154 research outputs found
Filtering Noise Caused by Sensor Selection for an Ultra-wide Band Position Tracking System
A filter designed to be optimal for alternating multi-sensor tracking systems is presented. This filter can be used on ultra-wide band position tracking systems such as the Ubisense system. In this thesis, a comprehensive evaluation of the accuracy of the Ubisense tracking system in a multi-room building is given. Then the multi-modality of the noise distribution of such a system is shown. A multi-sensor tracking system is then simulated and a Kalman filter is used to filter the measurements. It is shown that the Kalman filter is not optimal for such a system and the need for a filter that addresses the issue of multi-modality is explained. Finally a modified particle filter is designed and is shown to effectively reduce the noise in an alternating multi-sensor position tracking system
One Who Grew up Drinking Wolf Milk and Her Writing
Panel: Why I Write What I Writ
A Study on the Application of Task-based Language Teaching Method in a Comprehensive English Class in China
This study set out to investigate whether the implementation of Task-Based Language Teaching (TBLT) in a comprehensive English class would have a positive effect on students’ study motivation and language proficiency. A two-phase eight-cycle action research project was conducted in one of the author’s classes. Questionnaires, interviews, classroom observation and a teaching journal were employed as data collection instruments. The quantitative and qualitative analysis of the data revealed that the majority of students showed positive perceptions towards the use of TBLT in their English learning class and acknowledged a growth in their study motivation, indicated by increased interest, enjoyment and study autonomy, and their language skills, especially speaking and writing as well as some other related skills like information retrieving. However, problems arose in the process, showing that more literature reading and further research are needed by the author for better implementation of this language teaching approach in English learning classes in the future
Simulation of adaptive array algorithms for 3G CDMA systems
The increasing demand for mobile communication services without a corresponding increase in RF spectrum allocation motivates the need for new techniques to improve spectrum utilization. CDMA systems and adaptive antenna array are two approaches that show real promise for increasing spectrum efficiency. In this research, we investigate the performance of different adaptive array algorithms, blind and non-blind, in the CDMA systems. Three algorithms, least-squares despread re-spread multitarget constant modulus algorithm (LS-DRMTCMA), Wiener solution with pilot channel on reverse link of 3G CDMA and least-mean-square (LMS) algorithm with training sequence, are developed. A C++ simulation testbed is created to compare the performance of these algorithms. It is shown from the simulation results that system performance is greatly improved by using adaptive array. Wiener solution with pilot channel can outperform the other algorithms in all the test situations considered (e.g., AWGN channel, four types of fading channels). However the LMS algorithm with training sequence has less computational requirements than the other algorithms
Short-chain fatty acids are potential goalkeepers of atherosclerosis
Short-chain fatty acids (SCFAs) are metabolites produced by gut bacteria and play a crucial role in various inflammatory diseases. Increasing evidence suggests that SCFAs can improve the occurrence and progression of atherosclerosis. However, the molecular mechanisms through which SCFAs regulate the development of atherosclerosis have not been fully elucidated. This review provides an overview of the research progress on SCFAs regarding their impact on the risk factors and pathogenesis associated with atherosclerosis, with a specific focus on their interactions with the endothelium and immune cells. These interactions encompass the inflammation and oxidative stress of endothelial cells, the migration of monocytes/macrophages, the lipid metabolism of macrophages, the proliferation and migration of smooth muscle cells, and the proliferation and differentiation of Treg cells. Nevertheless, the current body of research is insufficient to comprehensively understand the full spectrum of SCFAs’ mechanisms of action. Therefore, further in-depth investigations are imperative to establish a solid theoretical foundation for the development of clinical therapeutics in this context
Grand Canonical Adaptive Resolution Simulation for Molecules with Electrons: A Theoretical Framework based on Physical Consistency
A theoretical scheme for the treatment of an open molecular system with
electrons and nuclei is proposed. The idea is based on the Grand Canonical
description of a quantum region embedded in a classical reservoir of molecules.
Electronic properties of the quantum region are calculated at constant
electronic chemical potential equal to that of the corresponding (large) bulk
system treated at full quantum level. Instead, the exchange of molecules
between the quantum region and the classical environment occurs at the chemical
potential of the macroscopic thermodynamic conditions. T he Grand Canonical
Adaptive Resolution Scheme is proposed for the treatment of the classical
environment; such an approach can treat the exchange of molecules according to
first principles of statistical mechanics and thermodynamic. The overall scheme
is build on the basis of physical consistency, with the corresponding
definition of numerical criteria of control of the approximations implied by
the coupling. Given the wide range of expertise required, this work has the
intention of providing guiding principles for the construction of a well
founded computational protocol for actual multiscale simulations from the
electronic to the mesoscopic scale.Comment: Computer Physics Communications (2017), in pres
Global shortfalls in documented actions to conserve biodiversity
Threatened species are by definition species that are in need of assistance. In the absence of suitable conservation interventions, they are likely to disappear soon1. There is limited understanding of how and where conservation interventions are applied globally, or how well they work2, 3. Here, using information from the International Union for Conservation of Nature Red List and other global databases, we find that for species at risk from three of the biggest drivers of biodiversity loss—habitat loss, overexploitation for international trade and invasive species4—many appear to lack the appropriate types of conservation interventions. Indeed, although there has been substantial recent expansion of the protected area network, we still find that 91% of threatened species have insufficient representation of their habitats within protected areas. Conservation interventions are not implemented uniformly across different taxa and regions and, even when present, have infrequently led to substantial improvements in the status of species. For 58% of the world’s threatened terrestrial species, we find conservation interventions to be notably insufficient or absent. We cannot determine whether such species are truly neglected, or whether efforts to recover them are not included in major conservation databases. If they are indeed neglected, the outlook for many of the world’s threatened species is grim without more and better targeted action
ITPKC polymorphism (rs7251246 T > C), coronary artery aneurysms, and thrombosis in patients with Kawasaki disease in a Southern Han Chinese population
ObjectivesKawasaki disease (KD) is a commonly acquired pediatric systemic vasculitis disease resulting in coronary artery aneurysm (CAA). The relationship between the ITPKC polymorphism (rs7251246) and the severity and susceptibility to KD in the Han Chinese population in Southern China remains unclear.MethodsWe enrolled 262 children as controls and 221 children with KD (46 [20.8%] with intravenous immunoglobulin resistance and 82 [37.1%] with CAA). The relationship between the ITPKC rs7251246 polymorphism, KD susceptibility, and CAA formation was investigated.ResultsWhile the ITPKC rs7251246 T>C polymorphism was not significantly associated with KD susceptibility, it was significantly related to the CAA risk in children with KD [CC/CT vs. TT: adjusted odds ratio [OR] 2.089, 95% confidence interval [CI] 1.085–4.020]. Male children with the rs7251246 CT/TT genotype had a significantly lower risk of thrombosis [CT/TT vs. CC: adjusted OR 0.251, 95% CI 0.068–0.923]. Children with KD, especially those with CAA, had significantly downregulated ITPKC mRNA compared to healthy children. ITPKC mRNA levels were lower in children with CAA who developed thrombosis (P=0.039). In children with KD, the CC genotype showed lower mRNA levels of ITPKC (P=0.035).ConclusionThe ITPKC rs7251246 T>C polymorphism may be a risk factor for CAA and thrombosis in children with KD in the Han Chinese population, likely due to differences in mature mRNA levels caused by interference of RNA splicing. Dual antiplatelet therapy for thrombosis is recommended for male children with the rs7251246 CC genotype
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