bluuebunny/crossref_metadata_2025 huggingface dataset:
Geometric prescribed‐time control of quadrotors with adaptive extended state observers
Authors: Wang Liping , Pei Hailong
Published: April 2024

This article studies an adaptive extended state observer (AESO) based prescribed‐time geometric attitude stabilization problem of quadrotors with endogenous uncertainties, exogenous disturbances, and actuator saturation, which can be estimated and compensated by AESOs. The employment of the geometric representation method for system attitude can effectively avoid ambiguity or singularity problems that may arise with other representations. The temporal and scale transformations are employed to solve the global boundedness problem on infinite time instead of the prescribed‐time convergence problem on finite time. By integrating the proposed controller with the backstepping technique, the system of quadrotors can be prescribed‐time stable. Further, a prescribed‐time geometric attitude control technique is devised such that the control signal is bounded and the state signals converge to a small domain near the equilibrium point in the prescribed time. The prescribed time is determined by the user and is independent of the initial conditions. The comparative simulations with different initial information are performed to demonstrate the effectiveness of the proposed design technique.
Segmented hybrid event‐triggered control for underactuated autonomous underwater vehicles with an asymmetrical prescribed performance constraint
Authors: Su Ziyi , Huang Bing , Miao Jianming , Lin Xiaogong
Published: April 2024

In this technical article, the trajectory‐tracking problem of event‐based adaptive prescribed performance control for underactuated autonomous underwater vehicles (AUVs) is considered. The primary innovation of this article is the proposal of a segmented event‐triggered mechanism (SETM) that incorporates preselected convergence time. This mechanism allows for the regulation of communication frequency in the control channel (controller‐to‐actuator) according to the dynamic characteristics of the AUV system at different stages. In addition to presenting new design scheme based on SETM, an enhanced vision known as segmented hybrid event‐triggered mechanism (SHETM) is introduced. Notably, the minimum and maximum triggering intervals (MITI and MATI) for these two ETMs can be calculated from the corresponding resettable dynamic variables presented in the trigger conditions. Subsequently, by utilizing the proposed asymmetrical prescribed performance control (APPC) strategy, the system's output tracking error behaviors in both transient and steady‐state stages can be qualitatively predetermined through design parameters within the boundary function. Moreover, the minimum learning parameter (MLP) based RBFNN adaptive control law is developed to counteract the effects of model uncertainties and ocean current perturbations. Finally, rigorous theoretical analysis and simulation results confirm the viability of the proposed scheme.
Predicting nature recovery for river restoration planning and ecological assessment: A case study from England, 1991–2042
Authors: Wilkes Martin A. , Mungee Mansi , Naura Marc , Bell Vicky A. , Brown Lee E.
Published: April 2024

The Global Biodiversity Framework established ambitious goals for nature recovery which governments must now incorporate into national legislation. In England, legally binding targets require authorities to halt the decline in species abundance by 2030 and reverse the decline by 2042. Riverine invertebrates represent a substantial proportion of the species contributing towards the targets. Thus, understanding the response of these species to potential river restoration actions is key to target delivery. We model counts for 188 riverine invertebrate taxa using zero‐inflated generalized Poisson models, applying the models to both inform river restoration planning and set expected values for use in ecological assessment. We identify catchment‐specific restoration strategies that combine one or more actions involving the removal of channel modifications, reductions in nitrate concentrations and reductions in total dissolved phosphorus concentrations as the most likely to deliver species abundance targets across three joint climate–socioeconomic scenarios. By hindcasting species abundances under alternative target frameworks, we also demonstrate a new approach to setting expected values in ecological assessment, accounting for changes in water temperature and hydrology that confound historical reference models presently used by regulators. Our findings represent the first systematic attempt to prioritise major actions to deliver species abundance targets in England, providing valuable insights for policymakers, river restoration practitioners and authorities responsible for monitoring river ecosystems.
A review of science teaching approaches for equity focusing on race, class, and religion from the perspectives of Freire's and Arendt's theories of education
Authors: Rüschenpöhler Lilith
Published: April 2024

This paper presents a literature review of science teaching approaches that seek to support equity in science classrooms, focusing on marginalization based on (i) race/ethnicity, (ii) social class/socioeconomic background, and (iii) religion. Considered were approaches that science teachers can use in science classes in secondary schools. They were analyzed and discussed against the backdrop of critical pedagogy by Paulo Freire and the educational theory by Hannah Arendt, which constitutes a novelty in science education research. The review used meta interpretation combined with systematic searches in the ERIC database. It is, thus, limited to works published in English. A total of 930 articles (2013–2021) were identified out of which 64 were fully analyzed. The analysis shows that most approaches strive to provide more equal access to the existing science knowledge and structures of the community. This corresponds to the introduction to the “old world” in a conservative interpretation of Arendt's term. I argue that in addition, it is necessary to employ a more radical interpretation of the “old world” as fundamentally plural which is done in translanguaging and grappling with racism. Further, the transformative nature of science education needs to be strengthened in terms of Freire's critical pedagogy and Arendt's concept of natality. This means allowing students to become aware of oppressive structures to induce change. Only youth participatory science, youth participatory action research, and grappling with racism explicitly aim for this. This shows that nuanced perspectives on equity in science education are needed.
Multiethnic integration: A path toward achieving sustainable development from the global perspective
Authors: Abbas Hafiz Syed Mohsin , Xu Xiaodong
Published: April 2024

