Calibration of double stripe 3D laser scanner systems using planarity and orthogonality constraints

In this study, 3D scanning systems that utilize a pair of laser stripes are studied. Three types of scanning systems are implemented to scan environments, rough surfaces of near planar objects and small 3D objects. These scanners make use of double laser stripes to minimize the undesired effect of occlusions. Calibration of these scanning systems is crucially important for the alignment of 3D points which are reconstructed from different stripes. In this paper, the main focus is on the calibration problem, following a treatment on the pre-processing of stripe projections using dynamic programming and localization of 2D image points with sub-pixel accuracy. The 3D points corresponding to laser stripes are used in an optimization procedure that imposes geometrical constraints such as coplanarities and orthogonalities. It is shown that, calibration procedure proposed here, significantly improves the alignment of 3D points scanned using two laser stripes

Stoics against stoics in Cudworth's "A Treatise of Freewill"

In his 'A Treatise of Freewill', Ralph Cudworth argues against Stoic determinism by drawing on what he takes to be other concepts found in Stoicism, notably the claim that some things are ‘up to us’ and that these things are the product of our choice. These concepts are central to the late Stoic Epictetus and it appears at first glance as if Cudworth is opposing late Stoic voluntarism against early Stoic determinism. This paper argues that in fact, despite his claim to be drawing on Stoic doctrine, Cudworth uses these terms with a meaning first articulated only later, by the Peripatetic commentator Alexander of Aphrodisias

Pittsburgh compound B imaging and cerebrospinal fluid amyloid-β in a multicentre European memory clinic study

The aim of this study was to assess the agreement between data on cerebral amyloidosis, derived using Pittsburgh compound B positron emission tomography and (i) multi-laboratory INNOTEST enzyme linked immunosorbent assay derived cerebrospinal fluid concentrations of amyloid-β 42 ; (ii) centrally measured cerebrospinal fluid amyloid-β 42 using a Meso Scale Discovery enzyme linked immunosorbent assay; and (iii) cerebrospinal fluid amyloid-β 42 centrally measured using an antibody-independent mass spectrometry-based reference method. Moreover, we examined the hypothesis that discordance between amyloid biomarker measurements may be due to interindividual differences in total amyloid-β production, by using the ratio of amyloid-β 42 to amyloid-β 40 . Our study population consisted of 243 subjects from seven centres belonging to the Biomarkers for Alzheimer’s and Parkinson’s Disease Initiative, and included subjects with normal cognition and patients with mild cognitive impairment, Alzheimer’s disease dementia, frontotemporal dementia, and vascular dementia. All had Pittsburgh compound B positron emission tomography data, cerebrospinal fluid INNOTEST amyloid-β 42 values, and cerebrospinal fluid samples available for reanalysis. Cerebrospinal fluid samples were reanalysed (amyloid-β 42 and amyloid-β 40 ) using Meso Scale Discovery electrochemiluminescence enzyme linked immunosorbent assay technology, and a novel, antibody-independent, mass spectrometry reference method. Pittsburgh compound B standardized uptake value ratio results were scaled using the Centiloid method. Concordance between Meso Scale Discovery/mass spectrometry reference measurement procedure findings and Pittsburgh compound B was high in subjects with mild cognitive impairment and Alzheimer’s disease, while more variable results were observed for cognitively normal and non-Alzheimer’s disease groups. Agreement between Pittsburgh compound B classification and Meso Scale Discovery/mass spectrometry reference measurement procedure findings was further improved when using amyloid-β 42/40 . Agreement between Pittsburgh compound B visual ratings and Centiloids was near complete. Despite improved agreement between Pittsburgh compound B and centrally analysed cerebrospinal fluid, a minority of subjects showed discordant findings. While future studies are needed, our results suggest that amyloid biomarker results may not be interchangeable in some individuals

Can machine learning help reveal the competitive advantage of elite beach volleyball players?

