Encroachment drives facilitation at alpine shrublines

Ongoing encroachment is driving recent alpine shrubline dynamics globally,but the role of shrub-shrub interactions in shaping shrublines and their relationships with stem density changes remain poorly understood.Here,the size and age of shrubs from 26 Salix shrubline populations along a 900-km latitudinal gradient(30°-38°N)were measured and mapped across the eastern Tibetan Plateau.Point pattern analyses were used to quantify the spatial distribution patterns of juveniles and adults,and to assess spatial associations between them.Mean intensity of univariate and bivariate spatial patterns was related to biotic and abiotic variables.Bivariate mark correlation functions with a quantitative mark(shrub height,basal stem diameter,crown width)were also employed to investigate the spatial relationships between shrub traits of juveniles and adults.Structural equation models were used to explore the relationships among conspecific interactions,patterns,shrub traits and recruitment dynamics under climate change.Most shrublines showed clustered patterns,suggesting the existence of conspecific facilitation.Clustered patterns of juveniles and conspecific interactions(potentially facilitation)tended to intensify with increasing soil moisture stress.Summer warming before 2010 triggered positive effects on population interactions and spatial patterns via increased shrub recruitment.However,summer warming after2010 triggered negative effects on interactions through reduced shrub recruitment.Therefore,shrub recruitment shifts under rapid climate change could impact spatial patterns,alter conspecific interactions and modify the direction and degree of shrublines responses to climate.These changes would have profound implications for the stability of alpine woody ecosystems.

Spatial Interaction Between the Industrial Undertaking Capacity and Global Value Chain Position of East Asian Countries

A comprehensive understanding of the spatial interaction between the industrial undertaking capability and the position of the global value chain of the 12 East Asian countries is conducive to strengthening regional cooperation, gaining a say in foreign trade and becoming the dominant player in the global division of labor system. The article reveals the operating rules of the interaction between the industrial undertaking capacity and the global value chain position of East Asian countries by calculating the Global Moran Index(Moran’s I), coupling coordination degree and other indicators. The results show that: in time, the values of industrial undertaking capacity and the positions of global value chain in East Asian countries showed a sustained and stable growth trend, and have a consistent trend of change. Spatially, both of the two indexes had significant positive spatial correlation, with Moran’s I showing an ‘inverted U’pattern, and the spatial aggregation distribution of global value chain position lagged behind the spatial aggregation distribution of industrial undertaking capacity by one year. In terms of spatial coupling coordination, the coupling coordination values of the two indicators show a steady upward trend. Combined with the comparative advantage of each country, this paper provides suggestions for promoting the positions of Chinese and other East Asian industries in the global value chain from the perspectives of enhancing independent innovation capability and upgrading industrial structure.

An interacting multiple model-based two-stage Kalman filter for vehicle positioning

To address the problem that a general augmented state Kalman filter or a two-stage Kalman filter cannot achieve satisfactory positioning performance when facing uncertain noise of the micro-electro-mechanical system（MEMS） inertial sensors, a novel interacting multiple model-based two-stage Kalman filter（IMM-TSKF） is proposed to adapt to the uncertain inertial sensor noise. Three bias filters are developed based on different noise characteristics to cover a wide range of noise levels. Then, an accurate estimation of biases is calculated by the interacting multiple model algorithm to correct the bias-free filter. Thus, the vehicle positioning system can achieve good performance when suffering from uncertain inertial sensor noise. The experimental results indicate that the average position error of the proposed IMMTSKF is 25% lower than that of the general TSKF.

Nurses’ stories about their interactions with patients at the Holy Family Hospital, Techiman, Ghana

Factors, which induced positive nurse-client interac-tions and barriers to positive nurse-client interactions from the perspective of nurses at Holy Family Hos-pital, were explored. In all, twelve State Registered Nurses participated in semi-structured interviews. Factors which induced positive nurse-client interac-tion included availability of adequate time, showing empathy, giving prompt care, considering nursing as a call (spiritual interpretation) and rendering holistic care. Factors which induced negative nurse-client interaction included differences in beliefs between the nurse and the client, perceptions of unfair treatment, payment requirement and processes, issues with clients’ relatives, client issues, miscommunications and misunderstandings about treatment needs, coer-cion, forced dependence, human resource issues, professional nursing issues, issues with work envi-ronment, nurse issues, lack of communication and good interaction, and dropping of professional ethics. Suggestions for nursing education, practice and ad-ministration have been outlined. Among them is the need to use role-play as a major teaching method for nursing students to develop empathic behaviours so that they can put themselves in clients’ situations. This understanding will allow them to practise quality nursing after completing their educational programs. There is also the need for policy makers in nursing to institute measures to hold nurses accountable if they abuse clients or clients’ relatives. Lastly, as an important tool, nurses and other health care workers can make use of reflective practice to evaluate their professional interactions with clients and their relatives. This will foster positive nurse-client interaction in future.

