Exposure to PM2.5 Related to Road Traffic: Comparison between Crossroads and Outside of Crossroads at Cotonou, Benin

Background: Several studies have analysed the pollution issues owing to road traffic in Cotonou, Benin. Concentration levels of particles are higher on high traffic than a low traffic. The exposure of human populations to air pollution is more intense on the roads. In Benin, the density of traffic on the crossroads is indeed more important. Are traffic locations such as crossroads, areas where the level of exposure PM2.5 is increased? Methods: This study was conducted along the 5 km high-traffic road in the city of Cotonou. It is a high traffic lane with two crossroads. Sampling and measurements were carried out in dry sea-son (January and February) and rainy season (June and July). For each season the measurements were made over two months from 7 am to 9 pm. PM2.5 measurements were made at different locations at crossroads and also along the track. To compare concentrations of PM2.5 at crossroads and outside of roundabout, we used the Generalized Linear Mixed Model. Results: In the rainy season the PM2.5 hourly concentrations ranged between 400 μg/m3 and 500 μg/m3 while in the dry season 100 μg/m3 and 300 μg/m3. In the rainy season, the average of PM2.5 concentration was 463.25 ± 66.21 μg/m3 at crossroads and 264.75 ± 50.97 μg/m3 outside of crossroads. In the dry season, the average of PM2.5 concentration was 232.75 ± 97.29 μg/m3 at crossroads and 123.31 ± 63.79 μg/m3 outside of crossroads. Both in dry and rainy seasons, PM2.5 concentration level peaks are observed from 7 am to 9 am and from 7 pm to 9 pm. The Generalized Linear Mixed Model showed that there is high significant difference between concentrations of PM2.5 at crossroads compared to outside of crossroads. Occupation of the roadside (in particular crossroads) for various economic activities is common practice in Cotonou thus health risk for people working around crossroads increases. Conclusion: Locations such as crossroads are areas where the level of exposure PM2.5 is highest on road traffics.

Design of beacon system based on MSP430 micro- controller

In order to solve the onboard recorder search problem, a new beacon system based on radio direction finding tech- nique, which indicates the orientation of the recorder, is designed. The system consists of phase-locked loop （PLL）, micro- processor, global position system （GPS） module, power module and so on. The scene simulation verifies the feasibility and reliability of the system. This beacon system can be applied to the recorder search in many fields, and can effectively reduce the search scope and improve work efficiency.

隧洞施工人员U-Beacon定位系统设计与开发

针对传统UWB定位技术在大范围隧洞内人员定位中存在布线成本高、施工周期长、风险高的问题,结合UWB定位技术和Beacon技术,提出一种基于U-Beacon的隧洞内人员定位系统,并针对隧洞复杂施工场景进行定位系统网络拓扑结构设计、U-Beacon定位系统部署方案设计及硬件电路设计。以施工人员佩戴便携式胸卡标签方式,提高系统易用性。采用TOA定位算法和Sage-husa自适应卡尔曼滤波算法对UWB测距数据进行定位和降噪处理,实现对洞室复杂施工环境的精准定位。实验结果表明,基于U-Beacon的人员定位系统大大降低施工成本,降低施工风险,同时Sage-husa自适应滤波算法在提高隧洞内定位精度和鲁棒性方面有很大的提升。

A tensile wearable SHF antenna with efficient communication in defense beacon technology

The study projects a flexible and compact wearable pear-shaped Super High Frequency(SHF)antenna that can provide detailed location recognition and tracking applicable to defense beacon technology.This mini aperture with electrical dimensions of 0.12λ_(0)×0.22λ_(0)×0.01λ_(0)attains a vast bandwidth over 3.1-34.5 GHz Super High Frequency(SHF)frequency band at S_(11)≤-10 dB,peak gain of 7.14 dBi and proportionately homogeneous radiation pattern.The fractional bandwidth(%BW)acquired is 168%that envelopes diversified frequency spectrum inclusive of X band specifically targeted to all kinds of defense and military operations.The proposed antenna can be worn on a soldier's uniform and hence the Specific Absorption Rate simulation is accomplished.The Peak SAR Value over 1 g of tissue is 1.48 W/kg and for 10 g of tissue is 0.27 W/kg well under the safety standards.The flexibility is proven by analyzing the full electromagnetic simulations for various bending conditions.Time response analysis is attained with its Fidelity Factor and Group Delay.Communication excellence is determined using Link Budget Analysis and it is seen that margin at 100 Mbps is 62 m and at 200 Mbps is 59 m.Prototype is fabricated along with experimental validation.All the results show harmony in shaping the antenna to provide critical situational awareness and data sharing capabilities required in defense beacon technology for location identification.

