3,503 research outputs found
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An Estimate of the Prevalence of Dementia in Idiopathic Parkinson's Disease
A review of the records for evidence of dementia using criteria adapted from the third edition of the Diagnostic and Statistical Manual of Mental Disorders in every patient (hospitalized and outpatient) with parkinsonism at a major medical center during an 18-month period revealed an overall prevalence of 10.9% in 339 patients with idiopathic Parkinson's disease. Demented patients were older, had a later age at onset of motor manifestations, and a more rapid progression of physical disability than nondemented patients. Duration of illness and levodopa use and the presence of tremor or depression were similar in demented and nondemented patients. Demented patients more often responded poorly or developed adverse effects to levodopa than nondemented patients. When Parkinson's disease began after age 70 years, dementia was noted over three times more frequently than when the disease began at an earlier age. The age-specific prevalence rate of dementia for patients older than 70 years was more than twice that for younger patients. Moreover, the number of records with evidence for dementia with idiopathic Parkinson's disease was 3.75 times greater than expected in comparison with data from a study of the prevalence of dementia in the elderly
Imperfect Homoclinic Bifurcations
Experimental observations of an almost symmetric electronic circuit show
complicated sequences of bifurcations. These results are discussed in the light
of a theory of imperfect global bifurcations. It is shown that much of the
dynamics observed in the circuit can be understood by reference to imperfect
homoclinic bifurcations without constructing an explicit mathematical model of
the system.Comment: 8 pages, 11 figures, submitted to PR
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Identification of MS-specific serum miRNAs in an international multicenter study.
ObjectiveTo identify circulating microRNAs (miRNAs) linked to disease, disease stage, and disability in MS across cohorts.MethodsSamples were obtained from the Comprehensive Longitudinal Investigation of Multiple Sclerosis (CLIMB, Boston, MA), EPIC (San Francisco, CA), AMIR (Beirut, Lebanon) as part of the SUMMIT consortium, and Stockholm Prospective Assessment of Multiple Sclerosis (Stockholm, Sweden) cohorts. Serum miRNA expression was measured using locked nucleic acid-based quantitative PCR. Four groups were compared: (1) MS vs healthy control (HC), (2) relapsing-remitting (RR) vs HC, (3) secondary progressive (SP) vs HC, and (4) RR vs SP. A Wilcoxon rank-sum test was used for the comparisons. The association between each miRNA and the Expanded Disability Status Scale (EDSS) score was assessed using the Spearman correlation coefficient. For each comparison, the p values were corrected for multiple comparisons using the approach of Benjamini and Hochberg to control the false discovery rate.ResultsIn the CLIMB cohort, 5 miRNAs (hsa-miR-484, hsa-miR-140-5p, hsa-miR-320a, hsa-miR-486-5p, and hsa-miR-320c) showed a significant difference between patients with MS and healthy individuals; among these, miR-484 remained significant after accounting for multiple comparisons (p = 0.01). When comparing RRMS with HCs, hsa-miR-484 showed a significant difference (p = 0.004) between the groups after accounting for multiple group comparisons. When SP and HC were compared, 6 miRNAs (hsa-miR-484, hsa-miR-140-5p, hsa-miR-142-5p, hsa-miR-320a, hsa-miR-320b, and hsa-miR-320c) remained significantly different after accounting for multiple comparisons. Disability correlation analysis with miRNA provided 4 miRNAs (hsa-miR-320a, hsa-miR-337-3p, hsa-miR-199a-5p, and hsa-miR-142-5p) that correlated with the EDSS during the internal reproducibility phase. Among these, hsa-miR-337-3p was the most statistically significant miRNA that negatively correlated with the EDSS in three of the MS cohorts tested.ConclusionsThese findings further confirm the use of circulating serum miRNAs as biomarkers to diagnose and monitor disease status in MS.Classification of evidenceThis study provides Class III evidence that levels of circulating miRNAs identify patients with MS
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A specific amino acid motif of HLA-DRB1 mediates risk and interacts with smoking history in Parkinson's disease.
