light signal
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2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Xuexiang Lin ◽  
Xiao-Yu Liu ◽  
Bo Zhang ◽  
Ai-Qing Qin ◽  
Kwok-Min Hui ◽  
...  

AbstractCurrent methods used for diagnosis of acute infection of pathogens rely on detection of nucleic acids, antigens, or certain classes of antibodies such as IgM. Here we report a virus enzyme assay as an alternative to these methods for detection of acute viral infection. In this method, we used a luciferin derivative as the substrate for detection of the enzyme activity of influenza viral neuraminidase as a means for diagnosis of influenza. The resulting commercial test, the qFLU Dx Test, uses a different supply chain that does not compete with those for the current tests. The assay reagents were formulated as a master mix that accommodated both the neuraminidase and luciferase reactions, thereby enabling rapid and prolonged production of stable light signal in the presence of influenza virus in the sample. The assay was evaluated using depository throat swab specimens. As expected, the assay exhibited similar detection rates for all influenza types and subtypes except for A(H7N9), which exhibited lower detection rate due to lower viral titer in the specimens. When throat swab specimens were diluted with the sample buffer of the test kit and tested with the qFLU Dx Test. The sensitivity and specificity were 82.41% (95% confidence interval: 79.66–85.84%) and 95.39% (95% confidence interval: 94.32–96.46%), respectively, for these diluted specimens in comparison to a real-time polymerase chain reaction assay. The uniqueness of the qFLU Dx Test as an enzymatic assay makes it highly complementary with currently available methods.


Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 85
Author(s):  
Saifur Rahman ◽  
Farman Ali ◽  
Fazal Muhammad ◽  
Muhammad Irfan ◽  
Adam Glowacz ◽  
...  

Hundreds of kilometers of optical fibers are installed for optical meshes (OMs) to transmit data over long distances. The visualization of these deployed optical fibers is a highlighted issue because the conventional procedure can only measure the optical losses. Thus, this paper presents distributed vibration sensing (DVS) estimation mechanisms to visualize the optical fiber behavior installed for OMs which is not possible by conventional measurements. The proposed technique will detect the power of light inside the optical fiber, as well as different physical parameters such as the phase of transmitted light inside the thread, the frequency of vibration, and optical losses. The applicability of optical frequency domain reflectometry (OFDR) and optical time-domain reflectometry (OTDR) DVS techniques are validated theoretically for various state detection procedures in optical fibers. The simulation model is investigated in terms of elapsed time, the spectrum of a light signal, frequency, and the impact of many external physical accidents with optical fibers.


2022 ◽  
Vol 12 ◽  
Author(s):  
Victor P. Bulgakov ◽  
Olga G. Koren

It is generally accepted that plants use the complex signaling system regulated by light and abscisic acid (ABA) signaling components to optimize growth and development in different situations. The role of ABA–light interactions is evident in the coupling of stress defense reactions with seed germination and root development, maintaining of stem cell identity and stem cell specification, stem elongation and leaf development, flowering and fruit formation, senescence, and shade avoidance. All these processes are regulated jointly by the ABA–light signaling system. Although a lot of work has been devoted to ABA–light signal interactions, there is still no systematic description of central signaling components and protein modules, which jointly regulate plant development. New data have emerged to promote understanding of how ABA and light signals are integrated at the molecular level, representing an extensively growing area of research. This work is intended to fill existing gaps by using literature data combined with bioinformatics analysis.


2022 ◽  
Vol 52 (1) ◽  
pp. 87-93
Author(s):  
D V Gorbatov ◽  
V A Konyshev ◽  
T O Lukinykh ◽  
O E Nanii ◽  
A G Novikov ◽  
...  

Abstract A numerical model is constructed for calculating lightning-induced rapid changes in the polarisation state of a light signal at the output of a fibre-optic communication line with an optical ground wire. It is shown that taking into account anisotropy of real optical fibres has a noticeable effect on the shape of the polarisation rotation speed time profile. It is found that the maximum rate of change in the polarisation state and its temporal profile depend on the location of the lightning strike in the fibre span, the magnitude of fibre anisotropy and the direction of propagation of a light wave.


