bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of six-degree-of-freedom geometric errors of a translation stage using three absolute position encoders
Authors: Kim Jong-Ahn , Lee Jae Yong , Kang Chu-Shik , Woo Jae Heun
Published: January 2024

This paper presents an effective method for evaluating the geometric errors of precision translation stages. It quantifies the six degrees of freedom (6-DOF) absolute posture of a moving platform on the stage, where a phase-encoded binary scale is fixed. This evaluation is accomplished using multi-axis readings obtained from three absolute position encoders. The scale errors are compensated using a reversal method, and distances between the measurement points are obtained without the need for additional calibration processes. Therefore, the proposed method can achieve both high accuracy and efficiency, even when implemented for on-site calibration. The performance of the prototype measurement system was evaluated by measuring the 6-DOF geometrics errors of a translation stage over a 100 mm range, and the measurement results showed agreement with the reference data within ±0.3 μm and ±1.2″.
Study of nanoindentation behavior of NiCrCoAl medium entropy alloys under indentation process using molecular dynamics
Authors: Ngo Thi-Thuy Binh , Nguyen Van-Thuc , Fang Te-Hua
Published: January 2024

The mechanical properties and deformation behavior of CoCrNiAl medium entropy alloy (MEA) subjected to indentation by an indenter tooltip on the substrate are explored using molecular dynamics (MD) simulation. The study investigates the effects of alloy compositions, temperature variations, and ultra vibration (UV) on parameters, such as total force, shear strain, shear stress, hardness, reduced modulus, substrate temperature, phase transformation, dislocation length, and elastic recovery. The findings indicate that higher alloy compositions result in increased total force, hardness, and reduced modulus, with Ni-rich compositions demonstrating superior mechanical strength. Conversely, increasing alloy compositions lead to reduced von Mises stress (VMS), phase transformation, dislocation distribution, and dislocation length due to the larger atomic size of Ni compared to other primary elements. At elevated substrate temperatures, atoms exhibit larger vibration amplitudes and interatomic separations, leading to weaker atomic bonding and decreased contact force, rendering the substrate softer at higher temperatures. Additionally, higher initial substrate temperatures enhance atom kinetic energy and thermal vibrations, leading to reduced material hardness and increased VMS levels. Increasing vibration frequency enlarges the indentation area on the substrate’s surface, concentrating shear strain and VMS with vibration frequency. Higher vibration amplitude and frequency amplify force, shear strain, VMS, substrate temperature, and dislocation distribution. Conversely, lower vibration amplitude and frequency result in a smaller average elastic recovery ratio. Moreover, increased amplitude and frequency values yield an amorphous-dominated indentation region and increased proportions of hexagonal close-packed and body-centered cubic structures. Furthermore, this study also takes into account the evaluation of a material’s ability to recover elastically during the indentation process, which is a fundamental material property.
Discontinuous to continuous transition changeover and magnetic helicity reversal in helimagnet nanodisks under torsion
Authors: Wan Xuejin , Zhong Anruo , Hu Yangfan , Lan Xiaoming , Wang Biao
Published: January 2024

A magnetic skyrmion is topologically protected because it possesses a non-zero topological charge. As a result, the creation or annihilation of a magnetic skyrmion is thought to be initiated by a sudden reversal of local magnetization, and thus cannot occur continuously. Here, we show that this viewpoint is only partially correct by studying the creation and annihilation of an isolated skyrmion in a nanodisk suffering coupled magnetic field and mechanical torsion. It was found that at a proper magnetic field, the torsion-induced chiral stress field can change the helicity of the magnetization structure and create or annihilate isolated skyrmion in a continuous way. In the torsion-magnetic-field phase diagram, there appears a critical point, where the type of the topological transition changes from a discontinuous to a continuous one. It was further proved that the critical condition for the continuous transition is the softness of magnetization at the center.
The complete set of eigenstates in one type of N-multiple quantum wells
Authors: Wang Bin-Hao , Mao Ning , Zhao Li-Chen
Published: January 2024

We provide a method to obtain a complete set of eigenstates analytically and the corresponding eigenvalues in one type of N-multiple well potentials. The quantum well profile can be adjusted by many different parameters, which could be applicable to many different physical situations. We demonstrate explicitly the series of eigenstates in double and triple well potentials, which can be used to describe Josephson oscillations and other tunneling dynamics conveniently. The analytic solutions can be used to discuss the topological vector potential hidden in the eigenstates of quantum wells, through performing our recently proposed method of extending Dirac’s monopole theory to a complex plane. Our results suggest that each node of eigenfunctions corresponds to the merging of a pair of magnetic monopoles with inverse charge. The underlying monopoles can be used to determine the phase jump of a pure real wave function with nodes, as observed from an experimental viewpoint.
Electronic, optical, and transport properties of boron arsenide monolayers tailored with hydrogenation and halogenation
Authors: Cai Shuo , Yu Heng , Wei Dong , Wei Yifei , Ma Yaqiang , Li Yi , Tang Yanan , Dai Xianqi
Published: January 2024

