25 research outputs found

    Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

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    BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

    Magnetically Functional Materials:Design and 3D Printing

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    3D printing has revolutionized the manufacturing landscape by offering unparalleled design flexibility, rapid prototyping, and the ability to produce small batches of customized components. In the same vein, development of magnetic bonded materials has opened new possibilities for the customization and fabrication of magnetic structures with potential applications in various industries, including automotive, aerospace, and medical devices. However, challenges remain in the field of 3D printing of magnetic materials, such as producing small quantities, customized designs and developing reliable fabrication methods for hard magnetic materials.Fused filament fabrication (FFF) 3D printing presents a promising solution to these challenges, as it enables the creation of intricate structures with tailored magnetic properties. Despite its potential, there is currently no commercial hard magnetic filament available. To address this gap, we developed a custom filament with various filling factors by using ABS as an effective binder for the hard magnetic particles. This approach allowed us to achieve precise control over the magnetic properties and optimize the performance of the printed components.As a proof of concept showing the versatility and utility of our custom hard magnetic filaments, we designed, and 3D printed a passive shimming system in a Halbach array configuration to improve the magnetic field homogeneity. This application showcases the potential of our filament for producing complex magnetic structures with tailored properties, which could lead to advancements in a wide range of industries that rely on magnetic materials.Additionally, a near-room-temperature magneto-responsive elastomer within the context of soft robotics was developed. The elastomer exhibits unique actuation properties, combining the advantages of magnetically and thermally responsive actuators, with potential applications in a wide range of industries. By employing specific types of soft magnetic materials, and mixing them with silicone rubber, a thermo-magneto actuator with a low responsive temperature was created. The study incorporated finite element modeling and experimental data to understand the elastomer's behavior, providing a foundation for future research in soft robotics applications.In summary, our work highlights the great potential of 3D printing for the development of hard magnetic materials and demonstrates the potential of FFF 3D printing to create customized magnetic components and addresses fabrication challenges in various applications

    Interpretable clustering of epigenetic marks by incorporating their relationships to genes and their functions

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    Recent advances in high-throughput technologies have allowed researchers to measure epigenetic information, such as the methylation levels of CpG sites or the accessibility levels of chromatin, for hundreds of thousands of genomic regions. Many statistical methods have been developed to cluster these epigenetic measurements into contiguous, functional regions involved in biological processes or disease. In this project, I proposed a new approach for clustering the epigenetic marks into regions. The proposed model defines each region as the set of epigenetic marks located within a predefined window around the transcript start site of a gene. Therefore, the one-to-one mapping between the regions and genes helps elucidate the epigenetic functions of regions by looking at the functions of genes mapped to the regions. The proposed statistical model uses a weighted linear model that combines the values of marks in each region to construct a gene-level representation for that region. The weights of marks in each region are estimated using a scalable, coordinate descent optimization algorithm. I evaluated the quality of the inferred gene-level representations on two types of epigenetic data: chromatin accessibility and DNA methylation. When applied to the chromatin accessibility data, the results showed that the gene-level representations inferred by the proposed model could represent the variations in the expression levels of genes across samples with higher accuracy compared to the baseline methods. The model performance declined when applied to the DNA methylation data. To address this observation, I investigated the role of the type and quality of the epigenetic data on the model performance and offered a set of recommendations for using the proposed model effectively.Science, Faculty ofGraduat

    Recurrent spatio-temporal modeling of check-ins in location-based social networks.

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    Social networks are getting closer to our real physical world. People share the exact location and time of their check-ins and are influenced by their friends. Modeling the spatio-temporal behavior of users in social networks is of great importance for predicting the future behavior of users, controlling the users' movements, and finding the latent influence network. It is observed that users have periodic patterns in their movements. Also, they are influenced by the locations that their close friends recently visited. Leveraging these two observations, we propose a probabilistic model based on a doubly stochastic point process with a periodic-decaying kernel for the time of check-ins and a time-varying multinomial distribution for the location of check-ins of users in the location-based social networks. We learn the model parameters by using an efficient EM algorithm, which distributes over the users, and has a linear time complexity. Experiments on synthetic and real data gathered from Foursquare show that the proposed inference algorithm learns the parameters efficiently and our method models the real data better than other alternatives

    Additive Manufacturing of Hard Magnetic Passive Shims to Increase Field Homogeneity of a Halbach Magnet

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    Obtaining a highly homogeneous magnetic field is desired for field-controlled applications. For example, the resolution of magnetic analysis methods can be improved by generating a stronger and more homogeneous field over the region of interest (ROI). A set of 3D-printed passive shims is fabricated using additive manufacturing to improve the magnetic field homogeneity of a Halbach magnet assembly. The feedstock is a custom acrylonitrile butadiene styrene (ABS)-hard magnet composite filament filled with 60% wt. isotropic NdFeB. Additionally, a method for investigating the remanence is developed and validated. The result reveals a good agreement between the new method and existing measurement techniques for the remanence of permanent magnets. It is also shown that the additive manufacturing procedure has negligible effects on the magnetic properties. Performing a parametric study over a rectangular ROI, an optimized shim configuration is achieved. In the optimized and 3D-printed configuration, the average norm of the magnetic flux density, Bnorm, is increased by 13% and, more importantly, a 43% increase in the magnetic uniformity is obtained. These results highlight the great potential of freeform manufacturing, namely, additive manufacturing, to tailor the properties of magnet structures

    Periodic point process.

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    <p>An event at time <i>t</i> = 0 triggers a poisson process. The solid curve shows the intensity of the proposed periodic point process with a Gaussian kernel and period <i>τ</i>, and the dashed curve shows a Hawkes process with an exponential decaying kernel.</p

    Scalability comparision.

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    <p>The time complexity of different temporal models and our spatial model (the other baseline spatial models also have approximately the same time complexity, so only one of them is depicted), for different network sizes (<i>left</i>), and for different sizes of events history (<i>right</i>).</p
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