Author(s):  
Mustafa H. Ali ◽  
Tariq A. Hassan ◽  
Hiba A. Abu-Alsaad

In metropolitan communication infrastructures a revolutionary technique is emerge known as terrestrial optical wireless communication (OWC), which makes a high-rise building connection is possible. Even with this solution, there are many other problems like the influence of haze and fog in the propagation channel which obstruct and scatter OWC propagation light and consequently led to a big attenuation, due to propagate in temporal, angular and spatial of the light signal. Not to mention the minimum visibility that discourages the implementation of the pointing errors (PE) and tracking system. This present work aims to analyze the interrelation between multiple scattering (dense fog, heavy fog, light fog, heavy haze and light haze) and receiver PE under modified duo-binary return-to-zero (MDRZ) system. We found that PE caused by beam swag is the main controlling factor and industriously minimize the link margin, signal-to-noise ratio (SNR), and raise the bit error rate (BER) when there is an increasing the turbulence strength and the track length. We recommended to guarantee transmitter– receiver alignment by installing a variable field of view (FOV) receiver (a tracking system) to overcome the scattering impact of the fog that make render urban laser communication effective in the presence of PE.


2021 ◽  
Vol 10 (4) ◽  
pp. 1-27
Author(s):  
Gregory Lemasurier ◽  
Gal Bejerano ◽  
Victoria Albanese ◽  
Jenna Parrillo ◽  
Holly A. Yanco ◽  
...  

Human–robot collaboration is becoming increasingly common in factories around the world; accordingly, we need to improve the interaction experiences between humans and robots working in these spaces. In this article, we report on a user study that investigated methods for providing information to a person about a robot’s intent to move when working together in a shared workspace through signals provided by the robot. In this case, the workspace was the surface of a tabletop. Our study tested the effectiveness of three motion-based and three light-based intent signals as well as the overall level of comfort participants felt while working with the robot to sort colored blocks on the tabletop. Although not significant, our findings suggest that the light signal located closest to the workspace—an LED bracelet located closest to the robot’s end effector—was the most noticeable and least confusing to participants. These findings can be leveraged to support human–robot collaborations in shared spaces.


Author(s):  
A.A. Gorbunov ◽  
T.M. Shipitsyna ◽  
E.B. Pilipenko-Koshel

According to the latest statistics, brain gliomas are the most common cause of death from CNS tumors. Brain gliomas are also ranked as the second (after stroke) cause of brain surgery The mortality rate from gliomas is high and sometimes reaches 80 %. It is because the tumor grows from undifferentiated cells, which causes its peracute development and malignant transformation. Symptoms of glioma occur at stages 3 and 4, when all treatment is symptomatic, and operations are palliative. In this regard, it is necessary to develop and introduce methods for non-surgical glioma treatment. These methods include the use of antisense oligonucleotides, optogenetics, and oncolytic viruses. The aim of antisense oligonucleotides is to replace a section in a glioma cell genome with a foreign one, which disrupts cell division and leads to apoptosis and necrosis of the entire tumor. Optogenetics excludes the introduction of substances into the body. It provides a certain light signal to glioma cells, which also suppresses the growth of an undifferentiated tumor. Oncolytic viruses are genetically modified viruses that identify tumor cells, penetrate into them and start a cascade of apoptotic reactions Despite all success, such methods are still studied at the laboratory level, their implementation in practical medicine is slow and cautious. However, insufficient knowledge retards the widespread use of potentially promising and effective drugs. Scientists around the world are developing methods to treat brain gliomas at different stages of their development. This article reflects modern achievements of scientists and neurosurgeons, describing new methods for brain glioma treatment. Key words: brain glioma, optogenetics, antisense oligonucleotides, oncolytic viruses, p53 gene. Согласно последним данным статистики, глиомы мозга являются наиболее частой причиной смертей от онкологии центральной нервной системы, а также занимают второе место по частоте как причина хирургических вмешательств на головной мозг, уступая инсультам. Смертность от глиом высока и порой достигает 80 %. Причина этого заключается в том, что опухоль растет из недифференцированных клеток, что обусловливает её молниеносный рост и быстрое озлокачествление. Симптомы глиомы возникают на 3–4 стадии развития, когда все лечение направлено на ликвидацию симптомов, а операции носят паллиативный характер. В связи с этим необходима разработка и внедрение методов по нехирургическому лечению глиом. Такими методами являются использование антисмысловых олигонуклеотидов, оптогенетика, применение онколитических вирусов. Суть использования антисмысловых олигонуклеотидов заключается в замене участка генома клетки глиомы на инородный, попавший извне, что нарушает деление клеток и приводит к апоптозу и некрозу всей опухоли. Оптогенетика исключает введение веществ в организм и заключается в подаче определенного светового сигнала на глиозные клетки, что также тормозит рост недифференцированной опухоли. Онколитические вирусы – это генномодифицированные вирусы, которые определяют опухолевые клетки, проникают в них и запускают каскад апоптотических реакций. Несмотря на все успехи, данные методы продолжают изучаться на уровне лабораторий, их внедрение в практическую медицину происходит медленно и со страхом. Однако недостаточная изученность тормозит широкое применение потенциально перспективных и эффективных лекарств. Учеными мира разрабатываются методы, позволяющие лечить глиомы мозга на разных стадиях их развития. Данная статья отображает современные достижения ученых и нейрохирургов в поисках возможности применения такого рода методов. Ключевые слова: глиома мозга, оптогенетика, антисмысловые олигонуклеотиды, онколитические вирусы, ген р53.


