npj Microgravity最新文献_第8页

Machine learning workflow for edge computed arrhythmia detection in exploration class missions. 探索类任务中边缘计算心律失常检测的机器学习工作流程。

IF 4.4 1区物理与天体物理

npj Microgravity Pub Date : 2024-06-22 DOI: 10.1038/s41526-024-00409-0

Cyril Mani, Tanya S Paul, Patrick M Archambault, Alexandre Marois

{"title":"Machine learning workflow for edge computed arrhythmia detection in exploration class missions.","authors":"Cyril Mani, Tanya S Paul, Patrick M Archambault, Alexandre Marois","doi":"10.1038/s41526-024-00409-0","DOIUrl":"10.1038/s41526-024-00409-0","url":null,"abstract":"Deep-space missions require preventative care methods based on predictive models for identifying in-space pathologies. Deploying such models requires flexible edge computing, which Open Neural Network Exchange (ONNX) formats enable by optimizing inference directly on wearable edge devices. This work demonstrates an innovative approach to point-of-care machine learning model pipelines by combining this capacity with an advanced self-optimizing training scheme to classify periods of Normal Sinus Rhythm (NSR), Atrial Fibrillation (AFIB), and Atrial Flutter (AFL). 742 h of electrocardiogram (ECG) recordings were pre-processed into 30-second normalized samples where variable mode decomposition purged muscle artifacts and instrumentation noise. Seventeen heart rate variability and morphological ECG features were extracted by convoluting peak detection with Gaussian distributions and delineating QRS complexes using discrete wavelet transforms. The decision tree classifier's features, parameters, and hyperparameters were self-optimized through stratified triple nested cross-validation ranked on F1-scoring against cardiologist labeling. The selected model achieved a macro F1-score of 0.899 with 0.993 for NSR, 0.938 for AFIB, and 0.767 for AFL. The most important features included median P-wave amplitudes, PRR20, and mean heart rates. The ONNX-translated pipeline took 9.2 s/sample. This combination of our self-optimizing scheme and deployment use case of ONNX demonstrated overall accurate operational tachycardia detection.","PeriodicalId":54263,"journal":{"name":"npj Microgravity","volume":"10 1","pages":"71"},"PeriodicalIF":4.4,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11193813/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141441152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Weightlessness leads to an increase granulosa cells in the growing follicle. 失重会导致生长卵泡中的颗粒细胞增加。

IF 4.4 1区物理与天体物理

npj Microgravity Pub Date : 2024-06-22 DOI: 10.1038/s41526-024-00413-4

Anna Yu Kikina, Mariia S Matrosova, Elena Yu Gorbacheva, Ksenia K Gogichaeva, Konstantin A Toniyan, Valery V Boyarintsev, Oleg V Kotov, Irina V Ogneva

引用次数: 0

Physical exercise restores adult neurogenesis deficits induced by simulated microgravity. 体育锻炼可恢复模拟微重力导致的成人神经发生缺陷。

IF 4.4 1区物理与天体物理

npj Microgravity Pub Date : 2024-06-21 DOI: 10.1038/s41526-024-00411-6

Alexandra Gros, Fandilla Marie Furlan, Vanessa Rouglan, Alexandre Favereaux, Bruno Bontempi, Jean-Luc Morel

{"title":"Physical exercise restores adult neurogenesis deficits induced by simulated microgravity.","authors":"Alexandra Gros, Fandilla Marie Furlan, Vanessa Rouglan, Alexandre Favereaux, Bruno Bontempi, Jean-Luc Morel","doi":"10.1038/s41526-024-00411-6","DOIUrl":"10.1038/s41526-024-00411-6","url":null,"abstract":"Cognitive impairments have been reported in astronauts during spaceflights and documented in ground-based models of simulated microgravity (SMG) in animals. However, the neuronal causes of these behavioral effects remain largely unknown. We explored whether adult neurogenesis, known to be a crucial plasticity mechanism supporting memory processes, is altered by SMG. Adult male Long-Evans rats were submitted to the hindlimb unloading model of SMG. We studied the proliferation, survival and maturation of newborn cells in the following neurogenic niches: the subventricular zone (SVZ)/olfactory bulb (OB) and the dentate gyrus (DG) of the hippocampus, at different delays following various periods of SMG. SMG exposure for 7 days, but not shorter periods of 6 or 24 h, resulted in a decrease of newborn cell proliferation restricted to the DG. SMG also induced a decrease in short-term (7 days), but not long-term (21 days), survival of newborn cells in the SVZ/OB and DG. Physical exercise, used as a countermeasure, was able to reverse the decrease in newborn cell survival observed in the SVZ and DG. In addition, depending on the duration of SMG periods, transcriptomic analysis revealed modifications in gene expression involved in neurogenesis. These findings highlight the sensitivity of adult neurogenesis to gravitational environmental factors during a transient period, suggesting that there is a period of adaptation of physiological systems to this new environment.","PeriodicalId":54263,"journal":{"name":"npj Microgravity","volume":"10 1","pages":"69"},"PeriodicalIF":4.4,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11192769/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141437789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dry immersion rapidly disturbs iron metabolism in men and women: results from the VIVALDI studies. 干浸法迅速干扰男性和女性的铁代谢：VIVALDI 研究的结果。

