120 research outputs found
Development and Validation of the Alzheimer’s Questionnaire
This series of studies was carried in order to develop and validate the Alzheimer’s Questionnaire (AQ). The underlying rationale for the creation of the AQ was to provide clinicians with a brief and easy-to-use informant-based assessment of symptoms associated with Alzheimer’s disease (AD). Initial studies of the AQ found that it has both high sensitivity and high specificity for differentiating individuals with AD and its prodrome, amnestic mild cognitive impairment (MCI). The AQ’s accuracy in identifying MCI was explored further in an additional study which sought to determine which items on the AQ were best predicted the presence of MCI. Four items were strongly associated with MCI which were: repetition of statements and/or questions [OR = 13.20 (3.02, 57.66)]; trouble knowing the day, date, month, year, and time [OR = 17.97 (2.63, 122.77)]; difficulty managing finances [OR = 11.60 (2.10, 63.99)]; and decreased sense of direction [OR = 5.84(1.09, 31.30)]. Concurrent validity was established through another study which found that the AQ correlated moderately with the MMSE (r = -0.56) and MoCA (r = -0.46) while a strong correlation (r = 0.79) was found with the Clinical Dementia Rating Sum of Boxes (CDR-SOB). Additional work found that the AQ correlated well with formal neuropsychological measures of episodic memory and executive function. Longitudinal analyses found that was AQ was a significant predictor of clinically meaningful decline as measured by the changes in CDR Global Score (OR = 1.20, 95% CI: 1.09, 1.32; p<0.001). In addition, AQ identified clinically meaningful change among MCI cases at a greater rate(24%) than the MMSE (17%). This series of studies demonstrates that the AQ is an accurate instrument that correlates well with known measures of MCI and AD
A NOVEL METHOD FOR SYNTHESIS OF METASTABLE TETRAGONAL ZIRCONIA NANOPOWDERS AT LOW TEMPERATURES
Zirconia (ZrO2) nanopowder was synthesized using sucrose and fructose as a chelating agent from zirconium hydroxide. The synthesized powders were characterized by X-ray diffraction (XRD), simultaneously thermal analysis (STA), BET surface area, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The above-experimental results showed that the synthesized powders had particle sizes in the range 40-60 nm and mean crystallite sizes of 7-8 nm. Finally, in this research, chelating agents of sucrose and fructose were compared and the obtained results demonstrated that using fructose, nanopowder of zirconia with tetragonal phase was obtained
Psychiatric disorders in Iranian children and adolescents
Objective: The aim of the present study was to investigate the epidemiology of psychiatric disorders in children and adolescents in five provinces of Iran: Tehran, Shiraz, Isfahan, Tabriz and Mashhad. Method: In the present study, we selected 9,636 children and adolescents aged 6-18 years through multistage cluster random sampling method from Tehran, Shiraz, Isfahan, Tabriz and Mashhad. We instructed the clinical psychologists to complete the Strengths and Difficulties Questionnaire (SDQ) for the participants, and those who received a high score on SDQ, completed the Persian version of Kiddie-SADS-Present and Lifetime Version (K-SADS-PL). We used descriptive analysis and 95 confidence interval to investigate the relationship between scores of the K- SADS questionnaire and demographic factors . We used one-way ANOVA to test the significant differences among the disorders according to sex, age and province of residence. Results: Based on the results, oppositional defiant disorder (ODD) (4.45) had the highest prevalence of psychiatric disorders in the five provinces and substance abuse and alcohol abuse (0) had the lowest prevalence. In addition, attention deficit hyperactivity disorder (ADHD) had the most prevalence in boys (5.03) and ODD had the most prevalence in girls (4.05). Among the three age groups, 6 to 9 year olds had the highest rates of ADHD (5.69); 10 to 14 and 15 to 18 year olds had the highest rates of ODD (4.32 and 4.37 respectively). Among the five provinces, Tehran and Mashhad allocated the highest rates of ODD; Isfahan and Shiraz had the highest rates of ADHD; and Tabriz had the highest rates of social phobia. Conclusion: The current study revealed that the overall frequency of psychiatric disorders based on Kiddie- SADS-Present and Lifetime Version (K-SADS-PL) was higher than a similar study. Moreover, in this study, among the five provinces, Tehran and Mashhad allocated the highest rates of ODD; Isfahan and Shiraz had the highest rates of ADHD; and Tabriz had the highest rates of social phobia. Therefore, these percentage of psychiatric disorders in Iran lead us toward a greater use of consultation and mental health services
