scholarly journals Development of an experimental installation for gray seal magnetoreception research

2021 ◽  
Vol 12 (3-2021) ◽  
pp. 157-163
Author(s):  
A.P. Yakovlev ◽  
Keyword(s):  
Reference Point ◽  
Geomagnetic Field ◽  
Helmholtz Coil ◽  
Long Distance ◽  
Gray Seal ◽  
Experimental Installation ◽  
Magnetic Sense ◽  
Selection Of

The assumption was made that Cetaceans, both whales and dolphins, are using geomagnetic field of Earth for orientations during migration. Pinnipeds also make long-distance migrations in open seas without apparent reference point. That may be an evidence of magnetic sense in pinnipeds. In this paper we describe development and construction of experimental installation based on Helmholtz coil for gray seal magnetoreception research. A technique of “selection of an object with specified characteristics” is described, adapted for conduction of experiments with pinnipeds.

scholarly journals Prognostics and health management technology for radar system

2020 ◽  
Vol 309 ◽  
pp. 04009
Author(s):  
Yongle Lyu ◽  
Zhuo Pang ◽  
Chuang Zhou ◽  
Peng Zhao
Keyword(s):  
Model Building ◽  
Health Management ◽  
Radar System ◽  
Prognostics And Health Management ◽  
Failure Model ◽  
Long Distance ◽  
Maintenance System ◽  
Management Technology ◽  
Key Techniques ◽  
Selection Of

Information-based war in the future has a higher requirement to the maintenance and support ability of radar system. Prognostics and Health Management(PHM) technology represents the research hotspot of maintenance system, and following key techniques need to be resolved to research on the radar PHM technology such as the acquirement and selection of health information and fault signs of a radar’s electronical components, mass data warehousing and mining, fusion of multi-source test data and multi-field characteristic information, failure model building and forecasting, automatic decision-making on maintenance, and at the same time improving the self built-in test abilities of radar’s components based on the optimization of Design For Testability(DFT). The radar PHM technology has the trend of “built-in to integrate”, “together with DFT” and “long-distance and distributed”. However, subjected to radar’s complexity and current PHM technique level, radar PHM engineering still meets many challenges, but has bright future.

Safety of hypomagnetic field and its effects on the skeletal system

2020 ◽  
Author(s):  
Peng Shang ◽  
Yanru Xue
Keyword(s):  
Magnetic Field ◽  
Bone Loss ◽  
Iron Metabolism ◽  
Geomagnetic Field ◽  
Osteoblast Differentiation ◽  
Hindlimb Unloading ◽  
The Moon ◽  
Skeletal System ◽  
Long Distance ◽  
Hypomagnetic Field

<p>    All organisms survive and multiply under the geomagnetic magnetic field (GMF) <sup>[1]</sup>. With the launch of the Moon and Mars space program, during long-distance space mission, astronauts will inevitably be exposed to an environment with a hypomagnetic field (HyMF), which several thousand times weaker than GMF<sup>[2]</sup>. Spatial hypomagnetic field exists on the surface of the moon or in the deep space of the solar system, and its magnetic intensity is less than 5 μT<sup>[3]</sup>. At present, the research on the effects of HyMF on the health of astronauts is mainly focused on the conditions of ground simulation experiments, including the central nervous system, blood system and brain cognition <sup>[4,5]</sup>. However, relevant safety of the skeletal system studies about HyMF are deficient. Our recent research indicated that the effects of HyMF on bone cannot be overlooked. In vivo, our study found that HyMF aggravated bone loss induced by hindlimb unloading (HLU) in rats and mice, which related to the changes in iron metabolism<sup>[6,7]</sup>. In addition, HyMF also inhibited the recovery of simulated microgravity-induced osteoporosis of mice, probably by restraining elevated iron return to normal levels<sup>[8]</sup>. Meanwhile, we found that HyMF can inhibit osteoblast differentiation and mineralization<sup>[9]</sup>, promote osteoclast formation and bone resorption in vitro<sup>[10]</sup>. The research results have significant academic values in the field of magneto-biology and the potential application values in space activities for the manned moon landing exploration.</p><p><strong>Key words:</strong> </p><p>Hypomagnetic field, geomagnetic field, safety management, iron storage.</p><p><strong>References</strong></p><p>[1]Dubrov A P. The Geomagnetic Field and Life: Geomagnetobiology. Bioscience. 1978. 978-1-4757-1610-8.</p><p>[2]Belyavskaya N. Biological effects due to weak magnetic field on plants. Advances in space Research, 2004, 34(7): 1566-1574.</p><p>[3]Mo W C, Ying L & He R Q. Hypomagnetic field, an ignorable environmental factor in space? Science China -Life Sciences, 2014. 57(7): 726-728.</p><p>[4]Mo WC, Liu Y & He RQ. A biological perspective of the hypomagnetic field: from definition towards mechanism. Prog Biochem Biophys, 2012, 39: 835–842 </p><p>[5]Jia B, Zhang WJ, Xie L, Zheng  Q, Tian ZC & Shang P<em>. </em>Effects of hypomagnetic field environment on hematopoietic system in mice. Space Medicine &Medical Engineering, 2011.24(5): 318-322.</p><p>[6] Jia B, Xie L, Zheng Q, Yang P F, Zhang W J & Shang P. A hypomagnetic field aggravates bone loss induced by hindlimb unloading in rat femurs. PloS one, 2014, 9(8): e105604.</p><p>[7] Yang J, Meng X, Dong D, Xue Y, Chen X & Shang P. Iron overload involved in the enhancement of unloading-induced bone loss by hypomagnetic field. Bone, 2018 Sep;114:235-245.</p><p>[8]Xue YR, Yang JC, Luo J, Ren L, Shen Y & Shang P, Disorder of iron metabolism inhibits the recovery of unloading-induced bone loss in hypomagnetic field. Journal of bone and mineral research.2020. DOI: 10.1111/JBMR.3949.</p><p>[9]Yang J, Zhang J, Ding C, Dong D & Shang P. Regulation of Osteoblast Differentiation and Iron Content in MC3T3-E1 Cells by Static Magnetic Field with Different Intensities. Biological trace element research, 2017, 184(7): 1-12.</p><p>[10]Zhang J, Meng X, Ding C, Xie L, Yang P & Shang P. Regulation of osteoclast differentiation by static magnetic fields. Electromagnetic biology and medicine, 2017, 36(1): 8-19.</p><p> </p>

