Average Power Research Articles

SEMANTICS OF THE CONCEPT OF “STEED”/“HORSE”IN THE RUSSIAN ART OF THE FIRST THIRD OF THE20TH CENTURY: “A HORSE AS A HORSE” AND “WE AREALL A LITTLE BIT HORSES”

SEMANTICS OF THE CONCEPT OF “STEED”/“HORSE”IN THE RUSSIAN ART OF THE FIRST THIRD OF THE20TH CENTURY: “A HORSE AS A HORSE” AND “WE AREALL A LITTLE BIT HORSES”

Air Handwriting using AI and ML

Air-writing refers to virtually writing linguistic characters through hand gestures in three dimensional space with six degrees of freedom. In this paper a generic video camera dependent convolutional neural network (CNN) based air-writing framework has been proposed. Gestures are performed using a marker of fixed color in front of a generic video camera followed by color based segmentation to identify the marker and track the trajectory of marker tip. A pre-trained CNN is then used to classify the gesture. The recognition accuracy is further improved using transfer learning with the newly acquired data. The performance of the system varies greatly on the illumi nation condition due to color based segmentation. In a less fluctuating illumination condition the system is able to recognize isolated unistroke numerals of multiple languages. The proposed framework achieved 97.7recognition rate in person inde pendent evaluation over English, Bengali and Devanagari numerals, respectively. Object tracking is considered as an important task within the field of Computer Vision. The invention of faster computers, availability of inexpensive and good quality video cameras and demands of automated video analysis has given popularity to object tracking techniques. Generally, video analysis procedure has three major steps: firstly, detecting of the object, secondly tracking its movement from frame to frame and lastly analysing the behaviour of that object. For object tracking, four different issues are taken into account; selection of suitable object representation, feature selection for tracking, object detection and object tracking. In real world, Object tracking algorithms are the primarily part of different applications such as: automatic surveillance, video indexing and vehicle navigation etc. The generated text can also be used for various purposes, such as sending messages, emails, etc. It will be a powerful means of communication for the deaf. It is an effective communication method that reduces mobile and laptop usage by eliminating the need to write. Key Words: Air Writing, Character Recognition, Object Detection, Real-Time Gesture Control System, Computer Vision , Hand tracking.

Rhein suppresses esophageal cancer development by regulating cell cycle through DNMT3B gene.

The mechanism by which DNMT3B facilitates esophageal cancer (ESCA) progression is currently unknown, despite its association with adverse prognoses in several cancer types. To investigate the potential therapeutic effects of the Chinese herbal medicine rhubarb on esophageal cancer (ESCA), we adopted an integrated bioinformatics approach. Gene Set Enrichment Analysis (GSEA) was first utilized to screen active anti-ESCA components in rhubarb. We then employed Weighted Gene Co-expression Network Analysis (WGCNA) to identify key molecular modules and targets related to the active components and ESCA pathogenesis. This system-level strategy integrating multi-omics data provides a powerful means to unravel the molecular mechanisms underlying the anticancer activities of natural products, like rhubarb. To investigate module gene functional enrichment, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted. In addition, we evaluated the predictive impact of DNMT3B expression on ESCA patients utilizing the Kaplan-Meier method. Finally, we conducted experiments on cell proliferation and the cell cycle to explore the biological roles of DNMT3B. In this study, we identified Rhein as the main active ingredient of rhubarb that exhibited significant anti-ESCA activity. Rhein markedly suppressed ESCA cell proliferation. Utilizing Weighted Gene Co-expression Network Analysis (WGCNA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, we determined that the blue module was associated with Rhein target genes and the cell cycle. Additionally, DNMT3B was identified as a Rhein target gene. Analysis of The Cancer Genome Atlas (TCGA) database revealed that higher DNMT3B levels were associated with poor prognosis in ESCA patients. Furthermore, Rhein partially reversed the overexpression of DNMT3B to inhibit ESCA cell proliferation. In vitro studies demonstrated that Rhein and DNMT3B inhibition disrupted the S phase of the cell cycle and affected the production of cell cycle-related proteins. In this study, we found that Rhein exerts its anti-proliferative effects in ESCA cells by targeting DNMT3B and regulating the cell cycle.