IF 5.1 1区物理与天体物理

npj Microgravity Pub Date : 2024-06-15 DOI: 10.1038/s41526-024-00399-z

Mathieu Horeau, Nastassia Navasiolava, Angelique Van Ombergen, Marc-Antoine Custaud, Adrien Robin, Martine Ropert, Inês Antunes, Marie-Pierre Bareille, Rebecca Billette De Villemeur, Guillemette Gauquelin-Koch, Frédéric Derbré, Olivier Loréal

引用次数: 0

Influence of the spaceflight environment on macrophage lineages. 太空飞行环境对巨噬细胞系的影响

IF 5.1 1区物理与天体物理

npj Microgravity Pub Date : 2024-06-11 DOI: 10.1038/s41526-023-00293-0

Rocky An, Virginia Katherine Blackwell, Bijan Harandi, Alicia C Gibbons, Olivia Siu, Iris Irby, Amy Rees, Nadjet Cornejal, Kristina M Sattler, Tao Sheng, Nicholas C Syracuse, David Loftus, Sergio R Santa Maria, Egle Cekanaviciute, Sigrid S Reinsch, Hami E Ray, Amber M Paul

{"title":"Influence of the spaceflight environment on macrophage lineages.","authors":"Rocky An, Virginia Katherine Blackwell, Bijan Harandi, Alicia C Gibbons, Olivia Siu, Iris Irby, Amy Rees, Nadjet Cornejal, Kristina M Sattler, Tao Sheng, Nicholas C Syracuse, David Loftus, Sergio R Santa Maria, Egle Cekanaviciute, Sigrid S Reinsch, Hami E Ray, Amber M Paul","doi":"10.1038/s41526-023-00293-0","DOIUrl":"10.1038/s41526-023-00293-0","url":null,"abstract":"Spaceflight and terrestrial spaceflight analogs can alter immune phenotypes. Macrophages are important immune cells that bridge the innate and adaptive immune systems and participate in immunoregulatory processes of homeostasis. Furthermore, macrophages are critically involved in initiating immunity, defending against injury and infection, and are also involved in immune resolution and wound healing. Heterogeneous populations of macrophage-type cells reside in many tissues and cause a variety of tissue-specific effects through direct or indirect interactions with other physiological systems, including the nervous and endocrine systems. It is vital to understand how macrophages respond to the unique environment of space to safeguard crew members with appropriate countermeasures for future missions in low Earth orbit and beyond. This review highlights current literature on macrophage responses to spaceflight and spaceflight analogs.","PeriodicalId":54263,"journal":{"name":"npj Microgravity","volume":"10 1","pages":"63"},"PeriodicalIF":5.1,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11166655/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141307411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bioreactor development for skeletal muscle hypertrophy and atrophy by manipulating uniaxial cyclic strain: proof of concept. 通过操纵单轴循环应变开发骨骼肌肥大和萎缩的生物反应器：概念验证。