In this study, density functional theory was used to demonstrate the effectiveness of a strategy involving chemical functionalization, specifically hydrogenation and halogenation, to tailor the electronic, optical, and transport properties of boron arsenide (BAs) monolayer. Compared to the half-functionalized BAs monolayers, the fully functionalized BAs monolayers (X–BAs–X, X = H, F, Cl, Br, and I) showed excellent stability. Moreover, functionalization not only disrupted the planar structure of BAs monolayer but also broke its mirror symmetry, enabling effective modulation of its bandgap and work function within the ranges of 0.29 eV–4.25 eV and 3.96 eV–6.98 eV, respectively. In addition, functionalization significantly enhanced optical absorption in the infrared and ultraviolet regions and induced the notable negative differential resistance effect in transmission devices. Thus, functionalization offers a versatile means for modulating the electronic, optical, and transport properties of BAs monolayers, thereby expanding their potential applications in optoelectronic and microelectronic devices.
A Galaxy Image Augmentation Method Based on Few-shot Learning and Generative Adversarial Networks
Authors: Yao Yiqi , Zhang Jinqu , Du Ping , Dong Shuyu
Published: January 2024

Galaxy morphology classifications based on machine learning are a typical technique to handle enormous amounts of astronomical observation data, but the key challenge is how to provide enough training data for the machine learning models. Therefore this article proposes an image data augmentation method that combines few-shot learning and generative adversarial networks. The Galaxy10 DECaLs data set is selected for the experiments with consistency, variance, and augmentation effects being evaluated. Three popular networks, including AlexNet, VGG, and ResNet, are used as examples to study the effectiveness of different augmentation methods on galaxy morphology classifications. Experiment results show that the proposed method can generate galaxy images and can be used for expanding the classification model’s training set. According to comparative studies, the best enhancement effect on model performance is obtained by generating a data set that is 0.5–1 time larger than the original data set. Meanwhile, different augmentation strategies have considerably varied effects on different types of galaxies. FSL-GAN achieved the best classification performance on the ResNet network for In-between Round Smooth Galaxies and Unbarred Loose Spiral Galaxies, with F1 Scores of 89.54% and 63.18%, respectively. Experimental comparison reveals that various data augmentation techniques have varied effects on different categories of galaxy morphology and machine learning models. Finally, the best augmentation strategies for each galaxy category are suggested.
Design and development of a single-laser 2D Thomson scattering measurement system for TS-6 merging tokamak/magnetic reconnection experiments
Authors: Kamiya S. , Yamaguchi H. , Kim J. , Akimitsu M. , Himeno S. , Tanabe H. , Narihara K. , Ono Y.
Published: January 2024

Nd:YAG Thomson scattering diagnostics is reliable measurement of electron temperature and density, but its 2D extension conventionally needs as many polychromators as measuring points and as many lasers as measuring paths. To reduce the numbers and costs, we designed and developed a single-laser 2D measurement system by use of multiple reflection and time-of-flight of laser light. A single laser pulse reflects between mirrors on both sides of the vacuum vessel and makes seven round trips, which enables measurement at m × 7 points with only m polychromators and a single laser. Here, we present the design to satisfy the resolution required for TS-6 merging tokamak and magnetic reconnection experiments and the system development, especially the time-separation of scattered light signals from different points with time-of-flight delays. The measured Thomson scattering signals from 7 × 2 points and the measured Raman scattered signals from points in four laser paths indicate the feasibility of Thomson scattering measurement at m × 4 points.
Non-iterative generation of binary amplitude holograms applied to holographic projection with digital micromirror devices
Authors: Hoyos-Peláez César Antonio , Velez-Zea Alejandro , Barrera-Ramírez John Fredy
Published: January 2024

In this work, we implement a fast non-iterative method for the generation of binary amplitude Fresnel holograms and demonstrate their application in a holographic projection scheme based on a digital micromirror device. To achieve this, we perform the binarization of phase-only holograms generated using an optimized Fresnel random phase. We analyze the quality of the resulting binary amplitude holograms and compare them with holograms obtained with the conventional iterative Fresnel algorithm as a function of the number of iterations and the propagation distance. Additionally, we evaluate the diffraction efficiency in both methods. We demonstrate that the holograms produced with our method present significantly advantages in computation speed without a significant reduction in the reconstruction quality. Both experimental and numerical results confirm the effectiveness of our proposal.
Development and comparison of primary facilities for traceable BSSRDF measurements
Authors: Santafé-Gabarda Pablo , Gevaux Lou , Ferrero Alejandro , Fontanot Tommaso , Audenaert Jan , Meuret Youri , Obein Gaël , Campos Joaquín
Published: January 2024

The bidirectional scattering-surface reflectance distribution function (BSSRDF) describes the radiance originated by the volume scattering and the surface reflectance of any position on the surface of a sample, when it is directionally irradiated at any other position. The present state of the technology for appearance rendering requires a more detailed physical description of translucent objects by traceable measurements of the BSSRDF. This work presents two primary facilities developed for traceable BSSRDF measurements by different measuring approaches. Their results on the same translucent samples have been compared and the achieved BSSRDF scale has been transferred to a commercial measuring system. This study highlights the problems of the different measuring instrument designs and provides the scientific community with more knowledge on the measurement of the BSSRDF, which will be crucial for future works on material appearance.
Probing the surface electrical properties of clay minerals with electrostatic force microscopy and kelvin probe force microscopy
Authors: Qin Zonghua , Nie Xin , Yu Wenbin , Yang Shuguang , Zhou Zongke , Yang Shuqin , Wan Quan
Published: January 2024

