Wing patterning genes of Nilaparvata lugens identification by transcriptome analysis, and their differential expression profile in wing pads between brachypterous and macropterous morphs

The brown planthopper, Nilaparvata lugens is an economically important pest on rice plants. This species produces macropterous and brachypterous morphs in response to environmental cues, which makes it very dififcult to control. The molecular basis of wing patterning in N. lugens is stil unknown. It is necessary to identify wing patterning genes of N. lugens, and also to clarify the expression differences of wing patterning genes between macropterous and brachypter-ous morphs. High-throughput deep sequencing of transcriptome of N. lugens wing pad yielded 116 744 580 raw reads and 113 042 700 clean reads. Al the reads were assembled into 55 963 unigenes with an average length of 804 bp. With the E-value cut-off of 1.0E–5,18 359 and 2 883 unigens had hits in NCBI-NR (NCBI non-redundant protein sequences) and NCBI-NT (NCBI nucleotide sequences) databases, respectively. A total of 16 502 unigenes were assigned to GO (gene ontology) classiifcation, 9 709 ungenes were grouped into 26 COG (cluster of orthologous groups of proteins) classiifcations, and 6 724 unigenes were assigned to different KEGG (Kyoto encyclopedia of genes and genomes) path-ways. In total, 56 unigenes which are homologous to wing patterning genes of Drosophila melanogaster or Tribolium castaneum were identiifed. Out of the 56 unigenes, 24 unigenes were selected, and their expression levels across the ifve nymphal stages between macropterous strain and brachypterous strain were examined by qRT-PCR. Two-way ANOVA analysis showed that development stage had signiifcant effects on the expression level of al the 24 genes (P<0.05). The expression levels of 8 genes (Nlen, Nlhh, Nlsal, NlAbd-A, Nlwg, Nlvg, Nlexd and NlUbx) were signiifcantly affected by wing morph. This is the ifrst transcriptome analysis of wing pads of hemimetabolous insect, N. lugens. The identiifed wing patterning genes would be useful resource for future exploration of molecular basis of wing development. The 8 differential y expressed wing patterning genes between macropterous strain and brachypterous strain would contribute to explain molecular mechanism of wing-morph differentiation in N. lugens.

A new monitoring index for ecological vulnerability and its application in the Yellow River Basin,China from 2000 to 2022

The ecological environment of the Yellow River Basin has become more fragile under the combined action of natural and manmade activities.However,the change mechanisms of ecological vulnerability in different sub-regions and periods vary,and the reasons for this variability are yet to be explained.Thus,in this study,we proposed a new remote sensing ecological vulnerability index by considering moisture,heat,greenness,dryness,land degradation,and social economy indicators and then analyzed and disclosed the spatial and temporal change patterns of ecological vulnerability of the Yellow River Basin,China from 2000 to 2022 and its driving mechanisms.The results showed that the newly proposed remote sensing ecological vulnerability index had a high accuracy,at 86.36%,which indicated a higher applicability in the Yellow River Basin.From 2000 to 2022,the average remote sensing ecological vulnerability index of the Yellow River Basin was 1.03,denoting moderate vulnerability level.The intensive vulnerability area was the most widely distributed,which was mostly located in the northern part of Shaanxi Province and the eastern part of Shanxi Province.From 2000 to 2022,the ecological vulnerability in the Yellow showed an overall stable trend,while that of the central and eastern regions showed an obvious trend of improvement.The gravity center of ecological vulnerability migrated southwest,indicating that the aggravation of ecological vulnerability in the southwestern regions was more severe than in the northeastern regions of the basin.The dominant single factor of changes in ecological vulnerability shifted from normalized difference vegetation index(NDVI)to temperature from 2000 to 2022,and the interaction factors shifted from temperature∩NDVI to temperature∩precipitation,which indicated that the global climate change exerted a more significant impact on regional ecosystems.The above results could provide decision support for the ecological protection and restoration of the Yellow River Basin.