Development and Application of Detection Methods for Capture and Transcription Elongation Rate of Bacterial Nascent RNA

Objective Detection and quantification of RNA synthesis in cells is a widely used technique for monitoring cell viability,health,and metabolic rate.After exposure to environmental stimuli,both the internal reference gene and target gene would be degraded.As a result,it is imperative to consider the accurate capture of nascent RNA and the detection of transcriptional levels of RNA following environmental stimulation.This study aims to create a Click Chemistry method that utilizes its property to capture nascent RNA from total RNA that was stimulated by the environment.Methods The new RNA was labeled with 5-ethyluridine(5-EU)instead of uracil,and the azido-biotin medium ligand was connected to the magnetic sphere using a combination of“Click Chemistry”and magnetic bead screening.Then the new RNA was captured and the transcription rate of 16S rRNA was detected by fluorescence molecular beacon(M.B.)and quantitative reverse transcription PCR(qRT-PCR).Results The bacterial nascent RNA captured by“Click Chemistry”screening can be used as a reverse transcription template to form cDNA.Combined with the fluorescent molecular beacon M.B.1,the synthesis rate of rRNA at 37℃is 1.2 times higher than that at 15℃.The 16S rRNA gene and cspI gene can be detected by fluorescent quantitative PCR,it was found that the measured relative gene expression changes were significantly enhanced at 25℃and 16℃when analyzed with nascent RNA rather than total RNA,enabling accurate detection of RNA transcription rates.Conclusion Compared to other article reported experimental methods that utilize screening magnetic columns,the technical scheme employed in this study is more suitable for bacteria,and the operation steps are simple and easy to implement,making it an effective RNA capture method for researchers.

Research on Signal of Field Monitor of 7220A Localizer Beacon Subsystem of ILS

From the actual perspective of working principle of localizer beacon subsystem of Instrument Landing System (ILS), consideration of the distance information from localizer antenna to field monitor antenna and wide aperture effect of localizer antenna, broke through the limitation of signals synthesized only far-field (FF), established the near-field (NF) model. The three-dimensional mathematical model of localizer beacon was designed, and the signals at both near-field and far-field were analyzed qualitatively. At the environment of Antenna Fault as well as Antenna Distribution Unit (ADU) phase shifter simulation, the characteristics of near-field and far-field were also compared. The simulation results showed that the model met the requirement of theory of localizer beacon, and the gap between two models was so evident, which resulted from the broken geometric symmetry in NF area. The model could provide valuable theoretical basis for performance evaluation and maintenance of the ILS, and meanwhile, provide reference for the further analysis of localizer beacon.

Real-time fluorescent quantitative immuno-PCR method for determination of fluoranthene in water samples with a molecular beacon

A reliable and sensitive competitive real-time fluorescent quantitative immuno-PCR （RTFQ-IPCR） assay using a molecular beacon was developed for the determination of trace fluoranthene （FL） in the environment.Under optimized assay conditions,FL can be determined in the concentration range from 1 fg/mL to 100 ng/mL,with y=0.194x ＋ 7.859,and a correlation coefficient of 0.967 was identified,with a detection limit of 0.6 fg/mL.Environmental water samples were successfully analyzed,recovery was between 90% and 116%,with intra-day relative standard deviation （RSD） of 6.7%-12.8% and inter-day RSD of 8.4%-15.2%.The results obtained from RTFQ-IPCR were confirmed by ELISA,showing good accuracy and suitability to analyze FL in field samples.As a highly sensitive method,the molecular beacon-based RTFQ-IPCR is acceptable and promising for providing reliable test results to make environmental decisions.

Use of siRNA molecular beacons to detect and attenuate mycobacterial infection in macrophages

