bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of Rho-kinase Inhibitor and hrsACE2 in COVID-19 Patients Management
Authors: Halim Wilson , Gervais de Liyis Bryan , Dalem Sukawati Cokorda Istri Intan
Published: November 2024

The Renin-angiotensin system (RAS) plays an important role in the SARS-CoV-2 infection through Angiotensin-converting enzyme 2 (ACE2). Human recombinant soluble ACE2 (hrsACE2) has been shown to act as a competitive interceptor for SARS-CoV-2 by preventing the binding of viral particles to the ACE2. In addition, Rho-kinase inhibitors have been proven to suppress SARS-CoV-2 infection through inhibition of the Rho-associated protein kinase (ROCK) pathway. The combined effect of hrsACE2 and Rho-kinase inhibitor increases the activity and levels of ACE2 in protection through the Ang1-7 MasR, Ang1-9, and other mechanisms of protection. This literature review is done by searching journals with “COVID-19”, “ACE2”, “hrsACE2”, “Rho- kinase inhibitor”, and “ROCK pathway” as well as Boolean logic “AND” and “OR”. Relevant journals are used as references to compile systematic writing. Based on research results, hrsACE2 and Rho-kinase inhibitors have been clinically proven to protect tissue through the elevated level of ACE2 by the mechanism of Rho-kinase inhibitor, which increased Ang1-7 MasR concentration that gives vasodilatation, anti-proliferative, anti-inflammation, and anti-fibrotic effect. Rho-kinase inhibitors significantly reduce the number of infected cells by SARS-CoV-2 in COVID-19 patients. The potential of the combination therapy of Rho-kinase inhibitor and hrsACE2 therapy can be an efficient therapeutic solution for COVID-19 patients so that further research can be carried out in the future.
A experimentação investigativa na formação de professores de ciências naturais: a importância da extensão universitária
Authors: Pereira Kézia de Jesus , Gomes Rotta Jeane Cristina
Published: November 2024

A experimentação investigativa pode promover o ensino e aprendizagem das ciências. Projetos de extensão universitária têm se destacado como espaços propícios para essa prática. Este trabalho teve como objetivo compreender como os egressos de uma licenciatura em ciências naturais percebem a contribuição da extensão universitária na promoção de experimentos investigativos. A pesquisa foi qualitativa e utilizou um questionário como instrumento de obtenção de dados, envolvendo a participação de dez egressos do curso.   Os dados foram analisados por meio da análise textual discursiva e organizados em três categorias. Os resultados indicaram que, embora as aulas da graduação tenham favorecido a realização de experimentos, a abordagem investigativa esteve mais presente naqueles realizados no projeto de extensão. 
Abstract
Investigative experimentation can promote science teaching and learning. University extension projects have stood out as favorable spaces for this practice. This study aims to understand how graduates from a degree course in natural sciences perceive the contribution of university extension in promoting investigative experiments. The research was qualitative and used a questionnaire as a data collection tool involving the participation of ten graduates of the course. The data was analyzed using discursive textual analysis and it was organized into three categories. Although the undergraduate classes favored experiments, the results indicated that the investigative approach was more present in those carried out in the extension project.
CARDIOPATIAS CONGÊNITAS: DA FISIOPATOLOGIA AO TRATAMENTO – RECONHECIMENTO E INTERVENÇÕES
Authors: Barcelos Carvalho Bárbara Aparecida , Gomes de Rezende Matheus , Alves Ferreira Aline , Almeida Isadora Luara , Barbosa Sobrinho Brenda Karoline , Machado Oliveira Bruno Rafaell , Belarmino de Sá Júnior Edelício , Santos Marinho Sophia , Fernandes Anderson Rodrigo , Carvalhaes Filho Carlos Antônio , Pires da Silva Neto José , Balz Rocha Grete Anélia
Published: November 2024

Este artigo revisa as principais cardiopatias congênitas, abordando suas manifestações clínicas, fisiopatologia e opções de tratamento. A compreensão dessas condições é essencial para diagnósticos precisos, terapias eficazes e estratégias preventivas, visando melhorar o prognóstico e a qualidade de vida dos pacientes. A revisão baseia-se em 10 artigos selecionados, que exploram a fisiopatologia, diagnóstico e terapêuticas, enriquecendo o conhecimento sobre essas cardiopatias. As condições são classificadas em cianóticas e acianóticas, com diferenças nas manifestações clínicas. As cardiopatias cianóticas, como a tetralogia de Fallot e a transposição das grandes artérias, apresentam cianose e comprometimento hemodinâmico grave. Já as acianóticas, como a comunicação interatrial e interventricular, apresentam sintomas menos intensos, mas exigem monitoramento. O diagnóstico precoce e o tratamento adequado são fundamentais para o prognóstico. Avanços em técnicas de imagem, como a ecocardiografia fetal, e em intervenções cirúrgicas minimamente invasivas têm aprimorado a detecção e o manejo dessas condições, reduzindo a mortalidade neonatal e melhorando a qualidade de vida. Embora as cardiopatias cianóticas frequentemente exijam correções cirúrgicas urgentes, as acianóticas necessitam de monitoramento constante e, em alguns casos, de intervenções cirúrgicas. O acompanhamento contínuo e a educação dos pais são cruciais para garantir o bem-estar a longo prazo. A colaboração entre especialistas tem contribuído significativamente para a melhoria dos resultados clínicos. Em resumo, com diagnósticos precoces e tratamentos adequados, é possível reduzir a mortalidade e oferecer uma vida saudável e ativa aos pacientes com cardiopatias congênitas.
 