The deterministic condition for the ground reaction force acting point on the combined knee valgus and tibial internal rotation moments in early phase of cutting maneuvers in female athletes

Background:Combined knee valgus and tibial internal rotation(VL+IR)moments have been shown to stress the anterior cruciate ligament(ACL)in several in vitro cadaveric studies.To utilize this knowledge for non-contact ACL injury prevention in sports,it is necessary to elucidate how the ground reaction force(GRF)acting point(center of pressure(CoP))in the stance foot produces combined knee VL+IR moments in risky maneuvers,such as cuttings.However,the effects of the GRF acting point on the development of the combined knee VL+IR moment in cutting are still unknown.Methods:We first established the deterministic mechanical condition that the CoP position relative to the tibial rotational axis differentiates the GRF vector’s directional probability for developing the combined knee VL+IR moment,and theoretically predicted that when the CoP is posterior to the tibial rotational axis,the GRF vector is more likely to produce the combined knee VL+IR moment than when the CoP is anterior to the tibial rotational axis.Then,we tested a stochastic aspect of our theory in a lab-controlled in vivo experiment.Fourteen females performed 60˚cutting under forefoot/rearfoot strike conditions(10 trials each).The positions of lower limb markers and GRF data were measured,and the knee moment due to GRF vector was calculated.The trials were divided into anterior-and posterior-CoP groups depending on the CoP position relative to the tibial rotational axis at each 10 ms interval from 0 to 100 ms after foot strike,and the occurrence rate of the combined knee VL+IR moment was compared between trial groups.Results:The posterior-CoP group showed significantly higher occurrence rates of the combined knee VL+IR moment(maximum of 82.8%)at every time point than those of the anterior-CoP trials,as theoretically predicted by the deterministic mechanical condition.Conclusion:The rearfoot strikes inducing the posterior CoP should be avoided to reduce the risk of non-contact ACL injury associated with the combined knee VL+IR stress.

Characteristics of a Laboratory Strain of Coleomegilla maculata with a Novel Heritable Wing Spot Pattern Trait

The lady beetle Coleomegilla maculata is a common New World insect that is naturally colored pink to red or orange with black spots on the forewings of the adult stage. Previous laboratory in-breeding resulted in selection for a strain lacking red pigment in the cuticle and eyes. An additional strain selected for a novel spotting pattern is described here. The inheritance of the new trait, “ten spotted” (10sp), was determined by classical crossing experiments. Inheritance of the trait was autosomal and exhibited incomplete dominance. Bionomic strain measurements were compared to the parental strains and were similar overall. Two expressed sequences from C. maculata that may be related to the new phenotype were compared to model insect genes encoding a melanin biosynthesis enzyme and a patterning transcription factor.

Stable Transition of Quadruped Rhythmic Motion Using the Tracking Differentiator

Since the quadruped robot possesses predominant environmental adaptability,it is expected to be employed in nature environments. In some situations,such as ice surface and tight space,the quadruped robot is required to lower the height of center of gravity( COG) to enhance the stability and maneuverability. To properly handle these situations,a quadruped controller based on the central pattern generator( CPG) model,the discrete tracking differentiator( TD) and proportional-derivative( PD) sub-controllers is presented. The CPG is used to generate basic rhythmic motion for the quadruped robot. The discrete TD is not only creatively employed to implement the transition between two different rhythmic medium values of the CPG which results in the adjustment of the height of COG of the quadruped robot,but also modified to control the transition duration which enables the quadruped robot to achieve the stable transition. Additionally,two specific PD sub-controllers are constructed to adjust the oscillation amplitude of the CPG,so as to avoid the severe deviation in the transverse direction during transition locomotion. Finally,the controller is validated on a quadruped model. A tunnel with variable height is built for the quadruped model to travel through. The simulation demonstrates the severe deviation without the PD sub-controllers,and the reduced deviation with the PD sub-controllers.

Landscape pattern change of a typical region in the Kubuqi Desert, Northwestern China

Spatial pattern analysis is the core component in landscape ecology research.We analyzed the landscape pattern and dynamic process of the Kubuqi Desert by using a typical region as a study area.This study area includes four towns;ShuLinZhao,WangAiZhao,BaiNiJing and JiGeSiTai.The area of cropland,fixed sand dune,woodland,residential area and wetland increased and centralized gradually,while the area of semi-fixed sand dune,drifting sand dune,meadow and washland decreased and dispersed gradually from 1987 to 2003.On the landscape level,the patch shape tended to be regular,and the landscape pattern tended to be simple,causing the fragmentation degree,heterogeneity and diversity of the landscape to decrease.Fixed sand dune.Semi-fixed sand dune,drifting sand dune,meadow and river flood plains were the five main export classes,and residential area,cropland and wetland were the three main import classes.The classes that had a relatively large total area and large average patch area had a smaller extent of gravity center migration,whereas the classes with small total area and small average patch area had a larger extent of gravity center migration;this is because the small patches are easily influenced by human activities or natural factors.In addition,the desertification area and desertification degree reduced gradually in the study area during the period from 1987 to 2003.

