and generating protein derivatives/mimics inaccessible by natural biological machinery,including post-translationally modified proteins,proteins comprised of unnatural amino acids,as well as mirror-image proteins.This review summarizes recent strides in synthetic method developments for chemical protein synthesis,including innovative techniques in solid-phase peptide synthesis,the challenges presented by difficult sequences in either synthesis or folding and the exploration of novel ligation reactions using both chemical and enzymatic methods.Furthermore,the review also delves into newly developed protocols for site-selective protein modifications and the generation of stapled or macrocyclized peptides/miniproteins,highlighting the power of chemical methods to make structurally diverse proteins.Recent applications of synthetic proteins in investigating post-translational modifications(phosphorylation,lipidation,glycosylation,ubiquitination,etc.),mirror-image biological processes and drug development are further discussed.Together,these topics provide a comprehensive overview of the current landscape of chemical protein synthesis.

中小学教师数据素养培养模式及其应用研究

随着大数据技术与教育教学领域的深度融合,数据驱动教学成为时代所趋。作为应对教学范式从基于经验向基于证据转变的趋势,教师是否具备良好的数据素养成为教学数据能否转化为有意义教学决策的关键。教师研修作为培养教师数据素养的重要途径,在以往的实践过程中存在教师合作参与效果不佳、自身认知负荷较大、新旧教学理念和教学行为存在认知冲突等问题,而调节学习理论通过对自我和集体进行教学干预可以有效提升协作学习效果。因此,本研究基于调节学习理论,设计自我调节和共享调节作为学习支架,采用项目式协作学习,构建出新型教师数据素养培养模式。通过对20名参与数据素养培训项目的中小学信息技术教师的实证研究发现:在调节学习视域下中小学教师数据素养培养模式可以有效促进教师数据素养发展,调节支架能够对数据聚合和数据推理这两项高阶技能产生积极效用,并且不同支架间存在协同作用,相互促进。该结论对今后培养教师数据素养具有一定的参考价值。

STEM教师教学设计能力在线培养模式研究

机器与人类劳动分工的不断裂变、重组,促使教育领域的研究者和实践者深入思考应该如何培养创新型、复合型、应用型的21世纪人才。STEM教育作为对这一命题的重要回应,尚面临着教师数量不足与质量不佳的困境。为改变STEM课程教学目标不明确、教学设计模式不清晰的现状,培育未来教师的设计思维并促使其外化为实践,打造从教师教育到教师实践无缝衔接的教育生态,是有效途径之一。本研究从设计理论、培养模式和标准框架的联合视角,构建了STEM协同教学设计模式,并通过创设整合了真实教学设计问题和虚拟导师等多元支架的虚拟实习环境,使教师投入到包含STEM教学设计要素的逆向设计活动中,在实践中发展STEM教学设计能力。初步研究表明,该模式在提升教师的STEM教学设计表现和协作能力上体现出一定的作用,在破解STEM课程中目标缺位与异位困境、满足教师完成STEM跨学科设计的需求、提供多元交互式设计实践机会等方面具有独特优势。

多元评价视域下STEM课堂教学特征与互动模式分析

STEM课堂作为STEM教育价值实现的载体,是培养综合型人才的重要手段。由于从教学理念到实践模式均区别于传统课堂,STEM课堂的整合型跨学科特征使得其在实践过程中对教师的教学行为提出了新的挑战。本研究以来自不同省市和地区的18节STEM课堂实录视频为研究对象,采用基于RTOP量规的整体性评价与基于弗兰德斯编码的过程性评价相结合的多元评价方式,对课堂的教学实施特征及互动模式进行深入分析,以提炼出优质课堂的实践模式。研究发现:优质课堂中的教师在观念指向上体现了以学生为中心的理念,采用了培养多元创新思维的教学策略,注重师生课堂话语交互表征的有效性,以及营造积极的情绪氛围,具备一定的学习成效证据意识。上述结论为当前STEM课堂在教学实践的改进上提供了一定的借鉴意义。