Plasma NfL is associated with the APOE ε4 allele, brain imaging measurements of neurodegeneration, and lower recall memory scores in cognitively unimpaired late-middle-aged and older adults
BACKGROUND: Plasma neurofilament light (NfL) is an indicator of neurodegeneration and/or neuroaxonal injury in persons with Alzheimer's disease (AD) and a wide range of other neurological disorders. Here, we characterized and compared plasma NfL concentrations in cognitively unimpaired (CU) late-middle-aged and older adults with two, one, or no copies of the APOE ε4 allele, the major genetic risk factor for AD. We then assessed plasma NfL associations with brain imaging measurements of AD-related neurodegeneration (hippocampal atrophy and a hypometabolic convergence index [HCI]), brain imaging measurements of amyloid-β plaque burden, tau tangle burden and white matter hyperintensity volume (WMHV), and delayed and total recall memory scores. METHODS: Plasma NfL concentrations were measured in 543 CU 69 ± 9 year-old participants in the Arizona APOE Cohort Study, including 66 APOE ε4 homozygotes (HM), 165 heterozygotes (HT), and 312 non-carriers (NC). Robust regression models were used to characterize plasma NfL associations with APOE ε4 allelic dose before and after adjustment for age, sex, and education. They were also used to characterize plasma NfL associations with MRI-based hippocampal volume and WMHV measurements, an FDG PET-based HCI, mean cortical PiB PET measurements of amyloid-β plaque burden and meta-region-of-interest (meta-ROI) flortaucipir PET measurements of tau tangle burden, and Auditory Verbal Learning Test (AVLT) Delayed and Total Recall Memory scores. RESULTS: After the adjustments noted above, plasma NfL levels were significantly greater in APOE ε4 homozygotes and heterozygotes than non-carriers and significantly associated with smaller hippocampal volumes (r = - 0.43), greater tangle burden in the entorhinal cortex and inferior temporal lobes (r = 0.49, r = 0.52, respectively), and lower delayed (r = - 0.27), and total (r = - 0.27) recall memory scores (p < 0.001). NfL levels were not significantly associated with PET measurements of amyloid-β plaque or total tangle burden. CONCLUSIONS: Plasma NfL concentrations are associated with the APOE ε4 allele, brain imaging biomarkers of neurodegeneration, and less good recall memory in CU late-middle-aged and older adults, supporting its value as an indicator of neurodegeneration in the preclinical study of AD
Psychiatric disorders in Iranian children and adolescents
Objective: The aim of the present study was to investigate the epidemiology of psychiatric disorders in children and adolescents in five provinces of Iran: Tehran, Shiraz, Isfahan, Tabriz and Mashhad. Method: In the present study, we selected 9,636 children and adolescents aged 6-18 years through multistage cluster random sampling method from Tehran, Shiraz, Isfahan, Tabriz and Mashhad. We instructed the clinical psychologists to complete the Strengths and Difficulties Questionnaire (SDQ) for the participants, and those who received a high score on SDQ, completed the Persian version of Kiddie-SADS-Present and Lifetime Version (K-SADS-PL). We used descriptive analysis and 95 confidence interval to investigate the relationship between scores of the K- SADS questionnaire and demographic factors . We used one-way ANOVA to test the significant differences among the disorders according to sex, age and province of residence. Results: Based on the results, oppositional defiant disorder (ODD) (4.45) had the highest prevalence of psychiatric disorders in the five provinces and substance abuse and alcohol abuse (0) had the lowest prevalence. In addition, attention deficit hyperactivity disorder (ADHD) had the most prevalence in boys (5.03) and ODD had the most prevalence in girls (4.05). Among the three age groups, 6 to 9 year olds had the highest rates of ADHD (5.69); 10 to 14 and 15 to 18 year olds had the highest rates of ODD (4.32 and 4.37 respectively). Among the five provinces, Tehran and Mashhad allocated the highest rates of ODD; Isfahan and Shiraz had the highest rates of ADHD; and Tabriz had the highest rates of social phobia. Conclusion: The current study revealed that the overall frequency of psychiatric disorders based on Kiddie- SADS-Present and Lifetime Version (K-SADS-PL) was higher than a similar study. Moreover, in this study, among the five provinces, Tehran and Mashhad allocated the highest rates of ODD; Isfahan and Shiraz had the highest rates of ADHD; and Tabriz had the highest rates of social phobia. Therefore, these percentage of psychiatric disorders in Iran lead us toward a greater use of consultation and mental health services