Variation of hydraulic parameters with different wing of a T-shape spur dike in bend channels

In the present research,by using a numerical model,some analyses were performed on flows around a T-shape spur dike and a support structure located at its upstream under different wing to length ratios of T-shape spur dike in the order of 0.25,0.50,0.75 and 1.00.In order to verify numerical model,physical model data were used in presence of a single T shape spur dike.Results from numerical model are desirably in agreement with those of physical one because the regression between both data is 0.86 up to 0.92.In this research,all hydraulic parameters of flows,streamlines and dimensions of flow separation zones were studied in order to select the most practical model.Increased W/L results in 7%–12%increase in the length of flow separation zone and in 2%increase in the width of this zone compared to W/L=0.25.

Balance control during gait initiation: State-of-the-art and research perspectives

It is well known that balance control is affected by aging, neurological and orthopedic conditions. Poor balance control during gait and postural maintenance are associated with disability, falls and increased mortality. Gait initiation-the transient period between the quiet standing posture and steady state walking-is a functional task that is classically used in the literature to investigate how the central nervous system(CNS) controls balance during a whole-body movement involving change in the base of support dimensions and center of mass progression. Understanding how the CNS in able-bodied subjects exerts this control during such a challenging task is a prerequisite to identifying motor disorders in populations with specific impairments of the postural system. It may also provide clinicians with objective measures to assess the efficiency of rehabilitation programs and better target interventions according to individual impairments. The present review thus proposes a state-of-the-art analysis on:(1) the balance control mechanisms in play during gait initiation in able bodied subjects and in the case of some frail populations; and(2) the biomechanical parameters used in the literature to quantify dynamic stability during gait initiation. Balance control mechanisms reviewed in this article included anticipatory postural adjustments, stance leg stiffness, foot placement, lateral ankle strategy, swing foot strike pattern and vertical center of mass braking. Based on this review, the following viewpoints were put forward:(1) dynamic stability during gait initiation may share a principle of homeostatic regulation similar to most physiological variables, where separate mechanisms need to be coordinated to ensure stabilization of vital variables, and consequently; and(2) rehabilitation interventions which focus on separate or isolated components of posture, balance, or gait may limit the effectiveness of current clinical practices.

A Survey of Human-centered Intelligent Robots:Issues and Challenges

Intelligent techniques foster the dissemination of new discoveries and novel technologies that advance the ability of robots to assist and support humans. The human-centered intelligent robot has become an important research field that spans all of the robot capabilities including navigation, intelligent control, pattern recognition and human-robot interaction. This paper focuses on the recent achievements and presents a survey of existing works on human-centered robots. Furthermore, we provide a comprehensive survey of the recent development of the human-centered intelligent robot and discuss the issues and challenges in the field.

Measurement on Camber Deformation of Wings of Free-flying Dragonflies and Beating-flying Dragonflies

The knowledge of wing orientation and deformation during flapping flight is necessary for a complete aerodynamic analysis, but to date those kinematic features have not been simultaneously quantified for free-flying insects. A projected comb-fringe (PCF) method has been developed for measuring spanwise camber changes on free-flying dragonflies and on beating-flying dragonflies through the course of a wingbeat, which bases on projecting a fringe pattern over the whole measurement area and then measuring the wing deformation from the distorted fringe pattern. Experimental results demonstrate substantial camber changes both along the wingspan and through the course of a wingbeat. The ratio of camber deformation to chord length for hind wing is up to 0.11 at 75% spanwise with a flapping angle of -0.66 degree for a free-flying dragonfly.