A superior near infrared fluorescent probe for revealing the relationship between peroxynitrite and Alzheimer's disease

The typical neurodegenerative Alzheimer's disease (AD) poses an increasing threat to human health as the population ages. Though increasing attention has been drawn for the etiology of AD over decades, regretfully, the exact pathogenesis of AD is not fully elucidated. The elevated levels of ROS are among the major pathological alterations in AD. Among them, peroxynitrite (ONOO-) exhibits a greater impact compared to other reactive oxygen species and plays an important role in AD, but the role ONOO- plays in AD progression remains unclear. In this work, the near-infrared (NIR) fluorophore (benzopyran derivative) was optimized by molecular skeleton modification, and a fluorophore DCM-Cl-OH with better spectral properties was obtained. On this basis, a NIR fluorescence probe DCM-Cl-P with excellent detection performance was obtained. Based on the high selectivity and fast response of the probe to ONOO-, DCM-Cl-P was used to visual detection of ONOO- in living cells and zebrafish, and further demonstrated the excessive accumulation of ONOO- in AD model mice. More importantly, through analysis of the correlation between ONOO- and amyloid-β protein (Aβ), ONOO- and the aggregation of Aβ were closely related and mutually reinforcing was demonstrated and ONOO- underwent significant changes in the early stage of the change of Aβ aggregation, indicating that ONOO- may serve as an early marker of AD. These findings have greatly promoted the research on the intrinsic relationship between ONOO- and AD, and provides a powerful means for pathological research of AD.

Ergodicity for a family of operators

The aim of this paper is to introduce the notions of power boundedness, Cesàro boundedness, mean ergodicity, and uniform ergodicity for a family of bounded linear operators on a Banach space. The authors present some elementary results in this setting and show that some main results about power bounded, Cesàro bounded, mean ergodic, and the uniform ergodic operator can be extended from the case of a linear bounded operator to the case of a family of bounded linear operators acting on a Banach space. Also, we show that the Yosida theorem can be extended from the case of a bounded linear operator to the case of a family of bounded linear operators acting on a Banach space.

Effect of an eight-week high-intensity interval training programme on circulating sphingolipid levels in middle-aged adults at elevated cardiometabolic risk (SphingoFIT)-Protocol for a randomised controlled exercise trial.

Evidence indicates that sphingolipid accumulation drives complex molecular alterations promoting cardiometabolic diseases. Clinically, it was shown that sphingolipids predict cardiometabolic risk independently of and beyond traditional biomarkers such as low-density lipoprotein cholesterol. To date, little is known about therapeutic modalities to lower sphingolipid levels. Exercise, a powerful means to prevent and treat cardiometabolic diseases, is a promising modality to mitigate sphingolipid levels in a cost-effective, safe, and patient-empowering manner. This randomised controlled trial will explore whether and to what extent an 8-week fitness-enhancing training programme can lower serum sphingolipid levels of middle-aged adults at elevated cardiometabolic risk (n = 98, 50% females). The exercise intervention will consist of supervised high-intensity interval training (three sessions weekly), while the control group will receive physical activity counselling based on current guidelines. Blood will be sampled early in the morning in a fasted state before and after the 8-week programme. Participants will be provided with individualised, pre-packaged meals for the two days preceding blood sampling to minimise potential confounding. An 'omic-scale sphingolipid profiling, using high-coverage reversed-phase liquid chromatography coupled to tandem mass spectrometry, will be applied to capture the circulating sphingolipidome. Maximal cardiopulmonary exercise tests will be performed before and after the 8-week programme to assess patient fitness changes. Cholesterol, triglycerides, glycated haemoglobin, the homeostatic model assessment for insulin resistance, static retinal vessel analysis, flow-mediated dilatation, and strain analysis of the heart cavities will also be assessed pre- and post-intervention. This study shall inform whether and to what extent exercise can be used as an evidence-based treatment to lower circulating sphingolipid levels. The trial was registered on www.clinicaltrials.gov (NCT06024291) on August 28, 2023.

