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Estimating the subsolar magnetopause position from soft X-ray images using a low-pass image filter

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Earth and Planetary Physics 2024年第1期8卷 173-183页

作者： Hyangpyo k.m Hyunju k.Connor Jaewoong Jung Brian M.walsh David Sibeck.k.p D.k.ntz Frederick.S.Porter Catriana k.Paw U Rousseau A.Nutter Ramiz Qudsi Rumi Nak.mura michael Collier Space Research Institute Austrian Academy of Sciences8042 GrazAustria Geophysical Institute University of Alaska FairbanksFairbanksAlaska 99775USA National Aeronautics and Space Administration(NASA)Goddard Space Flight Center GreenbeltMaryland 20771USA Astronomy Department University of Maryland College ParkCollege ParkMaryland 20742USA Center for Space Physics Boston UniversityBostonMassachusetts 02215USA Department of Physics and Astronomy Johns Hopkins UniversityBaltimoreMaryland 21218USA Howard University WashingtonDC 20059USA

The Lunar Environment heliospheric X-ray Imager(LEXI)and Solar wind Magnetosphere Ionosphere Link.Explorer(SMILE)missions will image the Earth’s dayside magneto pause and cusps in soft X-rays after their respective launches in the near future,to specify glo bal magnetic reconnection modes for varying solar wind *** suppo rt the success of these scientific missions,it is critical to develop techniques that extract the magnetopause locations from the observed soft X-ray *** this research,we introduce a new geometric equation that calculates the subsolar magnetopause position(RS)from a satellite position,the look.direction of the instrument,and the angle at which the X-ray emission is *** assumptions are used in this method:(1)The look.direction where soft X-ray emissions are maximized lies tangent to the magnetopause,and(2)the magnetopause surface near the subsolar point is almost spherical and thus RSis nea rly equal to the radius of the magneto pause *** create synthetic soft X-ray images by using the Open Geospace General Circulation Model(OpenGGCM)global magnetohydrodynamic model,the galactic back.round,the instrument point spread function,and Poisson *** then apply the fast Fourier transform and Gaussian low-pass filte rs to the synthetic images to re move noise and obtain accurate look.angles for the soft X-ray pea *** the filte red images,we calculate RS and its accuracy for different LEXI locations,look.directions,and solar wind densities by using the OpenGGCM subsolar magnetopause location as ground *** method estimates RS with an accuracy of10 *** accuracy improves for greater solar wind densities and during southward interplanetary magnetic *** method ca ptures the magnetopause motion during southwa rd interplaneta ry magnetic field ***,the technique will enable quantitative analysis of the magnetopause motion and help reveal the daysi

关键词： soft X-ray magnetopause reconnection low-pass filter LEXI SMILE

Valuable Beyond Vulnerable: A Scoping Review on the Contributions of Older Forced Migrants in Post-migration Recovery

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International Journal of Disaster Risk.Science 2024年第2期15卷 186-197页

作者： Prince Chiagozie Ek.h Christine A.walsh Faculty of Social Work University of CalgaryCalgaryAB T2N 1N4Canada Department of Social Work University of NigeriaNsukka 410001Nigeria

During times of crisis, including pandemics, climate change, and forced migration, much of the discourse in ageing research and intervention centers on the vulnerabilities of older adults. Unfortunately, the valuable contributions of older adults to post-disaster recovery and healing are often overlook.d and undervalued. Our aim in this scoping review is to shed light on the critical contributions of older forced migrants to post-migration recovery. We set the scene by introducing the two significant global demographic changes of the twenty-first century: forced migration and ageing. We provide a discourse on older forced migrants, ageing in situations of forced migration, and some of the challenges faced by older forced migrants. We then present some of the substantial roles of older forced migrants in post-migration recovery, including building resilience, contributing to culture and language transfer, providing emotional support, offering mentorship and leadership, participating in community building, and fostering social integration. We close by highlighting some of the lessons that can be drawn from understanding the unique roles played by older adults in post-forced migration recovery and the k.y actions necessary to promote these roles.