消费中心城市项目布局研究:分类、属性及途径

消费中心城市项目是消费中心聚集消费资源的重要载体,是服务消费者、引领消费潮流、发挥消费影响力的主要方式,项目成功与否是消费中心成败关键。对消费中心城市项目进行不同维度的分类,包括文化消费项目和物质消费项目、服务消费项目和商品消费项目、最终消费项目和中间消费项目、直接消费项目和间接消费项目、必要消费项目和非必要消费项目等,每种分类维度都有一定的分析意义。消费中心城市项目具有多种消费经济发展特性,包括消费的范围经济性、中心的规模经济性、文化消费的无限性和物质消费的有限性、消费的空间协调性、消费的系统制约性。在消费中心城市项目布局中,文化消费是关键,需要重点布局文化消费项目;物质消费带动潜力大,需要全面规划物质消费项目;空间资源紧张、空间成本高,需要通过中心紧密原则布局相关项目;消费系统配套性强,需要对消费中心城市项目进行超前和空间延展性布局;消费中心城市项目经济平衡作用显著,需要在欠发达地区做更多布局。

中国消费中心建设:现有格局、调整逻辑与发展路径

在制造业大国、生产中心背景下,我国又提出经济的消费转型,要建设消费大国,打造(国际)消费中心(城市)。当前,我国一些传统消费型城市经历了历史嬗变,后发的消费型城市更多立足于生产制造,一些偏远、基层城镇逐渐向消费中心转型,但大多数消费中心还未能实现专门性独立发展。从生产中心到消费中心有着很深的内在调整逻辑,包括经济增长动力改变,由供给推动向需求拉动转型;社会主要矛盾改变,更多化解发展不平衡不充分矛盾;经济水平提高,消费大发展的条件已经具备;资源和环境面临危机,需要以消费经济化解生产经济紧约束;国内外环境改变,消费中心担负经济突围重任。我国消费中心建设还存在诸多制约因素,如收入分配不合理,区域消费制约严重;过多生产作业加班,挤占生活消费空间;城市拥挤,消费流动不畅;公共设施落后,不能支撑消费大场景;更重生产,消费经济功能发挥有限;片面追求物质财富的拥有,全民生活消费筹划建设不够;内卷化竞争过于激烈,消费激情难以焕发;过多追名逐利,消费价值观有待重建。需要进行相关体制机制建设,政策调整方向包括适应生产劳动人工时间减少的趋势,增加消费时间;调整城市布局,畅通消费流;强化公共消费设施建设,营造消费大场景;调整收入分配,构建外向型消费结构;深化规律性认识,发挥好后工业时代消费对经济的主功能作用;引导消费,积极筹划消费蓝图;防范内卷化竞争,焕发全民消费激情;全面发展,重构生产价值和消费价值观体系。

“里和”与“外应”:气候变化下环湖地区的适应性治理

气候变化给青藏高原带来显著影响,更是对当地农牧民的生计造成冲击,研究当地气候变化影响及牧民应对策略,不仅是提高气候变化适应能力的起点,也是建立适应气候变化区域格局的重要支撑。基于2020和2023年对案例地Z村的两次实地调研,通过牧户问卷调查和深度访谈,按照适应性治理的三层特征,分析当地气候变化适应的成效与挑战。研究发现:面对降水和气温的变化、湖面扩大、植被变化和灾害影响,牧民积极采取多种办法来减少气候变化的影响,呈现较高的适应性与恢复力。这些适应行动的成功经验源于“里和”,包括人与人之间的合作以及人与自然间的和谐律动。但是“外应”不足仍是挑战,即案例地缺少必要的外部支持,不仅包括直接灾害救助,还包括对其适应能力可持续性的保护和应对潜在的草原生态变化。如果“外应”持续低迷,现有的适应能力终会耗尽。提出建立适应气候变化区域格局应遵循多中心治理的思路,将多个利益相关者联合起来,汇总不同地区气候变化应对的成功经验,形成多种知识的融合,才能形成对地方的有效“外应”,提高中国气候变化适应能力。

以学生为中心的食品酶学课程多维教学模式探析

以学生为中心的教学方式是引导学生全面发展、培养顺应时代需求的新工科人才的重要教学改革方向。该文针对食品酶学课程传统教学中存在的问题与教学要求,从知识构筑维度、课堂教学维度、课后提升维度和创新突破维度进行教学模式的探索与应用,实现对学生基础理论知识与创新实践能力的引导与培养,从课程教学方面为培养食品领域新工科人才提供助力。