The expanding universe of the geometric mean

AbstractIn this paper the authors seek to trace in an accessible fashion the rapid recent development of the theory of the matrix geometric mean in the cone of positive definite matrices up through the closely related operator geometric mean in the positive cone of a unital $$C^*$$ C ∗ -algebra. The story begins with the two-variable matrix geometric mean, moves to the breakthrough developments in the multivariable matrix setting, the main focus of the paper, and then on to the extension to the positive cone of the $$C^*$$ C ∗ -algebra of operators on a Hilbert space, even to general unital $$C^*$$ C ∗ -algebras, and finally to the consideration of barycentric maps that grow out of the geometric mean on the space of integrable probability measures on the positive cone. Besides expected tools from linear algebra and operator theory, one observes a surprisingly substantial interplay with geometrical notions in metric spaces, particularly the notion of nonpositive curvature. Added features include a glance at the probabilistic theory of random variables with values in a metric space of nonpositive curvature, and the appearance of related means such as the inductive and power means. The authors also consider in a much briefer fashion the extension of the theory to the setting of Lie groups and briefer still to the positive symmetric cones of finite-dimensional Euclidean Jordan algebras.

A Comparative Study on How AI is Partnering with Nature for a Sustainable Future.

Mounting ecological and socio-economic challenges demand a paradigm shift to sustainability. Artificial intelligence (AI) becomes a powerful means to pursue this objective; it establishes a “Symbiotic Synergy” with nature’s complex networks. This study attempts to investigate the SDGs using AI as a transformative tool, the sustainability of AI and its socio-economic impact. The research applies a multimethod approach, using surveys, case studies and categorizations to determine how AI is helping achieve the SGDs in harmony with nature. Key applications of AI in important domains are covered including agriculture and sanitation, renewable energy sector, hydrogen energy sector and the impact that AI is having leading to the future sustainable cities. Case studies and real-world examples demonstrate the effectiveness of AI technologies in forecasting energy demand, improving power dispatchment, and boosting performance within renewable resources. This study is a guide to the harnessing of AI potential for meeting SDGs, which leads us into an era where humans will attain great heights with cooperation between technology and nature.

Efficacy and Safety of Monoclonal Antibodies for the Treatment of Eosinophilic Esophagitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Monoclonal antibodies (MAbs) have clinical benefits for treating several atopic diseases. However, consensus on its use for eosinophilic esophagitis (EoE) is lacking. The present meta-analysis aimed to compare the efficacy and safety of MAbs versus placebo for treating EoE. We searched PubMed, Embase, and Cochrane Library for randomized controlled trials (RCTs). The primary outcomes were changes in peak esophageal eosinophils count/high power field (HPF) and mean esophageal eosinophils count/HPF. The secondary outcomes were changes in the EoE-Histology Scoring System (EoE-HSS), Endoscopic Reference Score (EREFS), dysphagia score, and adverse events (AEs). We compared binary outcomes using risk ratio (RR) and continuous outcomes using mean difference (MD) or standardized mean difference (SMD), with 95% confidence interval (CI). Considering the diversity of mechanistic properties of MAbs, a pre-specified subgroup analysis by MAb mechanism of action was performed for all outcomes, provided that at least two studies were in each subgroup. Heterogeneity was assessed using Cochran's Q test and I2 statistics. 6 RCTs were included (533 patients). Compared to placebo, MAbs led to a significant reduction in peak esophageal eosinophils count/HPF (MD -0.78; CI 95% -0.87, -0.6801) and mean esophageal eosinophils count/HPF (SMD-0.79; CI 95% -1.5, -0.08). Moreover, MAbs significantly reduced EoE-HSS scores (grade score: SMD-9.31; 95% CI -13.95, -4.6701; stage score: SMD -10.18; 95% CI -15.06, -5.31), EREFS (SMD-5.95; CI 95% -9.19, -2.71) and dysphagia score (SMD -1.79; CI 95% -3.36, -0.23) without increasing AEs compared to placebo. Among those MAbs whose mechanism of action includes the blockage of the receptor for IL-13 (Dupilumab, QAX576, and RPC4046), the scores of EoE-HSS grade, EoE-HSS stage, EREFS, and dysphagia were significantly reduced, and they presented a similar risk of overall and serious AEs compared to placebo. MAbs seem effective and safe in reducing esophageal eosinophil infiltrate, EoE-HSS score, EREFS score, and dysphagia symptoms in patients with EoE. However, further evidence is needed to establish its place in EoE management.