Parkinson's disease (PD) is a neurodegenerative disease in which genetic risk has been mapped to HLA, but precise allelic associations have been difficult to infer due to limitations in genotyping methodology. Mapping PD risk at highest possible resolution, we performed sequencing of 11 HLA genes in 1,597 PD cases and 1,606 controls. We found that susceptibility to PD can be explained by a specific combination of amino acids at positions 70-74 on the HLA-DRB1 molecule. Previously identified as the primary risk factor in rheumatoid arthritis and referred to as the "shared epitope" (SE), the residues Q/R-K/R-R-A-A at positions 70-74 in combination with valine at position 11 (11-V) is highly protective in PD, while risk is attributable to the identical epitope in the absence of 11-V. Notably, these effects are modified by history of cigarette smoking, with a strong protective effect mediated by a positive history of smoking in combination with the SE and 11-V (P = 10-4; odds ratio, 0.51; 95% confidence interval, 0.36-0.72) and risk attributable to never smoking in combination with the SE without 11-V (P = 0.01; odds ratio, 1.51; 95% confidence interval, 1.08-2.12). The association of specific combinations of amino acids that participate in critical peptide-binding pockets of the HLA class II molecule implicates antigen presentation in PD pathogenesis and provides further support for genetic control of neuroinflammation in disease. The interaction of HLA-DRB1 with smoking history in disease predisposition, along with predicted patterns of peptide binding to HLA, provide a molecular model that explains the unique epidemiology of smoking in PD
Assessing daily energy intake in adult women: validity of a food-recognition mobile application compared to doubly labelled water
Accurate dietary assessment is crucial for nutrition and health research. Traditional methods, such as food records, food frequency questionnaires, and 24-hour dietary recalls (24HR), have limitations, such as the need for trained interviewers, time-consuming procedures, and inaccuracies in estimations. Novel technologies, such as image-based dietary assessment apps, have been developed to overcome these limitations. SNAQ is a novel image-based food-recognition app which, based on computer vision, assesses food type and volume, and provides nutritional information about dietary intake. This cross-sectional observational study aimed to investigate the validity of SNAQ as a dietary assessment tool for measuring energy and macronutrient intake in adult women with normal body weight (n = 30), compared to doubly labeled water (DLW), a reference method for total daily energy expenditure (TDEE). Energy intake was also estimated using a one-day 24HR for direct comparison. Bland-Altman plots, paired difference tests, and Pearson's correlation coefficient were used to assess agreement and relationships between the methods. SNAQ showed a slightly higher agreement (bias = -329.6 kcal/day) with DLW for total daily energy intake (TDEI) compared to 24HR (bias = -543.0 kcal/day). While both SNAQ and 24HR tended to underestimate TDEI, only 24HR significantly differed from DLW in this regard (p < 0.001). There was no significant relationship between estimated TDEI and TDEE using SNAQ (R = 27%, p = 0.50) or 24HR (R = 34%, p = 0.20) and there were no significant differences in energy and macronutrient intake estimates between SNAQ and 24HR (Δ = 213.4 kcal/day). In conclusion, these results indicate that SNAQ provides a closer representation of energy intake in adult women with normal body weight than 24HR when compared to DLW, but no relationship was found between the energy estimates of DLW and of the two dietary assessment tools. Further research is needed to determine the clinical relevance and support the implementation of SNAQ in research and clinical settings. Clinical trial registration: This study is registered on ClinicalTrials.gov with the unique identifier NCT04600596 (https://clinicaltrials.gov/ct2/show/NCT04600596)
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Most Reported Genetic Associations with General Intelligence Are Probably False Positives
General intelligence (g) and virtually all other behavioral traits are heritable. Associations between g and specific single-nucleotide polymorphisms (SNPs) in several candidate genes involved in brain function have been reported. We sought to replicate published associations between g and 12 specific genetic variants (in the genes DTNBP1, CTSD, DRD2, ANKK1, CHRM2, SSADH, COMT, BDNF, CHRNA4, DISC1, APOE, and SNAP25) using data sets from three independent, well-characterized longitudinal studies with samples of 5,571, 1,759, and 2,441 individuals. Of 32 independent tests across all three data sets, only 1 was nominally significant. By contrast, power analyses showed that we should have expected 10 to 15 significant associations, given reasonable assumptions for genotype effect sizes. For positive controls, we confirmed accepted genetic associations for Alzheimer’s disease and body mass index, and we used SNP-based calculations of genetic relatedness to replicate previous estimates that about half of the variance in g is accounted for by common genetic variation among individuals. We conclude that the molecular genetics of psychology and social science requires approaches that go beyond the examination of candidate genes.Economic