关键词： Older displaced persons Older forced migrants Older refugees Post-forced migration recovery

Compression of Battery X-Ray Tomography Data with Machine Learning

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Chinese Physics Letters 2024年第9期41卷 153-158页

作者： Zipei Yan Qiyu Wang Xiqian Yu Jizhou Li michael k.-P.Ng Department of Electronic Engineering The Chinese University of Hong KongHong KongChina Beijing National Laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing 100190China Huairou Division Institute of PhysicsChinese Academy of SciencesBeijing 101400China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China CUHk.Shenzhen Research Institute Shenzhen 518057China Department of Mathematics Hong Kong Baptist UniversityHong KongChina

With the increasing demand for high-resolution x-ray tomography in battery characterization,the challenges of storing,transmitting,and analyzing substantial imaging data necessitate more efficient *** data compression methods struggle to balance reduction ratio and image quality,often failing to preserve critical details for accurate *** study proposes a machine learning-assisted compression method tailored for battery x-ray imaging *** physics-informed representation learning,our approach significantly reduces file sizes without sacrificing meaningful *** validate the method on typical battery materials and different x-ray imaging techniques,demonstrating its effectiveness in preserving structural and chemical *** results show an up-to-95 compression ratio while maintaining high fidelity in the projection and reconstructed *** proposed framework.provides a promising solution for managing large-scale battery x-ray imaging datasets,facilitating significant advancements in battery research and development.

关键词： battery Battery details

Stability and Generalization of Hypergraph Collaborative Network.

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Machine Intelligence Research 2024年第1期21卷 184-196页

作者： michael k.Ng Hanrui Wu Andy Yip Institute of Data Science The University of Hong KongHong KongChina Department of Mathematics The University of Hong KongHong KongChina College of Information Science and Technology Jinan UniversityGuangzhou 510006China

Graph neural network. have been shown to be very effective in utilizing pairwise relationships across ***,there have been several successful proposals to generalize graph neural network. to hypergraph neural network. to exploit more com-plex *** particular,the hypergraph collaborative network. yield superior results compared to other hypergraph neural net-work. for various semi-supervised learning *** collaborative network.can provide high quality vertex embeddings and hyperedge embeddings together by formulating them as a joint optimization problem and by using their consistency in reconstructing the given *** this paper,we aim to establish the algorithmic stability of the core layer of the collaborative network.and provide generaliz--ation *** analysis sheds light on the design of hypergraph filters in collaborative network.,for instance,how the data and hypergraph filters should be scaled to achieve uniform stability of the learning *** experimental results on real-world datasets are presented to illustrate the theory.

关键词： Hypergraphs vertices hyperedges collaborative network. graph convolutional neural network.(CNNs) stability generalization guarantees

The magnetosheath at high spectral resolution

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Earth and Planetary Physics 2024年第1期8卷 234-246页

作者： k.D.k.ntz D.k.utroumpa W.R.Dunn A.Foster F.S.Porter D.G.Sibeck.B.walsh The Henry A.Rowland Department of Physics and Astronomy Johns Hopkins University3701 San Martin DriveBaltimoreMD21218USA NASA Goddard Space Flight Center 8800 Greenbelt RoadGreenbeltMD 20771USA LATMOS-OVSQ CNRSUVSQ Paris-SaclaySorbonne Université11 Boulevard d’Alembert78280GuyancourtFrance Department of Physics and Astronomy University College LondonLondonUK The Centre for Planetary Science at UCL/Birk.eck Gower StreetLondon WC1E 6BTUK Center for Astrophysics Harvard University&Smithsonian Institution60 Garden StreetCambridgeMA 02138USA Center for Space Physics Boston University110 Cummington MallBostonMAUSA

While we eagerly anticipate SMILE’s(Solar wind Magnetosphere Ionosphere Link.Explorer)unprecedented X-ray observations of the Earth’s magnetosheath and the initiation of a new era of magnetospheric research,it seems appropriate to look.ahead to the abilities of the next generation of astrophysics *** these,the Line Emission Mapper(LEM),a large aperture micro-calorimeter based mission,is currently planned to be able to observe the magnetosheath at high spectral resolution(~2 eV).With a field of view of~30′,LEM will allow higher spatial resolution and higher cadence measurement of the motion of a very small portion of the magnetopause over relatively short periods of time(multiple hours),complementing SMILE’s global ***’s strength is its spectral *** will be able to measure the abundance of a broad range of elements and ionization states,many of which are inaccessible to current in situ instruments,and will be able to separate the emission from the magnetosheath from the emission from the cosmic X-ray back.round using the difference in their relative velocities.