MEI (MEI) is a global concern in achieving sustainable development (SD), which is trending due to ethnic and population diversity. By applying the Legal Rights Theory (LRT), statistics say that political and civil rights policies under the LRT are the two most promising attributes that promote and help MEI and SD globally. However, government stability and economic prosperity (EcP) must be associated with them. Moreover, political integration (PoI) and assistance are not directly effective in supporting MEI globally, nor does the presence of PoI significantly affect the MEI and progression of SD. At the same time, focusing on the income categorization of the countries under the influence of PoI, lower‐middle‐income countries are adversely affected, further fragmenting the societies and creating a hurdle in achieving SD. It concludes that in promoting MEI, governments should focus on legal rights policies and adapt the MEI policies of Singapore, China, and other EU countries for Agenda 2030.
Pseudoxanthoma Elasticum, a Difficult Diagnostic in Patient With Dark Skin
Authors: Fassanaro Carla , Stichelbout Morgane , Lambert Marc , Dezoteux Frédéric , Staumont-Sallé Delphine , Boileau Marie
Published: April 2024

Pseudoxanthoma elasticum is a genetic metabolic disease which leads to ectopic mineralisation in the elastic tissues of the skin, eyes and blood vessels. The clinical signs are small yellow or normal skin-coloured papules on the nape of the neck and lateral sides of the neck, as well as in flexural areas and periumbilical region. The skin becomes loose and wrinkled. The diagnosis on dark skin is particularly difficult. The dermatologist evokes the diagnosis and refers the patient to specialists in order to detect complications. We propose here a practical case study.
Massive Facial Keloid Precipitated by Chronic Suppuration and Mechanical Skin Traction: A Case Report
Authors: Banda Chihena H. , Ngalamika Owen , Zuze Victor M. , Bwanga Alick , Mumba Chibamba
Published: April 2024

Keloids are benign fibroproliferative tumours with a high recurrence rate of 20%–100%, therefore, multimodal treatment is recommended. We report the case of an exceptionally large facial keloid precipitated by a vicious cycle of chronic inflammation and mechanical skin traction and discuss the management challenges in a low resource setting. A 67-year-old man presented with a 10-year history of a facial keloid that rapidly enlarged to 2,800 g in 2 years causing difficulties eating, speaking, dressing, head movements and breathing. He had multiple other smaller keloids, hypertension, HIV, and a keloid family history. Surgical excision of the keloid including the multiple sinuses and cysts of enclosed skin with growing hair found inside was performed. A posterior skin flap was used to achieve tension free closure and monthly triamcinolone injections commenced. Histology showed keloidal collagen bundles in a fibrotic background, foci of a lymphoplasmacytic infiltrate and multinucleated foreign body type giant cells consistent with chronic inflammation. CD34 and S100 immunohistochemistry were both negative, ruling out the differential diagnoses that included dermatofibroma. Recovery was uneventful and the patient was discharged after 2 weeks. Notably, radiotherapy was not available in our country. We report this unique case of an extremely large keloid to demonstrate the role of suppurative chronic inflammation and high skin tension in accelerated keloid growth. This case also highlights the severe global disparity in the availability of effective keloid treatment and the urgent need for access to radiotherapy services especially in Africa where keloid prevalence is highest.
Potential Applications of Metal‐Doped Nanomaterials for Enhancing Solid‐State Hydrogen Storage
Authors: Abdulkadir B. A. , Teh L. P. , Rahman Khan M. M. , Setiabudi H. D.
Published: April 2024

Hydrogen energy is the primary replacement for fossil fuels in the future because of its advantages in terms of efficiency, cost‐effectiveness, and environmental friendliness. The fundamental issue with hydrogen, however, arises from its exceedingly low volumetric density; thus, developing efficient storage methods is critical to achieving a sustainable hydrogen economy. Hydrogen storage has demonstrated tremendous potential as a possible alternative for effective large‐scale storage. Due to their low cost, and high volumetric and gravimetric capacities, metal hydride‐based storage is considered the most prospective solid‐state storage material. Their low storage capacity nevertheless restricts their application effectively. Hence, the need to enhance the storage capacity by doping active metals becomes an interesting study area. With considerable success, metals, particularly transition metals, have been used to modify hydrides to improve their storage capacities. Owing to their strong and superior performance, active metals have demonstrated tremendous potential in increasing the performance of storage materials. This review critically examined recent developments in enhancing hydrogen storage characteristics through the incorporation of active metals. The preparation techniques for metal infiltration through different techniques, such as impregnation, ball/mechanical milling, and reflux were reported. The review describes significant advances in hydrogen storage characteristics due to metal doping and offers perspective recommendations for future research.
Exploring Ultrasonic‐Assisted Extraction and Eco‐Friendly Dyeing of Organic Cotton using Syzygium cumini Leaf Extracts
Authors: Akram Md. Washim , Uddin Banna Burhan , Mahmud Sayed Hasan , Easmin Shanzida , Repon Md. Reazuddin
Published: April 2024