As the world of competitive sports increasingly embraces data-driven techniques, our research explores the potential of machine learning in distinguishing elite from semi-elite beach volleyball players. This study is motivated by the need to understand the subtle yet crucial differences in player movements that contribute to high-level performance in beach volleyball. Utilizing advanced machine learning techniques, we analyzed specific movement patterns of the motion of the torso during spikes, captured through vest-mounted accelerometers. Our approach offers novel insights into the nuanced dynamics of elite play, revealing that certain movement patterns are distinctly characteristic of higher skill levels. One of our key contributions is the ability to classify spiking movements at different skill levels with an accuracy rate as high as 87%. This current research provides a foundation of what separates elite players from their semi-elite counterparts

Current Capacity for Diagnosing Alzheimer’s Disease in Germany and Implications for Wait Times

Background:Amyloid-targeting therapies for Alzheimer’s disease (AD) might become available in Germany soon. The combination of a large pool of prevalent cases and a complex diagnostic process to determine eligibility for these treatments is likely to challenge health systems’ capacity. Objective:To analyze Germany’s healthcare system capacity to identify treatment-eligible patients in a timely and equitable manner. Methods:We modeled patients’ diagnostic journey and projects wait times due to capacity constraints for AD specialist visits and PET scans from 2024 to 2043. Model parameters were derived from published data and expert input. Results:Wait times would be ∼50 months over the model horizon, if patients were referred to specialists based on a brief cognitive assessment in primary care. Wait times for patients with social health insurance are projected to be 1.9 times those of patients with private insurance, with peak wait times of around 76 and 40 months, respectively. Adding a blood test for the AD pathology as additional triage step would reduce wait times to below 24 months. Conclusions:In spite of having a well-resourced health system, Germany is projected to be unable to cope with the demand for biomarker-based AD diagnosis, if a disease-modifying AD treatment were introduced. As these treatments might become available by the end of 2024, decisive action, in particular dissemination of high-performing AD blood tests for triage in primary care, will be needed to prevent delays in access and potentially avoidable and inequitable disease progression

Synapse loss in the prefrontal cortex is associated with cognitive decline in amyotrophic lateral sclerosis

In addition to motor neurone degeneration, up to 50% of amyotrophic lateral sclerosis (ALS) patients present with cognitive decline. Understanding the neurobiological changes underlying these cognitive deficits is critical, as cognitively impaired patients exhibit a shorter survival time from symptom onset. Given the pathogenic role of synapse loss in other neurodegenerative diseases in which cognitive decline is apparent, such as Alzheimer's disease, we aimed to assess synaptic integrity in the ALS brain. Here, we have applied a unique combination of high-resolution imaging of post-mortem tissue with neuropathology, genetic screening and cognitive profiling of ALS cases. Analyses of more than 1 million synapses using two complimentary high-resolution techniques (electron microscopy and array tomography) revealed a loss of synapses from the prefrontal cortex of ALS patients. Importantly, synapse loss was significantly greater in cognitively impaired cases and was not due to cortical atrophy, nor associated with dementia-associated neuropathology. Interestingly, we found a trend between pTDP-43 pathology and synapse loss in the frontal cortex and discovered pTDP-43 puncta at a subset of synapses in the ALS brains. From these data, we postulate that synapse loss in the prefrontal cortex represents an underlying neurobiological substrate of cognitive decline in ALS

Jigsaw Puzzling Taps Multiple Cognitive Abilities and Is a Potential Protective Factor for Cognitive Aging

Prevention of neurocognitive disorders is currently one of the greatest unmet medical challenges. The cognitive effects of solving jigsaw puzzles (JPs) have not been studied so far, despite its frequent use as a leisure activity in all age cohorts worldwide. This study aimed at closing this gap between a lack of science and a frequent real-world use by investigating the cognitive abilities recruited by JP as well as the cognitive benefits of lifetime and 30-day JP experience. A total of 100 cognitively healthy adults (≥50 years of age) were randomized to either a 30-day home-based JP intervention (≥1 h/day) plus four sessions of cognitive health counseling (JP group) or four sessions of cognitive health counseling only (counseling group). We measured global visuospatial cognition by averaging the scores of eight z-standardized visuospatial cognitive abilities (perception, constructional praxis, mental rotation, speed, flexibility, working memory, reasoning, and episodic memory). JP skill was assessed with an untrained 40 piece JP and lifetime JP experience with retrospective self-report. JP skill was associated with all assessed cognitive abilities (rs ≥ 0.45, ps < 0.001), and global visuospatial cognition (r = 0.80 [95% CI: 0.72–0.86], p < 0.001). Lifetime JP experience was associated with global visuospatial cognition, even after accounting for other risk and protective factors (β = 0.34 [95% CI: 0.18–0.50], p < 0.001). The JP group connected on average 3589 pieces in 49 h. Compared to the counseling group, they improved in JP skill (Cohen’s d = 0.38 [95% CI: 0.21–0.54], p < 0.001), but not in global visuospatial cognition (Cohen’s d = -0.08, [CI: -0.27 to 0.10], p = 0.39). The amount of jigsaw puzzling was related to changes in global visuospatial cognition within the JP group, only after accounting for baseline performance (β = 0.33 [95% CI: 0.02–0.63], p = 0.03). In sum, our results indicate that jigsaw puzzling strongly engages multiple cognitive abilities and long-term, but not short-term JP experiences could relevantly benefit cognition.Trial Registration:ClinicalTrials.govIdentifier: NCT0266731

