scholarly journals Stochastic non-linear oscillator models of EEG: the Alzheimer's disease case

2015 ◽  
Vol 9 ◽  
Author(s):  
Parham Ghorbanian ◽  
Subramanian Ramakrishnan ◽  
Hashem Ashrafiuon
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Linear Oscillator ◽  
Disease Case ◽  
Non Linear ◽  
Non Linear Oscillator ◽  
Oscillator Models

scholarly journals Non-linear oscillator models for the X-ray bursting of the microquasar GRS 1915+105

2014 ◽  
Vol 352 (2) ◽  
pp. 699-714 ◽  
Author(s):  
E. Massaro ◽  
A. Ardito ◽  
P. Ricciardi ◽  
F. Massa ◽  
T. Mineo ◽  
...  
Keyword(s):  
Linear Oscillator ◽  
X Ray ◽  
Non Linear ◽  
Non Linear Oscillator ◽  
Oscillator Models

Case Studies in Dementia-Related Anxiety

GeroPsych ◽  
2020 ◽  
pp. 1-6
Author(s):  
Molly Maxfield ◽  
Jennifer R. Roberts ◽  
JoAnna Dieker
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Social Withdrawal ◽  
Cognitive Status ◽  
Generalized Anxiety ◽  
Neurocognitive Disorder ◽  
High Genetic Risk ◽  
Disease Case ◽  
Negative Perceptions

Abstract. Two clients seeking neuropsychological assessment reported anxiety about their cognitive status. We review the cases to increase our understanding of factors contributing to dementia-related anxiety. Case 1 met the criteria for mild neurocognitive disorder; the client’s memory was impaired, and she had a high genetic risk for Alzheimer’s disease. The client reported anxiety about negative perceptions of quality of life among individuals diagnosed with Alzheimer’s disease. Case 2 did not meet the criteria for a neurocognitive disorder. Anxiety about this client’s cognitive status appeared attributable to generalized anxiety disorder, given his anxiety about diverse topics. Both clients reported embarrassment about forgetfulness and social withdrawal. Dementia-related anxiety is believed to be relatively common, to exist on a continuum, to have unique social implications, and to stem from various sources, necessitating differing interventions.

scholarly journals Oral infections and orofacial pain in Alzheimer's disease: case report and review

2010 ◽  
Vol 4 (2) ◽  
pp. 145-150 ◽  
Author(s):  
Silvia Regina Dowgan T. de Siqueira ◽  
Thaís de Souza Rolim ◽  
Manoel Jacobsen Teixeira ◽  
Ricardo Nitrini ◽  
Renato Anghinah ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Facial Pain ◽  
Orofacial Pain ◽  
The Elderly ◽  
Secondary Headache ◽  
Behavioral Impairment ◽  
Common Cause ◽  
Oral Infections ◽  
Disease Case

Abstract Dental infections, frequent in the general population, are a common cause of inflammation with systemic impact, and are the most common cause of orofacial pain. Temporomandibular disorders are also frequent in the elderly and represent an important cause of secondary headache. Both inflammation and pain can also contribute to cognitive, functional and behavioral impairment of the elderly and aggravate symptoms of patients with Alzheimer's disease (AD). We report a case of a 74-year-old woman with AD and chronic facial pain who had a significant improvement in functional activities as well as in cognition and depressive symptoms after successful treatment of her facial pain. Patients with AD have higher compromise of oral health with infections and teeth loss. The investigation of orofacial pain should be performed in patients with AD, because of the associations reviewed and given the potential for improvement as highlighted by this case.

scholarly journals FMRI Functional Connectivity Evaluation in Alzheimer’s Stages: Linear and Non-Linear Approaches

2021 ◽  
Author(s):  
Hessam Ahmadi ◽  
Emad Fatemizadeh ◽  
Ali Motie Nasrabadi
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Functional Connectivity ◽  
Permutation Test ◽  
Pearson Correlation ◽  
Functional Integration ◽  
Clustering Coefficient ◽  
Kernel Trick ◽  
Non Linear ◽  
The Brain

Abstract Neuroimaging data analysis reveals the underlying interactions in the brain. It is essential, yet controversial, to choose a proper tool to manifest brain functional connectivity. In this regard, researchers have not reached a definitive conclusion between the linear and non-linear approaches, as both have pros and cons. In this study, to evaluate this concern, the functional Magnetic Resonance Imaging (fMRI) data of different stages of Alzheimer’s disease are investigated. In the linear approach, the Pearson Correlation Coefficient (PCC) is employed as a common technique to generate brain functional graphs. On the other hand, for non-linear approaches, two methods including Distance Correlation (DC) and the kernel trick are utilized. By the use of the three mentioned routines and graph theory, functional brain networks of all stages of Alzheimer’s disease (AD) are constructed and then sparsed. Afterwards, graph global measures are calculated over the networks and a non-parametric permutation test is conducted. Results reveal that the non-linear approaches have more potential to discriminate groups in all stages of AD. Moreover, the kernel trick method is more powerful in comparison to the DC technique. Nevertheless, AD degenerates the brain functional graphs more at the beginning stages of the disease. At the first phase, both functional integration and segregation of the brain degrades, and as AD progressed brain functional segregation further declines. The most distinguishable feature in all stages is the clustering coefficient that reflects brain functional segregation.

On Categorization of Seismic Load As Primary or Secondary for Piping Systems With Hardening Capacity

2018 ◽  
Author(s):  
Pierre B. Labbé
Keyword(s):  
Natural Frequency ◽  
Response Spectrum ◽  
A Priori ◽  
Effective Stiffness ◽  
Linear Oscillator ◽  
Seismic Load ◽  
Wide Range ◽  
Non Linear ◽  
Piping Systems ◽  
Non Linear Oscillator

The concept of primary/secondary categorization is first reviewed and generalized for its application to a non-linear oscillator subjected to a seismic load. Categorizing the seismic load requires calculating the input level associated with the oscillator ultimate capacity and comparing it to the level associated with the plastic yield. To resolve this problem, it is assumed that the non-linear oscillator behaves like a linear equivalent oscillator, with an effective stiffness (or frequency) and an effective damping. However, as it is not a priori possible to predict the equivalent stiffness and damping, a wide range of possibilities is systematically considered. The input motion is represented by its conventional response spectrum. It turns out that key parameters for categorization are i) the “effective stiffness factor” (varying from 0 for perfect damage behaviour to 1 for elastic-perfectly plastic) and the slope of the response spectrum in the vicinity of the natural frequency of the oscillator. Effective damping and spectrum sensitivity to damping play a second order role. A formula is presented that enables the calculation of the primary part of a seismically induced stress as a function of both the oscillator and input spectrum features. The formula is also presented in the form of a diagram. This paper follows-up on a similar paper presented by the author at the PVP 2017 Conference [1]. The new development introduced here is that the oscillator exhibits hardening capacity, while no hardening was assumed in [1]. It appears that the conclusions are slightly modified but the trend is very similar to the non-hardening case. Regarding piping systems, it appears that even when experiencing large plastic strains under beyond design input motions, their observed effective frequency is very close to their natural frequency, decreasing only by a few percents (experimental data from USA, Japan and India are processed). These observations lead to the conclusion that the seismic load, or the seismically induced inertial seismic strains, should basically be regarded as secondary.

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