The demand for natural dyes is increasing due to the negative environmental impacts of synthetic color. In fact, customers are becoming more concerned about their health and the environmentally friendly products. The aim of this research is to disclose the dye extraction process using the ultrasonic method and eco‐friendly dyeing of organic cotton knitted fabric. Initially, 10 g of Syzyguim cumini leaf powder was dissolved in 150 mL of purified water maintaining a 1 : 15 M : L ratio to extract the color. After that, the extracted dye solution was added to coloration bath following the M : L ratios of 1 : 16, 1 : 12, and 1 : 8 for producing dark, medium, and light shades, respectively. Post mordanting was done using natural lemon juice for colorfastness improvement. The color attributes were revealed by the spectrophotometric analysis. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to comprehend the successful relationship that exists among SCL dyes and organic cotton fibers, and the TGA analysis confirmed that dyed fabric is more stable than undyed fabric. Moreover, the colored sample‘s pH, formaldehyde level, and presence of forbidden Azo groups (aromatic amines) were examined. The test results revealed that very good to excellent color fastness properties were obtained and no harmful chemicals were detected in the dyed samples.
Modulation of Phase Separation Morphology by Configuration Engineering in Bulk Heterojunction Organic Solar Cells
Authors: Zhou Jie , Liu Shuang , Zhang Yuwei , Ma Yanfang , Liu Jianchuan
Published: April 2024

For bulk‐heterojunction organic solar cells (OSCs), molecular structure design to control molecular stacking is crucial to obtain ideally phase‐separated morphology and high device performance. Herein, the investigation focuses on two polythiophene‐quinoxaline (PTQ) derivatives (PTQ8 and PTQ10) blended with Y6, utilizing coarse‐grained molecular dynamics simulations based on the Lennard–Jones static potential (LJSP) method. The study reveals that the diminished photovoltaic efficiencies of PTQ8:Y6 blends, compared to PTQ10:Y6 blends, are not solely attributed to reduced driving forces. The introduction of fluorine‐substituted sites in the thiophene group of PTQ polymer is identified as a significant factor. This alteration causes PTQ polymers in PTQ8:Y6 blends to coil, compromising the crystalline structure. PTQ8's bifluorine group induces a repulsive effect on the quinoxaline group, leading to a coiled‐chain structure that hinders chain stacking. Conversely, PTQ10 exhibits a straighter chain conformation. Additionally, PTQ8's high solubility in chloroform prevents effective aggregation, further impeding suitable morphology formation. Coarse‐grained simulations employing LJSP prove effective in precisely exploring the morphology of OSCs, offering crucial insights for materials in this field.
Low Cycle Fatigue and Damage Evaluation on 16MnCr5 Alloy Steel
Authors: González‐Zapatero Walter F. , García Christian J. , Gómora César M. , Ambriz Ricardo Rafael , Jaramillo David
Published: April 2024

The 16MnCr5 alloy steel samples are evaluated in a normalized condition and put through low cycle fatigue (LCF) under constant amplitude strains of εa = 0.2%, 0.25%, 0.4%, and 0.6%. Mechanical properties are reported based on the LCF results. Fatigue damage is checked in specimens that have reached 80% of their nominal fatigue life by two methods that are different from traditional electronic microscopy: measuring the roughness of the surface and looking at it through full‐field optical microscopy. In addition, the electric resistivity is determined for the test specimens. It presents an increment from the blank value of 6.5 × 10−8 Ωm (free of fatigue damage) to 1.25 × 10−7 Ωm for the fatigue test specimen (εa = 0.6%). Finally, X‐ray diffraction patterns are determined for analyzing the residual equivalent strain at the microscale for the fatigued samples. The residual equivalent strain exhibits a trend toward increasing. For instance, it increases from 18.5 (blank value) to 34.0 με for the fatigue test specimen with εa = 0.6%.
Harnessing Interlayer Magnetic Coupling for Efficient, Field‐Free Current‐Induced Magnetization Switching in a Magnetic Insulator
Authors: Wang Leran , Leon Alejandro O. , He Wenqing , Liang Zhongyu , Li Xiaohan , Fang Xiaoxiao , Yang Wenyun , Peng Licong , Yang Jinbo , Wan Caihua , Bauer Gerrit E. W. , Luo Zhaochu
Published: April 2024

Owing to the unique features of low Gilbert damping, long spin‐diffusion lengths, and zero Ohmic losses, magnetic insulators are promising candidate materials for next‐generation spintronic applications. However, due to the localized magnetic moments and the complex metal–oxide interface between magnetic insulators and heavy metals, spin‐functional Dzyaloshinskii–Moriya interactions or spin Hall and Edelstein effects are weak, which diminishes the performance of these typical building blocks for spintronic devices. Herein, the exchange coupling between metallic and insulating magnets is exploited for efficient electrical manipulation of heavy metal/magnetic insulator heterostructures. By inserting a thin Co layer, the spin‐orbit torque efficiency is enhanced by more than 20 times, which significantly reduces the switching current density. Moreover, field‐free current‐induced magnetization switching caused by a symmetry‐breaking non‐collinear magnetic texture is demonstrated. This work launches magnetic insulators as an alternative platform for low‐power spintronic devices.
Evaluating streamflow and temperature effects on Bull Trout migration and survival with linear spatial capture–recapture models
Authors: Wohner Patti J. , Thurow Russell F. , Peterson James T.
Published: April 2024

Objective

In the U.S. Pacific Northwest, climate change is increasing air temperatures, decreasing warm season (April–September) streamflow, and increasing cool season (October–March) streamflow. Warmer water temperatures may alter conditions for migratory coldwater fishes like the Bull Trout Salvelinus confluentus. Consequently, an understanding of Bull Trout migration and survival is critical for species conservation and restoration. In the Salmon River basin, Idaho, 1992 and 1993 transpired to be two of the most opposing extreme years among the past three decades for warm season water temperature and streamflow. These extremes provided a unique opportunity to retrospectively compare Bull Trout survival and migration under potential climate change scenarios.