scholarly journals Evidence that fin whales respond to the geomagnetic field during migration

1992 ◽  
Vol 171 (1) ◽  
pp. 67-78 ◽  
Author(s):  
M. M. Walker ◽  
J. L. Kirschvink ◽  
G. Ahmed ◽  
A. E. Dizon
Keyword(s):  
United States ◽  
Geomagnetic Field ◽  
Bottom Slope ◽  
Northeastern United States ◽  
Fin Whale ◽  
Magnetic Sense ◽  
Parameters Analysis ◽  
Fin Whales ◽  
Bottom Depth ◽  
Geomagnetic Intensity

We challenge the hypothesis that fin whales use a magnetic sense to guide migration by testing for associations between geophysical parameters and the positions where fin whales were observed over the continental shelf off the northeastern United States. Monte Carlo simulations estimated the probability that the distribution of fin whale sighting was random with respect to bottom depth, bottom slope and the intensity and gradient of the geomagnetic field. The simulations demonstrated no overall association of sighting positions with any of these four geophysical parameters. Analysis of the data by season, however, demonstrated statistically reliable associations of sighting positions with areas of low geomagnetic intensity and gradient in winter and fall, respectively, but no association of sighting positions with bathymetric parameters in any season. An attempt to focus on migrating animals by excluding those observed feeding confirmed the associations of sighting positions with low geomagnetic intensity and gradient in winter and fall, respectively, and revealed additional associations with low geomagnetic gradients in winter and spring. These results are consistent with the hypothesis that fin whales, and perhaps other mysticete species, possess a magnetic sense that they use to guide migration.

Migration, trade, and religious change at the onset of colonialism, 1890–1905

2008 ◽  
Author(s):  
Felicitas Becker
Keyword(s):  
Reference Point ◽  
Religious Practice ◽  
Religious Change ◽  
Discrete Elements ◽  
Regional Politics ◽  
Long Distance ◽  
Low Profile ◽  
Oral Evidence ◽  
Big Men

This chapter sets out the hierarchical, exploitative conditions of the late pre-colonial period that villagers would react against. The elusiveness of ritual authority that characterized indigenous religious practice helps elaborate the relatively low profile of Islam in relationships of dependency beyond the coast. The chapter first discusses the coast in terms of a reference point in regional politics. The factors mitigating Muslim influence up-country are shown. It is tempting to suggest that big men turned to Islam to overcome the limitations of their role in local religious practice. Muslim practice was diverse on the coast and became discernible up-country in discrete elements, and big men had no reason to assume that they would be able to retain control over it. Additionally, the oral evidence on long-distance trade, viewed from the villages, and the effects of colonization, are presented. The role of coastal Muslims in the interior was nothing if not ambiguous. Inasmuch as Muslim practice was recognized as ritual practice, it faced both towards society and towards spirit forces.