Cognitive change is more positively associated with an active lifestyle than with training interventions in older adults at risk of dementia: a controlled interventional clinical trial

Background: While observational studies show that an active lifestyle including cognitive, physical, and social activities is associated with a reduced risk of cognitive decline and dementia, experimental evidence from corresponding training interventions is more inconsistent with less pronounced effects. The aim of this study was to evaluate and compare training- and lifestyle-related changes in cognition. This is the first study investigating these associations within the same time period and sample. Methods: Fifty-four older adults at risk of dementia were assigned to 10 weeks of physical training, cognitive training, or a matched wait-list control condition. Lifestyle was operationalized as the variety of self-reported cognitive, physical, and social activities before study participation. Cognitive performance was assessed with an extensive test battery prior to and after the intervention period as well as at a 3-month follow-up. Composite cognition measures were obtained by means of a principal component analysis. Training- and lifestyle-related changes in cognition were analyzed using linear mixed effects models. The strength of their association was compared with paired t-tests. Results: Neither training intervention improved global cognition in comparison to the control group (p = .08). In contrast, self-reported lifestyle was positively associated with benefits in global cognition (p < .001) and specifically in memory (p < .001). Moreover, the association of an active lifestyle with cognitive change was significantly stronger than the benefits of the training interventions with respect to global cognition (ps < .001) and memory (ps < .001). Conclusions: The associations of an active lifestyle with cognitive change over time in a dementia risk group were stronger than the effects of short-term, specific training interventions. An active lifestyle may differ from training interventions in dosage and variety of activities as well as intrinsic motivation and enjoyment. These factors might be crucial for designing novel interventions, which are more efficient than currently available training interventions

Evaluation of frailty in geriatric patients undergoing cardiac rehabilitation after cardiac procedure:results of a prospective, cross-sectional study

BACKGROUND: Frailty is an indicator of a decline in quality of life and functional capacity in cardiac rehabilitation (CR) patients. Currently, there is no standardized assessment tool for frailty used in CR. The aim of this study was to determine if the Clinical Frailty Scale (CFS) is feasible for assessing frailty in CR.METHODS: Prospective, cross-sectional study within the framework of the ongoing multicenter prehabilitation study "PRECOVERY". Patients ≥75 years undergoing CR after cardiac procedure (n=122) were recruited in four German inpatient CR facilities. Assessments included: CFS, Katz-Index, hand grip strength (HGS), Short Physical Performance Battery (SPPB) and six-minute-walk test (6MWT). Outcomes were frailty (CFS≥4) and the correlation of frailty with assessments of functional capacity, activities of daily living and clinical parameters. Statistical analysis included descriptive statistics and correlations, using the spearman correlation coefficient and chi-square test to test for significance.RESULTS: Data from 101 patients (79.9±4.0 years; 63% male) were analyzed. The mean CFS score was 3.2±1.4; 41.6% were defined as frail (CFS≥4). The mean time required to assess the CFS was 0.20 minutes. The findings show that CFS correlates significantly (p&lt;0.001) with the following factors: Katz-Index, HGS, SPPB-Score and 6MWT (r≤-0.575). In addition, CFS correlated with small to moderate effects with co-morbidities (r=0.250), as-needed medications and need for nursing assistance (r≤0.248).CONCLUSIONS: The CFS assessment can be performed in under one minute and it correlates significantly with assessments of functional capacity, activities of daily living and clinical parameters in the CR setting.TRIAL REGISTRATION: German Clinical Trials Register (DRKS; http:// www. drks. de; DRKS00032256). Retrospectively registered on 13 July 2023.</p