Interaction between castanospermine an immunosuppressant and cyclosporin A in rat cardiac transplantation

AIM: To investigate the interaction between castanospermine and cyclosporin A(Cs A) and to provide an explanation for it.METHODS: The alkaloid castanospermine was prepared from the seeds of Castanospermum austral consistently achieving purity. Rat heterotopic cardiac transplantation and mixed lymphocyte reactivity were done using genetically inbred strains of PVG(donor) and DA(recipient). For the mixed lymphocyte reaction stimulator cells were irradiated with 3000 rads using a linear accelerator. Cyclosporin A was administered by gavage and venous blood collected 2 h later(C_2). The blood levels of Cs A(Neoral) were measured by immunoassay which consisted of a homogeneous enzyme assay(EMIT) on Cobas Mira. Statistical analyses of interactions were done by an acceleratedfailure time model with Weibull distribution for allograft survival and logistic regression for the mixed lymphocyte reactivity.RESULTS: Castanospermine prolonged transplant survival times as a function of dose even at relatively low doses. Cyclosporin A also prolonged transplant survival times as a function of dose particularly at doses above 2 mg/kg. There were synergistic interactions between castanospermine and Cs A in the prolongation of cardiac allograft survival for dose ranges of Cs A by castanospermine of(0 to 2) mg/kg by(0 to 200) mg/kg(HR = 0.986; 95%CI: 0.981-0.992; P < 0.001) and(0 to 3) mg/kg by(0 to 100) mg/kg(HR = 0.986; 95%CI: 0.981-0.992; P < 0.001) respectively. The addition of castanospermine did not significantly increase the levels of cyclosporin A on day 3 or day 6 for all doses of Cs A. On the contrary, cessation of castanospermine in the presence of Cs A at 2 mg/kg significantly increased the Cs A level(P = 0.002). Castanospermine inhibited mixed lymphocyte reactivity in a dose dependent manner but without synergistic interaction. CONCLUSION: There is synergistic interaction between castanospermine and Cs A in rat cardiac transplantation. Neither the mixed lymphocyte reaction nor the metabolism of Cs A provides an explanation.

Mechanical synergistic interaction between adjacent corrosion defects and its effect on pipeline failure

This work provides a new comprehensive assessment method to determine the complex mechanical interaction of adjacent corrosion defects.Firstly,a three-dimensional(3D)finite element model of pipelines containing adjacent defects(involving longitudinally aligned,circumferentially aligned,and diagonally aligned defects)was developed and validated by full-scale burst tests.Then,the synergistic stress interaction between adjacent defects was analyzed,and the relationship between the burst position of the pipeline and defect spacing was determined.At last,the applicability of several commonly used critical spacing rules for identifying the interaction between adjacent defects was compared and discussed in detail.The results show that the failure position of the pipeline containing adjacent defects is related to the relative position of defects.For longitudinally aligned corrosion defects,the stronger the interaction between defects(i.e.,the shorter the distance between two defects),the closer the failure position of the pipeline to the center of the defect spacing.For circumferentially aligned corrosion defects,the failure position of the pipe tends to move from the defect edge to the geometric center of the defect with increasing defect spacing.For diagonally aligned defects,the failure position is generally located on the path connecting the defect and the spacing.The currently available evaluation criteria for identifying circumferentially interacting defects display the most accuracy,and the identification effect of diagonally aligned defects is the poorest.In addition,the critical spacing rule proposed by Li presents the highest precision in identifying the interacting defects.The results are expected to provide a stress synergistic failure assessment method for pipelines containing cluster corrosion defects in engineering.