Methods

We evaluated prespawning and postspawning migrations and survival of fluvial Bull Trout that were radio-tagged and tracked from 1992 to 1994. We used a Cormack–Jolly–Seber linear spatial capture–recapture model to simultaneously model the migration and survival of radio-tagged prespawn (n = 58) and postspawn (n = 23) Bull Trout among weeks and river reaches with streamflow, water temperature, and habitat covariates.

Result

Most individual prespawning migrations were similar among tagged fish, whereas postspawn fish adopted multiple migration and overwintering strategies. Movements of prespawn Bull Trout were larger when (1) weekly average daily maximum streamflow increased and (2) weekly average daily maximum water temperature increased. The model estimated that at least 52% of spawners survived to spawning, and mean weekly prespawning apparent survival was higher in the low-streamflow year (1992) than in the year with higher and more variable streamflow (1993). Survival of 1992–1994 fish during the 38-week postspawning period was intermediate to that in the prespawning period. Detections of prespawn Bull Trout were generally higher at sites with more complex habitats, less large woody debris, and fewer undercut banks.

Conclusion

We found that the prespawn life stage can represent a shorter time frame (14–18 weeks) with increased mortality compared to the longer postspawning period (38 weeks). Bull Trout apparent survival increased with lower streamflow variability, indicating that expected future changes in climate may adversely affect Bull Trout.
An empirical study of the impact of COVID‐19 on container freight rates: Evidence from the panel data of China
Authors: Chen Kaimin , Ding Yi , Zou Benqing , Jin Hua , Yang Yang
Published: April 2024

The container shipping industry has undergone significant changes in the post‐COVID‐19 era. This study examines the impact of the pandemic on container freight rates (CFR) through a demand analysis approach, using 11 major international container trade lanes from Shanghai, China as a case study. We analyze the CFR data on both weekly and monthly bases, with a focus on retaining more individual and time information using long panel data. To better reveal the pandemic's impact on CFR, we introduce interactive terms and simultaneous equations in our model. Our empirical analysis shows that the pandemic has not only directly and positively affected CFR, but, more importantly, has also indirectly promoted the growth of container shipping cost by stimulating the demand for containerized goods exported from China. Additionally, the connectivity or capacity of a given trade lane has inhibited the pandemic's effects on CFR to a certain extent. These findings provide insights into the remarkable growth of CFR from the demand side in 2020.
Pesticidal activity of extra cellular metabolites extracted from the green muscardian fungi Metarhizium anisopliae
Authors: R Sowmya , Karthick Raja Namasivayam S. , D Sowmya , Sivasuriyan Krithika Shree
Published: April 2024

The present study was undertaken to screen the pesticidal activity of extra cellular metabolites derived from entomopathogenic fungus Metarhizium anisopliae against Spodoptera litura and Aphis crassivora an important aphid pest under laboratory and pot culture condition. Fungal strain used in the study was isolated from the soil by serial dilution technique. Isolated fungal strain was mass multiplied in a liquid medium sabouraud maltose yeast extract broth under optimum condition (28°C). Culture filtrate and the collected culture derived from the medium was used for the source of metabolites. The culture filtrate was extracted with ethyl acetate, acetone and the concentrated extract was screened for pesticidal activity against Spodoptera litura and Aphis crassivora adopting leaf disc and pot culture assay respectively. Extracted metabolites showed pesticidal activity against both insect pests. However, notable effect was recorded in ethyl acetate derived metabolites. The ethyl acetate extract treatment recorded 91.2% mortality at a concentration of 100 μg against Spodoptera litura and 100% mortality at a concentration of 100 μg against Aphis crassivora. Phytotoxicity was determined by measuring the germination index (GI) of groundnut seeds by exposing it to the crude metabolites extracted in ethyl acetate and acetone. The results showed that the germination index was high on ethyl acetate extract which was recorded to be 98.0% and germination index of acetone extract was found to be 90.0%. Production of insecticidal metabolites from M. anisopliae under laboratory condition proposed the possible utilization of metabolites as an effective, safe pesticidal agent against economic important insect pests. No impact on the seedling emergence revealed non phytotoxic effect of the metabolites.
Toward a Multilingual Perspective on Reading: Aligning Emergent Bilinguals' Resources with Theories of Reading and Implications for Instruction
Authors: Ascenzi‐Moreno Laura
Published: April 2024