Many surface processes of clay minerals require in-depth understanding of their surface electrical properties, such as surface charge density, surface potential distribution, etc In this paper, electrostatic force microscopy (EFM) and Kelvin probe force microscopy (KPFM) were used to study the surface charge densities, surface potentials, electric field intensities, and electric field force gradients of three common clay minerals: kaolinite, montmorillonite, and illite. The properties were directly imaged, and the average surface permanent charge densities of kaolinite, montmorillonite, and illite were obtained to be −0.0060, −2.136, and −5.456 μC m−2, respectively. In addition, a good linear relationship was found between the surface charge densities obtained by KPFM and the layer charges calculated from the mineral chemical formulas of three clay minerals.
Natural rubber based elastocaloric solid-state refrigeration device: design and performances of a single stage system
Authors: Sion Marianne , Jay Jacques , Coativy Gildas , Komiya Atsuki , Sebald Gaël
Published: January 2024

The elastocaloric effect denotes the ability of a material to release or absorb heat when the material is stretched and released respectively. This effect may be used to design an alternative cooling device. This work focuses on the development of a cooling device using natural rubber (NR) as the elastocaloric material. It consists of a solid–solid heat exchange between a cyclically stretched elastocaloric material and two exchangers, respectively put in contact with the elastocaloric material when it is stretched or released. An experimental device was designed and tested in order to assess the temperature span and cooling power (PC) achievable by NR based single stage device. The effect of the thickness of the NR is also discussed. It is shown that it was possible to transfer nearly 60% of the heat absorption potential of the NR from the cold heat exchanger. From the measurements, the highest PC was found to be 390 mW (430 W kg−1) for a 600 µm thick sample, and 305 mW (540 W kg−1) for a 400 µm thick sample. The temperature span was found to be similar for both materials, ranging 1.5 °C–1.9 °C.
Chemical Profiling of Shen-Wu-Yi-Shen Tablets Using UPLC-Q-TOF-MS/MS and Its Quality Evaluation Based on UPLC-DAD Combined with Multivariate Statistical Analysis
Authors: Mei Yudan , Hu Yumei , Tao Xiaoqian , Shang Jing , Qian Mengyu , Suo Fengtai , Li Jifeng , Cao Liang , Wang Zhenzhong , Xiao Wei
Published: January 2024

Shen-Wu-Yi-Shen tablets (SWYST) is a traditional Chinese medicine prescription used for treating chronic kidney disease (CKD). This study aims to characterize the constituents in SWYST and evaluate the quality based on the quantification of multiple bioactive components. SWYST samples were analyzed with ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and a data-processing strategy. As a result, 215 compounds in SWYST were unambiguously identified or tentatively characterized, including 14 potential new compounds. Meanwhile, strategies based on characteristic fragments for rapid identification were summarized, indicating that the qualitative method is accurate and feasible. Notably, the glucose esters of laccaic acid D-type anthraquinone were first found and their fragmentation patterns were described by comparing that of O-glycoside isomers. Besides, based on comparisons of the cleavage ways of mono-acyl glucose with different acyl groups or acylation sites, differences in fragmentation pathways between 1,2-di-O-acyl glucose and 1,6-di-O-acyl glucose were proposed for the first time and verified by reference substances. In addition, a validated UPLC-DAD was established for the determination of 11 major bioactive components related to treatment of CKD (albiflorin, paeoniflorin, 2,3,5,4′-tetrahydroxy-stilbene-2-O-β-d-glucoside (TSG), 1-O-galloyl-2-O-cinnamoyl-β-d-glucose, emodin-8-O-β-d-glucoside, chrysophanol-O-β-d-glucoside, aloe-emodin, rhein, emodin, chrysophanol and physcion). Moreover, TSG and 1-O-galloyl-2-O-cinnamoyl-β-d-glucose were found as the quality markers related to the origins of SWYST based on multivariate statistical analysis. Conclusively, the findings in this work provide a feasible reference for further studies on quality research and mechanisms of action in treating CKD.
Sexual and Gender Minorities’ Vaccine Uptake and Behavioral Change in Response to the Mpox Outbreak in the United States: August 2022 Through November 2022
Authors: Grov Christian , Zohra Fatima , Mirzayi Chloe , Stief Matthew , D’Angelo Alexa B , Dearolf Michelle , Westmoreland Drew A , Carneiro Pedro , Nash Denis , Carrico Adam W
Published: January 2024

Background

In the summer of 2022, the United States faced a nationwide outbreak of mpox, with cases concentrated in sexual and gender minorities who have sex with men. Understanding rates of mpox vaccine uptake and concomitant behavioral change is essential to guide the implementation of targeted public health responses to the potential reemergence of mpox.