Application of interacting multiple model in integrated positioning system of vehicle

To solve low precision and poor stability of the extended Kalman filter （EKF） in the vehicle integrated positioning system owing to acceleration, deceleration and turning （hereinafter referred to as maneuvering） , the paper presents an adaptive filter algorithm that combines interacting multiple model （IMM） and non linear Kalman filter. The algorithm describes the motion mode of vehicle by using three state spacemode]s. At first, the parallel filter of each model is realized by using multiple nonlinear filters. Then the weight integration of filtering result is carried out by using the model matching likelihood function so as to get the system positioning information. The method has advantages of nonlinear system filter and overcomes disadvantages of single model of filtering algorithm that has poor effects on positioning the maneuvering target. At last, the paper uses IMM and EKF methods to simulate the global positioning system （OPS）/inertial navigation system （INS）/dead reckoning （DR） integrated positioning system, respectively. The results indicate that the IMM algorithm is obviously superior to EKF filter used in the integrated positioning system at present. Moreover, it can greatly enhance the stability and positioning precision of integrated positioning system.

Positive Interactions： Crucial Organizers in a Plant Community

For more than a century, ecologists have concentrated on competition as a crucial process for community organization. However, more recent experimental investigations have uncovered the striking Influence of positive Interactions on the organization of plant communities. Complex combinations of competition and positive interactions operating simultaneously among plant species seem to be widespread In nature. In the present paper, we reviewed the mechanism and ecological importance of positive Interactions In plant communities, emphasizing the certainties and uncertainties that have made It an attractive area of research. Positive Interactions, or facilitation, occur when one species enhances the survival, growth, or richness of another. The Importance of facilitation in plant organization increases with ablotlc stress and the relative Importance of competition decreases. Only by combining plant interactions and the many fields of biology can we fully understand how and when the positive Interactions occur.

Vigilance behavior of Pyrenean chamois Rupicapra pyrenaica pyrenaica:Effect of sex and position in the herd

The Pyrenean chamois Rupicapra pyrenaica pyrenaica is a mountain-dwelling ungulate with an extensive presence in open areas. Optimal group size results from the trade off between advantages （a reduction in the risk of predation） and disadvantages （competition between members of the herd） of group living. In addition, advantages and disadvantages of group living may vary depending on the position of each individual within the herd. Our objective was to study the effect of central vs. peripheral position in the herd on feeding and vigilance behavior in male and female Pyrenean chamois and to ascertain if a group size effect existed. We used focal animal sampling and recorded social interactions when a focal animal was involved. With males, vigilance rate was higher in the central part of the group than at the periphery, probably due to a higher density of animals in the central part of the herd and a higher probability of being disturbed by conspecifics. With females, vigilance rate did not differ according to position in the herd. Females spent more time feeding than males, and males showed a higher frequency of the vigilance behavior than females. We did not observe a clear relationship between group size and vigilance behavior. The differences in vigilance behavior might be due to social interactions

Positive interactions by cushion plants in high mountains:fact or artifact?

Positive interactions are defined as non-trophic interactions where at least one of the interacting species is benefited in terms of fitness and the other remains unaffected.Nevertheless,the bidirectional feedbacks between species may be positive,neutral or negative.Thus,if facilitated species induce negative effects on their‘nurses’,the assumed definition of positive interactions could be reconsidered.Methods We assessed if ecological interactions between cushions of Azorella madreporica and their facilitated species are positive.Specifically,we tested if cover of facilitated species has any costs for cushion plants from an ecophysiological perspective,and if these costs increase with the amount of cover of facilitated species.In addition,through pathway analysis and correlations,we assessed if cover and richness of facilitated species have a direct and/or indirect effect on the fitness of cushion plants.Important Findings We found that facilitated plant species induced a significant cost for their nurses(cushion plants),and this cost increases with cover of the facilitated species.Additionally,the facilitated species exert a strong direct negative effect on the cushion’s fitness and a moderate indirect negative cost evident through the nutrient status and physiological performance of cushion plants.We thus contribute evidence that positive interactions between high mountain cushion plants of central Chile and their‘facilitated’species may be an artifact more than a fact,especially when bidirectional effects are considered;contrasting with the majority of studies that document only one side of the interaction.

