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The deep-space multi-object orbit determination system and its application to Hayabusa2’s asteroid proximity operations

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Astrodynamics 2020年第4期4卷 377-392页

作者： Hiroshi Takeuchi Kent Yoshikawa Yuto Takei Yusuke Oki Shota Kikuchi Hitoshi Ikeda stefania soldini Naoko Ogawa Yuya Mimasu Go Ono Fuyuto Terui Naoya Sakatani Manabu Yamada Toru Kouyama Shingo Kameda Takanao Saiki Yuichi Tsuda Institute of Space and A stronautical Science Japan A erospace Exploration AgencySagamihara 252-5210Japan The Graduate University for Aduanced Studies Hayama 240-0193Japan Research and Development Directorate Japan Aerospace Exploration AgencySagamihara 252-5210Japan University of Liverpool Liverpool L693BXUK Chiba Institute of Technology Narashino 275-0016Japan National Institute of Aduanced Industrial Science and Technology Koto-ku 135-0064Japan Rikkyo University Toshima-ku 171-8501Japan

The deep-space multi-object orbit determination system(DMOODS)and its application in the asteroid proximity operation of the Hayabusa2 mission are *** was developed by the Japan Aerospace Exploration Agency(JAXA)for the primary purpose of determining the trajectory of deep-space spacecraft for JAXA’s planetary *** weighted least-squares batch filter is used for the orbit estimator of *** orbit estimator supports more than 10 data types,some of which are used for relative trajectory measurements between multiple space objects including natural satellites and small *** system consists of a set of computer programs running on Linux-based consumer PCs on the ground,which are used for orbit determination and the generation of radiometric tracking data,such as delta differential one-way ranging and doppler tracking *** the asteroid proximity phase of Hayabusa2,this system played an essential role in operations that had very strict navigation requirements or operations in which few optical data were obtained owing to special constraints on the spacecraft attitude or distance from the *** example is orbit determination during the solar conjunction phase,in which the navigation accuracy is degraded by the effect of the solar *** large range bias caused by the solar corona was accurately estimated with DMOODS by combining light detection and ranging(LIDAR)and ranging measurements in the superior solar conjunction phase of *** the orbiting operations of target markers and the MINERVA-II2 rover,the simultaneous estimation of six trajectories of four artificial objects and a natural object was made by *** type of simultaneous orbit determination of multi-artificial objects in deep-space has never been accomplished before.

关键词： orbit determination optical navigation gravity measurements superior solar conjunction delta differential one-way ranging(delta-DOR)

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Hayabusa2’s superior solar conjunction mission operations: Planning and post-operation results

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Astrodynamics 2020年第4期4卷 265-288页

作者： stefania soldini Hiroshi Takeuchi Sho Taniguchi Shota Kikuchi Yuto Takei Go Ono Masaya Nakano Takafumi Ohnishi Takanao Saiki Yuichi Tsuda Fuyuto Terui Naoko OgawaYuya MimasuTadateru Takahashi Atsushi Fujii Satoru NakazawaKent Yoshikawa Yusuke Oki Chikako Hirose Hirotaka Sawada Tomohiro Yamaguchi Makoto Yoshikawa Department of Mechanical Materials and Aerospace EngineeringUniversity of LiverpoolLiverpool L693BXUK Institute of Space and Astronautical Science Japan Aerospace Exploration AgencySagamihara 252-5210Japan Fujitsu Limited Tokyo 105-7123Japan Mitsubishi Electric Corporation Tokyo 100-8310Japan

In late 2018,the asteroid Ryugu was in the Sun's shadow during the superior solar conjunction *** the Sun-Earth-Ryugu angle decreased to below 3°,the Hayabusa2 spacecraft experienced 21 days of planned blackout in the Earth-probe communication *** was the first time a spacecraft had experienced solar conjunction while hovering around a minor *** the safety of the spacecraft,a low energy transfer trajectory named Ayu was designed in the Hill reference frame to increase its altitude from 20 to 110 *** trajectory was planned with the newly developed optNEAR tool and validated with real time *** article shows the results of the conjunction operation,from planning to fight data.

关键词： superior solar conjunction Hayabusa2 Ryugu hovering satellite mission operations

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小行星表面风化层跨尺度迁移的离散元建模

小行星表面风化层跨尺度迁移的离散元建模

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北京力学会第30届学术年会

作者：宋志军于洋 stefania soldini 程彬 Patrick Michel

本文以小行星表面风化层颗粒的跨尺度迁移过程为背景,针对传统离散元法(DEM)在模拟这一过程所面临的困难,提出一种小行星表面风化层跨尺度迁移的离散元建模方法。模拟结果表明,该方法能够准确高效地追踪小行星表面风化层材料的连续跨尺... 详细信息

本文以小行星表面风化层颗粒的跨尺度迁移过程为背景,针对传统离散元法(DEM)在模拟这一过程所面临的困难,提出一种小行星表面风化层跨尺度迁移的离散元建模方法。模拟结果表明,该方法能够准确高效地追踪小行星表面风化层材料的连续跨尺度迁移过程。