2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Cuinan Yue ◽  
Zhihui Wang ◽  
Puxiang Yang

Abstract Background Light is the ultimate energy source of plant photosynthesis, which has an important impact on the growth, development, physiology and biochemistry of tea plant. Photosensitive etiolated tea plant belongs to a kind of colored leaf plant, which is a physiological response to light intensity. Compared with conventional green bud and leaf of tea plant, the accumulation of pigment compounds (chlorophyll and carotenoids, etc.) closely related to a series of reactions of photosynthesis in photosensitive etiolated tea plant is reduced, resulting in the difference of leaf color of tea. This specific tea resource has high application value, among which high amino acid is one of its advantages. It can be used to process high-quality green tea with delicious taste and attractive aroma, which has been widely attention. The mechanism of the color presentation of the etiolated mutant tea leaves has been given a high topic and attention, especially, what changes have taken place in the pigment compounds of tea leaves caused by light, which makes the leaves so yellow. At present, there have been a lot of research and reports. Purpose of the review We describe the metabolism and differential accumulation of key pigment compounds affecting the leaf color of photosensitive etiolated tea that are triggered by light, and discuss the different metabolism and key regulatory sites of these pigments in different light environments in order to understand the “discoloration” matrix and mechanism of etiolated tea resources, answer the scientific question between leaf color and light. It provides an important strategy for artificial intervention of discoloration of colored tea plant. Conclusion The differential accumulation of pigment compounds in tea plant can be induced phytochrome in response to the change of light signal. The synthesis of chlorophyll in photoetiolated tea plants is hindered by strong light, among which, the sites regulated by coproporphyrinogen III oxidase and chlorophyllide a oxidase is sensitive to light and can be inhibited by strong light, resulting in the aggravation of leaf etiolation. The phenomenon can be disappeared or weakened by shading or reducing light intensity, and the leaf color is greenish, but the increase of chlorophyll-b accumulation is more than that of chlorophyll-a. The synthesis of carotenoids is inhibited strong light, and high the accumulation of carotenoids is reduced by shading. Most of the genes regulating carotenoids are up-regulated by moderate shading and down-regulated by excessive shading. Therefore, the accumulation of these two types of pigments in photosensitive etiolated tea plants is closely related to the light environment, and the leaf color phenotype shape of photosensitive etiolated tea plants can be changed by different light conditions, which provides an important strategy for the production and management of tea plant.


2021 ◽  
Vol 2143 (1) ◽  
pp. 012031
Author(s):  
Suning Gong ◽  
Zhiying Huan ◽  
Mingmei JI ◽  
Xinxin Chen ◽  
Yuanqiu Bao

Abstract With the rapid growth of the number of motor vehicles in the city, traffic congestion is more serious every day, part of it is caused by the coding delay with the red light on, not real traffic jams, now we need a control system that can really change the traffic flow. In this paper, ITLCS (intelligent traffic signal control system) based on OpenCV image processing technology is proposed to adjust the timing of traffic signal according to road density, instead of setting a level that is balanced with other lanes, so that high-load traffic lanes can be used for a long time. The camera facing the roadway in the system takes pictures of the driving route, then takes pictures of the driving density of pedestrians and vehicles, and compares each image through processing technology, after the system is processed, the traffic light signal timing can be adjusted immediately, which greatly reduces the time spent on the inactive green light and can effectively deal with the traffic congestion problem.


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