Palavras-chave: cardiopatias congênitas; mecanismos patológicos; abordagem terapêutica; diagnóstico; procedimentos intervencionistas.
EFICÁCIA DO VALOR ENERGÉTICO DO FARELO DA LOBEIRA (Solanum lycocarpum) OFERTADO A BOVINOS COM BASE EM MODELOS MATEMÁTICOS : ESTUDO EXPERIMENTAL
Authors: Diniz Camatini Heloisa Stephanie , Barbosa Alves Junior Carlos Donato , Souza de Oliveira Cleber , Moreira Souza Gustavo Henrique , Amaral Rodrigues Camilo Henrique Otávio , Palma Soares Leonardo , Aguilar Barreto Vinícius , Munhoz de Moraes Bianca , Costa de vasconcelos Nathália , Junior Guido Ademir , Gomes de Alencar Araripe Marcio , Da Silva Barros Debora , Bastos Costa Nayara
Published: November 2024

O conhecimento dos valores nutricionais dos alimentos é crucial para um bom desenvolvimento e rendimento dos ruminantes. Além disso, em decorrência do alto custo dos alimentos convencionais, é necessário obter novas fontes de alimentação confiáveis para adequação na dieta destes animais. Sendo assim, objetivou-se avaliar a predição do valor energético do farelo da lobeira (Solanum lycocarpum) por intermédio de modelos matemáticos. O experimento foi conduzido no Laboratório de Nutrição Animal e Bromatologia da Fazenda Escola Univan- Itajaí- SC.  Utilizou-se 20 amostras do fruto da lobeira para as análises. Os valores bromatológicos e a quantificação matemática para a predição do valor energético foram obtidos com a metodologia recomendada por Detmann et al.. (2021). Os valores bromatológicos encontrados foram: Matéria seca (29,99%), proteína bruta (8,45%), proteína insolúvel em detergente ácido (1,87%), proteína insolúvel em detergente neutro (2,21%), matéria mineral (2,34%), fibra insolúvel em detergente neutro(19,70%), fibra insolúvel em detergente ácido (9,47%), extrato etéreo (2,91%), carboidratos não fibrosos (68,18%), pectina (7,18%), amido (51%) e lignina (1,08%). Os resultados da predição do valor energético foram: proteína bruta verdadeiramente digestível (6,73%), potencial digestivo do fdn (18,25%), potencial digestivo do extrato etéreo (0,84%), potencial digestivo dos carboidratos não fibrosos (65,10%), nutrientes digestíveis totais (80,17%), energia digestível (3,43%) e energia metabolizável (2,94%). Concluiu-se que o farelo de lobeira é uma fonte alternativa eficaz na substituição dos alimentos tradicionalmente utilizados na dieta dos animais ruminantes, com plena capacidade de fornecer energia e proteína de alto valor biológico.
FACETAS DIRETAS DE RESINA COMPOSTA PARA MASCARAMENTO DE SUBSTRATOESCURECIDO: REVISÃO SISTEMÁTICA DE LITERATURA
Authors: Oliveira Thamilles Batista de , Silva Frank Gigianne Texeira e , Estrela Júlio Rafael , Nóbrega Vinícius Nito , Casimiro Emilly Aniery , Nóbrega Rebeca Verônica , Gualberto Débora Lídia , Pereira Paulina Barbara
Published: November 2024

A presente pesquisa teve como objetivo avaliar, através de uma revisão sistemática de literatura, a aplicação de facetas diretas de resina composta para o mascaramento de substrato escurecido. As bases de dados utilizadas para busca de artigos foram: Biblioteca Virtual em Saúde (BVS), Scientific Electronic Library Online (Scielo), PubMed® e Portal de Periódicos da Capes. Foram incluídos artigos publicados entre os anos de 2019 e 2023; de livre acesso gratuito; que abordavam sobre a aplicação de facetas diretas de resina composta sendo um dos objetivos do procedimento mascarar substratos escurecidos. Foram excluídos artigos repetidos e aqueles que não tinham como método de pesquisa o relato de caso clínico. Um total de 16 artigos foram encontrados. A literatura atual permitiu verificar que as facetas diretas em resina composta constituem uma excelente opção de técnica que pode ser utilizada mediante tratamento odontológico para mascarar substratos escurecidos. Verificou-se ainda que é possível fazer a associação de procedimentos. Facetas diretas e inserção de pino de fibra de vidro e/ou clareamento, por exemplo, quanto associados, podem levar a resultados bastante satisfatórios. Em conclusão, os achados demostram que o facetamento direto de resina composta é capaz de devolver a cor, textura e forma de elementos dentários. Pode ser eficientemente aplicada para mascarar substratos escurecidos, levando a resultados satisfatórios, principalmente em termos de estética e funcionalidade. O procedimento apresenta ainda a vantagem de ser uma opção minimamente invasiva, economicamente mais viável, que pode ser realizado com rapidez e possibilita efeitos imediatos. Contudo, ficou evidente que cada caso precisa ser analisado isoladamente. Torna-se necessário um conhecimento acentuado da técnica a fim de mapear se a sua aplicação será efetiva em termos estéticos e funcionais.
A Study on Micro-Industry Women Entrepreneurs in the Obtainment of Halal Certification: Challenges and Success Factors
Authors: Syakirah Afaf , Jamaludin Mohammad Aizat , Ahmad Fadzillah Nurrulhidayah , Rosli Nur Liana Izzaty
Published: November 2024

