Design of transfers from Earth-Moon L 1/L2 libration point orbits to a destination object

Within the context of both manned and robotic spaceflight activities, orbits near the Earth-Moon L1 and L2 libration points could support lunar surface operations and serve as staging areas for future missions to near-Earth asteroids as well as Mars. In fact, an Earth-Moon L2 libration point orbit has been proposed as a potential hub for excursions to Mars as well as activities in support of planetary exploration. Yet, the dynamical environment within the Earth-Moon system is complex and, consequently, trajectory design in the vicinity of Earth-Moon L1 and L2 is nontrivial. Routine transfers between an Earth-Moon L1/L2 facility and Mars also requires design strategies to deliver trajectory arcs that are characterized by a coupling between different multi-body gravitational environments across two-, three- and four body systems. This investigation employs an approach to solve the general problem for transfers from the Earth-Moon libration point orbits to a destination object. Mars, Jupiter, and a near-Earth asteroid (2006RH120) are incorporated as sample destination objects, and general trajectory design procedures for multiple transfer scenarios including manifold and non-manifold options are developed by utilizing simplified models based on the knowledge of the circular restricted three-body problem. Then, the solutions are transitioned to higher-fidelity models; results for multiple departure/arrival scenarios are compared

A stochastic method to compute the L2L^2 localisation landscape

The $L^2$ localisation landscape of L. Herviou and J. H. Bardarson is a generalisation of the localisation landscape of M. Filoche and S. Mayboroda. We propose a stochastic method to compute the $L^2$ localisation landscape that enables the calculation of landscapes using sparse matrix methods. We also propose an energy filtering of the $L^2$ landscape which can be used to focus on eigenstates with energies in any chosen range of the energy spectrum. We demonstrate the utility of these suggestions by applying the $L^2$ landscape to Anderson's model of localisation in one and two dimensions, and also to localisation in a model of the quantum Hall effect.Comment: 9 pages, 6 figure

Access to Mars from Earth-Moon Libration Point Orbits:

This investigation is focused specifically on transfers from Earth-Moon L(sub 1)/L(sub 2) libration point orbits to Mars. Initially, the analysis is based in the circular restricted three-body problem to utilize the framework of the invariant manifolds. Various departure scenarios are compared, including arcs that leverage manifolds associated with the Sun-Earth L(sub 2) orbits as well as non-manifold trajectories. For the manifold options, ballistic transfers from Earth-Moon L(sub 2) libration point orbits to Sun-Earth L(sub 1)/L(sub 2) halo orbits are first computed. This autonomous procedure applies to both departure and arrival between the Earth-Moon and Sun-Earth systems. Departure times in the lunar cycle, amplitudes and types of libration point orbits, manifold selection, and the orientation/location of the surface of section all contribute to produce a variety of options. As the destination planet, the ephemeris position for Mars is employed throughout the analysis. The complete transfer is transitioned to the ephemeris model after the initial design phase. Results for multiple departure/arrival scenarios are compared

聴覚障害特別支援学校小学部における外国語教育の現状と課題

令和２（2020）年度から小学校学習指導要領が全面実施され、第３学年以上が外国語を学んでいる。特別支援学校においては，各教科の目標、各学年の目標及び内容並びに指導計画の作成と内容の取扱いについては、小学校学習指導要領第２章に示すものに準ずるとされている（文部科学省，2017b）。しかし、山澤・小田（2016）の調査では、「発音や聞き取り、アクセント、イントネーションなどの児童の聴覚活用が課題となる」という教員の声が挙げられた。聴覚障害がある児童が音声を中心に学ぶ小学校の外国語学習にどのように取り組めばよいかを検討することは喫緊かつ重要な課題である。そこで本研究では、聴覚障害特別支援学校小学部における外国語教育の授業実践や教員の指導体制などに関する先行研究を分析し、そこから見えてきた成果や課題をまとめ、「読むこと」「書くこと」「聞くこと」「話すこと」に困難を抱える聴覚障害のある児童に対する適切な指導の在り方について考察することを目的とした。これにより、今後の聴覚障害のある児童に対する外国語教育の在り方について提案した。The Courses of Study for Elementary Schools was fully implemented in 2020, and foreign languages have been taught in the third grade and above. In special needs schools, the objectives of each subject, the objectives and contents of each grade level, and the preparation of instructional plans and handling of contents follow those shown in Chapter 2 of the Courses of Study for Elementary Schools (Ministry of Education, Culture, Sports, Science and Technology, 2017b). However, in a survey conducted by Yamazawa and Oda (2016), teachers mentioned that the auditory utilization of children, such as pronunciation, listening comprehension, accent, and intonation, is a challenge. It is an urgent and important issue to examine how to address foreign language learning in elementary schools where children with hearing impairment learn mainly through speech. The purpose of this study is to analyze previous research on foreign language teaching practices and teachers’ instructional systems in elementary education divisions of special needs needs for the deaf, to summarize the results and issues that emerged, and to consider how to provide appropriate instruction for children with hearing disabilities who have difficulties in reading, writing, listening, and speaking. Through this study, we proposed the future of foreign language education for children with hearing disabilities