A classification system for teachers’ motivational behaviors recommended in self-determination theory interventions
Teachers’ behavior is a key factor that influences students’ motivation. Many theoretical models have tried to explain this influence, with one of the most thoroughly researched being self-determination theory (SDT). We used a Delphi method to create a classification of teacher behaviors consistent with SDT. This is useful because SDT-based interventions have been widely used to improve educational outcomes. However, these interventions contain many components. Reliably classifying and labeling those components is essential for implementation, reproducibility, and evidence synthesis. We used an international expert panel (N = 34) to develop this classification system. We started by identifying behaviors from existing literature, then refined labels, descriptions, and examples using the Delphi panel’s input. Next, the panel of experts iteratively rated the relevance of each behavior to SDT, the psychological need that each behavior influenced, and its likely effect on motivation. To create a mutually exclusive and collectively exhaustive list of behaviors, experts nominated overlapping behaviors that were redundant, and suggested new ones missing from the classification. After three rounds, the expert panel agreed upon 57 teacher motivational behaviors (TMBs) that were consistent with SDT. For most behaviors (77%), experts reached consensus on both the most relevant psychological need and influence on motivation. Our classification system provides a comprehensive list of TMBs and consistent terminology in how those behaviors are labeled. Researchers and practitioners designing interventions could use these behaviors to design interventions, to reproduce interventions, to assess whether these behaviors moderate intervention effects, and could focus new research on areas where experts disagreed. (PsycInfo Database Record (c) 2023 APA, all rights reserved
A classification system for teachers’ motivational behaviors recommended in self-determination theory interventions.
Teachers’ behavior is a key factor that influences students’ motivation. Many theoretical models have tried to explain this influence, with one of the most thoroughly researched being self-determination theory (SDT). We used a Delphi method to create a classification of teacher behaviors consistent with SDT. This is useful because SDT-based interventions have been widely used to improve educational outcomes. However, these interventions contain many components. Reliably classifying and labeling those components is essential for implementation, reproducibility, and evidence synthesis.We used an international expert panel (N = 34) to develop this classification system. We started by identifying behaviors from existing literature, then refined labels, descriptions, and examples using the Delphi panel’s input. Next, the panel of experts iteratively rated the relevance of each behavior to SDT, the psychological need that each behavior influenced, and its likely effect on motivation. To create a mutually exclusive and collectively exhaustive list of behaviors, experts nominated overlapping behaviors that were redundant, and suggested new ones missing from the classification. After three rounds, the expert panel agreed upon 57 teacher motivational behaviors (TMBs) that were consistent with SDT. For most behaviors (77%), experts reached consensus on both the most relevant psychological need and influence on motivation. Our classification system provides a comprehensive list of TMBs and consistent terminology in how those behaviors are labeled. Researchers and practitioners designing interventions could use these behaviors to design interventions, to reproduce interventions, to assess whether these behaviors moderate intervention effects, and could focus new research on areas where experts disagreed
Informant-reported cognitive symptoms that predict amnestic mild cognitive impairment