加快构建辽宁“一体两翼”对外开放新格局

辽宁是东北亚开放的窗口和“一带一路”建设的重要节点,加快构建“一体两翼”对外开放新格局是辽宁深化改革、扩大开放、实现高质量发展和全面振兴全方位振兴的重要举措。从贸易开放、资金开放、技术开放、社会开放四个维度构建“一体两翼”对外开放效果评价体系,采用因子分析法对2021年我国内地31个省份对外开放度进行评价,结果显示:辽宁对外开放度在全国处于较低水平,外贸外资因子、教育文化因子和旅游因子得分显著低于广东、上海和浙江,是影响辽宁对外开放水平的主要因素。从外资外贸、教育文化、旅游方面的主因子视角和对接国际高标准规则优化营商环境,加强区域合作开放平台建设,完善国际合作交通网络等政策方面,提出加快构建辽宁“一体两翼”对外开放新格局的对策建议。

“双循环”新发展格局与上海国际科技创新中心建设新思路

科技创新是构建“双循环”新发展格局的关键支撑。构建“双循环”新发展格局,为上海深入推进科创中心建设、加快提升科创中心策源功能提供了重大战略机遇。研究表明,构建“双循环”新发展格局有利于上海科创中心更好地汇聚配置高端优质要素、化解科技重大风险挑战、加快提升科创策源功能,进而促进创新价值实现。在构建“双循环”新发展格局中,上海科创中心发展也面临一些瓶颈制约,主要表现为缺乏引领卓越创新的领军企业、企业创新能力亟须提升,缺乏支撑全面创新的制度供给、创新体制机制亟须完善,缺乏包容草根创新的社会环境、创新文化氛围亟须营造。进一步加强科创中心建设要有全新的思路,应牢牢把握“强基、健体、提质、增效”4个关键词。

基于CFD的翼吊布局民机反推出流模式设计与验证

格栅式反推力装置通过改变格栅导向叶片来控制反推气流的流量和方向。反推出流模式描述了反推气流方向沿短舱周向的分布,需要满足反推效率、重吸入特性、有效出流面积等要求。文章开展典型翼吊布局民用飞机反推出流模式设计与验证。通过全机反推流动CFD数值模拟,分析反推气流行进轨迹以及作用因素,揭示反推气流重吸入流动机制,优化反推出流模式设计方案。通过风洞试验,验证反推出流模式设计方案在65 kn滑跑速度时无重吸入,同时确认CFD数值模拟方法能够准确预测反推重吸入速度边界以及进气道畸变位置,可用于全机反推出流模式设计与验证。

唐代织锦中翼马纹样的研究及其设计实践

为了揭示传统瑞兽题材纹样的现代审美价值,并丰富现代产品设计的文化内涵,文章通过文献研究法、图文互证法,以唐代织锦为实物载体,对唐代翼马纹样的造型特征、构图形式、色彩特征3个方面进行艺术特征分析。提取出典型的翼马纹样并展开对元素的提取、重构、优化和组合,得出与当代美学相适应的设计图案,并将此设计图案应用于纺织类和文创类产品当中。通过将唐代织锦中翼马纹样创新再设计的实践,探讨翼马纹样和现代设计相结合的方法,增强传统纹样的表现力,潜移默化地提高大众对传统文化的关注度。

旋翼无人机与直升机二次曲面散射中心提取与重建方法

采用快速物理光学(FPO)方法模拟二次曲面片剖分后的旋翼无人机目标散射场,该方法考虑了目标的物理机理,可采用大尺寸比例细分和属性散射中心(ASC)模型提取目标的散射中心。为解决ASC参数估计中的不适定问题,减少计算时间和精度误差,提出一种正交匹配追踪(OMP)与基于成功历史记录的自适应参数差分进化(SHADE)相结合的稀疏方法。数值算例表明,文中方法能够有效准确地提取复杂目标的散射中心,同时在10 GHz频段时,面片数目减少了两到三个数量级。根据散射中心提取结果,得到了旋翼无人机的多个小散射中心围绕中央散射中心呈中心对称分布,而直升机的多个散射中心呈近似平行分布的结论,为利用雷达目标电磁散射特性差异进行低慢小目标精准识别提供可靠仿真依据与理论基础。