Methods

Between August 2022 and November 2022, 8551 individuals recruited via geosocial networking apps completed a brief survey that assessed mpox vaccine uptake, intentions to get a mpox vaccine, and behavioral change.

Results

In August, 17.4% of participants reported having received at least 1 dose of the mpox vaccine. By November, this prevalence estimate was 35.0%. Black participants were significantly less likely to be vaccinated, and vaccine hesitancy increased among Black participants over time. Among those who had not yet received a vaccination, the intention to get vaccinated decreased over time. We observed trends that coincided with the evolving outbreak, such as decreased worry about mpox and less engagement in risk reduction behaviors over time.

Conclusions

Despite a 2-fold increase in mpox vaccine uptake between August 2022 and November 2022 in sexual and gender minorities who have sex with men, disparities in vaccine uptake were observed among Black participants. Findings will guide the implementation of public health responses to the potential reemergence of mpox and other viral infectious diseases (eg, meningitis) with a specific focus on optimizing vaccine uptake in Black communities.
Histopathological myocardial changes in patients with severe aortic stenosis referred for surgical valve replacement: a cardiac magnetic resonance correlation study
Authors: Abecasis João , Lopes Pedro , Maltes Sergio , Santos Rita Reis , Ferreira António , Ribeiras Regina , Andrade Maria João , Uva Miguel Sousa , Gil Victor , Félix Ana , Ramos Sancia , Cardim Nuno
Published: January 2024

Aims

Myocardial fibrosis (MF) takes part in left ventricular (LV) remodelling in patients with aortic stenosis (AS), driving the transition from hypertrophy to heart failure. The structural changes that occur in this transition are not fully enlightened. The aim of this study was to describe histopathological changes at endomyocardial biopsy (EMB) in patients with severe AS referred to surgical aortic valve replacement (AVR) and to correlate them with LV tissue characterization from pre-operative cardiac magnetic resonance (CMR).

Methods and results

One-hundred fifty-eight patients [73 (68–77) years, 50% women] were referred for surgical AVR because of severe symptomatic AS, with pre-operative CMR (n = 143) with late gadolinium enhancement (LGE), T1, T2 mapping, and extracellular volume fraction (ECV) quantification. Intra-operative septal EMB was obtained in 129 patients. MF was assessed through Masson’s Trichrome histochemistry. Immunohistochemistry was performed for both inflammatory cells and extracellular matrix (ECM) characterization (Type I Collagen, Fibronectin, Tenascin C). Non-ischaemic LGE was present in 106 patients (67.1%) [median fraction: 5.0% (2.0–9.7)]. Native T1 was above normal [1053 ms (1024–1071)] and T2 within the normal range [39.3 ms (37.3–42.0)]. Median MF was 11.9% (6.54–19.97), with predominant type I collagen perivascular distribution (95.3%). Sub-endocardial cardiomyocyte ischaemic-like changes were identified in 45% of EMB. There was no inflammation, despite ECM remodelling expression. MF quantification at EMB was correlated with LGE mass (P = 0.008) but not with global ECV (P = 0.125).

Conclusion

Patients with severe symptomatic AS referred for surgical AVR have unspecific histological myocardial changes, including signs of cardiomyocyte ischaemic insult. ECM remodelling is ongoing, with MF heterogeneity. These features may be recognized by comprehensive CMR protocols. However, no single CMR parameter captures the burden of MF and histological myocardial changes in this setting.
Clinical and prognostic implications of left ventricular dilatation in heart failure
Authors: Kasa Gizem , Teis Albert , Juncà Gladys , Aimo Alberto , Lupón Josep , Cediel German , Santiago-Vacas Evelyn , Codina Pau , Ferrer-Sistach Elena , Vallejo-Camazón Nuria , López-Ayerbe Jorge , Bayés-Genis Antoni , Delgado Victoria
Published: January 2024

Aims

To assess the agreement between left ventricular end-diastolic diameter index (LVEDDi) and volume index (LVEDVi) to define LV dilatation and to investigate the respective prognostic implications in patients with heart failure (HF).

Methods and results

Patients with HF symptoms and LV ejection fraction (LVEF) < 50% undergoing cardiac magnetic resonance were evaluated retrospectively. LV dilatation was defined as LVEDDi or LVEDVi above the upper normal limit according to published reference values. Patients were followed up for the combined endpoint of cardiovascular death or HF hospitalization during 5 years. A total of 564 patients (median age 64 years; 79% men) were included. LVEDDi had a modest correlation with LVEDVi (r = 0.682, P < 0.001). LV dilatation was noted in 84% of patients using LVEDVi-based definition and in 73% using LVEDDi-based definition, whereas 20% of patients displayed discordant definitions of LV dilatation. During a median follow-up of 2.8 years, patients with both dilated LVEDDi and LVEDVi had the highest cumulative event rate (HR 3.00, 95% CI 1.15–7.81, P = 0.024). Both LVEDDi and LVEDVi were independently associated with the primary outcome (hazard ratio 3.29, 95%, P < 0.001 and 2.8, P = 0.009; respectively).