Longitudinal intravital imaging of the retina reveals long-term dynamics of immune infiltration and its effects on the glial network in experimental autoimmune uveoretinitis, without evident signs of neuronal dysfunction in the ganglion cell layer
A hallmark of autoimmune retinal inflammation is the infiltration of the retina with cells of the innate and adaptive immune system, leading to detachment of the retinal layers and even to complete loss of the retinal photoreceptor layer. As the only optical system in the organism, the eye enables non-invasive longitudinal imaging studies of these local autoimmune processes and of their effects on the target tissue. Moreover, as a window to the central nervous system (CNS), the eye also reflects general neuroinflammatory processes taking place at various sites within the CNS. Histological studies in murine neuroinflammatory models, such as experimental autoimmune uveoretinitis (EAU) and experimental autoimmune encephalomyelitis, indicate that immune infiltration is initialized by effector CD4(+) T cells, with the innate compartment (neutrophils, macrophages, and monocytes) contributing crucially to tissue degeneration that occurs at later phases of the disease. However, how the immune attack is orchestrated by various immune cell subsets in the retina and how the latter interact with the target tissue under in vivo conditions is still poorly understood. Our study addresses this gap with a novel approach for intravital two-photon microscopy, which enabled us to repeatedly track CD4(+) T cells and LysM phagocytes during the entire course of EAU and to identify a specific radial infiltration pattern of these cells within the inflamed retina, starting from the optic nerve head. In contrast, highly motile [Formula: see text] cells display an opposite radial motility pattern, toward the optic nerve head. These inflammatory processes induce modifications of the microglial network toward an activated morphology, especially around the optic nerve head and main retinal blood vessels, but do not affect the neurons within the ganglion cell layer. Thanks to the new technology, non-invasive correlation of clinical scores of CNS-related pathologies with immune infiltrate behavior and subsequent tissue dysfunction is now possible. Hence, the new approach paves the way for deeper insights into the pathology of neuroinflammatory processes on a cellular basis, over the entire disease course
Klimaschutzverträge für die Industrietransformation
KLIMASCHUTZVERTRÄGE FÜR DIE INDUSTRIETRANSFORMATION
Klimaschutzverträge für die Industrietransformation / Hauser, Philipp Daniel (Rights reserved) ( -
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The Promises and Pitfalls of Genoeconomics
This article reviews existing research at the intersection of genetics and economics, presents some new findings that illustrate the state of genoeconomics research, and surveys the prospects of this emerging field. Twin studies suggest that economic outcomes and preferences, once corrected for measurement error, appear to be about as heritable as many medical conditions and personality traits. Consistent with this pattern, we present new evidence on the heritability of permanent income and wealth. Turning to genetic association studies, we survey the main ways that the direct measurement of genetic variation across individuals is likely to contribute to economics, and we outline the challenges that have slowed progress in making these contributions. The most urgent problem facing researchers in this field is that most existing efforts to find associations between genetic variation and economic behavior are based on samples that are too small to ensure adequate statistical power. This has led to many false positives in the literature. We suggest a number of possible strategies to improve and remedy this problem: (a) pooling data sets, (b) using statistical techniques that exploit the greater information content of many genes jointly, and (c) focusing on economically relevant traits that are most proximate to known biological mechanisms.EconomicsSociolog
A Theory of Cheap Control in Embodied Systems
We present a framework for designing cheap control architectures for embodied
agents. Our derivation is guided by the classical problem of universal
approximation, whereby we explore the possibility of exploiting the agent's
embodiment for a new and more efficient universal approximation of behaviors
generated by sensorimotor control. This embodied universal approximation is
compared with the classical non-embodied universal approximation. To exemplify
our approach, we present a detailed quantitative case study for policy models
defined in terms of conditional restricted Boltzmann machines. In contrast to
non-embodied universal approximation, which requires an exponential number of
parameters, in the embodied setting we are able to generate all possible
behaviors with a drastically smaller model, thus obtaining cheap universal
approximation. We test and corroborate the theory experimentally with a
six-legged walking machine. The experiments show that the sufficient controller
complexity predicted by our theory is tight, which means that the theory has
direct practical implications. Keywords: cheap design, embodiment, sensorimotor
loop, universal approximation, conditional restricted Boltzmann machineComment: 27 pages, 10 figure
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