关键词：离散元小行星风化层迁移跨尺度建模

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Calcium-sensitive protein MLC1 as a possible modulator of the astrocyte functional state

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Neural Regeneration Research 2025年第7期20卷 2008-2010页

作者： Elena Ambrosini Angela Lanciotti Maria stefania Brignone Department of Neuroscience Istituto Superiore di SanitàRomeItaly

Astrocytes,the main population of glial cells in the central nervous system(CNS),exert essential tasks for the control of brain tissue homeostasis,supporting neuron and other glial cell activity from the developmental stage to adult *** maintain the optimal functionality of the brain,astroglial cells are particularly committed to reacting to every change in tissue homeostatic conditions,from mild modifications of the physiological environment,a process called astrocyte activation,to the more severe alterations occurring in pathological situations causing astrocyte reactivity or reactive astrogliosis(Escartin et al.,2021).During these reactive states,astrocytes mount an active,progressive response encompassing morphological,molecular,and interactional remodeling,leading to the acquisition of new functions and the loss of others,whose intensity,duration,and reversibility are dependent on the nature of the stimulus and regulated in a context-specific manner.

关键词： alterations modulator maintain

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Novel perspectives for neurodegeneration prevention: effects of bioactive polyphenols

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Neural Regeneration Research 2021年第7期16卷 1411-1412页

作者： stefania Crispi stefania Filosa Institute of Biosciences and Bioresources National Research Councilvia P.CastellinoNaplesItaly Department of Marine Biotechnology Stazione Zoologica Anton DohrnNapoliItaly Istituto di Ricovero e Cura a Carattere Scientifico Neuromed PozzilliItaly

Neurodegenerative diseases are becoming a big challenge for modern *** disorders strongly impact on patient and their ***, since the population is becoming older, these pathologies will deeply influence medical and socio-economic conditions in the next ***, efforts are needed to find new strategies devoted to define new protocols and identify novel substances able to prevent neurodegeneration or to improve the quality of life of people affected by neurodegenerative diseases(Alzheimer's Disease International, 2019).

关键词： prevention diseases neurodegeneration

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Polyphenols-gut microbiota interplay and brain neuromodulation

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Neural Regeneration Research 2018年第12期13卷 2055-2059页

作者： stefania Filosa Francesco Di Meo stefania Crispi Institute of Biosciences and Bioresources National Research Council National Research Council via P. Castellino Naples Italy Istituto di Ricovero e Cura a Carattere Scientifico Neuromed Pozzilli Italy

Increasing evidence suggests that food ingested polyphenols can have beneficial effects in neuronal protection acting against oxidative stress and inflammatory injury. Moreover, polyphenols have been reported to promote cognitive functions. Biotransformation of polyphenols is needed to obtain metabolites active in brain and it occurs through their processing by gut microbiota. Polyphenols metabolites could directly act as neurotransmitters crossing the blood-brain barrier or indirectly by modulating the cerebrovascular system. The microbiota-gut-brain axis is considered a neuroendocrine system that acts bidirectionally and plays an important role in stress responses. The metabolites produced by microbiota metabolism can modulate gut bacterial composition and brain biochemistry acting as neurotransmitters in the central nervous system. Gut microbiota composition can be influenced by dietary ingestion of natural bioactive molecules such as probiotics, prebiotics and polyphenol. Microbiota composition can be altered by dietary changes and gastrointestinal dysfunctions are observed in neurodegenerative diseases. In addition, several pieces of evidence support the idea that alterations in gut microbiota and enteric neuroimmune system could contribute to onset and progression of these age-related disorders. The impact of polyphenols on microbiota composition strengthens the idea that maintaining a healthy microbiome by modulating diet is essential for having a healthy brain across the lifespan. Moreover, it is emerging that they could be used as novel therapeutics to prevent brain from neurodegeneration.

关键词： polyphenols gut-microbiota gut-brain axis metagenomic neurodegeneration neurotransmitters prebiotics probiotics

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Increased population density reduces body growth and female investment in a simultaneous hermaphrodite

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Current Zoology 2017年第2期63卷 151-157页

作者： Elio CANNARSA stefania MECONCELLI Department of Life Sciences and Systems Biology Universita di Torino Via Accademia Albertina 13 10123 Torino Italy.