Tuberculosis is one of the leading infectious diseases plaguing mankind and is mediated by the facultative pathogen, Mycobacterium tuberculosis(MTB). Once the pathogen enters the body, it subverts the host immune defenses and thrives for extended periods of time within the host macrophages in the lung granulomas, a condition called latent tuberculosis(LTB). Persons with LTB are prone to reactivation of the disease when the body's immunity is compromised. Currently there are no reliable and effective diagnosis and treatment options for LTB, which necessitates new research in this area. The mycobacterial proteins and genes mediating the adaptive responses inside the macrophage is largely yet to be determined. Recently, it has been shown that the mce operon genes are critical for host cell invasion by the mycobacterium and for establishing a persistent infection in both in vitro and in mouse models of tuberculosis. The Yrb E and Mce proteins which are encoded by the MTB mce operons display high degrees of homology to the permeases and the surface binding protein of the ABC transports, respectively. Similarities in structure and cell surface location impute a role in cell invasion at cholesterol rich regions and immunomodulation. The mce4 operon is also thought to encode a cholesterol transport system that enables the mycobacterium to derive both energy and carbon from the host membrane lipids and possibly generating virulence mediating metabolites, thus enabling the bacteria in its long term survival within the granuloma. Various deletion mutation studies involving individual or whole mce operon genes have shown to be conferring varying degrees of attenuation of infectivity or at times hypervirulence to the host MTB, with the deletion of mce4 A operon gene conferring the greatest degree of attenuation of virulence. Antisense technology using synthetic si RNAs has been used in knocking down genes in bacteria and over the years this has evolvedinto a powerful tool for elucidating the roles of various genes mediating infectivity and survival in mycobacteria. Molecular beacons are a newer class of antisense RNA tagged with a fluorophore/quencher pair and their use for in vivo detection and knockdown of mR NA is rapidly gaining popularity.

A Self-Adaptive Back-off Optimization Scheme Based on Beacons Probability Prediction for Vehicle Ad-Hoc Networks

In order to improve the broadcast reception rates of beacon messages in vehicle ad-hoc networks,a conclusion that the relationship between collision probability and minimum contention window size and the relationship between expiration probability and minimum window size was reached by building a Markov model. According to this conclusion, a back-off algorithm based on adjusting the size of minimum contention window called CEB is proposed, and this algorithm is on the basis of the differential size between the number of expiration beacons and preset threshold. Simulations were done to compare the performance of CEB with that of RBEB and BEB, and the results show that the performance of the new proposed algorithm is better than that of RBEB and BEB.

Vehicular Beacon Broadcast Scheduling Based on Age of Information(AoI)

Vehicular beaconing plays an important role to facilitate various applications in the paradigm of Internet of Vehicles(IoV). Due to high dynamic and resource limitation in IoV, how to schedule the vehicular beacon broadcast is challenging, especially in dense scenarios. In this paper, we investigate the beacon broadcast scheduling problem considering the Age of Information(AoI). We first propose an algorithm minimizing the expected sum of AoI considering the limited communication resource and vehicle mobility. Then the performance of the proposed algorithm is analyzed. With the proposed algorithm, the optimal solution can be obtained under certain conditions. Extensive simulations are conducted to verify the efficiency, effectiveness and fairness of the proposed solution.

Preliminary observation results of the Coherent Beacon Systemonboard the China Seismo-Electromagnetic Satellite-1

This paper reports, for the first time, observation results of the Coherent Beacon System(CBS) onboard the China SeismoElectromagnetic Satellite-1(CSES-1). We describe the CBS, and the Computerized Ionospheric Tomography(CIT) algorithm program is validated by numerical experiment. Two examples are shown, for daytime and nighttime respectively. The Equatorial Ionization Anomaly(EIA) can be seen, and the northern crest core is located at ～20°N in the reconstruction image at 07:28 UTC on 20 July 2018(daytime).Disturbances are shown in the reconstruction image at 18:40 UTC on 13 July 2018(nighttime). We find that beacon measurements are more consistent with ionosonde measurements than model results, by comparing Nm F2 at three sites at Lanzhou, Chongqing, and Kunming; consistency with ionosonde measurements validates beacon measurements. Finally, we have studied Vertical Total Electron Content(VTEC) variations from ground to ～500 km(the height of CSES-1 orbit) and ratios of VTEC between beacon measurements and CODE(Center for Orbit Determination in Europe) data. VTEC variation from ground to ～500 km has a range of 7.2–16.5 TECU for the daytime case and a range of 1.1–1.7 TECU for the nighttime case. The Beacon/CODE ratio of VTEC varies with latitude and time. The mean Beacon/CODE ratio is 0.69 for the daytime case and 0.26 for the nighttime case. The fact that the nighttime case yields lower ratios indicates the higher altitude of the ionosphere during nighttime when the ionosphere is assumed to be a thin layer.