This article puts forth a multilingual perspective on reading to counter the prevailing monolingualism that dominates reading instruction. First, it brings theories together to develop a cohesive understanding of teaching reading with emergent bilinguals at the center. Second, it illuminates ways educators can design reading instruction, which is responsive to and normalizes emergent bilinguals' resources. In taking up a multilingual perspective of reading, educators have a challenge and opportunity to engage in intellectual and practical work to ensure emergent bilinguals' strengths are at the center of reading instruction.
When Writers Lead the Lesson: Students as Teachers in Elementary Composing Spaces
Authors: Rowe Lindsey W. , Johnson Julie
Published: April 2024

The purpose of this article is to describe how teachers implemented student‐led minilessons in writing instruction. We use observations from two elementary classrooms to provide examples of student‐led instruction focused on digital and translingual composing. Through these examples, we outline three steps teachers can take to support student‐led composing instruction: (1) look for innovative student composing practices, (2) yield the floor to students, and (3) lend support as needed. We conclude by discussing how student‐led composing instruction positions children as experts and models in the classroom.
Bakersfield College erases student shortfall by attracting more adult learners
Authors: D’Orio Wayne
Published: April 2024

When COVID‐19 reduced the enrollment at California's Bakersfield College by 14% in just two years, Dr. Brian A. Rodríguez knew his job would be more important than ever.
The DEI slide: How colleges and universities are managing the cultural shift
Authors: May Rachel
Published: April 2024

Kentucky and Wisconsin are the most recent states to grapple with proposed bans of Diversity, Equity, and Inclusion initiatives. While the University of Wisconsin Board of Regents originally voted against the proposed DEI bill, they eventually reached an agreement with state legislators. The UW system was granted $800 million from the state for employee pay raises and construction projects, in exchange for freezing DEI hiring, changing position titles of existing DEI staff to “student success” roles, and eliminating DEI statements from student applications.
The need for recovery: An investigation into short‐term work‐related fatigue in veterinary nurses
Authors: Foxx Flora , Orpet Hilary
Published: April 2024

Background

Veterinary nursing is physically and emotionally demanding, putting veterinary nurses at risk of acute work‐related fatigue (AWRF). Despite the increased recognition of chronic occupational syndromes such as burnout and compassion fatigue in recent years, few studies have investigated how AWRF impacts individuals and the profession.

Methods

An anonymous survey open to all UK‐based registered veterinary nurses (RVNs) was distributed via email and social media. The survey investigated work patterns, hobbies, opinions about work and intentions to leave the veterinary profession. An English translation of the need for recovery (NFR) scale was used to quantify the AWRF.

Results

The median NFR score from 387 responses was 81.8, indicating high levels of AWRF. Long shifts, sole‐charge work and overtime were associated with higher scores, while having support at work and a better work–life balance were associated with lower scores. Higher scores were correlated with intentions to leave the profession.

Limitations

Although validated as a measure of AWRF, the unidimensional NFR scale oversimplifies the complexities of fatigue. A limited number of RVNs responded to the survey, reducing statistical power.

Conclusion

Although there is no single solution to staff turnover, the results from this survey suggest that addressing AWRF may improve retention of RVNs.
Introduction to the special issue: Authoritarianism and religion in South Asia: Trends and twists
Authors: Mostofa Shafi Md. , Subedi DB , Brasted Howard
Published: April 2024

Religious sentiments have become a potent tool for political elites, altering national identities and citizenship criteria. This manipulation, driven by majoritarian ideologies, has marginalized religious minorities, leading to discrimination, violence, and legal persecution against them. Hindu, Islamic, and Buddhist nationalisms seem to collectively erode secular democracy in South Asia. Moreover, right‐wing populist leaders, notably Modi in India and the Rajapaksas in Sri Lanka, have merged religious nationalism with authoritarian political orientations posing a challenge to democratic foundations and impacting significantly on the dynamics of state and societal relations. This is the context in which this World Affairs 2024 special issue delves into the relationship(s) between religion, politics, and authoritarianism in the South Asian region. It examines the evolving “religion‐politics” nexus or “complex” to explicate the relationship between religion and authoritarianism, particularly with respect to authoritarian governments mobilizing religion as a readily available resource for popular political mobilization, legitimization, and power consolidation. India's BJP employs Hindutva ideology to marginalize minorities, Bangladesh's regime uses Islam for political legitimacy, and Sri Lanka's Sinhala‐Buddhist nationalism fosters exclusionary policies. By fostering social and cultural polarization, this fusion of authoritarianism with religious nationalism poses a serious challenge to the secular state. The articles in this special issue explore these themes comprehensively, delving into the ideological foundations of political decisions and their consequences for marginalized communities. By shedding light on this multifaceted interplay, the collection offers valuable insights into South Asia's sociopolitical landscape, serving as a vital resource for scholars, policy makers, and global observers seeking to understand the region's complex dynamics.
Analytical analysis of water and engine oil base nanofluid flow with the influence of viscous dissipation and variable viscosity on stretching surface
Authors: Rehman Ali , Khun Ma Chau , Inc Mustafa , Ragoub Lakhdar , Rezapour Shahram , Muhammad Taseer
Published: April 2024