Micro-Industry Women Entrepreneurs (MIWE) are essential in local economic development. Despite the growing halal industry worldwide, micro-industry participation in halal certification remains relatively low, especially in Perlis. This study intends to explore the challenges and success factors MIWE faces in obtaining halal certification in Perlis, particularly in the food sector. It examined the challenges hindering women entrepreneurs from adopting halal certification for their food products and the factors contributing to their success in this process and implementation. The study employed a qualitative research method for data collection. Semi-structured interviews were conducted with fifteen (15) informants involving seven (7) MIWE in the food manufacturing sector, one (1) halal auditor, four (4) agency officers and three (3) halal executives. An inductive-deductive analysis revealed that the industry struggled with a lack of employees to manage halal certification, small market access, insufficient IT skills in handling the MYeHALAL system and a lack of concerns about halal certification among entrepreneurs. The success factors enabling the entrepreneurs to obtain and maintain halal certification included a strong understanding of halal concepts and requirements, commitment and motivation of MIWE in implementation, and initiatives and support from government authorities and staff. This study is crucial as it contributes to a deeper understanding of the critical factors for the sustainability of halal certification among MIWE.
Integration of risk management systems to ensure enterprise security and competitive advantages
Authors:   State Biotechnological University, Horobko Roman
Published: November 2024

In today’s world, where the level of uncertainty and the number of risks is constantly increasing, the issue of security is becoming highly relevant to organizations in various industries. Integrating such systems into the organization’s structure ensures an effective response to risks and is essential to modern management. The paper examines the main approaches to integrating risk management systems that allow organizations to respond to potential threats promptly. Special attention is paid to the security mechanism, which guarantees promptness and efficiency of actions in response to identified risks. It is essential that the integration of risk management systems not only reduces risks but also contributes to increasing the efficiency of the company’s activities in conditions of rapid changes. Various approaches to risk management were considered during the research. Special attention is paid to strategies focused on risk management, including preventive measures and rapid response mechanisms. Preventive measures are vital to preventing risks from occurring or reducing their impact. For example, it can introduce new technologies or improve internal processes to minimize potential technical failures. On the other hand, quick response mechanisms allow us to quickly solve the problems that arise, minimizing the negative consequences. The paper proposed an integrated risk management system covering all levels of organizational management — from strategic to operational. This concept allows you to create a holistic security system considering long-term strategies and current operational processes. Integrating risk management at different levels ensures a balance between safety and economic efficiency in the decision-making process. Based on the analysis of the best risk management practices, several recommendations were developed for implementing adequate security mechanisms. The main emphasis is on adapting generally accepted methodologies to the specific conditions of each organization’s activity. In addition, it was recommended that risk management policies and procedures be developed and implemented to provide a unified approach to identifying, assessing, and responding to risks. The study results showed that the effective integration of risk management systems allows for a significant reduction of the level of risks and ensures the stable functioning of the organization even in conditions of high uncertainty. Keywords: integration of risk management systems, security mechanism, risk monitoring, risk management, risk identification, risk minimization, automated systems, organizational security, preventive measures, crisis situations.
Footnotes, artistic conception, and strategies in translation of ancient Chinese poetry into English
Authors: Hee May Yee , Wong Xin Yi , Yuan Jiang , Amini Mansour
Published: November 2024

In Chinese poetry, artistic conceptions (Yi Jing), i.e., the soul of poetry portrayed beyond the words, has often underrated. This research explored the translatability of Chinese poetry from the perspective of maintaining artistic concepts by applying Vinay and Darbelnet ‘s model, exploration of the strategies, and footnotes. Five ancient poems that contained significant Chinese culture specific items were selected. The strategies utilized in the translation of the ancient poetries from Chinese to English language were identified and described, in addition to the thematic analysis used to analyze the content of footnotes and how artistic conception was preserved in the poem translations. Findings showed that “equivalence” is the most used strategy in the translation of the five poems, followed by “modulation”, “literal translation”, “transliteration”, “borrowing and adaptation”. Moreover, the difficulty of poetry translation from Chinese to English was identified to be mostly related to the elements that reflected on the cultural and historical background. It was concluded that adding footnotes can help to preserve the artistic conceptions and intentions of the source text without causing confusion among readers in translating ancient Chinese poems. The findings could provide insights on the translatability of poetry and how footnotes help in maintaining artistic conception and the intended meaning, emphasising on appropriate strategies for preserving the artistic conception.
The Design and Implementation of a Smartphone App to Teach English Language Components and Its Effect on EFL Learners’ Achievement Motivation
Authors: Gordani Yahya , Khajavi Yaser
Published: November 2024