Safety Evaluation of Stop-Sign Mounted Beacons—A Cross-Sectional Study

Agencies in Iowa have utilized both overhead flashing beacons and stop-sign mounted beacons. Although several studies have shown that overhead flashing beacons are effective, some concerns have been raised about driver confusion. The main concern is that a driver may interpret a multiface flashing beacon with a red indication for their approach as an all-way stop control. As a result, the Iowa DOT has been advocating use of stop-sign mounted beacons rather than overhead flashing beacons. Since little information is available about this countermeasure, data for intersections with (treatment) and without (control) stop-sign mounted beacons were identified and a cross-sectional analysis conducted (due to few confirmable installation dates). Rural stop-controlled intersections with stop-sign mounted beacons in Iowa (USA) were identified (40 in total). Intersection characteristics such as number of approaches, intersection angle etc. were extracted. Additionally, characteristics of individual approaches such as roadway surface (gravel/paved), advanced stop-sign rumble strips, and advance signing were recorded. One or more control locations were manually selected for each treatment intersection based on matching roadway configuration, presence of lighting, advance stop line rumble strips, number of approaches, channelization, traffic volume, and proximity. Propensity scores were estimated to match 40 control locations for comparison. Negative binomial models for different injury combinations at nighttime and daytime were developed with an indicator variable for presence and absence of stop-sign mounted beacons. Presence of stop-sign mounted beacons was associated with a 5% - 54% reduction in nighttime crashes. Injury nighttime crashes decreased by 54% and total nighttime crashes reduced by 18%.

REAL-TIME DETECTION OF SURVIVIN mRNA EXPRESSION IN CERVICAL CANCER CELL LINES USING MOLECULAR BEACON IMAGING

Objective To detect the expression of survivin mRNA in cervical cancer cell lines using molecular beacon imaging technology. Methods Human cervical cancer cells (HeLa and SiHa) and human fetal lung fibroblast HFL-I were cultured in vitro. After adding 100nmol/L survivin mRNA molecular beacon, the fluorescent signals were observed under fluorescent microscope. The expressions of survivin in cervical cancer cells and HFL-I cell were examined by immunocytochemical streptravidin-biothin peroxidase (SP) assay at the same time. Results Two kinds of survivin mRNA molecular beacon, with different color fluorescence, had strong fluorescent signal in cervical cancer cell lines, and the signal in SiHa cell line was stronger, but these signals were not found in HFL-I ; Immunocytochemical staining of positive survivin was located in the cytoplasm of cervical cancer cell lines HeLa and SiHa, whereas, no expression of survivin was detected in HFL-I cell line. Conclusion The technology of molecular beacon imaging can be used to detect the expression of survivin mRNA in viable cells successfully, and may provide a new approach to the diagnosis of early stage cervical cancer and the following-up in the clinic.

Inversion of Ionospheric Electron Density from GPS Beacon Observations

This paper studies the mathematical foundation of time-dependent three-dependent three-dimensional (3-D) computerized ionospheric tomography (CIT) for reconstructing ionospheric electron density,N_e,from ground-based GPS beacon obser\|vations,After simplifying the relation between N_e and time, the time-dependent 3-D inversion in consideration is reduced to a 3-D tomography with incomplete projections. To see clearly the effects of the incompleteness on the quality of reconstruction under 3-D condition,the fromula of 3-D parallelbeam tomography is deduced theoretically. After establishing the mathematical foundation,simulations based on actual GPS ray paths with the help of the IRI-90 model are performed, and reasonable time-dependent 3-D distribution images of N_e are obtained when taking proper layout of the network and allowing variable resolutions. The quality of the reconstruction is rather good when compared with the images from the IRI90 model directly. Therefore, results in this paper demonstrate that imaging of the ionospheric electron density distribution from GPS beacon observations is reasonable in theory and feasible in pratice.

Real-time Monitoring of Nucleotide Excision of Molecular Beacon Catalyzed by Klenow Fragment

Klenow fragment（KF） uses the activity of a separate exonuclease to excise nucleotide, which is a crucial step in DNA replication and repair. Here is a novel sensitive and convenient method introduced for real-time monitoring nucleotide excision by KF with a molecular beacon as a detecting probe in a homogeneous solution. This method, which overcomes the drawbacks of traditional methods such as discontinuity, time consuming and low sensitivity, was used to assay KF activity and the detection limit reached up to 0.4 U/mL. In addition, the method was applied to investigating the effects of metal ions and chemical drugs on the reaction. The results demonstrate that it is a potential high-throughput assay for screening inhibitors and activity analysis of KF in vitro.