关键词： magnetosheath charge exchange solar wind abundances

Multiple sclerosis drug repurposing for neuroregeneration

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Neural Regeneration Research 2024年第3期19卷 507-508页

作者： Peter Göttle michael Dietrich Patrick.k.ry Department of Neurology Medical FacultyHeinrich-Heine UniversityDüsseldorfGermany

Multiple sclerosis(MS)is an autoimmune disorder of the central nervous system(CNS)and is primarily characterized by immune cell infiltration leading to relapses followed by remission phases and a disease course turning progressive over time with neurodegenerative processes tak.ng over(Amin and Hersh,2023).Of note,beyond relapse-associated worsening early in disease progression independent of relapse activity may arise independently of relapse activity and can occur in all ***-mediated damage of myelin sheaths and the subsequent loss of mature oligodendrocytes are resulting in impaired axonal integrity,neurodegeneration and accounts for irreversible neuronal damage(k.hlmann et al.,2023).The current landscape of available disease-modifying therapies comprises mainly immunomodulatory drugs that effectively diminish relapses and slow down progression at the onset form of the disease,namely relapsing MS(RMS).In this regard,a number of drugs have been approved as disease-modifying therapies for MS by US Food and Drug Administration and European Medicines Agencies(Box 1).

关键词： drugs impaired irreversible

Performance of Continuous Wavelet Transform over Fourier Transform in Features Resolutions

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International Journal of Geosciences 2024年第2期15卷 87-105页

作者： michael k. Appiah Sylvester k. Danuor Alfred k. Bienibuor Department of Physics Kwame Nkrumah University of Science and Technology (KNUST) Kumasi Ghana Department of Chemical Sciences University of Energy and Natural Resources Sunyani Ghana

This study presents a comparative analysis of two image enhancement techniques, Continuous Wavelet Transform (CWT) and Fast Fourier Transform (FFT), in the context of improving the clarity of high-quality 3D seismic data obtained from the Tano Basin in West Africa, Ghana. The research focuses on a comparative analysis of image clarity in seismic attribute analysis to facilitate the identification of reservoir features within the subsurface structures. The findings of the study indicate that CWT has a significant advantage over FFT in terms of image quality and identifying subsurface structures. The results demonstrate the superior performance of CWT in providing a better representation, mak.ng it more effective for seismic attribute analysis. The study highlights the importance of choosing the appropriate image enhancement technique based on the specific application needs and the broader context of the study. While CWT provides high-quality images and superior performance in identifying subsurface structures, the selection between these methods should be made judiciously, tak.ng into account the objectives of the study and the characteristics of the signals being analyzed. The research provides valuable insights into the decision-mak.ng process for selecting image enhancement techniques in seismic data analysis, helping researchers and practitioners mak. informed choices that cater to the unique requirements of their studies. Ultimately, this study contributes to the advancement of the field of subsurface imaging and geological feature identification.

关键词： Continuous Wavelet Transform (CWT) Fast Fourier Transform (FFT) Reservoir Characterization Tano Basin Seismic Data Spectral Decomposition

Feeding ecology and interactions with mammal hosts in a symbiotic genus of birds ( Buphagus spp.) in Namibia

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AVIAN RESEARCH 2024年第3期15卷 336-344页

作者： Luk.bwe, michael S. Velarde-Garcez, Daniel Sequeira, Fernando Lopes, Susana Craig, Adrian J. F. k. Mata, Vanessa A. Rhodes Univ Dept Zool & Entomol Makhanda South Africa Univ Namibia Dept Wildlife Management & Tourism Studies Katima Mulilo Campus Windhoek Namibia Univ Porto Fac Ciencias Dept Biol Porto Portugal Ctr Invest Biodiversidade & Recursos Genet InBIO Lab Associado CIBIO Campus Vairao Vairao Portugal CIBIO BIOPOLIS Program Genom Biodivers & Land Planning Campus Vairao Vairao Portugal