The researchers applied a smartphone e-learning app run on the Android operating systemto teach English vocabulary and grammar and investigated its effectiveness in boosting motivation among English as Foreign Language (EFL) learners. The app was designed via Java programming tools and the Android development environment. To test the app’s effectiveness, sixtyupper-intermediate EFL learners were selected to participate in the study. The participants were then randomly assigned to an experimental and a control group. At first, the participants in the two groups were administered a questionnaire on their achievement motivation. This was followed by twenty sessions of instruction based on the developed app for the experimental group, the traditional teaching practice by a teacher, and the textbook for the control group. After the instruction, the post-test of achievement motivation was administered to both groups. The Mann-Whitney U test showed that integrating the app in EFL classes can significantly affect the mastery and performance types of achievement motivation among language learners.
English Language Learners’ Readiness towards Mobile Assisted Language Learning
Authors: Che Ahamad Muhammad Hilmi , Zulkepli Noraini , Tan Hooi Syn
Published: November 2024

Learning a second language (i.e. English) with the use of mobile technology has been widely accepted around the world. While there are numbers of research focusing on its effectiveness, students’ readiness in accepting the learning approach is yet to be studied. This research aims to investigate the level of readiness among students towards learning the English language via mobile. An adapted version of Parasuraman’s Technology Readiness Index (TRI) questionnaires was employed as the research instrument. A total of 180 respondents from a public university in Malaysia was involved in the study. The research found that the students projected a moderate level of readiness. This is as they are highly optimistic and innovative towards mobile learning but also have a high level of discomfort and insecurities towards it. It is suggested for further research to be carried out to identify the factors influencing students’ readiness and widen the sample by including other tertiary institutions.
The Impact of Web-Based Language Teaching on Advanced EFL Learners' Self-Regulation and Self-Actualization
Authors: Fadaei Homa , Dashtestani Reza
Published: November 2024

This quantitative research has been prepared to study the effect of web-based language teaching on advanced EFL learners' self-regulation and self-actualization. In doing so, 40 advanced students of both genders were chosen based on the convenience sampling method. They were approximately between eighteen to twenty-eight years of age at a private language institute in Kerman, Iran. Different instructional and testing materials, including the Oxford Placement Test, Short Index of Self Actualization Inventory, and Academic Self-Regulation Questionnaire were applied to gather the required data. Results revealed a significant improvement in self-regulation and self-actualization of the students in the case group. It means E-learning had an impact on advanced EFL learners' self-regulation and self-actualization. The results of this work could be beneficial for educators, trainers, instructors, and material developers to take into account the efficacy of such instructional materials and devote greater resources to developing and implementing them.
Strain-induced bandgap engineering in 2D ψ-graphene materials: a first-principles study
Authors: Kumar Kamal , de Leeuw Nora H , Adam Jost , Mishra Abhishek Kumar
Published: November 2024

High mechanical strength, excellent thermal and electrical conductivity, and tunable properties make two-dimensional (2D) materials attractive for various applications. However, the metallic nature of these materials restricts their applications in specific domains. Strain engineering is a versatile technique to tailor the distribution of energy levels, including bandgap opening between the energy bands. ψ-Graphene is a newly predicted 2D nanosheet of carbon atoms arranged in 5,6,7-membered rings. The half and fully hydrogenated (hydrogen-functionalized) forms of ψ-graphene are called ψ-graphone and ψ-graphane. Like ψ-graphene, ψ-graphone has a zero bandgap, but ψ-graphane is a wide-bandgap semiconductor. In this study, we have applied in-plane and out-of-plane biaxial strain on pristine and hydrogenated ψ-graphene. We have obtained a bandgap opening (200 meV) in ψ-graphene at 14% in-plane strain, while ψ-graphone loses its zero-bandgap nature at very low values of applied strain (both +1% and −1%). In contrast, fully hydrogenated ψ-graphene remains unchanged under the influence of mechanical strain, preserving its initial characteristic of having a direct bandgap. This behavior offers opportunities for these materials in various vital applications in photodetectors, solar cells, LEDs, pressure and strain sensors, energy storage, and quantum computing. The mechanical strain tolerance of pristine and fully hydrogenated ψ-graphene is observed to be −17% to +17%, while for ψ-graphone, it lies within the strain span of −16% to +16%.
Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond
Authors: Ma Thomas , Chu John
Published: November 2024

Bioactivity-guided fractionation (BGF) has historically been a fruitful natural product discovery workflow. However, it is plagued by increasing rediscovery rates in recent years and new methods capable of exploring the natural product chemical space more broadly and more efficiently is in urgent need. Chemical structure metagenomics as one such method is the theme of this Perspective. It emphasizes a chemical-structure-centered viewpoint toward natural product research. Key to chemical structure metagenomics is the ability to predict the structure of a natural product based on its biosynthetic gene sequences, which facilitated the discovery of numerous new bioactive molecules and helped uncover oversampled/underexplored niches of decades of BGF based discovery. While microbial nonribosomal peptides have been the focus of chemical structure metagenomics efforts thus far, it is in principle applicable to other natural product families. The future outlook of this new approach will also be discussed.
The Analysis of Work Motivation, Job Training and Non-Physical Work Environment on Employee Performance
Authors: Febrian Wenny Desty , Alfiyanti Selly
Published: November 2024

This summary aims to describe the impact of motivation, job training, and non-physical work environment on employee performance. This research explores how these factors affect the productivity and work results of individuals in an organization. By looking at the relationship between motivation, training, and work environment that is not related to the physical, this study aims to provide a deeper understanding of the factors that can improve employee performance. In this study, researchers used the Quantitative Research Method with a population of 40 permanent employees at the XYZ Slimming Center Clinic, Branch West Jakarta, using the associative analysis method and SPSS 26 software.
The Model of Leadership Style and Work Productivity
Authors: Syafri Muhammad
Published: November 2024