Sex allocation theory applied to hermaphrodites assumes that there is a trade off between the alloca- tion of resources to male and female functions, within a fixed reproductive resource budget. Charnov＇s classic resource allocation model predicts a more female-biased sex allocation when competition among different sperm donors is low due to diminishing fitness returns for male investment. By manipulating the social group size, one automatically changes the population density at which individ- uals live. Increasing population density may affect reproductive allocation, leading to resource compe- tition and/or to increased concentration of harmful metabolites. This could lead to an over- or under- estimation of the individual adjustment of sex allocation responses to mating opportunities. In this article, we tested the effects of density and social group size separately on female investment and body growth （considered as proxy of the overall energy budget） in the simultaneously hermaphroditic polychaete worm Ophryotrocha diadema. We manipulated social group size （i.e., monogamous and promiscuous regimes） and density （i.e., 4 levels） using a full-factorial design, to identify the underlying factor affecting female allocation （in terms of egg production） and body growth. In contrast to findings of previous experiments, we found that an increase in population density reduced body growth and egg production of hermaphrodites irrespective of social group size. We advance the hypothesis that the increase of catabolites and oxygen consumption in high-density conditions reduces the overall resource budget and this could obscure group size effects on female fecundity.

关键词： body growth female fecundity mating group size Ophryotrocha diadema resource budget.

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Modeling the methyldiethanolamine-piperazine scrubbing system for CO2 removal： Thermodynamic analysis

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Frontiers of Chemical Science and Engineering 2016年第1期10卷 162-175页

作者： stefania Moioli Laura A. Pellegrini Dipartimento di Chimica Materiali e Ingegneria Chimica 'G. Natta' Politecnico di Milano Piazza Leonardo da Vinci 32 1-20 33 Milano Italy

Aqueous solutions of methyldiethanolamine （MDEA） and piperazine （PZ） are commonly used solvent nowadays. In this work a thermodynamic analysis with the Electrolyte-NRTL model has been performed for systems composed of acidic gases and MDEA＋ PZ aqueous solution. ASPEN Plus＇s has been used for thermodynamic modeling. Values of binary interaction parameters for liquid phase activity coefficients have been estimated from regressions of experimental data. Moreover, the influence of the interactions between ion pairs and MDEA or PZ molecular species has been analyzed. The final aim is to obtain a reliable tool for design and simulation of absorption and stripping columns, fundamentals also in order to carry out energy saving studies.

关键词： vapor-liquid equilibrium methyldietanola- mine piperazine regression Electrolyte-NRTL

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Ascitic fluid analysis for diagnosis and monitoring of spontaneous bacterial peritonitis

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World Journal of Gastroenterology 2009年第31期15卷 3845-3850页

作者： Oliviero Riggio stefania Angeloni Department of Clinical Medicine "Sapienza" University of Rome

Polymorphonuclear (PMN) cell count in the ascitic fluid is essential for the diagnosis and management of spontaneous bacterial peritonitis (SBP). To date, PMN cell count is routinely performed by traditional manual counting. However, this method is time-consuming, costly, and not always timely available. Therefore, considerable efforts have been made in recent years to develop an alternative test for a more rapid diagnosis and monitoring of SBP. The use of urinary reagent strips was proposed to achieve an "instant" bedside diagnosis of SBP. A series of reports evaluated the urine strip test for SBP diagnosis and reported promising results. However, a recent large multicenter study revealed a surprising lack of diagnostic effi cacy of the urine screening test for SBP diagnosis. Another method, more recently proposed as an alternative to the manual PMN count, is the measurement of lactoferrin in ascitic fluid, but the data available on the diagnostic value of this test are limited to a single study. However, both urinary reagent strips and ascitic lactoferrin tests are qualitative methods and need, therefore, to be further confirmed by standard cytology of the ascitic fluid. To date, the only quantitative method proposed as a valid alternative to manual PMN counting is automated blood cell counters, commonly used in all laboratories for blood cell counting. Data available in the literature on the diagnostic performance of this method are limited but very promising, and this tool seems to have the potential to replace the manual counting method.

关键词： Ascites Ascitic fluid lactoferrin Automatedblood cell counter Paracentesis Polymorphonuclear cell count Urinary reagent strips

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Image grid display:A study on automatic scrolling presentation

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Visual Informatics 2017年第1期1卷 16-24页

作者： Marco Porta stefania Ricotti Department of Electrical Computer and Biomedical EngineeringUniversity of PaviaPaviaItaly

In this paper we describe a study on image grid display with automatic vertical *** scroll operations are normally carried out manually by the user,in the context of RSVP(Rapid Serial Visual Presentation)techniques this work considers a presentation mode in which the image grid is automati-cally *** experiments carried out with 50 testers,we have investigated user performance while looking for specific target subjects within large collections of *** numbers of columns and scrolling speeds have been *** search task implied both clicking on the identified target pictures and simply vocally stating their visual *** this purpose,and to identify possible specific gaze behaviours,eye tracking technology has been *** obtained results show that number of columns and scroll speed do affect search ***,the user’s gaze tends to focus on different screen areas depending on the values of these two *** it is not possible to definitely find an optimal columns-speed combination that is valid in all cases,the particular context of use can suggest feasible solutions according to one’s *** the best of our knowledge,image grid display with automatic scrolling has never been studied to date.

关键词： Image griddisplay Automatic scrolling Image presentationmodes Image collections Rapid serialvisual presentation

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