162 research outputs found

    Machine Learning-based Indoor Positioning Systems Using Multi-Channel Information

    Get PDF
    The received signal strength indicator (RSSI) is a metric of the power measured by a sensor in a receiver. Many indoor positioning technologies use RSSI to locate objects in indoor environments. Their positioning accuracy is significantly affected by reflection and absorption from walls, and by non-stationary objects such as doors and people. Therefore, it is necessary to increase transceivers in the environment to reduce positioning errors. This paper proposes an indoor positioning technology that uses the machine learning algorithm of channel state information (CSI) combined with fingerprinting. The experimental results showed that the proposed method outperformed traditional RSSI-based localization systems in terms of average positioning accuracy up to 6.13% and 54.79% for random forest (RF) and back propagation neural networks (BPNN), respectively

    Machine Learning-based Indoor Positioning Systems Using Multi-Channel Information

    Get PDF
    The received signal strength indicator (RSSI) is a metric of the power measured by a sensor in a receiver. Many indoor positioning technologies use RSSI to locate objects in indoor environments. Their positioning accuracy is significantly affected by reflection and absorption from walls, and by non-stationary objects such as doors and people. Therefore, it is necessary to increase transceivers in the environment to reduce positioning errors. This paper proposes an indoor positioning technology that uses the machine learning algorithm of channel state information (CSI) combined with fingerprinting. The experimental results showed that the proposed method outperformed traditional RSSI-based localization systems in terms of average positioning accuracy up to 6.13% and 54.79% for random forest (RF) and back propagation neural networks (BPNN), respectively

    Energy and nitrogenous waste from glutamate/glutamine catabolism facilitates acute osmotic adjustment in non-neuroectodermal branchial cells

    Get PDF
    Maintenance of homeostasis is one of the most important physiological responses for animals upon osmotic perturbations. Ionocytes of branchial epithelia are the major cell types responsible for active ion transport, which is mediated by energy-consuming ion pumps (e.g., Na+-K+-ATPase, NKA) and secondary active transporters. Consequently, in addition to osmolyte adjustments, sufficient and immediate energy replenishment is essenttableial for acclimation to osmotic changes. In this study, we propose that glutamate/glutamine catabolism and trans-epithelial transport of nitrogenous waste may aid euryhaline teleosts Japanese medaka (Oryzias latipes) during acclimation to osmotic changes. Glutamate family amino acid contents in gills were increased by hyperosmotic challenge along an acclimation period of 72 hours. This change in amino acids was accompanied by a stimulation of putative glutamate/glutamine transporters (Eaats, Sat) and synthesis enzymes (Gls, Glul) that participate in regulating glutamate/glutamine cycling in branchial epithelia during acclimation to hyperosmotic conditions. In situ hybridization of glutaminase and glutamine synthetase in combination with immunocytochemistry demonstrate a partial colocalization of olgls1a and olgls2 but not olglul with Na+/K+-ATPase-rich ionocytes. Also for the glutamate and glutamine transporters colocalization with ionocytes was found for oleaat1, oleaat3, and olslc38a4, but not oleaat2. Morpholino knock-down of Sat decreased Na+ flux from the larval epithelium, demonstrating the importance of glutamate/glutamine transport in osmotic regulation. In addition to its role as an energy substrate, glutamate deamination produces NH4+, which may contribute to osmolyte production; genes encoding components of the urea production cycle, including carbamoyl phosphate synthetase (CPS) and ornithine transcarbamylase (OTC), were upregulated under hyperosmotic challenges. Based on these findings the present work demonstrates that the glutamate/glutamine cycle and subsequent transepithelial transport of nitrogenous waste in branchial epithelia represents an essential component for the maintenance of ionic homeostasis under a hyperosmotic challenge

    Effects of epidural compression on stellate neurons and thalamocortical afferent fibers in the rat primary somatosensory cortex