The purpose of this study was to determine (1) the effect of leadership of the Head of the West Java Provincial Education Office on the work productivity of employees of the West Java Provincial Education Office; (2) the effect of employee discipline on the work productivity of employees of the West Java Provincial Education Office; and (3) the effect of leadership and employee discipline on the work productivity of employees of the West Java Provincial Education Office. The research method used is descriptive and explanatory survey method using a sample of West Java Provincial Education Office employees as respondents, totaling 50 people. Based on the results of the study, the research results show that leadership in the West Java Provincial Education Office is generally good, but there are several things that need attention, namely the lack of smooth communication between employees and leaders, a less conducive work atmosphere, less attention to employee conditions and unclear task structures; employee discipline is considered quite good, but it is necessary to improve discipline, namely punctuality of attendance, obedience in following SOPs, and responsibility in maintaining work infrastructure; leadership affects employee work productivity, where the better leadership will result in better work productivity of employees of the West Java Provincial Education Office; discipline affects employee work productivity, so that the higher employee discipline, the higher work productivity will be; and leadership and employee discipline together affect employee work productivity, but when viewed partially it turns out that leadership is more dominant in influencing employee work productivity than employee discipline.
Lecanemab: A Breakthrough in Alzheimer’s Disease Treatment
Authors: Sireesha Vankodoth , Chaitanya N. , Ch Meghana. , Megana K.
Published: November 2024

Lecanemab is a groundbreaking treatment for Alzheimer’s disease, showing significant promise in slowing cognitive decline in patients with early-stage disease. Lecanemab is the most recent monoclonal antibody to target beta-amyloid and is licensed only for the treatment of mild cognitive impairment or mild dementia associated with Alzheimer's disease. Lecanemab represents a fresh approach to targeting the pathophysiology underlying the condition, and the encouraging outcomes of the Phase 3 trial provide hope to patients and their families. Although more research is need to determine lecanemab's safety and efficacy, the results of the Phase 3 trial suggest that it could greatly improve AD treatment options. This review explores the mechanism of action, clinical trial data, potential impacts, and future directions for this monoclonal antibody therapy.
Exploration of multiple enhancing pathways of digital economy development of city clusters using fuzzy-set qualitative comparative analysis
Authors: Cong Xuhui , Liu Bocong , Wang Liang , Su Peikun , Zhang Shenghui , Liu Yijia , Ustinovičius Leonas , Skibniewski Miroslaw J.
Published: November 2024

As a crucial catalyst for worldwide economic expansion, the digital economy (DE) has garnered widespread attention and has been regarded as crucial for the promotion of economic growth and innovation. The development of the DE brings both significant opportunities and challenges to city clusters. It enhances urban competitiveness, improves residents’ quality of life, and strengthens urban governance, which is of great significance for the development of city clusters. In this context, although previous studies comprehensively analyzed the advancement of the DE of certain cities and revealed their strategies, challenges, and successful experiences in the development of their DE, research on the determinants and enhancing pathways of the digital economy development of city clusters (DEDCC) is scant. As the core node of DE development, city clusters, as well as their potential and influence, cannot be ignored. Therefore, this study investigates the Shandong Peninsula Urban Agglomeration in China, constructs a theoretical analysis framework for the DEDCC, and utilizes fsQCA (Fuzzy-set Qualitative Comparative Analysis) to examine the complex causal processes of the DEDCC. The fsQCA method is utilized from a configurational perspective to explore the complex driving mechanisms of DEDCC. The objective is to investigate the pathways for enhancing DEDCC and provide insights for the DE development of other city clusters. Results reveal the following: (1) the reciprocal collaboration between market factors and fundamental factors should be examined to accelerate the high-quality DEDCC. (2) technological innovation (TI) capacity is a crucial determinant of the high-quality DEDCC. (3) the coordinated development of the market, the foundation, and TI should be prioritized to achieve the high-quality DEDCC.
JWST COMPASS: The 3–5 μm Transmission Spectrum of the Super-Earth L 98-59 c
Authors: Scarsdale Nicholas , Wogan Nicholas , Wakeford Hannah R. , Wallack Nicole L. , Batalha Natasha E. , Alderson Lili , Aguichine Artyom , Wolfgang Angie , Teske Johanna , Moran Sarah E. , López-Morales Mercedes , Kirk James , Gordon Tyler , Gao Peter , Batalha Natalie M. , Alam Munazza K. , Adams Redai Jea
Published: November 2024

We present a JWST Near-InfraRed Spectrograph (NIRSpec) transmission spectrum of the super-Earth exoplanet L 98-59 c. This small (R

p
= 1.385 ± 0.085R
⊕, M

p
= 2.22 ± 0.26 R
⊕), warm (T
eq = 553 K) planet resides in a multiplanet system around a nearby, bright (J = 7.933) M3V star. We find that the transmission spectrum of L 98-59 c is featureless at the precision of our data. We achieve precisions of 22 ppm in NIRSpec G395H’s NRS1 detector and 36 ppm in the NRS2 detector at a resolution R ∼ 200 (30 pixel wide bins). At this level of precision, we are able rule out primordial H2–He atmospheres across a range of cloud pressure levels up to at least ∼0.1 mbar. By comparison to atmospheric forward models, we also rule out atmospheric metallicities below ∼300× solar at 3σ (or, equivalently, atmospheric mean molecular weights below ∼10 g mol−1). We also rule out pure methane atmospheres. The remaining scenarios that are compatible with our data include a planet with no atmosphere at all, or higher-mean-molecular-weight atmospheres, such as CO2- or H2O-rich atmospheres. This study adds to a growing body of evidence suggesting that planets ≲1.5 R
⊕ lack extended atmospheres.
Characterization of Blue and Yellow Straggler Stars of Berkeley 39
Authors: Chand Komal , Rao Khushboo K. , Vaidya Kaushar , Panthi Anju
Published: November 2024