Conclusion

The majority of patients with HF and LVEF < 50% present both increased LVEDDi and LVEDVi whereas 20% show discordant linear and volumetric definitions of LV dilatation. Patients with increased LVEDDi and LVEDVi have the worst clinical outcomes suggesting that the assessment of these two metrics is needed for better risk stratification.
Sustaining essential health services in Lao PDR in the context of donor transition and COVID-19
Authors: Kim Eunkyoung , Park Yu Lee , Lo Ying-Ru , Keoprasith Bounserth , Panyakeo Suphab
Published: January 2024

Lao People’s Democratic Republic (Lao PDR) aims at graduating from least developed country status by 2026 and must increase the level of domestic financing for health. This paper examines how the government has prepared for the decline of external assistance and how donors have applied their transition approaches. Adapting a World Health Organization (WHO) framework, reflections and lessons were generated based on literature review, informal and formal consultations and focus group discussions with the Lao PDR government and development partners including budget impact discussion. The government has taken three approaches to transition from external to domestic funding: mobilizing domestic resources, increasing efficiency across programs and prioritization with a focus on strengthening primary health care (PHC). The government has increased gradually domestic government health expenditures as a share of the government expenditure from 2.6% in 2013 to 4.9% in 2019. The Ministry of Health has made efforts to design and roll out integrated service delivery of maternal, newborn, child, and adolescent health services, immunization and nutrition; integrated 13 information systems of key health programs into one single District Health Information Software 2; and prioritized PHC, which has led to shifting donors towards supporting PHC. Donors have revisited their aid policies designed to improve sustainability and ownership of the government. However, the government faces challenges in improving cross-programmatic efficiency at the operational level and in further increasing the health budget due to the economic crisis aggravated during Coronavirus disease 2019 (COVID-19). Working to implement donor transition strategies under the current economic situation and country challenges, calls into question the criteria used to evaluate transition. This criterion needs to include more appropriate indicators other than gross national income per capita, which does not reflect a country’s readiness and capacity of the health system. There should be a more country-tailored strategy and support for considering the context and system-wide readiness during donor transition.
Leveraging global investments for polio eradication to strengthen health systems’ resilience through transition
Authors: Tediosi Fabrizio , Villa Simone , Levison Darcy , Ekeman Ebru , Politi Claudio
Published: January 2024

Since the launch of the Global Polio Eradication Initiative in 1988, more than US$20 billion has been invested globally in polio eradication. The World Health Organization and its partners are currently supporting Member States to transition the functions used to eradicate polio to strengthen their health systems. This study analyses global polio activities through the lens of health systems and the Common Goods for Health (CGH). Polio activities include key health system functions such as surveillance and response systems and immunization, which are essential to maintaining resilient health systems. They also support essential functions such as policy development, planning, training and capacity building, which are often underfunded in many countries. To improve overall resilience, it is critical to continue to integrate these functions into local health systems so that the capacity built through the polio eradication programme can be used for broader public health purposes. It is vital that this integration process be tailored to each country’s unique health system context, rather than using a one-size-fits-all approach. While integration of all polio activities into local health systems is ideal, the transition to domestic financing may be coordinated with other global health financing mechanisms. This would reduce funding fragmentation and transaction costs, and allow for a focus on health system functions as a whole rather than just disease-specific efforts. The transition to domestic financing of polio activities could be staggered, prioritizing the transition to domestic funding for activities with limited global externalities, while seeking longer-term external funding for those that are global CGH.
Understanding China’s shifting priorities and priority-setting processes in development assistance for health
Authors: Guo Bingqing , Fan Victoria , Strange Austin , Grépin Karen Ann
Published: January 2024

Over the past two decades, China has become a distinctive and increasingly important donor of development assistance for health (DAH). However, little is known about what factors influence China’s priority-setting for DAH. In this study, we provide an updated analysis of trends in the priorities of Chinese DAH and compare them to comparable trends among OECD Development Assistance Committee (DAC) donors using data from the AidData’s Global Chinese Development Finance Dataset (2000–2017, version 2.0) and the Creditor Reporting System (CRS) database (2000–2017). We also analyse Chinese medical aid exports before and after the start of the COVID-19 pandemic using a Chinese Aid Exports Database. We further explore the potential factors influencing China’s shifting priority-setting processes by reviewing Chinese official documents following Walt and Gilson’s policy analysis framework (context–actors–process–content) and by testing our conjectures empirically. We find that China has become an important DAH donor to most regions if measured using project value, including but not limited to Africa. China has prioritized aid to African and Asian countries as well as to CRS subsectors that are not prioritized by DAC donors, such as medical services and basic health infrastructure. Chinese quarterly medical aid exports almost quintupled after the start of the COVID-19 pandemic. Noticeably, China has allocated more attention to Asia, eye diseases and infectious disease outbreaks over time. In contrast, the priority given to malaria has declined over the same period. Regarding factors affecting priority shifts, the outbreaks of SARS and Ebola, the launch of the Belt and Road Initiative and the COVID-19 pandemic appear to be important milestones in the timeline of Chinese DAH. Unlike stereotypes of China as a ‘lone wolf’ donor, our analysis suggests multilateral processes are influential in informing and setting Chinese DAH priorities.
The impact of shifts in PEPFAR funding policy on HIV services in Eastern Uganda (2015–21)
Authors: Zakumumpa Henry , Paina Ligia , Ssegujja Eric , Shroff Zubin Cyrus , Namakula Justin , Ssengooba Freddie
Published: January 2024