    Get PDF
    A number of neurological disorders such as epidural hematoma can cause compression of cerebral cortex. We here tested the hypothesis that sustained compression of primary somatosensory cortex may affect stellate neurons and thalamocortical afferent (TCA) fibers. A rat model with barrel cortex subjected to bead epidural compression was used. Golgi‑Cox staining analyses showed the shrinkage of dendritic arbors and the stripping of dendritic spines of stellate neurons for at least 3 months post‑lesion. Anterograde tracing analyses exhibited a progressive decline of TCA fiber density in barrel field for 6 months post‑lesion. Due to the abrupt decrease of TCA fiber density at 3 days after compression, we further used electron microscopy to investigate the ultrastructure of TCA fibers at this time. Some TCA fiber terminal profiles with dissolved or darkened mitochondria and fewer synaptic vesicles were distorted and broken. Furthermore, the disruption of mitochondria and myelin sheath was observed in some myelinated TCA fibers. In addition, expressions of oxidative markers 3‑nitrotyrosine and 4‑hydroxynonenal were elevated in barrel field post‑lesion. Treatment of antioxidant ascorbic acid or apocynin was able to reverse the increase of oxidative stress and the decline of TCA fiber density, rather than the shrinkage of dendrites and the stripping of dendritic spines of stellate neurons post‑lesion. Together, these results indicate that sustained epidural compression of primary somatosensory cortex affects the TCA fibers and the dendrites of stellate neurons for a prolonged period. In addition, oxidative stress is responsible for the reduction of TCA fiber density in barrels rather than the shrinkage of dendrites and the stripping of dendritic spines of stellate neurons

    Photon emission correlation spectroscopy as an analytical tool for quantum defects

    Full text link
    Photon emission correlation spectroscopy has a long history in the study of atoms, molecules, and, more recently, solid-state quantum defects. In solid-state systems, its most common use is as an indicator of single-photon emission, a key property for quantum technology. However, photon correlation data can provide a wealth of information about quantum emitters beyond their single-photon purity − \,-\,information that can reveal details about an emitter's electronic structure and optical dynamics that are hidden by other spectroscopy techniques. We present a standardized framework for using photon emission correlation spectroscopy to study quantum emitters, including discussion of theory, data acquisition, analysis, and interpretation. We highlight nuances and best practices regarding the commonly-used g(2)(τ=0)<0.5g^{(2)}(\tau=0)<0.5 test for single-photon emission. Finally, we illustrate how this experimental technique can be paired with optical dynamics simulations to formulate an electronic model for unknown quantum emitters, enabling the design of quantum control protocols and assessment of their suitability for quantum information science applications.Comment: 20 pages, 7 figures. Updates in version 2 include an expanded section VI and the addition of two figures and an appendi

    Template-Assisted Self Assembly of Fluorescent Nanodiamonds for Scalable Quantum Technologies

    Full text link
    Milled nanodiamonds containing nitrogen-vacancy (NV) centers provide an excellent platform for sensing applications as they are optically robust, have nanoscale quantum sensitivity, and form colloidal dispersions which enable bottom-up assembly techniques for device integration. However, variations in their size, shape, and surface chemistry limit the ability to position individual nanodiamonds and statistically study properties that affect their optical and quantum characteristics. Here, we present a scalable strategy to form ordered arrays of nanodiamonds using capillary-driven, template-assisted self assembly. This method enables the precise spatial arrangement of isolated nanodiamonds with diameters below 50 nm across millimeter-scale areas. Measurements of over 200 assembled nanodiamonds yield a statistical understanding of their structural, optical, and quantum properties. The NV centers' spin and charge properties are uncorrelated with nanodiamond size, but rather are consistent with heterogeneity in their nanoscale environment. This flexible assembly method, together with improved understanding of the material, will enable the integration of nanodiamonds into future quantum photonic and electronic devices.Comment: 28 pages, 17 figure

    Modernização e ressignificação: as contradições na formação do espaço urbano oeirense (1900-1945).

