Derivation of memory function from its equation of motion

2003 ◽  
Vol 41 (6) ◽  
pp. 567-574 ◽  
Author(s):  
Shaminder Singh ◽  
Sunita Srivastava ◽  
C.N. Kumar ◽  
K. Tankeshwar*
2021 ◽  
Vol 63 (12) ◽  
pp. 2009
Author(s):  
Д.А. Конюх

In the frame of the random matrix theory, it was shown, that the relaxation of the projection of the initial plane wave with the wave vector q is described by the equation of motion with the memory function which corresponds to the complex dynamical Young modulus E(ω). In the harmonic scalar model of displacements with the absence of energy dissipation, the Ioffe-Regel crossover arises universally in amorphous systems with the dimension d≥3. Vibrations above the Ioffe-Regel crossover are related to the diffusive nature and can be described by the diffusion equation with the damping Γ(q)∝ q².


2010 ◽  
Vol 34 (8) ◽  
pp. S18-S18
Author(s):  
Wei Jiang ◽  
Enyi Wen ◽  
Min Gong ◽  
Yang Bi ◽  
Xiaojuan Zhang ◽  
...  

Author(s):  
Sunmin Park ◽  
Sunna Kang ◽  
Da Sol Kim

Abstract. Folate and vitamin B12(V-B12) deficiencies are associated with metabolic diseases that may impair memory function. We hypothesized that folate and V-B12 may differently alter mild cognitive impairment, glucose metabolism, and inflammation by modulating the gut microbiome in rats with Alzheimer’s disease (AD)-like dementia. The hypothesis was examined in hippocampal amyloid-β infused rats, and its mechanism was explored. Rats that received an amyloid-β(25–35) infusion into the CA1 region of the hippocampus were fed either control(2.5 mg folate plus 25 μg V-B12/kg diet; AD-CON, n = 10), no folate(0 folate plus 25 μg V-B12/kg diet; AD-FA, n = 10), no V-B12(2.5 mg folate plus 0 μg V-B12/kg diet; AD-V-B12, n = 10), or no folate plus no V-B12(0 mg folate plus 0 μg V-B12/kg diet; AD-FAB12, n = 10) in high-fat diets for 8 weeks. AD-FA and AD-VB12 exacerbated bone mineral loss in the lumbar spine and femur whereas AD-FA lowered lean body mass in the hip compared to AD-CON(P < 0.05). Only AD-FAB12 exacerbated memory impairment by 1.3 and 1.4 folds, respectively, as measured by passive avoidance and water maze tests, compared to AD-CON(P < 0.01). Hippocampal insulin signaling and neuroinflammation were attenuated in AD-CON compared to Non-AD-CON. AD-FAB12 impaired the signaling (pAkt→pGSK-3β) and serum TNF-α and IL-1β levels the most among all groups. AD-CON decreased glucose tolerance by increasing insulin resistance compared to Non-AD-CON. AD-VB12 and AD-FAB12 increased insulin resistance by 1.2 and 1.3 folds, respectively, compared to the AD-CON. AD-CON and Non-AD-CON had a separate communities of gut microbiota. The relative counts of Bacteroidia were lower and those of Clostridia were higher in AD-CON than Non-AD-CON. AD-FA, but not V-B12, separated the gut microbiome community compared to AD-CON and AD-VB12(P = 0.009). In conclusion, folate and B-12 deficiencies impaired memory function by impairing hippocampal insulin signaling and gut microbiota in AD rats.


GeroPsych ◽  
2014 ◽  
Vol 27 (4) ◽  
pp. 161-169 ◽  
Author(s):  
Nienke A. Hofrichter ◽  
Sandra Dick ◽  
Thomas G. Riemer ◽  
Carsten Schleussner ◽  
Monique Goerke ◽  
...  

Hippocampal dysfunction and deficits in episodic memory have been reported for both Alzheimer’s disease (AD) and major depressive disorder (MDD). Primacy performance has been associated with hippocampus-dependent episodic memory, while recency may reflect working memory performance. In this study, serial position profiles were examined in a total of 73 patients with MDD, AD, both AD and MDD, and healthy controls (HC) by means of CERAD-NP word list memory. Primacy performance was most impaired in AD with comorbid MDD, followed by AD, MDD, and HC. Recency performance, on the other hand, was comparable across groups. These findings indicate that primacy in AD is impaired in the presence of comorbid MDD, suggesting additive performance decrements in this specific episodic memory function.


2014 ◽  
Author(s):  
Mitchell Metzger ◽  
Morgan Myers ◽  
Emily Embrescia ◽  
David F. Vanata

2013 ◽  
Author(s):  
Gurinder S. Bains ◽  
Lee Berk ◽  
Noha Daher ◽  
Pooja Deshpande ◽  
Everett Lohman ◽  
...  

2012 ◽  
Vol 8 (1) ◽  
pp. 1-15
Author(s):  
Gy. Sitkei

Motion of particles with air resistance (e.g. horizontal and inclined throwing) plays an important role in many technological processes in agriculture, wood industry and several other fields. Although, the basic equation of motion of this problem is well known, however, the solutions for practical applications are not sufficient. In this article working diagrams were developed for quick estimation of the throwing distance and the terminal velocity. Approximate solution procedures are presented in closed form with acceptable error. The working diagrams provide with arbitrary initial conditions in dimensionless form of general validity.


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