A parameter to featuring the cultural landscape genes of traditional settlements in China: a perspective of geographical information

Creative transformation and innovative development of traditional cultures is a pressing social need in China because of the deep reform and rapid socio-economic developments. It is crucial to understand the natural features of cultural landscapes of traditional settlements because they are indispensable components of these heritages. Although there are significant findings on the cultural features of traditional settlements, people still face substantial difficulties in using Geographical Information Systems (GIS) to directly handle their cultural factors due to a lack of theoretical models or described methods. To address this issue, at first, this study analyzed the component elements and contents of Cultural Landscape Genes of Traditional Settlements (CLGTS) from the perspective of Geographical Information (GI). Then, the concept “Feature Parameter of Geographical Information of CLGTS (FPGI-CLGTS)” was proposed based on the above. Simultaneously, the connotations, identification rules, and mathematical meanings of FPGI-CLGTS were also explored deeply. Next, this study developed the identification methods of FPGI-CLGTS. Finally, this study examined FPGI-CLGTS through an experiment on the spatial layouts CLGTS of six samples in Hunan, China. Through this study, FPGI-CLGTS has enormous potential to reveal the critical cultural features and values of traditional settlements.

Bill 7633 on the restriction of the use of Russian text sources in Ukrainian research and education: analysing language policy in times of war

AbstractFor centuries, Ukraine has been a site of conflicts over language rights. During 70 years of Soviet leadership, Ukraine experienced’relentless Russification’ (Reznik in Language of conflict: discourses of the Ukrainian crisis (pp. 169–191). Bloomsbury Publishing, London, 2020 p. 170). After breaking from Soviet rule, the Ukrainian language became an increasingly powerful symbol and means of national identity. Since the full-scale Russian invasion of Ukraine in 2022, the language issues have gained yet more public and political attention. Addressing the urgency, the Ukrainian parliament adopted, in the first reading, Bill 7633, aiming to restrict the use of any Russian sources in Ukrainian school and academia, a bill that was met with criticism and experienced intensified debates. This article analyses a range of text sources (both governmental and non-governmental) debating Bill 7633, using Discourse Analysis, and reveals how ‘liberal values’ and ‘lived liberalism’ (Fedirko et al. in Social Anthropol/Anthropol soc 29(2):373–386, 2021) are practiced or violated through problematising or justifying the Bill. Thus, the article contributes to the (recently emerged, i.e. since the start of Russian annexation of the Crimea in 2014) body of research on political and public discourses of the Ukrainian conflict (Epstein in Studies in East Eur Thought 74(4), 475–481; Jones, 2020; Lanvers and Lunyova in Eur J Lang Policy 15(1), 25–68; Slobozhan et al. in Soc Netw Anal Min 12(1), 1–12, 2022). Results show a comprehensive range of arguments both for and against Bill 7633 in both governmental and non-governmental texts which is interpreted as a form of liberalism in fragments (Fedirko in Social Anthropol/Anthropol Soc, 29(2), 471–489, 2021). The conclusion debates the unreserved applicability of western conceptualisation of liberal language policy in the context of war and prolonged linguistic contestations.

The Narrations of Female Companions in Surat Al-Ma’idah According to Imam Al-Suyuti in his Book Al-Dur Al-Manthur fi Al-Tafsir Bilma’athoor (Asma’ bint Yazid as an Example)

This research aims to briefly introduce Imam Al-Suyuti and study the narrations of one of the female companions, other than the Mothers of the Believers, in Surah Al-Ma’idah in his book “Al-Dur Al-Manthur fi Al-Tafsir bi Al-Ma’thur”. This woman is Asma’ bint Yazid. This study will be through basic rules in the science of Hadith and the science of interpretation and combining them. It is through these narrations it becomes clear to us the explanation of its narrators, the judging on it, the types of chain of transmission, the general meaning of the narration, and what can be learned from it, as well as an explanation of the exegetical aspects of the verse related to the narration in terms of explaining the interpretation, the reasons for the revelation, the aspects of the readings, and the rhetorical aspects of the verse, if any.

Underlying catastrophes: umbilics and pattern formation

AbstractBifurcation theory provides a very general means to classify the local changes in numbers of zeros of vector fields, but not a general means to find where a given bifurcation occurs, at least at higher codimensions. Instead, it turns out, these bifurcations can be found by looking for their underlying catastrophes. Here I show that the concept of underlying catastrophes can be extended to the umbilics. The umbilics are important in opening up qualitatively different forms of bifurcations beyond the ‘corank 1’ catastrophes of folds, cusps, swallowtails, etc. An example is given showing how four zeros of a vector field bifurcating from a single point, may do so either via a 3-parameter swallowtail catastrophe involving equilibria of similar stabilities, or via a 4-parameter umbilic catastrophe involving equilibria of opposing stabilities. This opens an avenue to studying spatiotemporal pattern formation around high codimension bifurcation points, and I conclude with some illustrative examples.