We characterize blue straggler stars (BSSs) and yellow straggler stars (YSSs) of the open cluster (OC) Berkeley 39 using multiwavelength observations including the Swift/Ultraviolet and Optical Telescope (UVOT). Our analysis also makes use of ultraviolet (UV) data from Galaxy Evolution Explorer, optical data from Gaia DR3 and Panoramic Survey Telescope and Rapid Response System, and infrared data from Two Micron All Sky Survey, Spitzer/IRAC, and Wide-field Infrared Survey Explorer. Berkeley 39 is a ∼6 Gyr old Galactic OC located at a distance of ∼4200 pc. We identify 729 sources as cluster members utilizing a machine-learning algorithm, ML-MOC, on Gaia DR3 data. Of these, 17 sources are classified as BSS candidates and four as YSS candidates. We construct multiwavelength spectral energy distributions (SEDs) of 16 BSS and two YSS candidates, within the Swift/UVOT field, to analyze their properties. Out of these, eight BSS candidates and both the YSS candidates are successfully fitted with single-component SEDs. Five BSS candidates show marginal excess in the near-UV (NUV; fractional residual <0.3 in all but one UVOT filter), whereas three BSS candidates show moderate to significant excess in the NUV (fractional residual >0.3 in at least two UVOT filters). We present the properties of the BSS and YSS candidates, estimated based on the SED fits.
A JWST MIRI MRS View of the η Tel Debris Disk and Its Brown Dwarf Companion
Authors: Chai Yiwei , Chen Christine H. , Worthen Kadin , Li Alexis , Sefilian Antranik A. , Balmer William , Hines Dean C. , Law David R. , Sargent B. A. , Wyatt Mark , Lu Cicero X. , Perrin Marshall D. , Rebollido Isabel , Rickman Emily , Sloan G. C.
Published: November 2024

We report JWST Mid-Infrared Instrument (MIRI) Medium Resolution Spectrograph (MRS) observations of the β Pic moving-group member, η Tel A, along with its brown dwarf binary companion, η Tel B. Following point-spread-function subtraction, we recover the spatially resolved flux from the debris disk around η Tel A, along with the position of the companion exterior to the disk. We present a new 5–26 μm epoch of spectroscopy for the disk, in which we discover a 20 μm silicate feature, and the first ever 11–21 μm spectrum of η Tel B, which indicates a bare photosphere. We derive a new epoch of relative astrometry for the companion, extending the baseline of measurements to 25 yr, and find that it is currently located near the apocenter of an eccentric long-period orbit. The companion’s orbit is close enough to the disk that it should significantly perturb the planetesimals within it, resulting in a detectable mid-IR pericenter glow and near alignment with the companion. Contrary to expectations, however, we find that the disk appears to be axisymmetric and potentially misaligned with the companion in the MIRI MRS data. We posit that this may be due to the presence of an additional, as-yet-undetected ∼0.7–30 M

J
planet orbiting interior to the disk, with a semimajor axis of ∼3–19 au.
A Young Super Star Cluster Powering a Nebula of Retained Massive Star Ejecta
Authors: Pascale Massimo , Dai Liang
Published: November 2024

We suggest that “Godzilla” of the lensed Sunburst galaxy (z = 2.37) is a young super star cluster powering a nebula of gravitationally trapped stellar ejecta. Employing Hubble Space Telescope photometry and spectroscopy from the Very Large Telescope (VLT) MUSE and VLT/X-Shooter, we infer the physical and chemical properties of the cluster and nebula, finding that Godzilla is young, 4–6 Myr; massive, 2 × 106
M
⊙ (1000/μ); of stellar metallicity, Z ≃ 0.25 Z
⊙; and has a compact far-UV component of ≲1 pc (1000/μ), where μ is the flux magnification factor. The gas is significantly enriched with N and He, indicating stellar wind material, and has highly elevated O relative to the stellar metallicity, indicating entrainment of core-collapse supernova (CCSN) ejecta. The high density, n
e ≃ 107−8 cm−3, implies a highly pressurized intracluster environment. We propose that the pressure results from CCSN-driven supersonic turbulence in warm, self-shielding gas, which has accumulated in the cluster center after runaway radiative cooling and is dense enough to resist removal by CCSNe. The nebula gas shows subsolar C/O, Ne/O, and Si/O, which may reflect the CCSN element yields for initial stellar masses >40 M
⊙. A comparison to element yield synthesis models for young star clusters shows that the gas abundances are consistent with complete retention and mixture of stellar winds and CCSN ejecta until the inferred cluster age. The inferred O and He enhancement may have implications for the formation of multiple stellar populations in globular clusters, as stars formed from this gas would contradict the observed abundances of second-population stars.
Why Do Semianalytic Models Predict Higher Scatter in the Stellar Mass–Halo Mass Relation Than Cosmological Hydrodynamic Simulations?
Authors: Porras-Valverde Antonio J. , Forbes John C. , Somerville Rachel S. , Stevens Adam R. H. , Holley-Bockelmann Kelly , Berlind Andreas A. , Genel Shy
Published: November 2024