In this study, we will look at the analytical characterization of water and motor oil‐based nanofluid flow and the effects of viscous dissipation and variable viscosity on stretching surfaces. The primary goal of this research is to improve heat transfer efficiency in a range of systems, including cooling applications, refrigeration systems, and heat exchangers. The addition of nanoparticles to the base fluid increases its thermal conductivity, which boosts heat transfer rates. The flow system considers the impact of viscous dissipation. In addition, this methodology accounts for temperature and velocity slips during stretching. We utilized the proper transformations to convert a set of PDEs to NLODEs. To solve this system of equations, we use hybrid nanofluid. The impact of different parameters obtained from temperature and velocity equations involving the porosity parameter, power law number, ratio velocity, dynamic viscosity, Forchheimer parameter, and Eckert number input factors are shown in the form of graphs.
Sozialprofil, Amtsführung und Problemlagen
Authors: Bogumil Jörg , Gehne David H. , Süß Louisa Anna
Published: April 2024

In diesem Kapitel werden die Ergebnisse der Befragung der eBm dargestellt. Insgesamt erreichte der Fragebogen eine Rücklaufquote von 23 % (n = 1491), die sich je nach Bundesland jedoch deutlich unterscheidet (s. Tab. 1.2). Aufgrund der hohen Varianz der Rücklaufquote nach Bundesland wurde eine Gewichtung des Datensatzes vorgenommen, um die Über- bzw. Unterrepräsentation einzelner Bundesländer auszugleichen. Im Folgenden werden folgende Bereiche der Befragung vorgestellt: das Sozialprofil, politische Profil der eBm, die kommunalpolitischen Rahmenbedingungen, die Amtsführung, die Motivation und die Bedeutung von Parteien und Wählervereinigungen sowie Erfahrungen mit Anfeindungen im Amt.
Exploring Seiberg-like N-alities with eight supercharges
Authors: Dey Anindya
Published: April 2024

Abstract

We show that a large subclass of 3d $$ \mathcal{N} $$
N
= 4 quiver gauge theories consisting of unitary and special unitary gauge nodes with only fundamental/bifundamental matter have multiple Seiberg-like IR duals. A generic quiver $$ \mathcal{T} $$
T
in this subclass has a non-zero number of balanced special unitary gauge nodes and it is a good theory in the Gaiotto-Witten sense. We refer to this phenomenon as IR N-ality and the set of mutually IR dual theories as the N-al set associated with the quiver $$ \mathcal{T} $$
T
. Starting from $$ \mathcal{T} $$
T
, we construct a sequence of dualities by step-wise implementing a set of quiver mutations which act locally on the gauge nodes. The associated N-al theories can then be read off from this duality sequence. The quiver $$ \mathcal{T} $$
T
generically has an emergent Coulomb branch global symmetry in the IR, such that the rank of the IR symmetry is always greater than the rank visible in the UV. We show that there exists at least one theory in the N-al set for which the rank of the IR symmetry precisely matches the rank of the UV symmetry. In certain special cases that we discuss in this work, the correct emergent symmetry algebra itself may be read off from this preferred theory (or theories) in addition to the correct rank. Finally, we give a recipe for constructing the 3d mirror associated with a given N-al set and show how the emergent Coulomb branch symmetry of $$ \mathcal{T} $$
T
is realized as a UV-manifest Higgs branch symmetry of the 3d mirror. This paper is the second in a series of four papers on 3d $$ \mathcal{N} $$
N
= 4 Seiberg-like dualities, preceded by the work [1].
Euclidean wormholes for individual 2d CFTs
Authors: Chandra Jeevan
Published: April 2024

Abstract

We interpret appropriate families of Euclidean wormhole solutions of AdS3 gravity in individual 2d CFTs as replica wormholes described by branching around the time-symmetric apparent horizons of black holes sourced by the backreaction of heavy point particles. These wormholes help describe a rich formalism to coarse grain pure states in 2d CFTs dual to the black hole geometries because the wormhole amplitudes match with the Renyi entropies of CFT states obtained by decohering the pure states in a specific way. This formalism can be generalised to coarse grain pure states in several copies of the CFT dual to multi-boundary black holes using wormhole solutions with higher genus boundaries using which we illustrate that coarse graining away the interior of multi-boundary black holes sets the mutual information between any two copies of the dual CFT to zero. Furthermore, this formalism of coarse graining pure states can be extended to decohere transition matrices between pure states which helps interpret more general families of wormhole solutions including those with non replica-symmetric boundary conditions in individual CFTs. The pseudo entropy of the decohered transition matrices has interesting holographic interpretation in terms of the area of minimal surfaces on appropriate black hole or wormhole geometries. The wormhole solutions which show up in the coarse graining formalism also compute the Renyi entropies of Hawking radiation after the Page time in a setup which generalizes the West Coast model to 3d gravity. Using this setup, we discuss the evaporation of one-sided black holes sourced by massive point particles and multi-boundary black holes in 3d gravity.
Boosted rotating dyonic strings in Salam-Sezgin model
Authors: Ma Liang , Pang Yi , Lü H.
Published: April 2024

Abstract

We show that the bosonic sector of the N = (1, 0), 6D Salam-Sezgin gauged supergravity model possesses a T-duality symmetry upon a circle reduction to D = 5. We then construct a simple magnetic rotating string solution with two equal angular momenta. Applying the T-duality transformation to this solution, we obtain the general boosted rotating dyonic black string solutions whose global structures and thermodynamic quantities are also analyzed. Owing to the fact that the solutions are not asymptotically flat, we find that there are two distinct globally-different non-extremal solutions with two different sets of thermal dynamic variables, with both satisfying the thermodynamic first law and the corresponding Small relations. However, their BPS limit becomes the same and we show that it preserves one quarter of supersymmetry by directly solving the corresponding Killing spinor equations.
Four-dimensional $$\mathcal{N}$$ = 2 superconformal long circular quivers
Authors: Beccaria M. , Korchemsky G.P.
Published: April 2024