    Get PDF
    A presente dissertação visa a analisar a produção do espaço urbano oeirense e suas eventuais contradições compreendendo o período de 1900 a 1945, atentando para a ideia de crise atribuída à perda do status de capital e à introdução de alguns signos do moderno, tomados pelas elites como forma de ressignificação da cidade. Portanto, neste propósito, constitui-se um projeto de modernização urbana ilusória e de exclusão, pois apenas o núcleo central urbano foi merecedor dessa ação. Enquanto isso, o subúrbio estava fora de qualquer tentativa de melhoramento, embora fantasmagoricamente o discurso de modernização para todos fosse divulgado de modo homogêneo entre o grupo político e os letrados locais. Buscamos ainda identificar o ressentimento presente no imaginário local e suas formas reativas, como também as relações do cotidiano dos citadinos. No entanto, esta política de reforma urbana, além de ser destinadas a obras que priorizavam a cultura moderna e o embelezamento urbano, imprimiu um conjunto de normas e condutas, inclusive higiênicas aos moradores da área central. Muitas das quais pretendiam afastar sujeiras e doenças epidêmicas, mas, nesse meio tempo, as zonas suburbana e rural eram consumidas por doenças como a febre tifoide e a malária, sem nenhuma intervenção pública no sentido de preveni-las. Por fim, nesta pesquisa, apoiamo-nos em diversas fontes, sendo elas documentais, fotográficas, orais e bibliográficas. Buscamos encontrar nelas as evidências do passado local, que nos possibilitaram compreender o cotidiano da sociedade oeirense.This dissertation aims to examine the first attempts to modernize in Oeiras-PI, the time frame of 1900-1945, including the idea of seeking crisis attributed to this city by the intellectuals and the local political elite after the transfer of capital to these featuring the "decadent", generalizing the effect of the political crisis and some material loss. Which in turn, not elapsed in its entirety by the loss of capital status, but by their own economic conditions of the state and the municipality, however, not noted by this group insisted that the tirade of "crisis." It also aims to understand the transformations in everyday life oeirense from some achievements, such as theater, traveling cinema, newspaper production, and strengthening the local economy caused by the extraction of latex maniçoba in the early years of the twentieth century. Only after 1930 the political and intellectual discourse points to the advent of local progress, which now has the following material and symbolic transformations: a) urban sanitation; b) construction of the town hall, with modern architecture to the city standards; c) Installation of electric light; d) construction of the airfield with weekly landing; e) film and square. The arrival of these elements of modernity in a society characterized by parochial habits causes changes in sociability and sensitivities both within the elite and among the popular. The sources used in this work are based on surveys of official documents, oral, pictures, newspapers and local literature

    Effect of Antrodia

    Get PDF
    Antrodia camphorata is a rare Taiwanese medicinal mushroom. Antrodia camphorata extract has been reported to exhibit antioxidant, anti-inflammation, antimetastasis, and anticancer activities and plays a role in liver fibrosis, vasorelaxation, and immunomodulation. Critical vascular inflammation leads to vascular dysfunction and cardiovascular diseases, including abdominal aortic aneurysms, hypertension, and atherosclerosis. Platelet activation plays a crucial role in intravascular thrombosis, which is involved in a wide variety of cardiovascular diseases. However, the effect of Antrodia camphorata on platelet activation remains unclear. We examined the effects of Antrodia camphorata on platelet activation. In the present study, Antrodia camphorata treatment (56–224 μg/mL) inhibited platelet aggregation induced by collagen, but not U46619, an analogue of thromboxane A2, thrombin, and arachidonic acid. Antrodia camphorata inhibited collagen-induced calcium (Ca2+) mobilization and phosphorylation of protein kinase C (PKC) and Akt. In addition, Antrodia camphorata significantly reduced the aggregation and phosphorylation of PKC in phorbol-12, 13-dibutyrate (PDBu) activated platelets. In conclusion, Antrodia camphorata may inhibit platelet activation by inhibiting of Ca2+ and PKC cascade and the Akt pathway. Our study suggests that Antrodia camphorata may be a potential therapeutic agent for preventing or treating thromboembolic disorders
    • …
    corecore