Semianalytic models (SAMs) systematically predict higher-stellar mass scatter at a given halo mass than hydrodynamical simulations and most empirical models. Our goal is to investigate the physical origin of this scatter by exploring modifications to the physics in the SAM Dark Sage. We design two black hole formation models that approximate results from the IllustrisTNG 300-1 hydrodynamical simulation. In the first model, we assign a fixed black hole mass of 106
M
⊙ to every halo that reaches 1010.5
M
⊙. In the second model, we disregard any black hole growth as implemented in the standard Dark Sage model. Instead, we force all black hole masses to follow the median z = 0 black hole mass–halo mass relation in IllustrisTNG 300-1 with an imposed fixed scatter. We find that each model on its own does not significantly reduce the scatter in stellar mass. To explore the effects of active galactic nucleus (AGN) feedback in addition to black hole seeding, we replace the native Dark Sage AGN feedback model with a simple model where we turn off cooling for galaxies with black hole masses above 108
M
⊙. With the additional modification in AGN feedback, we find that the supermassive black hole seeding and fixed conditional distribution models create a significant reduction in the scatter in stellar mass at halo masses between 1011–14
M
⊙. These results suggest that AGN feedback in SAMs acts in a qualitatively different way than feedback implemented in cosmological simulations. Either or both may require substantial modification to match the empirically inferred scatter in the stellar mass–halo mass relation.
The Variability of Persistent Radio Sources of Fast Radio Bursts
Authors: Yang Ai Yuan , Feng Yi , Tsai Chao-Wei , Li Di , Shi Hui , Wang Pei , Yang Yuan-Pei , Zhang Yong-Kun , Niu Chen-Hui , Yao Ju-Mei , Cui Yu-Zhu , Su Ren-Zhi , Li Xiao-Feng , Zhang Jun-Shuo , Zhu Yu-Hao , Cotton W. D.
Published: November 2024

Over 700 bright millisecond-duration radio transients, known as fast radio bursts (FRBs), have been identified to date. Nevertheless, the origin of FRBs remains unknown. Two repeating FRBs (FRB 20121102A and FRB 20190520B) have been verified to be associated with persistent radio sources (PRSs), making them the best candidates to study the nature of FRBs. Monitoring the variability in PRSs is essential for understanding their physical nature. We conducted 22 observations of the PRSs linked to FRB 20121102A and FRB 20190520B using the Karl G. Jansky Very Large Array, to study their variability. We have observed significant flux variability for the PRSs of FRB 20121102A and FRB 20190520B, with a confidence level exceeding 99.99%, based on the observations covering the longest timescale recorded to date. The observed variability of the two PRSs exhibits no significant difference in amplitude across both short and long timescales. We found that the radio-derived star formation rates of the two FRB hosts are significantly higher than those measured by the optical H
α
emissions, indicating that their host galaxies are highly obscured or most radio emissions are not from star formation processes. The observed timescale of PRS flux evolution constrained the magnetic field of FRB 20121102A with B
∥ ≳ 1 mG and FRB 20190520B with B
∥ ≳ 0.1 mG.
Tracing the Propagation of Shocks in the Equatorial Ring of SN 1987A over Decades with the Hubble Space Telescope
Authors: Tegkelidis Christos , Larsson Josefin , Fransson Claes
Published: November 2024

The nearby SN 1987A offers a unique opportunity to investigate the complex shock interaction between the ejecta and circumstellar medium. We track the evolution of the optical hot spots within the equatorial ring (ER) by analyzing 33 Hubble Space Telescope imaging observations between 1994 and 2022. By fitting the ER with an elliptical model, we determine its inclination to be 42.°85 ± 0.°50 with its major axis oriented −6.°24 ± 0.°31 from the west. We identify 26 distinct hot spots across the ER, with additional ones emerging over time, particularly on the western side. The hot spots initially show high velocities ranging from 390 to 1660 km s−1, followed by a deceleration phase around day ∼ 8000. Subsequent velocities vary from 40 to 660 km s−1. The light curves of the hot spots reach maxima between 7000 and 9000 days, suggesting a connection with the deceleration. Many spots are spatially resolved and show elongation perpendicular to the direction of motion, indicative of a short cooling time. To explain these results, we propose that each hot spot comprises dense substructures embedded in less dense gas. The initial velocities are then phase velocities, where the break occurs when the blast wave leaves the ER, while the late velocities reflect the propagation of radiative shocks in the dense substructures. We estimate that the dense substructures have a volumetric filling factor of

∼
0.3

n
e

/

10
6

cm

−
3

−
2

%

and a total mass of

∼
0.24

n
e

/

10
6

cm

−
3

−
1

×

10

−
2

M
⊙

.
Holographic Beam Measurements of the Canadian Hydrogen Intensity Mapping Experiment (CHIME)
Authors: Amiri Mandana , Chakraborty Arnab , Foreman Simon , Halpern Mark , Hill Alex S , Hinshaw Gary , Landecker T. L. , MacEachern Joshua , Masui Kiyoshi W. , Mena-Parra Juan , Milutinovic Nikola , Newburgh Laura , Ordog Anna , Pen Ue-Li , Pinsonneault-Marotte Tristan , Reda Alex , Siegel Seth R. , Singh Saurabh , Wang Haochen , Wulf Dallas ,   The CHIME Collaboration
Published: November 2024