Abstract

We study four-dimensional $$\mathcal{N}$$ = 2 superconformal circular, cyclic symmetric quiver theories which are planar equivalent to $$\mathcal{N}$$ = 4 super Yang-Mills. We use localization to compute nonplanar corrections to the free energy and the circular half-BPS Wilson loop in these theories for an arbitrary number of nodes, and examine their behaviour in the limit of long quivers. Exploiting the relationship between the localization quiver matrix integrals and an integrable Bessel operator, we find a closed-form expression for the leading nonplanar correction to both observables in the limit when the number of nodes and ’t Hooft coupling become large. We demonstrate that it has different asymptotic behaviour depending on how the two parameters are compared, and interpret this behaviour in terms of properties of a lattice model defined on the quiver diagram.
Mitral annular disjunction in out-of-hospital cardiac arrest patients—a retrospective cardiac MRI study
Authors: Troger Felix , Klug Gert , Poskaite Paulina , Tiller Christina , Lechner Ivan , Reindl Martin , Holzknecht Magdalena , Fink Priscilla , Brunnauer Eva-Maria , Gizewski Elke R. , Metzler Bernhard , Reinstadler Sebastian , Mayr Agnes
Published: April 2024

Background

Mitral annular disjunction (MAD), defined as defective attachment of the mitral annulus to the ventricular myocardium, has recently been linked to malignant arrhythmias. However, its role and prognostic significance in patients requiring cardiopulmonary resuscitation (CPR) remain unknown. This retrospective analysis aimed to describe the prevalence and significance of MAD by cardiac magnetic resonance (CMR) imaging in out-of-hospital cardiac arrest (OHCA) patients.

Methods

Eighty-six patients with OHCA and a CMR scan 5 days after CPR (interquartile range (IQR): 49 days before – 9 days after) were included. MAD was defined as disjunction-extent ≥ 1 mm in CMR long-axis cine-images. Medical records were screened for laboratory parameters, comorbidities, and a history of arrhythmia.

Results

In 34 patients (40%), no underlying cause for OHCA was found during hospitalization despite profound diagnostics. Unknown-cause OHCA patients showed a higher prevalence of MAD compared to definite-cause patients (56% vs. 10%, p < 0.001) and had a MAD-extent of 6.3 mm (IQR: 4.4–10.3); moreover, these patients were significantly younger (43 years vs. 61 years, p < 0.001), more often female (74% vs. 21%, p < 0.001) and had fewer comorbidities (hypertension, hypercholesterolemia, coronary artery disease, all p < 0.005). By logistic regression analysis, the presence of MAD remained significantly associated with OHCA of unknown cause (odds ratio: 8.49, 95% confidence interval: 2.37–30.41, p = 0.001) after adjustment for age, presence of hypertension, and hypercholesterolemia.

Conclusions

MAD is rather common in OHCA patients without definitive aetiology undergoing CMR. The presence of MAD was independently associated to OHCA without an identifiable trigger. Further research is needed to understand the exact role of MAD in OHCA patients.

Graphical Abstract

Study synopsis - MAD occurs frequently in unknown-cause OHCA and represents an independent marker after adjustment for age, hypertension, and hypercholesterolemia. (Illustration created with biorender.com). MAD mitral annular disjunction, OHCA out-of-hospital cardiac arrest
Comparative analysis of metacyclogenesis and infection curves in different discrete typing units of Trypanosoma cruzi
Authors: Cáceres Tatiana M. , Cruz-Saavedra Lissa , Patiño Luz Helena , Ramírez Juan David
Published: April 2024

Chagas disease (CD), caused by the complex life cycle parasite Trypanosoma cruzi, is a global health concern and impacts millions globally. T. cruzi’s genetic variability is categorized into discrete typing units (DTUs). Despite their widespread presence in the Americas, a comprehensive understanding of their impact on CD is lacking. This study aims to analyze life cycle traits across life cycle stages, unraveling DTU dynamics. Metacyclogenesis curves were generated, inducing nutritional stress in epimastigotes of five DTUs (TcI (MG), TcI (DA), TcII(Y), TcIII, TcIV, and TcVI), resulting in metacyclic trypomastigotes. Infection dynamics in Vero cells from various DTUs were evaluated, exploring factors like amastigotes per cell, cell-derived trypomastigotes, and infection percentage. Statistical analyses, including ANOVA tests, identified significant differences. Varying onset times for metacyclogenesis converged on the 7th day. TcI (MG) exhibited the highest metacyclogenesis potential. TcI (DA) stood out, infecting 80% of cells within 24 h. TcI demonstrated the highest potential in both metacyclogenesis and infection among the strains assessed. Intra-DTU diversity was evident among TcI strains, contributing to a comprehensive understanding of Trypanosoma cruzi dynamics and genetic diversity.
Tracking magma pathways and surface faulting in the Southwest Rift Zone and the Koaʻe fault system (Kīlauea volcano, Hawai ‘i) using photogrammetry and structural observations
Authors: Mannini Stefano , Ruch Joël , Hazlett Richard W. , Downs Drew T. , Parcheta Carolyn E. , Lundblad Steven P. , Anderson James L. , Perroy Ryan , Oestreicher Nicolas
Published: April 2024

