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Cross-cultural differences in the association between neuropsychiatric symptoms and Alzheimer's disease (AD) biomarkers are not well understood. This study aimed to (1) compare depressive symptoms and frequency of reported apathy across diagnostic groups of participants with normal cognition (CN), mild cognitive impairment (MCI), and dementia, as well as ethnic groups of Hispanic Americans (HA) and European Americans (EA); (2) evaluate the relationship between depression and apathy with Aβ deposition and brain atrophy. Statistical analyses included ANCOVAs, chi-squared, nonparametric tests, correlations, and logistic regressions. Higher scores on the Geriatric Depression Scale (GDS-15) were reported in the MCI and dementia cohorts, while older age corresponded with lower GDS-15 scores. The frequency of apathy differed across diagnoses within each ethnicity, but not when comparing ethnic groups. Reduced volume in the rostral anterior cingulate cortex (ACC) significantly correlated with and predicted apathy for the total sample after applying false discovery rate corrections (FDR), controlling for covariates. The EA group separately demonstrated a significant negative relationship between apathy and superior frontal volume, while for HA, there was a relationship between rostral ACC volume and apathy. Apathy corresponded with higher Aβ levels for the total sample and for the CN and HA groups. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Commercially available plasma p‐tau217 biomarker tests are not well studied in ethnically diverse samples. METHODS: We evaluated associations between ALZPath plasma p‐tau217 and amyloid‐beta positron emission tomography (Aβ‐PET) in Hispanic/Latino (88% of Cuban or South American ancestry) and non‐Hispanic/Latino older adults. One‐ and two‐cutoff ranges were derived and evaluated to assess agreement with Aβ‐PET. RESULTS: A total of 239 participants underwent blood draw and Aβ‐PET (age 70.8 ± 7.8, 55.2% female, education 15.6 ± 3.4 years, 48.9% Hispanic/Latino, 94.9% white). Plasma p‐tau217 showed excellent discrimination of Aβ‐PET positive and negative participants (visual read: AUC = 0.91 [0.87–0.95], p < 0.001; Centiloids quantification: AUC = 0.90 [0.86–0.94]). There was a greater percent agreement between low p‐tau217 and negative Aβ‐PET (95.8%) than high p‐tau217 and positive Aβ‐PET (86.3%). Analyses within ethnicity‐specific subgroups suggested similar p‐tau217 performance. DISCUSSION: Plasma p‐tau217 (ALZPath) relates to brain Aβ in Hispanic/Latino and non‐Hispanic/Latino older adults. Independent validation and replication are necessary to establish reference ranges and inform appropriate contexts of use across ethno‐racially diverse populations. HIGHLIGHTS: Plasma p‐tau217 (ALZPath) and Aβ‐PET were measured in Hispanic/Latino and non‐Hispanic/Latino older adults.Plasma p‐tau217 accurately discriminated Aβ‐PET positive and negative participants.Applying a two‐cutoff "intermediate" plasma p‐tau217 approach could reduce need for more invasive and costly testing.Plasma p‐tau217 associations with Aβ‐PET were strong within both Hispanic/Latino and non‐Hispanic/Latino groups. [ABSTRACT FROM AUTHOR]

While the availability of low-cost micro electro-mechanical systems (MEMS) accelerometers, gyroscopes, and magnetometers initially seemed to promise the possibility of using them to easily track the position and orientation of virtually any object that they could be attached to, this promise has not yet been fulfilled. Navigation-grade accelerometers and gyroscopes have long been the basis for tracking ships and aircraft, but the signals from low-cost MEMS accelerometers and gyroscopes are still orders of magnitude poorer in quality (e.g., bias stability). Therefore, the applications of MEMS inertial measurement units (IMUs), containing tri-axial accelerometers and gyroscopes, are currently not as extensive as they were expected to be. Even the addition of MEMS tri-axial magnetometers, to conform magnetic, angular rate, and gravity (MARG) sensor modules, has not fully overcome the challenges involved in using these modules for long-term orientation estimation, which would be of great benefit for the tracking of human–computer hand-held controllers or tracking of Internet-Of-Things (IoT) devices. Here, we present an algorithm, GMVDμK (or simply GMVDK), that aims at taking full advantage of all the signals available from a MARG module to robustly estimate its orientation, while preventing damaging overcorrections, within the context of a human–computer interaction application. Through experimental comparison, we show that GMVDK is more robust to magnetic disturbances than three other MARG orientation estimation algorithms in representative trials. [ABSTRACT FROM AUTHOR]

Introduction: This study investigated the role of proactive semantic interference (frPSI) in predicting the progression of amnestic Mild Cognitive Impairment (aMCI) to dementia, taking into account various cognitive and biological factors. Methods: The research involved 89 older adults with aMCI who underwent baseline assessments, including amyloid PET and MRI scans, and were followed longitudinally over a period ranging from 12 to 55 months (average 26.05 months). Results: The findings revealed that more than 30% of the participants diagnosed with aMCI progressed to dementia during the observation period. Using Cox Proportional Hazards modeling and adjusting for demographic factors, global cognitive function, hippocampal volume, and amyloid positivity, two distinct aspects of frPSI were identified as significant predictors of a faster decline to dementia. These aspects were fewer correct responses on a frPSI trial and a higher number of semantic intrusion errors on the same trial, with 29.5% and 31.6 % increases in the likelihood of more rapid progression to dementia, respectively. Discussion: These findings after adjustment for demographic and biological markers of Alzheimer's Disease, suggest that assessing frPSI may offer valuable insights into the risk of dementia progression in individuals with aMCI. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Alzheimer's disease studies often lack ethnic diversity. METHODS: We evaluated associations between plasma biomarkers commonly studied in Alzheimer's (p‐tau181, GFAP, and NfL), clinical diagnosis (clinically normal, amnestic MCI, amnestic dementia, or non‐amnestic MCI/dementia), and Aβ‐PET in Hispanic and non‐Hispanic older adults. Hispanics were predominantly of Cuban or South American ancestry. RESULTS: Three‐hundred seventy nine participants underwent blood draw (71.9 ± 7.8 years old, 60.2% female, 57% Hispanic of which 88% were Cuban or South American) and 240 completed Aβ‐PET. P‐tau181 was higher in amnestic MCI (p = 0.004, d = 0.53) and dementia (p < 0.001, d = 0.97) than in clinically normal participants and discriminated Aβ‐PET[+] and Aβ‐PET[‐] (AUC = 0.86). P‐tau181 outperformed GFAP and NfL. There were no significant interactions with ethnicity. Among amnestic MCI, Hispanics had lower odds of elevated p‐tau181 than non‐Hispanic (OR = 0.41, p = 0.006). DISCUSSION: Plasma p‐tau181 informs etiological diagnosis of cognitively impaired Hispanic and non‐Hispanic older adults. Hispanic ethnicity may relate to greater likelihood of non‐Alzheimer's contributions to memory loss. Highlights: Alzheimer's biomarkers were measured in Hispanic and non‐Hispanic older adults.Plasma p‐tau181 related to amnestic cognitive decline and brain amyloid burden.AD biomarker associations did not differ between Hispanic and non‐Hispanic ethnicity.Hispanic individuals may be more likely to have non‐Alzheimer causes of memory loss. [ABSTRACT FROM AUTHOR]