Although donor transitions from HIV programmes are increasingly common in low-and middle-income countries, there are limited analyses of long-term impacts on HIV services. We examined the impact of changes in President’s Emergency Plan for AIDS Relief (PEPFAR) funding policy on HIV services in Eastern Uganda between 2015 and 2021.We conducted a qualitative case study of two districts in Eastern Uganda (Luuka and Bulambuli), which were affected by shifts in PEPFAR funding policy. In-depth interviews were conducted with PEPFAR officials at national and sub-national levels (n = 46) as well as with district health officers (n = 8). Data were collected between May and November 2017 (Round 1) and February and June 2022 (Round 2). We identified four significant donor policy transition milestones: (1) between 2015 and 2017, site-level support was withdrawn from 241 facilities following the categorization of case study districts as having a ‘low HIV burden’. Following the implementation of this policy, participants perceived a decline in the quality of HIV services and more frequent commodity stock-outs. (2) From 2018 to 2020, HIV clinic managers in transitioned districts reported drastic drops in investments in HIV programming, resulting in increased patient attrition, declining viral load suppression rates and increased reports of patient deaths. (3) District officials reported a resumption of site-level PEPFAR support in October 2020 with stringent targets to reverse declines in HIV indicators. However, PEPFAR declared less HIV-specific funding. (4) In December 2021, district health officers reported shifts by PEPFAR of routing aid away from international to local implementing partner organizations. We found that, unlike districts that retained PEPFAR support, the transitioned districts (Luuka and Bulambuli) fell behind the rest of the country in implementing changes to the national HIV treatment guidelines adopted between 2017 and 2020. Our study highlights the heavy dependence on PEPFAR and the need for increasing domestic financial responsibility for the national HIV response.
Managing transitions from external assistance: cross-national learning about sustaining effective coverage
Authors: Shroff Zubin Cyrus , Sparkes Susan P , Paina Ligia , Skarphedinsdottir Maria , Gotsadze George , Zakumumpa Henry , Tang Kun , Perera Prasadini N , Yuan MyMai , Hanson Kara
Published: January 2024

The often-prominent role of external assistance in health financing in low- and middle-income countries raises the question of how such resources can enable the sustained or even expanded coverage of key health services and initiatives even after donor funding is no longer available. In response to this question, this paper analyses the process and outcomes of donor transitions in health—where countries or regions within countries are no longer eligible to receive grants or concessional loans from external sources based on eligibility criteria or change in donor policy. The comparative analysis of multiple donor transitions in four countries—China, Georgia, Sri Lanka and Uganda—identifies 16 factors related to policy actors, policy process, the content of donor-funded initiatives and the broader political-economic context that were associated with sustained coverage of previously donor supported interventions. From a contextual standpoint, these factors relate to favourable economic and political environments for domestic systems to prioritize coverage for donor-supported interventions. Clear and transparent transition processes also enabled a smoother transition. How the donor-supported initiatives and services were organized within the context of the overall health system was found to be critically important, both before and during the transition process. This includes a targeted approach to integrate, strengthen and align key elements of the governance, financing, input management and service delivery arrangements with domestic systems. The findings of this analysis have important implications for how both donors and country policy makers can better structure external assistance that enables sustained coverage regardless of the source of funding. In particular, donors can better support sustained coverage through supporting long-term structural and institutional reform, clear co-financing policies, ensuring alignment with local salary scales and engaging with communities to ensure a continued focus on equitable access post-transition.
Linking climate stressors to ecological processes in ecosystem models, with a case study from the Gulf of Alaska
Authors: Rovellini Alberto , Punt André E , Bryan Meaghan D , Kaplan Isaac C , Dorn Martin W , Aydin Kerim , Fulton Elizabeth A , Alglave Baptiste , Baker Matthew R , Carroll Gemma , Ferriss Bridget E , Haltuch Melissa A , Hayes Adam L , Hermann Albert J , Hernvann Pierre-Yves , Holsman Kirstin K , Liu Owen R , McHuron Elizabeth , Morzaria-Luna Hem Nalini , Moss Jamal , Surma Szymon , Weise Madison T
Published: January 2024

As climate stressors are impacting marine ecosystems and fisheries across the world, ecosystem models that incorporate environmental variables are increasingly used to inform ecosystem-based fisheries management. The assumptions around the mechanistic links between climate stressors and the biological processes in these models are important, but the implications for model outcomes of which stressors are captured and how they affect modeled biological processes are seldom explored. Using a whole-ecosystem model (Atlantis) for the Gulf of Alaska, we explore the effects of capturing physical (increased temperature) and biogeochemical (decreased low trophic level productivity) climate stressors, and disentangle the effects of each stressor on the productivity of forage fish, groundfish, and fish-eating seabirds. We then test the effects of alternative model specifications of temperature-driven habitat determination and bioenergetics. Increased temperature resulted in increased weight-at-age and higher natural mortality, while decreased productivity resulted in decreased weight-at-age and higher natural mortality. Model specification of temperature dependence of movement and spawning influenced model outcomes, and decoupling these processes from temperature led to overly optimistic biomass predictions. As the use of ecosystem models to inform fisheries management becomes more operational, we illustrate that the assumptions around the links between climate stressors and ecological processes influence model outcomes.
Deterministic and stochastic processes generating alternative states of microbiomes
Authors: Hayashi Ibuki , Fujita Hiroaki , Toju Hirokazu
Published: January 2024