A new class of composite indicators: The penalized power mean

In this paper we propose a new aggregation method for constructing composite indicators based on a penalization of the power mean. The idea underlying this approach consists in multiplying the power mean by a factor that accounts for the horizontal heterogeneity among indicators while penalizing units with a larger heterogeneity. In line with the minimum loss of information principle, the penalization factor proposed is proven to be linked to the loss of information generated when the indicators are substituted with their power means. As a consequence, the aggregation approach gives rise to the class of penalized power means and the penalized Benefit of the Doubt aggregative approach. Including heterogeneity makes the aggregation approach more suitable for refined rankings. Interestingly, the penalized power mean of order one coincides with the Mazziotta Pareto Index. Some theoretical properties of the penalized power means are proven, thus supporting the Mazziotta Pareto index. An empirical analysis of the Human Development Index in 2019 is presented. Comparisons of the rankings induced by the penalized and non-penalized Benefit of the Doubt and power mean aggregation approaches are shown. There are three main findings: the penalized power means satisfy the properties characterizing weakly monotone aggregation functions; the penalization reduces ranking variations while differentiating units with close means; and the geometric mean provides composite indicators whose ranking is closest to those obtained with power means of different order.

An efficient aerodynamic optimization method based on approximate gradient analysis

With the rapid development of the computer capability and the continuous improvement of CFD (Computational Fluid Dynamics) technology, optimization design has gradually become a powerful and reliable means to solve the aerodynamic design problems. Among all kinds of optimization methods, gradient-based optimization algorithm can find the local optimal solution quickly, which is widely used in engineering problems. However, the computation of gradient is very expensive when an engineering problem involves large number of design variables. In this paper, an optimization method based on approximate gradient analysis is introduced, where the one-dimensional linear searches during the optimization process are evaluated with high-fidelity flow field analyses, while the gradients are evaluated with low-fidelity flow field analyses, leading to a significant saving in the computational cost of high-fidelity analysis. This method is demonstrated using a numerical example and RAE2822 airfoil optimization, and it is finally applied to the aerodynamic optimization of a wing-body configuration, which obtains good optimization results.

The Power Threat Meaning Framework: a qualitative study of depression in adolescents and young adults.

Depression constitutes one of our largest global health concerns and current treatment strategies lack convincing evidence of effectiveness in youth. We suggest that this is partly due to inherent limitations of the present diagnostic paradigm that may group fundamentally different conditions together without sufficient consideration of etiology, developmental aspects, or context. Alternatives that complement the diagnostic system are available yet understudied. The Power Threat and Meaning Framework (PTMF) is one option, developed for explanatory and practical purposes. While based on scientific evidence, empirical research on the framework itself is still lacking. This qualitative study was performed to explore the experiences of adolescents and young adults with depression from the perspective of the PTMF. We conducted semi-structured interviews with 11 Swedish individuals aged 15- 22 years, mainly female, currently enrolled in a clinical trial for major depressive disorder. Interviews were transcribed verbatim and analyzed with framework analysis informed by the PTMF. A complex multitude of adversities preceding the onset of depression was described, with a rich variety of effects, interpretations, and reactions. In total, 17 themes were identified in the four dimensions of the PTMF, highlighting the explanatory power of the framework in this context. Not all participants were able to formulate coherent narratives. The PTMF provides a framework for understanding the complexities, common themes, and lived experiences of young individuals with depression. This may be essential for the development of new interventions with increased precision and effectiveness in the young.

Optimization and sensitivity analysis of heat transfer for Powell–Eyring fluid between rotating rolls with temperature-dependent viscosity: A mathematical modeling approach