Positive interactions can produce species-rich communities and increase species turnover through time

Aims The process of facilitation,where a species increases the survival,growth,and fitness of another species,is becoming increasingly recognized as a critical factor in shaping the structure of plant communities.This process is particularly important in stressful environments.Yet few studies have attempted to incorporate positive interactions into community ecological theories such as the neutral theory of biodiversity.Here,we use an equalizing trade-off model as a foundation to study the potential impact of facilitation on species richness and community temporal turnover.Methods Based on a spatially explicit birth–death trade-off model,we assume that the occurrence of facilitation is dependent on the presence of interspecific neighbours.We further propose that the realized birth rate for a given individual subject to facilitation is proportional to the number of interspecific neighbours within its neighbourhood.Thus,in our model,the individuals of rare species will benefit more from the existence of heterospecific individuals than common species.Important Findings As the facilitative coefficient increased,the species richness for simulated communities at the dynamically stochastic equilibrium was also increasing.Simulations also demonstrated that facilitation could increase the replacement of species through time:communities with facilitation become more dissimilar(i.e.have smaller Bray–Curtis similarity values)than communities without or with a lower degree of facilitation after the same time interval.Facilitation from interspecific neighbours on rare species increased their population sizes and consequently made them less prone to extinction,thus enhancing species richness.Meanwhile,in a saturated community,with the increase of species richness,mean population size of entire communities decreased,making species more prone to extinction on average,and thus increased the community temporal turnover.Our results suggest that future experimental work on the effect of facilitation on community-level properties should focus not just on species richness but also on other descriptors of community dynamics such as the temporal species turnover.

Positioning in Dynamic Testing of Slender Bridges

The positioning combined with multi-functioning and interactive mechanics in dynamic testing of slender bridges are treated in present paper. The approach takes into account multiple functions in dynamic testing of slender bridges constructed of thin-walled structural members with their hierarchical configuration. Theoretical, numerical and experimental in situ assessments of the problem are presented. Some results of the application in situ are submitted.

基于透镜阵列多元聚焦的连续晶体三维位置灵敏探测器设计和仿真

连续晶体闪烁体探测器可以实现γ射线作用点的三维位置定位。本文提出一种新的探测器结构,引入透镜阵列实现作用点定位。探测器采集多元聚焦图像,从而改变对连续晶体闪烁光分布探测的需求。文中建立连续晶体、透镜阵列和光子计数器阵列的模型进行模拟研究,建立多元聚焦的光路反演重建算法定位γ射线作用点的三维位置。通过重建结果分析评估基于透镜阵列的连续晶体探测器性能,这种结构具有较好的定位能力和位置分辨。对于尺寸为48 mm×48 mm×45 mm的硅酸钇镥(LYSO)闪烁晶体,实现了xy平面位置分辨优于1.54 mm,z方向位置分辨优于3.13 mm。基于连续晶体和透镜阵列结构的探测器还可对多作用点的情形进行重建,分析三组选定位置的重建结果,该结构对双作用点定位具有可行性。

上游行业垄断对中国制造业企业GVC分工地位的影响研究

利用制造业企业微观数据,基于垄断成因系统分析不同类型上游垄断对制造业企业GVC分工地位可能造成的差异影响,并考察中间品贸易便利化的调节效应。研究表明:上游行业垄断通过阻碍企业技术创新和降低中间产品质量抑制制造业企业GVC分工地位攀升。具体而言,由企业自身高效率形成的上游技术垄断有利于企业GVC分工地位攀升,政府保护所形成的上游行政垄断明显不利于企业GVC分工地位攀升。异质性分析发现,上游垄断对民营企业、中小型企业、资本密集型行业GVC分工地位的负向影响更大;上游技术垄断更有利于大型企业、资本和技术密集型行业GVC分工地位的攀升,而上游行政垄断明显更不利于劳动和资本密集型行业GVC分工地位的攀升。此外,中间品贸易便利化加强上游行业垄断对制造业企业GVC分工地位的负向影响。

基于双传感器的枕式包装机速度自动调节系统

包装机速度调节系统存在进入稳态耗时长、稳态误差大和调节精度低的问题,导致产品破损率高,提出基于双传感器的枕式包装机速度自动调节系统。系统硬件采用温度传感器和位置传感器,结合可编程逻辑控制器(Programmable Logic Controller,PLC)转换和调配各个机构的速度,实现包装机速度自动调节;系统软件采用等时间原则,确定包装盒传输到封端位置和温度的时间,从而匹配速度,根据齿轮传动原理确定速度变化量,实现枕式包装机速度自动调节。实验结果表明,设计系统进入稳态的耗时仅为20 s,包装破损率均低于7.5%,该系统减小了超调量、缩短耗时、提高控制精度,降低了不同尺寸产品包装破损率,具有较好的通用性和可靠性。