The structure of microbiomes is often classified into discrete or semi-discrete types potentially differing in community-scale functional profiles. Elucidating the mechanisms that generate such “alternative states” of microbiome compositions has been one of the major challenges in ecology and microbiology. In a time-series analysis of experimental microbiomes, we here show that both deterministic and stochastic ecological processes drive divergence of alternative microbiome states. We introduced species-rich soil-derived microbiomes into eight types of culture media with 48 replicates, monitoring shifts in community compositions at six time points (8 media × 48 replicates × 6 time points = 2304 community samples). We then confirmed that microbial community structure diverged into a few state types in each of the eight medium conditions as predicted in the presence of both deterministic and stochastic community processes. In other words, microbiome structure was differentiated into a small number of reproducible compositions under the same environment. This fact indicates not only the presence of selective forces leading to specific equilibria of community-scale resource use but also the influence of demographic drift (fluctuations) on the microbiome assembly. A reference-genome-based analysis further suggested that the observed alternative states differed in ecosystem-level functions. These findings will help us examine how microbiome structure and functions can be controlled by changing the “stability landscapes” of ecological community compositions.
Tradeoffs between phage resistance and nitrogen fixation drive the evolution of genes essential for cyanobacterial heterocyst functionality
Authors: Kolan Dikla , Cattan-Tsaushu Esther , Enav Hagay , Freiman Zohar , Malinsky-Rushansky Nechama , Ninio Shira , Avrani Sarit
Published: January 2024

Harmful blooms caused by diazotrophic (nitrogen-fixing) Cyanobacteria are becoming increasingly frequent and negatively impact aquatic environments worldwide. Cyanophages (viruses infecting Cyanobacteria) can potentially regulate cyanobacterial blooms, yet Cyanobacteria can rapidly acquire mutations that provide protection against phage infection. Here, we provide novel insights into cyanophage:Cyanobacteria interactions by characterizing the resistance to phages in two species of diazotrophic Cyanobacteria: Nostoc sp. and Cylindrospermopsis raciborskii. Our results demonstrate that phage resistance is associated with a fitness tradeoff by which resistant Cyanobacteria have reduced ability to fix nitrogen and/or to survive nitrogen starvation. Furthermore, we use whole-genome sequence analysis of 58 Nostoc-resistant strains to identify several mutations associated with phage resistance, including in cell surface-related genes and regulatory genes involved in the development and function of heterocysts (cells specialized in nitrogen fixation). Finally, we employ phylogenetic analyses to show that most of these resistance genes are accessory genes whose evolution is impacted by lateral gene transfer events. Together, these results further our understanding of the interplay between diazotrophic Cyanobacteria and their phages and suggest that a tradeoff between phage resistance and nitrogen fixation affects the evolution of cell surface-related genes and of genes involved in heterocyst differentiation and nitrogen fixation.
Effects of Guizhi and Erxian Decoction on menopausal hot flashes: insights from the gut microbiome and metabolic profiles
Authors: Zong Yun , Mao Ting , Yao Peixun , Liang Jingtao , Lai Yawei , Chen Zhenyue , Chen Siyang , Huang Lei , Guo Yong , Zhu Min , Zhao Jingbing , Liu Yaqian , Li Yanfang , Guo Kaixin , Tang Hui , Ke Xuehong , Zhou Ying
Published: January 2024

Aims

To examine the influence of GED on the gut microbiota and metabolites using a bilateral ovariectomized (OVX) rat model. We tried to elucidate the underlying mechanisms of GED in the treatment of menopausal hot flashes.

Methods and results

16S rRNA sequencing, metabonomics, molecular biological analysis, and fecal microbiota transplantation (FMT) were conducted to elucidate the mechanisms by which GED regulates the gut microbiota. GED significantly reduced OVX-induced hot flashes and improved disturbances in the gut microbiota metabolites. Moreover, FMT validated that the gut microbiota can trigger hot flashes, while GED can alleviate hot flash symptoms by modulating the composition of the gut microbiota. Specifically, GED upregulated the abundance of Blautia, thereby increasing l(+)-ornithine levels for the treatment of menopausal hot flashes. Additionally, GED affected endothelial nitric oxide synthase and heat shock protein 70 (HSP70) levels in the hypothalamic preoptic area by changing the gut microbiota composition.

