منابع مشابه
Acetylcholinesterase inhibitors and gait: a steadying hand?
Cognitive impairment, complex movement disorders, and high risk of falls are all interrelated , levodopa-unresponsive symptoms in patients with advanced Parkinson's disease. Although Parkinson's disease is conventionally viewed as a motor syndrome that results from nigrostriatal dopaminergic denervation, there is also an intricate interplay between multisystem degeneration and neurotransmitter ...
متن کاملElectromagnetic Gyroscopic Motion
1 Mathematics Department, Preparatory Year Deanship, UmmAl-Qura University, P.O. Box 5555, Makkah 21955, Saudi Arabia 2 Faculty of Science, Tanta University, P.O. Box 31527, Tanta, Egypt 3 Mathematics Department, Faculty of Girls Education and Science, Taif University, Al-Khurmah Branch, P.O. Box 888, Taif 21974, Saudi Arabia 4 Electricity Department, Faculty of Engineering, Umm Al-Qura Univers...
متن کاملStrongly stable gyroscopic systems
Here, gyroscopic systems are time-invariant systems for which motions can be characterized by properties of a matrix pencil L(λ) = λ2I + λG − C, where GT = −G and C > 0. A strong stability condition is known which depends only on |G| (= (GT G)1/2 ≥ 0) and C. If a system with coefficients G0 and C satisfies this condition then all systems with the same C and with a G satisfying |G| ≥ |G0| are al...
متن کاملTopological mechanics of gyroscopic metamaterials.
Topological mechanical metamaterials are artificial structures whose unusual properties are protected very much like their electronic and optical counterparts. Here, we present an experimental and theoretical study of an active metamaterial--composed of coupled gyroscopes on a lattice--that breaks time-reversal symmetry. The vibrational spectrum displays a sonic gap populated by topologically p...
متن کاملConstructing rules for dismantling ships.
Labor groups, environmental activists, and shipping experts have begun finalizing international guidelines that would reduce threats from toxic substances released during the ship scrapping process and would protect the health and safety of laborers who dismantle ships. In June 2001, government representatives and stakeholders in the ship dismantling industry gathered in Geneva, Switzerland, to...
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ژورنال
عنوان ژورنال: Nature
سال: 1907
ISSN: 0028-0836,1476-4687
DOI: 10.1038/075561a0