教师引导风格对非良构问题领域的PBL学习影响研究——基于认知网络分析方法

以往衡量问题导向学习(Problem-based learning, PBL)的效果主要采用总结性评价,缺乏对学习者学习过程的关注与分析。但在非良构问题领域的PBL学习中,学习过程是呈现学习者专业思维能力发展的关键。如何通过分析PBL中的会话内容对专业思维能力进行建模,教师在这一发展过程中又充当何种角色,是PBL领域学者们关注的话题。本研究选择医学教育这一典型的非良构问题领域作为研究情境,采用不同的教师引导风格进行PBL教学,通过认知网络分析对学习者的专业思维发展过程及导师引导策略进行分析建模。研究结果揭示了赋权促进型引导风格较指导控制型引导风格对于学习者的社会性知识建构和学科思维能力培养具有更好的效果。此外,本研究也展现出认知网络分析这种创新的质性数据量化分析方法,在建模和评价社会性学习过程中的学科思维能力方面具有较大的应用潜力。

基于不同通用引物比较分析肠道微生物群落变化

肠道微生物对于人体健康的重要作用已经得到广泛证实,目前,对肠道微生物的研究大多采用基于扩增细菌16S rRNA基因V3-V4区的高通量测序分析,对古菌的关注较少。本研究选择了一对可以同时扩增细菌和古菌16S rRNA基因的引物,通过比较人为干扰肠道微生物前后的群落变化,说明这对引物适宜分析人类肠道细菌和古菌群落变化并具有一定优越性。采集志愿者粪便样品,同时用仅能扩增细菌引物(B引物)和细菌古菌通用引物(AB引物)进行扩增和高通量测序;使用几个常用的rRNA数据库判断引物对细菌的覆盖度和对古菌的扩增能力。结果表明,AB引物在可以展示B引物扩增出的细菌群落的基础上,可以得到肠道中常见的产甲烷古菌的序列,同时也展示出人为干扰肠道微生物前后的群落结构变化。AB引物可以仅通过一次扩增和测序同时分析肠道中的细菌和古菌群落,更加全面展示肠道微生物群落结构,适用于肠道微生物相关研究。

蛋白质工程：从定向进化到计算设计

定向进化通过建立突变体文库与高通量筛选方法,快速提升蛋白的特定性质,是目前蛋白质工程最为常用的蛋白质设计改造策略。近十年随着计算机运算能力大幅提升以及先进算法不断涌现,计算机辅助蛋白质设计改造得到了极大的重视和发展,成为蛋白质工程新开辟的重要方向。以结构模拟与能量计算为基础的蛋白质计算设计不但能改造酶的底物特异性与热稳定性,还可从头设计具有特定功能的人工酶。近年来机器学习等人工智能技术也被应用于计算机辅助蛋白质设计改造,并取得瞩目的成绩。文中介绍了蛋白质工程的发展历程,重点评述当前计算机辅助蛋白质设计改造方面的进展与应用,并展望其未来发展方向。

基于里德堡原子天线的微波场强仪比对验证

基于里德堡原子的微波场强测量可基于量子效应接收和测量微波电场,被认为在微波场强计量领域具备实用化潜力。通过对激光器、激光光路、室温铯原子天线等组件的定制与优化,制作了集成式原子微波场强仪。在微波暗室中,将基于该集成设备的测量方法及结果与现有计量体系下的微波场强计量标准,即标准场及标准场探头方法的结果进行比对。在3.10GHz点频上的比对结果为:1)高功率(4.17V/m~14.85V/m)下,重复性为0.44%~0.71%,非线性度为3.8%,比对误差为-2.61%~3.31%;2)低功率(2.00V/m~4.69V/m)下,重复性为0.28%~0.80%,非线性度为1.7%,比对误差为-5.08%~4.30%。结果表明,该原子微波场强仪的测试结果与现有标准场法测量结果吻合,而在重复性等指标上表现更优。

可搬运原子微波电场测量仪

近年来,基于里德堡原子的微波电场测量研究进展迅速,将光学平台上的原子微波电场测量系统一体化和集成化是工程应用的前提条件。据此,本文介绍了里德堡原子微波电场测量原理以及确定跃迁共振频率的方法,同时结合852 nm激光调制转移稳频和509 nm激光电磁诱导透明稳频方案研制了可搬运的原子微波电场测量仪。利用此仪器,演示了直接溯源至国际标准单位制的微波电场测量以及微弱微波信号的探测。