Adaptation of Conduit Artery Vascular Smooth Muscle Tone to Induced Hypertension

We studied the changes in vascular smooth muscle (VSM) cell tone during the adaptation of rat common carotids to induced hypertension. Hypertension was induced in 8 week old male Wistar rats by total ligation of the aorta between the two kidneys. Mean blood pressure increased abruptly from 92±2 mm Hg (mean±SE) to 145±4 mm Hg and remained constant thereafter. Rats were sacrificed 2, 4, 8, and 56 days after surgery and the left common carotid artery was excised for analysis. Pressure-diameter curves were measured in vitro under normal, maximally contracted, and totally relaxed VSM. The VSM tone was analyzed in terms of its basal tone (active stress at low strains) and its myogenic tone (increase in active stress at high strains). Our results show that the capacity of the VSM to develop maximal active stress is not altered in hypertension. Basal tone, however, increases rapidly in the acute hypertension phase (2-8 days postsurgery) and drops to nearly control values at 56 days postsurgery. Also, the onset of myogenic response decreases to lower strains following the step change in pressure, to be restored back to control levels at 56 days postsurgery. We conclude that VSM adaptation is most significant in the acute hypertension phase and acts as a first, rapid defense mechanism for the arterial wall. The VSM tone returns back to normal levels once the slower geometrical and structural remodeling is developed sufficiently to restore the biomechanical environment and function of the arterial wall to control levels. © 2002 Biomedical Engineering Society. PAC2002: 8719Rr, 8719Ff, 8719U

Finite element analysis of cementless femoral stems based on mid- and long-term radiological evaluation

Comparison of stress shielding ~5 and ~10 years postoperatively (Fig. 5). (XLSX 12 kb

Carcinosarcoma of the Renal Pelvis and Urinary Bladder: A Case Report

Carcinosarcomas are rare biphasic malignant neoplasms with an epithelial and a spindle cell component. We present a 62-year-old man with a history of noticeably abdominal distension, proved by surgery to be caused by carcinosarcoma of the renal pelvis and urinary bladder, occupying the entire left abdominal flank. We also illustrate the appearance of this rare entity on sonography and computed tomography

Adaptation of conduit artery vascular smooth muscle tone to induced hypertension

We studied the changes in vascular smooth muscle (VSM) cell tone during the adaptation of rat common carotids to induced hypertension. Hypertension was induced in 8 week old male Wistar rats by total ligation of the aorta between the two kidneys. Mean blood pressure increased abruptly from 92 +/- 2mm Hg (mean +/- SE) to 145 +/- 4 mm Hg and remained constant thereafter. Rats were sacrificed 2, 4, 8, and 56 days after surgery and the left common carotid artery was excised for analysis. Pressure-diameter curves were measured in vitro under normal, maximally contracted, and totally relaxed VSM. The VSM tone was analyzed in terms of its basal tone (active stress at low strains) and its myogenic tone (increase in active stress at high strains). Our results show that the capacity of the VSM to develop maximal active stress is not altered in hypertension. Basal tone, however, increases rapidly in the acute hypertension phase (2-8 days postsurgery) and drops to nearly control values at 56 days postsurgery. Also, the onset of myogenic response decreases to lower strains following the step change in pressure, to be restored back to control levels at 56 days postsurgery. We conclude that VSM adaptation is most significant in the acute hypertension phase and acts as a first, rapid defense mechanism for the arterial wall. The VSM tone returns back to normal levels once the slower geometrical and structural remodeling is developed sufficiently to restore the biomechanical environment and function of the arterial wall to control levels

Comparative genetic diversity in a sample of pony breeds from the UK and North America:A case study in the conservation of global genetic resources

Most species exist as subdivided ex situ daughter population(s) derived from a single original group of individuals. Such subdivision occurs for many reasons both natural and manmade. Traditional British and Irish pony breeds were introduced to North America (U.S.A. and Canada) within the last 150 years, and subsequently equivalent breed societies were established. We have analyzed selected U.K. and North American equivalent pony populations as a case study for understanding the relationship between putative source and derived subpopulations. Diversity was measured using mitochondrial DNA and a panel of microsatellite markers. Genetic signatures differed between the North American subpopulations according to historical management processes. Founder effect and stochastic drift was apparent, particularly pronounced in some breeds, with evidence of admixture of imported mares of different North American breeds. This demonstrates the importance of analysis of subpopulations to facilitate understanding the genetic effects of past management practices and to lead to informed future conservation strategies