IF 5.1 1区物理与天体物理

npj Microgravity Pub Date : 2024-06-11 DOI: 10.1038/s41526-023-00320-0

Khaled Y Kamal, Mariam Atef Othman, Joo-Hyun Kim, John M Lawler

{"title":"Bioreactor development for skeletal muscle hypertrophy and atrophy by manipulating uniaxial cyclic strain: proof of concept.","authors":"Khaled Y Kamal, Mariam Atef Othman, Joo-Hyun Kim, John M Lawler","doi":"10.1038/s41526-023-00320-0","DOIUrl":"10.1038/s41526-023-00320-0","url":null,"abstract":"Skeletal muscles overcome terrestrial, gravitational loading by producing tensile forces that produce movement through joint rotation. Conversely, the microgravity of spaceflight reduces tensile loads in working skeletal muscles, causing an adaptive muscle atrophy. Unfortunately, the design of stable, physiological bioreactors to model skeletal muscle tensile loading during spaceflight experiments remains challenging. Here, we tested a bioreactor that uses initiation and cessation of cyclic, tensile strain to induce hypertrophy and atrophy, respectively, in murine lineage (C2C12) skeletal muscle myotubes. Uniaxial cyclic stretch of myotubes was conducted using a StrexCell® (STB-1400) stepper motor system (0.75 Hz, 12% strain, 60 min day^-1). Myotube groups were assigned as follows: (a) quiescent over 2- or (b) 5-day (no stretch), (c) experienced 2-days (2dHY) or (d) 5-days (5dHY) of cyclic stretch, or (e) 2-days of cyclic stretch followed by a 3-day cessation of stretch (3dAT). Using ß-sarcoglycan as a sarcolemmal marker, mean myotube diameter increased significantly following 2dAT (51%) and 5dAT (94%) vs. matched controls. The hypertrophic, anabolic markers talin and Akt phosphorylation (Thr308) were elevated with 2dHY but not in 3dAT myotubes. Inflammatory, catabolic markers IL-1ß, IL6, and NF-kappaB p65 subunit were significantly higher in the 3dAT group vs. all other groups. The ratio of phosphorylated FoxO3a/total FoxO3a was significantly lower in 3dAT than in the 2dHY group, consistent with elevated catabolic signaling during unloading. In summary, we demonstrated proof-of-concept for a spaceflight research bioreactor, using uniaxial cyclic stretch to produce myotube hypertrophy with increased tensile loading, and myotube atrophy with subsequent cessation of stretch.","PeriodicalId":54263,"journal":{"name":"npj Microgravity","volume":"10 1","pages":"62"},"PeriodicalIF":5.1,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11167039/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141307408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Harmonizing heterogeneous transcriptomics datasets for machine learning-based analysis to identify spaceflown murine liver-specific changes. 协调异构转录组学数据集，进行基于机器学习的分析，以识别太空飞行小鼠肝脏特异性变化。

IF 5.1 1区物理与天体物理

npj Microgravity Pub Date : 2024-06-11 DOI: 10.1038/s41526-024-00379-3

Hari Ilangovan, Prachi Kothiyal, Katherine A Hoadley, Robin Elgart, Greg Eley, Parastou Eslami

{"title":"Harmonizing heterogeneous transcriptomics datasets for machine learning-based analysis to identify spaceflown murine liver-specific changes.","authors":"Hari Ilangovan, Prachi Kothiyal, Katherine A Hoadley, Robin Elgart, Greg Eley, Parastou Eslami","doi":"10.1038/s41526-024-00379-3","DOIUrl":"10.1038/s41526-024-00379-3","url":null,"abstract":"NASA has employed high-throughput molecular assays to identify sub-cellular changes impacting human physiology during spaceflight. Machine learning (ML) methods hold the promise to improve our ability to identify important signals within highly dimensional molecular data. However, the inherent limitation of study subject numbers within a spaceflight mission minimizes the utility of ML approaches. To overcome the sample power limitations, data from multiple spaceflight missions must be aggregated while appropriately addressing intra- and inter-study variabilities. Here we describe an approach to log transform, scale and normalize data from six heterogeneous, mouse liver-derived transcriptomics datasets (ntotal = 137) which enabled ML-methods to classify spaceflown vs. ground control animals (AUC ≥ 0.87) while mitigating the variability from mission-of-origin. Concordance was found between liver-specific biological processes identified from harmonized ML-based analysis and study-by-study classical omics analysis. This work demonstrates the feasibility of applying ML methods on integrated, heterogeneous datasets of small sample size.","PeriodicalId":54263,"journal":{"name":"npj Microgravity","volume":"10 1","pages":"61"},"PeriodicalIF":5.1,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11167036/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141307410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characterizing dehydration in short-term spaceflight using evidence from Project Mercury. 利用 "水星计划 "的证据描述短期太空飞行中的脱水现象。

IF 5.1 1区物理与天体物理

npj Microgravity Pub Date : 2024-06-11 DOI: 10.1038/s41526-024-00374-8

Robert J Reynolds, Mark Shelhamer, Erik L Antonsen, William R Carpentier

{"title":"Characterizing dehydration in short-term spaceflight using evidence from Project Mercury.","authors":"Robert J Reynolds, Mark Shelhamer, Erik L Antonsen, William R Carpentier","doi":"10.1038/s41526-024-00374-8","DOIUrl":"10.1038/s41526-024-00374-8","url":null,"abstract":"Short-term spaceflight is commonly perceived as posing minimal risk to human health and performance. However, despite their duration, short-term flights potentially induce acute physiological changes that create risk to crews. One such change is dehydration (primarily body water loss) due to a heat-stressed environment. Such loss, if severe and prolonged, can lead to decrements in performance as well as increase the risk of more serious medical conditions. Though the general mechanisms of dehydration are broadly understood, the rate and extent of dehydration in short-term spaceflight has not been characterized. Combining data from the six spaceflights of the US Mercury program with a causal diagram illustrating the mechanisms of dehydration, we fit a path model to estimate the causal effects for all pathways in the causal model. Results demonstrate that Mercury astronauts experienced some degree of dehydration across the range of suited time and that the relationship between suited time and dehydration appears to be logarithmic. We discuss causal interpretations of the results and how the results from this and similar analyses can inform countermeasure development for short-term spaceflight.","PeriodicalId":54263,"journal":{"name":"npj Microgravity","volume":"10 1","pages":"64"},"PeriodicalIF":5.1,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11166991/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141307409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ocular perfusion pressure is not reduced in response to lower body negative pressure. 眼部灌注压不会因身体负压降低而降低。