The origin of Wx^(la) provides new insights into the improvement of grain quality in rice

Appearance and taste are important factors in rice(Oryza sativa) grain quality. Here, we investigated the taste scores and related eating-quality traits of533 diverse cultivars to assess the relationships between—and genetic basis of—rice taste and eating-quality. A genome-wide association study highlighted the Wx gene as the major factor underlying variation in taste and eating quality. Notably, a novel waxy(Wx) allele, Wx^(la), which combined two mutations from Wx^(b) and Wx^(in), exhibited a unique phenotype. Reduced GBSSI activity conferred Wx^(la) rice with both a transparent appearance and good eating quality. Haplotype analysis revealed that Wx^(la) was derived from intragenic recombination. In fact,the recombination rate at the Wx locus was estimated to be 3.34 kb/c M, which was about 75-fold higher than the genome-wide mean, indicating that intragenic recombination is a major force driving diversity at the Wx locus. Based on our results, we propose a new network for Wx evolution, noting that new Wx alleles could easily be generated by crossing genotypes with different Wx alleles. This study thus provides insights into the evolution of the Wx locus and facilitates molecular breeding for quality in rice.

Enabling technology and core theory of synthetic biology

Synthetic biology provides a new paradigm for life science research(“build to learn”)and opens the future journey of biotechnology(“build to use”).Here,we discuss advances of various principles and technologies in the mainstream of the enabling technology of synthetic biology,including synthesis and assembly of a genome,DNA storage,gene editing,molecular evolution and de novo design of function proteins,cell and gene circuit engineering,cell-free synthetic biology,artificial intelligence(AI)-aided synthetic biology,as well as biofoundries.We also introduce the concept of quantitative synthetic biology,which is guiding synthetic biology towards increased accuracy and predictability or the real rational design.We conclude that synthetic biology will establish its disciplinary system with the iterative development of enabling technologies and the maturity of the core theory.

Genetic architecture and key genes controlling the diversity of oil composition in rice grains

Rice grain oil is a valuable nutrient source.However,the genetic basis of oil biosynthesis in rice grains remains unclear.In this study,we performed a genome-wide association study on oil composition and oil concentration in a diverse panel of 533 cultivated rice accessions.High variation for 11 oil-related traits was observed,and the oil composition of rice grains showed differentiation among the subpopulations.We identified 46 loci that are significantly associated with grain oil concentration or composition,16 of which were detected in three recombinant inbred line populations.Twenty-six candidate genes encoding enzymes involved in oil metabolism were identified from these 46 loci,four of which(PAL6,LIN6,MYR2,and ARA6)were found to contribute to natural variation in oil composition and to show differentiation among the subpopulations.Interestingly,population genetic analyses revealed that specific haplotypes of PAL6 and LIN6 have been selected in japonica rice.Based on these results,we propose a possible oil biosynthetic pathway in rice grains.Collectively,our results provide new insights into the genetic basis of oil biosynthesis in rice grains and can facilitate marker-based breeding of rice varieties with enhanced oil and grain quality.

Enzymatic clickable functionalization of peptides via computationally engineered peptide amidase

Directed peptides C-terminal modification enabled by the engineered biomolecular catalyst-peptide amidase 12 B has been achieved via computational protein engineering. The engineered enzyme exhibits great promising potential in the C-terminal modification of opioid peptides using prop-2-yn-1-amine(PYA) or prop-2-en-l-amine(PEA) as the nucleophile. A variety of opioid peptides could be readily functionalized at the C-terminal chain in high yield in a mild and selective manner. Notably, modified opioid peptides bearing alkynyl moiety could be further functionalized through well-established click reaction.

Cross-species binding spectrum of ACE2 to SARS-CoV-2 RBD

Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARSCo V-2)is the cause of COVID-19,which has posed a massive threat to human health,economy,and security worldwide(Bai et al.,2022).Genomic analysis of SARS-Co V-2 and related coronaviruses revealed that SARS-Co V and SARS-Co V-2likely had ancestors(Xu et al.,2020),which might originate in bats,followed by subsequent spread within intermediate hosts(spillover hosts)and then transmission to humans(Wang et al.,2021).