We present the first results of the holographic beam-mapping program for the Canadian Hydrogen Intensity Mapping Experiment (CHIME). We describe the implementation of a holographic technique as adapted for CHIME, and introduce the processing pipeline which prepares the raw holographic timestreams for analysis of beam features. We use data from six bright sources across the full 400–800 MHz observing band of CHIME to provide measurements of the copolar and cross-polar beam response in both amplitude and phase for all 1024 dual-polarized feeds in the array. In addition, we present comparisons with independent probes of the CHIME beam, which indicate the presence of polarized beam leakage. Holographic measurements of the beam have already been applied in science with CHIME, e.g., in estimating the detection significance of far-sidelobe fast radio bursts, and in validating the beam models used for CHIME’s first detections of 21 cm emission (in cross-correlation with measurements of large-scale structure from galaxy surveys and the Lyα forest). Measurements presented in this paper, and future holographic results, will provide a unique data set to characterize the CHIME beam and improve the experiment’s prospects for a detection of the baryon acoustic oscillation signal.
Equilibrium States of Galactic Atmospheres. I. The Flip Side of Mass Loading
Authors: Voit G. Mark , Pandya Viraj , Fielding Drummond B. , Bryan Greg L. , Carr Christopher , Donahue Megan , Oppenheimer Benjamin D. , Somerville Rachel S.
Published: November 2024

This paper presents a new framework for understanding the relationship between a galaxy and its circumgalactic medium (CGM). It focuses on how imbalances between heating and cooling cause either expansion or contraction of the CGM. It does this by tracking all of the mass and energy associated with a halo’s baryons, including their gravitational potential energy, even if feedback has pushed some of those baryons beyond the halo’s virial radius. We show how a star-forming galaxy’s equilibrium state can be algebraically derived within the context of this framework, and we analyze how the equilibrium star formation rate depends on supernova feedback. We consider the consequences of varying the mass loading parameter

η

M

≡

M

̇

wind

/

M

̇

*

relating a galaxy’s gas mass outflow rate (

M

̇

wind

) to its star formation rate (

M

̇

*

) and obtain results that challenge common assumptions. In particular, we find that equilibrium star formation rates in low-mass galaxies are generally insensitive to mass loading, and when mass loading does matter, increasing it actually results in more star formation because more supernova energy is needed to resist atmospheric contraction.
Proposed Importance of HOCO Chemistry: Inefficient Formation of CO2 from CO and OH Reactions on Ice Dust
Authors: Ishibashi Atsuki , Molpeceres Germán , Hidaka Hiroshi , Oba Yasuhiro , Lamberts Thanja , Watanabe Naoki
Published: November 2024

With the advent of JWST ice observations, dedicated studies on the formation reactions of detected molecules are becoming increasingly important. One of the most interesting molecules in interstellar ice is CO2. Despite its simplicity, the main formation reaction considered, CO + OH → CO2 + H through the energetic HOCO* intermediate on ice dust, is subject to uncertainty because it directly competes with the stabilization of HOCO as a final product, which is formed through energy dissipation of HOCO* to the water ice. When energy dissipation to the surface is effective during the reaction, HOCO can be a dominant product. In this study, we experimentally demonstrate that the major product of the reaction is indeed not CO2, but rather the highly reactive radical HOCO. The HOCO radical can later evolve into CO2 through H-abstraction reactions, but these reactions compete with additional reactions, leading to the formation of carboxylic acids (R-COOH). Our results highlight the importance of HOCO chemistry and encourage further exploration of the chemistry of this radical.
Exploration of Halo Substructures in Integrals-of-motion Space with Gaia Data Release 3
Authors: Liu Haoyang , Du Cuihua , Ye Dashuang , Zhang Jian , Deng Mingji
Published: November 2024

Using kinematic data from the Gaia Data Release 3 catalog, along with metallicity estimates robustly derived from Gaia BP/RP spectra, we have explored the Galactic stellar halo in search of both known and potentially new substructures. By applying the Hierarchical Density-Based Spatial Clustering of Applications with Noise clustering algorithm in integrals-of-motion space (i.e., E, L

z
, and L
⊥

=

L

x

2

+

L

y

2

), we identified five previously known substructures: Gaia-Sausage-Enceladus (GSE), Helmi streams, I'itoi and Sequoia, and the hot thick disk. We additionally found NGC 3201 and NGC 5139 in this work, and NGC 3201 shares similar distributions in phase space and metallicities to Arjuna, which possibly implies that they have the same origin. Three newly discovered substructures are Prograde Substructure 1 (PG1), Prograde Substructure 2 (PG2), and the Low Energy Group. PG1, with a higher V

ϕ
than typical GSE member stars, is considered as either a low-eccentricity and metal-rich part of GSE or part of the metal-poor disk. PG2, sharing kinematic similarities with Aleph, is thought to be its relatively highly eccentric component or the mixture of Aleph and the disk. The Low Energy Group, whose metal-poor component of metallicity distribution function has a mean value [M/H] ∼ −1.29 (compared to that of Heracles [M/H] ∼ −1.26), may have associations with Heracles.