IF 5.1 1区物理与天体物理

npj Microgravity Pub Date : 2024-06-08 DOI: 10.1038/s41526-024-00404-5

Eric A Hall, Richard S Whittle, Ana Diaz-Artiles

{"title":"Ocular perfusion pressure is not reduced in response to lower body negative pressure.","authors":"Eric A Hall, Richard S Whittle, Ana Diaz-Artiles","doi":"10.1038/s41526-024-00404-5","DOIUrl":"10.1038/s41526-024-00404-5","url":null,"abstract":"Lower body negative pressure (LBNP) has been proposed as a countermeasure to mitigate the cephalad fluid shift occurring during spaceflight, which may be associated with the development of Spaceflight Associated Neuro-ocular Syndrome (SANS). This study quantifies the effect of LBNP on intraocular pressure (IOP), mean arterial pressure at eye level (MAPeye), and ocular perfusion pressure (OPP). Twenty-four subjects (12 male, 12 female) were subjected to graded LBNP in 0° supine and 15° head-down tilt (HDT) postures from 0 mmHg to -50 mmHg in 10 mmHg increments. IOP decreased significantly with LBNP pressure in 0° supine (by 0.7 ± 0.09 mmHg per 10 mmHg LBNP pressure, p < 0.001) and in 15° HDT (by 1.0 ± 0.095 mmHg per 10 mmHg of LBNP pressure, p < 0.001). MAPeye significantly decreased by 0.9 ± 0.4 mmHg per 10 mmHg of LBNP pressure in 0° supine (p = 0.016) but did not significantly change with LBNP in 15° HDT (p = 0.895). OPP did not significantly change with LBNP in 0° supine (p = 0.539) but it significantly increased in 15° HDT at 1.0 ± 0.3 mmHg per 10 mmHg of LBNP pressure (p = 0.010). Sex did not have a significant effect on OPP, MAPeye, or IOP in any condition. In 15° HDT, the reduction in IOP during increasing negative pressure, combined with the relatively constant MAPeye, led to the increase in OPP. Furthermore, results suggest that LBNP, while effective in reducing IOP, is not effective in reducing OPP across all postures investigated.","PeriodicalId":54263,"journal":{"name":"npj Microgravity","volume":"10 1","pages":"67"},"PeriodicalIF":5.1,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11162494/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141293955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cold atom microwave clock based on intracavity cooling in China space station. 中国空间站基于腔内冷却的冷原子微波钟。

IF 5.1 1区物理与天体物理

npj Microgravity Pub Date : 2024-06-06 DOI: 10.1038/s41526-024-00407-2

Siminda Deng, Wei Ren, Jingfeng Xiang, Jianbo Zhao, Lin Li, Di Zhang, JinYin Wan, Yanling Meng, XiaoJun Jiang, Tang Li, Liang Liu, Desheng Lü

{"title":"Cold atom microwave clock based on intracavity cooling in China space station.","authors":"Siminda Deng, Wei Ren, Jingfeng Xiang, Jianbo Zhao, Lin Li, Di Zhang, JinYin Wan, Yanling Meng, XiaoJun Jiang, Tang Li, Liang Liu, Desheng Lü","doi":"10.1038/s41526-024-00407-2","DOIUrl":"10.1038/s41526-024-00407-2","url":null,"abstract":"Atomic clocks with higher frequency stability and accuracy than traditional space-borne atomic clocks are the cornerstone of long-term autonomous operation of space-time-frequency systems. We proposed a space cold atoms clock based on an intracavity cooling scheme, which captures cold atoms at the center of a microwave cavity and then executes in situ interactions between the cold atoms and microwaves. As a result of the microgravity environment in space, the cold atoms can interact with the microwaves for a longer time, which aids in realizing a high-precision atomic clock in space. This paper presents the overall design, operational characteristics, and reliability test results of the space atomic clock based on the intracavity cooling scheme designed for the operation onboard the China space station. In addition, the engineering prototype performance of the space cold atoms microwave clock is also presented. The ground test results for the clock show a fractional frequency stability of 1.1 × 10-12 τ-1/2 reaching 2.5 × 10-15 at 200,000 s, providing solid technical and data support for its future operation in orbit.","PeriodicalId":54263,"journal":{"name":"npj Microgravity","volume":"10 1","pages":"66"},"PeriodicalIF":5.1,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11156933/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141285371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0