Calculation and analysis of the number of return photons from sodium laser beacon excited by the long pulse laser with circular polarization

The number of return photons from sodium laser beacon（SLB） greatly suffers down-pumping, recoil, and geomagnetic field when the long pulse laser with circular polarization interacts with sodium atoms in the mesosphere. Considering recoil and down-pumping effects on the number of return photons from SLB, the spontaneous radiation rates are obtained by numerical computations and fittings. Furthermore, combining with the geomagnetic field effects, a new expression is achieved for calculating the number of return photons. By using this expression and considering the stochastic distribution of laser intensity in the mesosphere under different turbulence models for atmosphere, the number of return photons excited by the narrow-band single mode laser and that by the narrow-band three-mode laser are respectively calculated. The results show that the narrow-band three-mode laser with a specific spectrum structure has a higher spontaneous radiation rate and more return photons than a narrow-band single mode laser. Of note, the effect of the atmospheric turbulence on the number of return photons is remarkable. Calculation results indicate that the number of return photons under the HV5/7 model for atmospheric turbulence is much higher than that under the Greenwood and Mod HV models.

Evaluation of Driver Behavior in Response to Stop Sign Beacons

Crashes at rural intersections are frequently a result of failure to yield. As a result, agencies attempt to find countermeasures that encourage drivers to stop and yield appropriately. A number of countermeasures have been utilized to reduce crashes and improve intersection safety. However, some treatments have been shown to have mixed results, while for others only limited information about effectiveness is available. Because even low-cost treatments require some maintenance, it is important for agencies to have good information about the effectiveness of the various treatments before investments are made. Stop sign beacons are one such low-cost measure. This paper discusses results of research which evaluated stop sign beacons. Stop sign beacons were installed at 10 stop-controlled approaches in the US state of Iowa. The beacons were set to activate only when an approaching driver was traveling over a set speed threshold which was set based on whether a driver would be able to stop. Video data were collected before, at 1-month, and at 12-month after installation. Type of stop (i.e., rolling, no-stop), stop location in reference to the stop bar, and location of initial brake application were reduced from the video data. The percentage of drivers who began braking before or after 350 feet were compared. This threshold indicates the point at which drivers would need to engage in hard braking based on approach speed and stopping sight distance. At one month, 6 of the 9 intersections experienced an increase in the percentage of vehicles braking at 350 feet or before. At 12-month, drivers at more than half of the approaches were braking sooner than the before period. Results also indicate stopping behavior improved after installation of the beacons. Most of the approaches (70%) showed an increase in the percentage of drivers who came to a full stop at 1-month compared to the period before installation. At 12-month, 71% of approaches showed an increase in drivers who came to a complete stop. Similar results were found for stopping location. Around 80% of approaches experienced an increase in the percentage of vehicle that stopped at or before the stop bar at the 1-month period after installation and 86% of approaches had an increase at 12-month.

Beacon of Hope

Having savored the afterglow of the vibrant Beijing 2022 Winter Olympics and its magnificent closing ceremony on February 20,China is now gearing up for its next big event–the annual sessions of its national legislature and top political advisory body,known as the“two sessions.”The 13th National People’s Congress(NPC)will convene its fifth session on March 5,while the 13th National Committee of the Chinese People’s Political Consultative Conference(CPPCC)will hold its fifth session on March 4.Thousands of national lawmakers and political advisors from across the country will gather in Beijing for the“two sessions,”which embrace every aspect of the country’s development and the people’s wellbeing.

China Shines as a Beacon of Human Solidarity

China's commitment and contribution to multilateralism is laudable.IN his Lunar New Year greetings video,United Nations Secretary-General António Guterres took the opportunity on Chinese New Year’s Eve to commend China for its commitment to multilateralism.The global battle against the COVID-19 pandemic,as well as climate change,continues in February 2022,which has also seen heated and ominous disagreements that threaten dire conflict.All present challenges unprecedented in recent history.Amid this turmoil,Guterres declared that the Olympic spirit,as represented by the Beijing 2022 Winter Olympics,“shines as a beacon of human solidarity.”Such acknowledgement and words of goodwill from the world’s top diplomat are merited in light of China’s key contributions to multilateralism over decades,most specifically during the last several years.They are evident in three distinctive examples.

An Internet of Things Platform with Google Eddystone Beacons

Consumer adoption of Internet of Things devices is increasing rapidly. About 66% of consumers mean to buy an associated home gadget by 2019. Beacon technology helps in providing actionable insights to businesses through visual heat maps generated by the consumers and these maps are further processed by machine learning algorithms. Google’s open source Eddystone beacon format released in 2015, mitigates the problem of high cost and provides an open source alternative for developers. The aim of the proposed work is to provide a low cost, reliable, flexible, scalable and open source alternative for small and medium scale enterprises. In the proposed work, an Internet of Things platform is configured and developed. The Raspberry Pi is configured as an Eddystone beacon through a NodeJs server. An android app is developed which is the front end of the platform and web services are deployed on the cloud.