Magnetoreception of Invertebrates

2017 ◽  
pp. 366-388 ◽  
Author(s):  
Martin Vacha
Keyword(s):  
Geomagnetic Field ◽  
Fruit Fly ◽  
Fundamental Question ◽  
The Other ◽  
Research Teams ◽  
Behavioral Aspect ◽  
Experimental Approaches ◽  
Level Of Knowledge ◽  
Magnetic Sense ◽  
Invertebrate Model

Exploiting invertebrates, such as the fruit fly Drosophila or nematode Caenorhabditis, with a modifiable genome seems to be key to answering the fundamental question of the molecular principle of magnetoreception. This review presents the state of knowledge on invertebrate sensitivity to geomagnetic field (GMF) over the last 20 years from a number of viewpoints, with particular emphasis on the behavioral aspect of testing. It shows that experimental approaches are generally specific to the particular research teams, and positive replication at other laboratories is practically nonexistent. The questions surrounding an animal compass are fascinating, but to achieve a level of knowledge of the magnetic sense at least closer to the other senses, a standardized, commercially available, and routinely applicable test on the classic invertebrate model to the natural GMF is still badly needed.

Environmental analysis in the selection of alternative corridors in a long-distance linear project: A methodological proposal

2006 ◽  
Vol 80 (3) ◽  
pp. 266-278 ◽  
Author(s):  
Alejandro J. Rescia ◽  
Elizabeth N. Astrada ◽  
Julieta Bono ◽  
Carlos A. Blasco ◽  
Paula Meli ◽  
...  
Keyword(s):  
Environmental Analysis ◽  
Long Distance ◽  
Selection Of

On the way from misery to happiness? A longitudinal perspective on economic migration and well-being

2018 ◽  
Vol 8 (3) ◽  
pp. 307-355
Author(s):  
Fabian Kratz
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Panel Study ◽  
Well Being ◽  
Long Distance ◽  
Economic Migration ◽  
Nationally Representative ◽  
Dynamic Relationships ◽  
Migration Type ◽  
Selection Of

Abstract The assessment of returns from migration lies at the very heart of migration research. While a growing body of literature examines the links between migration and well-being, dynamic relationships require further elaboration. Using the longest running, nationally representative panel study with information on well-being, the German Socio-Economic Panel (1985–2016) this article addresses two essential, as yet unresolved, questions: How does the favourable self-selection of economic migrants affect their well-being before relocation?How does the well-being of economic migrants develop when individuals approach migration, and thereafter? Results show that—although favourably selected regarding determinants of well-being—economically motivated migrants are not happier before relocating than those who stay. Furthermore, economic migration has a causal impact on well-being, net of both observed and unobserved differences between migrants and stayers. This impact is transitory for women and long-lasting for men. For men, the results corroborate the view that migration enables access to opportunity structures favouring the pursuit of individual happiness. Results also differ by migration type: While long-distance movers and return migrants show a period of depressed happiness before a move, these findings do not hold for short-distance and onward migrants. Furthermore, moving towards urban areas results in stronger permanent effects than moving towards rural areas.

Geomagnetic field affects spring migratory direction in a long distance migrant

2010 ◽  
Vol 64 (8) ◽  
pp. 1317-1323 ◽  
Author(s):  
Ian Henshaw ◽  
Thord Fransson ◽  
Sven Jakobsson ◽  
Cecilia Kullberg
Keyword(s):  
Geomagnetic Field ◽  
Long Distance ◽  
Migratory Direction

scholarly journals Ontogenetic development of migration: Lagrangian drift trajectories suggest a new paradigm for sea turtles

2010 ◽  
Vol 7 (50) ◽  
pp. 1319-1327 ◽  
Author(s):  
Graeme C. Hays ◽  
Sabrina Fossette ◽  
Kostas A. Katselidis ◽  
Patrizio Mariani ◽  
Gail Schofield
Keyword(s):  
Climate Change ◽  
Breeding Season ◽  
Sea Turtles ◽  
Rapid Evolution ◽  
New Paradigm ◽  
Breeding Area ◽  
Long Distance ◽  
Environmental Forcing ◽  
Nesting Beaches ◽  
Selection Of

Long distance migration occurs in a wide variety of taxa including birds, insects, fishes, mammals and reptiles. Here, we provide evidence for a new paradigm for the determinants of migration destination. As adults, sea turtles show fidelity to their natal nesting areas and then at the end of the breeding season may migrate to distant foraging sites. For a major rookery in the Mediterranean, we simulated hatchling drift by releasing 288 000 numerical particles in an area close to the nesting beaches. We show that the pattern of adult dispersion from the breeding area reflects the extent of passive dispersion that would be experienced by hatchlings. Hence, the prevailing oceanography around nesting areas may be crucial to the selection of foraging sites used by adult sea turtles. This environmental forcing may allow the rapid evolution of new migration destinations if ocean currents alter with climate change.

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