<p>Abstract</p> <p>Background</p> <p>Differentiating amnestic mild cognitive impairment (aMCI) from normal cognition is difficult in clinical settings. Self-reported and informant-reported memory complaints occur often in both clinical groups, which then necessitates the use of a comprehensive neuropsychological examination to make a differential diagnosis. However, the ability to identify cognitive symptoms that are predictive of aMCI through informant-based information may provide some clinical utility in accurately identifying individuals who are at risk for developing Alzheimer's disease (AD).</p> <p>Methods</p> <p>The current study utilized a case-control design using data from an ongoing validation study of the Alzheimer's Questionnaire (AQ), an informant-based dementia assessment. Data from 51 cognitively normal (CN) individuals participating in a brain donation program and 47 aMCI individuals seen in a neurology practice at the same institute were analyzed to determine which AQ items differentiated aMCI from CN individuals.</p> <p>Results</p> <p>Forward stepwise multiple logistic regression analysis which controlled for age and education showed that 4 AQ items were strong indicators of aMCI which included: repetition of statements and/or questions [OR 13.20 (3.02, 57.66)]; trouble knowing the day, date, month, year, and time [OR 17.97 (2.63, 122.77)]; difficulty managing finances [OR 11.60 (2.10, 63.99)]; and decreased sense of direction [OR 5.84 (1.09, 31.30)].</p> <p>Conclusions</p> <p>Overall, these data indicate that certain informant-reported cognitive symptoms may help clinicians differentiate individuals with aMCI from those with normal cognition. Items pertaining to repetition of statements, orientation, ability to manage finances, and visuospatial disorientation had high discriminatory power.</p
Dynamic temporary blood facility location-allocation during and post-disaster periods
The key objective of this study is to develop a tool (hybridization or integration of different techniques) for locating the temporary blood banks during and post-disaster conditions that could serve the hospitals with minimum response time. We have used temporary blood centers, which must be located in such a way that it is able to serve the demand of hospitals in nearby region within a shorter duration. We are locating the temporary blood centres for which we are minimizing the maximum distance with hospitals. We have used Tabu search heuristic method to calculate the optimal number of temporary blood centres considering cost components. In addition, we employ Bayesian belief network to prioritize the factors for locating the temporary blood facilities. Workability of our model and methodology is illustrated using a case study including blood centres and hospitals surrounding Jamshedpur city. Our results shows that at-least 6 temporary blood facilities are required to satisfy the demand of blood during and post-disaster periods in Jamshedpur. The results also show that that past disaster conditions, response time and convenience for access are the most important factors for locating the temporary blood facilities during and post-disaster periods
Morphological and Pathological Evolution of the Brain Microcirculation in Aging and Alzheimer’s Disease
Key pathological hallmarks of Alzheimer’s disease (AD), including amyloid plaques, cerebral amyloid angiopathy (CAA) and neurofibrillary tangles do not completely account for cognitive impairment, therefore other factors such as cardiovascular and cerebrovascular pathologies, may contribute to AD. In order to elucidate the microvascular changes that contribute to aging and disease, direct neuropathological staining and immunohistochemistry, were used to quantify the structural integrity of the microvasculature and its innervation in three oldest-old cohorts: 1) nonagenarians with AD and a high amyloid plaque load; 2) nonagenarians with no dementia and a high amyloid plaque load; 3) nonagenarians without dementia or amyloid plaques. In addition, a non-demented (ND) group (average age 71 years) with no amyloid plaques was included for comparison. While gray matter thickness and overall brain mass were reduced in AD compared to ND control groups, overall capillary density was not different. However, degenerated string capillaries were elevated in AD, potentially suggesting greater microvascular “dysfunction” compared to ND groups. Intriguingly, apolipoprotein ε4 carriers had significantly higher string vessel counts relative to non-ε4 carriers. Taken together, these data suggest a concomitant loss of functional capillaries and brain volume in AD subjects. We also demonstrated a trend of decreasing vesicular acetylcholine transporter staining, a marker of cortical cholinergic afferents that contribute to arteriolar vasoregulation, in AD compared to ND control groups, suggesting impaired control of vasodilation in AD subjects. In addition, tyrosine hydroxylase, a marker of noradrenergic vascular innervation, was reduced which may also contribute to a loss of control of vasoconstriction. The data highlight the importance of the brain microcirculation in the pathogenesis and evolution of AD
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