Conclusions

Our study illuminated the underlying mechanisms by which GED attenuated the hot flashes through modulation of the gut microbiota and explored the regulatory role of the gut microbiota on HSP70 expression in the preoptic anterior hypothalamus, thereby establishing a foundation for further exploration of the role of the gut–brain axis in hot flashes.
Forecasting the population development of within-season insect crop pests in sub-Saharan Africa: the Pest Risk Information Service
Authors: Day Charlotte , Murphy Sean T , Styles Jon , Taylor Bryony , Beale Tim , Holland William , Williams Frances , Shaw Andy , Finegold Cambria , Oronje MaryLucy , Oppong-Mensah Birgitta , Phiri Noah , Lowry Alyssa , Finch Elizabeth A , Mahony Josephine , Wood Suzy , Durocher-Granger Léna , Chacha Duncan , Maczey Norbert , Gonzalez-Moreno Pablo , Thomas Sarah E , Beeken Joe , Lewis Jane , Saldana Gerado Lopez , Duah Solomon , Bundi Mary , Wasilwa Lusike , Amata Ruth , Musila Ruth , Mutisya Daniel , Gitonga Christine K , Kalama Patrick , Nyasani Johnson O , Matimelo Matthews , Mgomba Henry , Gaitu Christopher , Ocloo Christopher , Adjei-Mensah Isaac , Ohene-Mensah Godfried , Nboyine Jerry Asalma , Susuwele Blessings
Published: January 2024

Smallholder farmers are the mainstay of the agricultural economies of sub-Saharan Africa (SSA), where they produce several crops, predominantly centered on maize. Smallholder productivity remains limited resulting from a range of confounding factors, but a primary cause is loss from pests and diseases, particularly insects. To improve productivity, recommendations for the mitigation of crop loss globally include early-warning and management systems for in-season indigenous pests. There are many early-warning systems in temperate regions; however, such systems are poorly established in Africa. This is in part due to the need for a combination of pest modeling, data handling and dissemination infrastructure, capacity, and resource provision. While each of these components is progressing in Africa, the means to successfully deploy such systems remain limited. To bridge this, the development of the Pest Risk Information Service (PRISE) began in 2017 for farmers in SSA. Implemented in Kenya, Ghana, Malawi, and Zambia, PRISE developed temperature-driven phenology models for major maize, bean, and tomato pests. Using downscaled and processed Earth Observation data to drive the models, PRISE partnered with African national agencies to communicate pre- and in-season pest alerts that forecast the time to act against key insect pests. Alerts were designed to be integrated into country-specific Good Agricultural Practice (GAP) recommendations to provide a complementary package to agricultural stakeholders. End line studies with farmers showed that those who received information about the target crops including PRISE pest forecasts, generally reported better outcomes in terms of reduced losses and increased incomes compared with farmers who did not.
Infectious Diseases Evaluation of the Child With Suspected Hemophagocytic Lymphohistiocytosis
Authors: Deza Leon Maria , Otto William R , Danziger-Isakov Lara , Kumar Ashish , Scaggs Huang Felicia
Published: January 2024

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of excessive and maladaptive inflammation. In this review, we discuss how the clinical and laboratory features of HLH overlap with infection and propose a diagnostic and treatment strategy to identify patients with infections mimicking HLH.
Energetic particles in the central starburst, disc, and halo of NGC253
Authors: Rephaeli Yoel , Sadeh Sharon
Published: January 2024

Detailed modelling of the spectro-spatial distributions of energetic electrons and protons in galactic discs and haloes of starburst galaxies (SBGs) is needed in order to follow their interactions with the magnetized interstellar medium and radiation fields, determine their radiative yields, and for estimating their residual spectral densities in intergalactic environments. We have developed a semi-analytical approach for calculating the particle spectro-spatial distributions in the disc and halo based on a diffusion model for particle propagation from acceleration sites in the central SB and disc regions, including all their relevant interaction modes. Important overall normalization of our models is based on previous modelling of the Galactic disc (with the galprop code), scaled to the higher star-formations rate in NGC253, and on spatially resolved radio measurements of the central SB and disc. These provide the essential input for determining the particle distributions and their predicted radiative yields in the outer disc and inner halo for a range of values of the key parameters that affect diffusion rate and energy losses. Results of our work clearly indicate that quantitative description of non-thermal emission in SBGs has to be based on modelling of the particle distributions in the entire disc, not just the central SB region.
On the sensitivity of weak gravitational lensing to the cosmic expansion function
Authors: Schmidt Christian F , Bartelmann Matthias
Published: January 2024

We analyse the functional derivative of the cosmic-shear power spectrum $C_\ell ^\gamma$ with respect to the cosmic expansion function. Our interest in doing so is two-fold: (i) In view of attempts to detect minor changes of the cosmic expansion function that may be due to a possibly time-dependent dark-energy density, we wish to know how sensitive the weak-lensing power spectrum is to changes in the expansion function. (ii) In view of recent empirical determinations of the cosmic expansion function from distance measurements, independent of specific cosmological models, we wish to find out how uncertainties in the expansion function translate to uncertainties in the cosmic-shear power spectrum. We find the following answers: relative changes of the expansion function are amplified by the cosmic-shear power spectrum by a factor ≈2–6, weakly depending on the scale factor where the change is applied, and the current uncertainty of one example for an empirically determined expansion function translates to a relative uncertainty of the cosmic-shear power spectrum of $\approx 10~{{\ \rm per\ cent}}$.