基于改进自适应IMM算法的高速列车组合定位

针对列车高精度定位问题,该文提出基于改进自适应交互多模型(IMM)的高速列车高精度组合定位方法。首先,根据列车定位需求和各传感器特点,设计了卫星接收器、轮轴测速传感器、测速雷达以及单轴陀螺仪4种传感器的组合定位方案。然后,针对IMM融合滤波算法因先验信息不准导致固定参数设置不当的问题,引入Sage-Husa自适应滤波和转移概率矩阵(TPM)自适应更新集成为自适应IMM算法。针对多模型切换的滞后问题,利用子模型似然函数值能快速反映模型变化趋势的特点,将似然函数值设为判定标志,并引入判定窗对TPM矩阵元素进行修正,有效提升了模型的切换速度。最后,基于改进自适应IMM算法对4种传感器定位信息进行融合滤波,实现高速列车的高精度组合定位。仿真结果表明:改进后的算法相比其他自适应IMM算法提升定位精度1.6%~14.7%,并且能通过提高模型间切换速度来有效降低位置误差峰值,同时具备较好的抗噪性能。

深度报道中河南形象的立场表达——以转述语为对象

立场研究历经对言/作者主体性、交互主体性和话语主体性的关注,凝练了立场主体、立场客体和立场表达三个要素。以这三个要素为主要节点,可以建构包括主体定位、交互程度和索引指向为一级指标的系统,用以描述西方网络媒介涉豫深度报道中以转述语为载体的立场表达。这些报道主要依靠以公众为主体的转述语来确定自己的身份认同,使用占据绝对优势的扩展类非叙实转述词语来获取读者的承认,征用大量的描述性报道句来实现对涉豫事实的话语性改造。与河南形象相关的呈现、认同和承认都是在事实的基础上以话语为依归而动态交互的。

急性呼吸窘迫综合征患者清醒俯卧位通气体验的质性研究

目的 深入探索急性呼吸窘迫综合征患者行清醒俯卧位通气治疗的体验。方法 采用描述性质性研究,于2023年4-6月对17例行俯卧位通气的急性呼吸窘迫综合征患者进行半结构化访谈,采用内容分析法分析资料。结果 通过对质性数据的总结和分析,共提炼出4个主题,包括治疗动机和期望、患者体验和感受、俯卧位依从性的促进因素、俯卧位依从性的障碍因素。结论 急性呼吸窘迫综合征患者清醒俯卧位通气的体验受一系列因素的影响。对于需行清醒俯卧位通气的患者,提高患者舒适度、增强患者治疗动机和期望、调动家庭社会支持系统以及支持患者的自我管理努力将有助于提高患者的依从性。

基于动力定位平台的虚拟仿真系统

针对船舶动力定位平台控制方式和推力分配纯数字仿真可信度低,难以直观感受动力定位平台航行效果等问题,基于虚拟引擎构建了一套动力定位虚拟仿真平台。平台由虚拟仿真子平台、数值仿真子平台和数据管理系统组成。虚拟仿真子平台实现环境和人机交互、数值仿真子平台实现控制方式和推力分配算法仿真,数据管理系统传输数据驱动虚拟仿真平台,并在虚拟环境中实现动力定位平台的可视化。仿真结果表明,平台可有效地验证航行效果并能合理分配推力,对实验虚拟仿真的可视化设计具有促进作用。

论乡村振兴与全国统一大市场建设的良性互动

乡村振兴与全国统一大市场建设良性互动既是构建新发展格局的题中之义,也是全面建设社会主义现代化国家的关键举措。乡村振兴与全国统一大市场建设良性互动意义重大,应深刻把握其基本逻辑、深刻内涵与互动路径。当前,乡村振兴与全国统一大市场建设具有相同的底层逻辑,都需要解决地区发展不平衡、解决贸易壁垒,解决要素畅通受阻、解决市场割裂等问题。因此,应坚持以市场为导向,畅通城乡商品要素双向流通,打破市场壁垒;推进乡村优势产业联动供给,激发市场活力;拓展乡村资本数据建设渠道,驱动市场发展;完善乡村基础设施配套服务,夯实市场基础;推进城乡融合区域协调发展,提升市场效能等多种途径推进乡村振兴与全国统一大市场建设的良性互动。