This study explores the flow of a non-Newtonian fluid between two rolls that are counter-rotating at the same speed and of equal size. The fluid's viscosity depends on temperature, and we investigate its theoretical impact on the thickness of the sheet and other engineering parameters relevant to the process. We derive non-dimensional mass and momentum balance equations using suitable transformation and the lubrication approximation theory. The expressions for velocity distribution, pressure gradient, flow rate, temperature profile, and pressure fields have been obtained by utilizing the perturbation method. After obtaining these expressions, we compute engineering quantities such as the roll separation force, streamline, Nusselt number, and the power input required to drive both cylinders based on the system's kinematical and geometrical parameters. We also obtain numerical solutions using the finite difference method and built-in (BVP method) in Maple. Further, we use response surface methodology and analysis of variance to determine what the mathematical models mean and whether they are good enough for sensitivity and optimization analysis of the heat transmission and roll separation force. Using statistical tools such as the R2, we determine that our Nusselt number and roll separation force provide the best solution for the considered model. Additionally, it has been observed that as the Weissenberg number increases, velocity tends to rise; conversely, velocity decreases with a higher velocity ratio. Also, the temperature profile is notably influenced by the Brickman number and increases with the increase in the Brickman number. It has also been noted that as the values of velocities ratio increase, the separation points shift toward the nip region, while concurrently, the coating thickness decreases. Furthermore, we also demonstrate that compression between analytical and numerical solutions for the considered problem of fluid flow, which suggests that the results presented here are reasonable. Finally, we compare our work with published studies to validate our findings. Hence, these factors help in an efficient fluid coating process and improve the substrate life.

On the generalization of Hermite-Hadamard type inequalities for [formula omitted]-convex function via fractional integrals

The main motivation in this article is to prove new integral identities and related results. In this paper, we deal with E`-convex function, Hermite-Hadamard type inequalities, and Katugampola fractional integrals. Firstly, we established the Hermite-Hadamard type inequalities for E`-convex function via Katugampola fractional integrals operators. After that we obtain several new identities and give new results of Holder's inequality, Jensen's integral inequality, Young's inequality, and Power mean inequality for E`-convex function by using Katugampola fractional integral operators. We make connections of our results with various results recognized in the literature.

PUPLIC DIPLOMACY AND ITS IMPACT IN THE STATES FOREIGN POLICY (QATAR TYPICAL)

The subject of the research tagged (public diplomacy and its role in the foreign policy of the state (Qatar as a model)) dealt with how and the extent of the impact of public diplomacy on the foreign policy of the state, and the importance that the researcher sees for public diplomacy at the international level and its role in making events, directing political policies and decisions and influencing international relations is a basic starting point for studying the subject, and then crystallizing it into a problem worth researching and studying. Which lies in a major question is the meaning of how public diplomacy affects the making and implementation of the foreign policy of the state, has divided the research into three basic sections, the first topic: looking at the concept of public diplomacy and concepts approach, the second topic: focuses on the dimensions of public diplomacy and tools, The third section seeks to clarify its role in the foreign policy of the state by studying the public diplomacy of the State of Qatar as a model for the state that is interested in this form of diplomacy and employs it in its international relations. This led to different results, the most important of which is that the definitions of public diplomacy differed according to the stages they went through and based on the circumstances and variables of the international reality at each stage, and the future of public diplomacy depends on scientific research based on the participation of researchers from different sciences such as communication sciences, media, public opinion, politics and international relations. In this regard, the State of Qatar has been able to overcome its demographic and geographical weaknesses by providing a range of strategic soft power means, including public diplomacy

Parallel patterns of genetic diversity and structure in circumboreal species of the Sphagnum capillifolium complex.

Shared geographical patterns of population genetic variation among related species is a powerful means to identify the historical events that drive diversification. The Sphagnum capillifolium complex is a group of closely related peat mosses within the Sphagnum subgenus Acutifolia and contains several circumboreal species whose ranges encompass both glaciated and unglaciated regions across the northern hemisphere. In this paper, we (1) inferred the phylogeny of subg. Acutifolia and (2) investigated patterns of population structure and genetic diversity among five circumboreal species within the S. capillifolium complex. We generated RAD sequencing data from most species of the subg. Acutifolia and samples from across the distribution ranges of circumboreal species within the S. capillifolium complex. We resolved at least 14 phylogenetic clusters within the S. capillifolium complex. Five circumboreal species show some common patterns: One population system comprises plants in eastern North America and Europe, and another comprises plants in the Pacific Northwest or around the Beringian and Arctic regions. Alaska appears to be a hotspot for genetic admixture, genetic diversity, and sometimes endemic subclades. Our results support the hypothesis that populations of five circumboreal species within the S. capillifolium complex survived in multiple refugia during the last glacial maximum. Long-distance dispersal out of refugia, population bottlenecks, and possible adaptations to conditions unique to each refugium could have contributed to current geographic patterns. These results indicate the important role of historical events in shaping the complex population structure of plants with broad distribution ranges.