Volcanic islands are often subject to flank instability, resulting from a combination of magmatic intrusions along rift zones and gravitational spreading causing extensional faulting at the surface. Here, we study the Koaʻe fault system (KFS), located south of the summit caldera of Kīlauea volcano in Hawaiʻi, one of the most active volcanoes on Earth, prone to active faulting, episodic dike intrusions, and flank instability. Two rift zones and the KFS are major structures controlling volcanic flank instability and magma propagation. Although several magmatic intrusions occurred over the KFS, the link between these faults, two nearby rift zones and the flank instability, is still poorly studied. To better characterize the KFS and its structural linkage with the surrounding fault and rift zones, we performed a detailed structural analysis of the extensional fault system, coupled with a helicopter photogrammetric survey, covering part of the south flank of Kīlauea. We generated a high-resolution DEM (~ 8 cm) and orthomosaic (~ 4 cm) to map the fracture field in detail. We also collected ~ 1000 ground structural measurements of extensional fractures during our three field missions (2019, 2022, and 2023). We observed many small, interconnected grabens, monoclines, rollover structures, and en-echelon fractures that were in part previously undocumented. We estimate the cumulative displacement rate across the KFS during the last 600 ~ 700 years and found a decrease toward the west of the horizontal component from 2 to 6 cm per year, consistent with GNSS data. Integrating morphology observations, fault mapping, and kinematic measurements, we propose a new kinematic model of the upper part of the Kīlauea’s south flank, suggesting a clockwise rotation and a translation of a triangular wedge. This wedge is bordered by the extensional structures (ERZ, SWRZ, and the KFS), largely influenced by gravitational spreading. These findings illustrate a structural linkage between the two rift zones and the KFS, the latter being episodically affected by dike intrusions.
Evidence of heat sensitivity in people with Parkinson’s disease
Authors: Hunt Andrew P. , Pagnussat Aline Souza , Lehn Alexander , Moore Daniel , Schweitzer Daniel , Laakso E-Liisa , Hennig Ewald , Morris Meg E. , Kerr Graham , Stewart Ian
Published: April 2024

Examining how heat affects people with Parkinson’s disease is essential for informing clinical decision-making, safety, well-being, and healthcare planning. While there is evidence that the neuropathology associated with Parkinson’s disease affects thermoregulatory mechanisms, little attention has been given to the association of heat sensitivity to worsening symptoms and restricted daily activities in people with this progressive disease. Using a cross-sectional study design, we examined the experiences of people diagnosed with Parkinson’s disease in the heat. Two-hundred and forty-seven people completed an online survey (age: 66.0 ± 9.2 years; sex: male = 102 (41.3%), female = 145 (58.7%)), of which 195 (78.9%) reported becoming more sensitive to heat with Parkinson’s disease. Motor and nonmotor symptoms worsened with heat in 182 (73.7%) and 203 (82.2%) respondents, respectively. The most commonly reported symptoms to worsen included walking difficulties, balance impairment, stiffness, tremor, fatigue, sleep disturbances, excess sweating, difficulty concentrating, and light-headedness when standing. Concerningly, over half indicated an inability to work effectively in the heat, and nearly half reported that heat impacted their ability to perform household tasks and social activities. Overall, heat sensitivity was common in people with Parkinson’s disease and had a significant impact on symptomology, day-to-day activities and quality of life.
Physical health-related quality of life trajectories over two years following breast cancer diagnosis in older women: a secondary analysis
Authors: Wong Shan S. , Levine Beverly J. , Van Zee Kimberly J. , Naftalis Elizabeth Z. , Avis Nancy E.
Published: April 2024

Purpose

To identify distinct trajectories of physical health-related quality of life (HRQoL) in older women over the first two years following breast cancer diagnosis, and to examine characteristics associated with trajectory group membership.

Methods

A secondary analysis of a longitudinal study of women diagnosed with stage I-III breast cancer who completed surveys within eight months of diagnosis and six, twelve, and eighteen months later that focuses on a subset of women aged ≥ 65 years (N = 145).Physical HRQoL was assessed using the Physical Component Score (PCS) of the SF-36 Health Survey. Finite mixture modeling identified distinct PCS trajectories. Multivariable logistic regression identified variables predictive of low PCS group membership.

Results

Two distinct patterns of PCS trajectories were identified. The majority (58%) of women had PCS above the age-based SF-36 population norms and improved slightly over time. However, 42% of women had low PCS that remained low over time. In multivariable analyses, older age, difficulty paying for basics, greater number of medical comorbidities, and higher body mass index were associated with low PCS group membership. Cancer treatment and psychosocial variables were not significantly associated.

Conclusion

A large subgroup of older women reported very low PCS that did not improve over time. Older age, obesity, multiple comorbidities, and lower socioeconomic status may be risk factors for poorer PCS in women with breast cancer. Incorporating routine comprehensive geriatric assessments that screen for these factors may help providers identify older women at risk for poorer physical HRQoL post breast cancer treatment.