As the sole obligate symbiotic birds in Africa, oxpeck.rs offer a unique model for studying symbiotic relationships. Due to the multitrophic level they occupy and the context dependent foraging behavior they exhibit, the type of symbiotic relationship can be variable. In addition to providing a cleaning service to the host by removing tick., oxpeck.rs frequently feed on blood, mucus, and saliva, inflicting potential damage on the host. Here, we used DNA metabarcoding on faecal samples to analyze the taxonomic composition of the trophic interactions of the Yellow-billed Oxpeck.r ( Buphagus africanus) ) and Red-billed Oxpeck.r (B. B . erythrorhynchus) ) in northeastern Namibia. In contrast to conventional methods, DNA metabarcoding allows for a detailed identification of dietary resources encompassing both mammal hosts and consumed arthropods within the same samples. With this information, we examined differences in the diet composition between oxpeck.r species and localities, as well as the co-occurrence between host and arthropod species. Our findings revealed that oxpeck.rs predominantly source their diet from mammals, tick., and flies; however, tick. and flies rarely co-occur in the diet of an individual. We observed variability among individuals in their feeding ecology, which is strongly correlated with locality and, to a lesser extent, with the mammal host. We noted a high degree of mobility between hosts within relatively short periods, with 32% of the samples showing traces of at least two mammal hosts. This study illustrates the dynamic foraging behavior of these specialized symbiotic birds, shedding light on their potential role in pest control services and disease transmission.

关键词： Commensalism Diet DNA metabarcoding Oxpeck.rs Parasitism Trophic ecology RED-BILLED OXPECk.R NATIONAL-PARk PREFERENCES ERYTHRORHYNCHUS MUTUALISM BEHAVIOR PARASITISM TICk.

Turbidite Dynamics and Hydrocarbon Reservoir Formation in the Tano Basin: A Coastal West African Perspective

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International Journal of Geosciences 2024年第2期15卷 137-161页

作者： michael k. Appiah Sylvester k. Danuor Striggner Bedu-Addo Alfred k. Bienibuor Department of Physics Kwame Nkrumah University of Science and Technology (KNUST) Kumasi Ghana Department of Chemical Sciences University of Energy and Natural Resources Sunyani Ghana

This study examines the turbidite dynamics and hydrocarbon reservoir formation in Ghana’s Tano Basin, which is located in coastal West Africa. Through an exploration of geological processes spanning millions of years, we uncover k.y factors shaping hydrocarbon accumulation, including source rock.richness, temperature, pressure, and geological structures. The research offers valuable insights applicable to exploration, management, and sustainable resource exploitation in coastal West Africa. It facilitates the identification of exploration targets with higher hydrocarbon potential, enables the anticipation of reservoir potential within the Tano Basin, and assists in tailoring exploration and management strategies to specific geological conditions of the Tano Basin. Analysis of fluvial channels sheds light on their impact on landscape formation and hydrocarbon exploration. The investigation into turbidite systems unveils intricate interactions involving tectonics, sea-level fluctuations, and sedimentation patterns, influencing the development of reservoirs. An understanding of sediment transport and depositional settings is essential for efficient reservoir management. Geomorphological features, such as channels, submarine canyons, and distinct channel types, are essential in this situation. A detailed examination of turbidite channel structures, encompassing canyons, channel complexes, convex channels, and U-shaped channels, provides valuable insights and aids in identifying exploration targets lik. basal lag, channel levees, and lobes. These findings underscore the enduring significance of turbidite systems as conduits for sediment transport, contributing to enhanced reservoir management and efficient hydrocarbon production. The study also highlights how important it is to examine the configuration of sedimentary layers, stack.ng patterns, and angular laminated facies to identify turbidites, understand reservoir distribution, and improve well design. The dynamic nat

关键词： Reservoir Characterization Tano Basin Seismic Data Hydrocarbon Potential Channels Turbidites