Performance measurements of Bluetooth 5 technique under interference

Abstract. This thesis focuses on experimental performance of the Bluetooth 5 technology and compares results with the previous version. Bluetooth technology, institute of electrical and electronics engineers (IEEE) Std. 802.15.4, and other techniques share the same unlicensed 2.4 GHz industrial, scientific, and medical (ISM) spectrum. Various technologies are operating in the same frequency band, and if the channel utilized by these technologies overlap, end in cross-technology interference (CTI). Measurements have been performed in indoor scenario and ZigBee nodes were used as an interference. Performance output of the Bluetooth 5 is compared to a previous release Bluetooth low energy (BLE) 4 which is currently one of the popular technologies in commercial wireless devices and expected to be even more widespread in the future. This new Bluetooth technology has featured increased data rate, low power consumption, longer range, higher broadcasting capacity, and improved coexistence with other wireless technologies operating in the same frequency band. The main goal of this work was to evaluate the experimental communication range and throughput of the BLE 5 coded version under interference. Nordic Semiconductor nRF52840 chipset has been used for measurements and result shows the practical communication range and throughput of BLE 5 coded version under interference. In this work, with error correction coding, one-third BLE link gain was achieved when considering packet error rate (PER) less than 10%. In addition, ZigBee interference was found to be very harmful for the Bluetooth communication when operating in the same frequency band

Ab initio molecular dynamics using density based energy functionals: application to ground state geometries of some small clusters

The ground state geometries of some small clusters have been obtained via ab initio molecular dynamical simulations by employing density based energy functionals. The approximate kinetic energy functionals that have been employed are the standard Thomas-Fermi $(T_{TF})$ along with the Weizsacker correction $T_W$ and a combination $F(N_e)T_{TF} + T_W$. It is shown that the functional involving $F(N_e)$ gives superior charge densities and bondlengths over the standard functional. Apart from dimers and trimers of Na, Mg, Al, Li, Si, equilibrium geometries for $Li_nAl, n=1,8$ and $Al_{13}$ clusters have also been reported. For all the clusters investigated, the method yields the ground state geometries with the correct symmetries with bondlengths within 5\% when compared with the corresponding results obtained via full orbital based Kohn-Sham method. The method is fast and a promising one to study the ground state geometries of large clusters.Comment: 15 pages, 3 PS figure

Proceedings of the Sixth International Workshop on Web Caching and Content Distribution

OVERVIEW The International Web Content Caching and Distribution Workshop (WCW) is a premiere technical meeting for researchers and practitioners interested in all aspects of content caching, distribution and delivery on the Internet. The 2001 WCW meeting was held on the Boston University Campus. Building on the successes of the five previous WCW meetings, WCW01 featured a strong technical program and record participation from leading researchers and practitioners in the field. This report includes all the technical papers presented at WCW'01. Note: Proceedings of WCW'01 are published by Elsevier. Hardcopies of these proceedings can be purchased through the workshop organizers. As a service to the community, electronic copies of all WCW'01 papers are accessible through Technical Report BUCS‐TR‐2001‐017, available from the Boston University Computer Science Technical Report Archives at http://www.cs.bu.edu/techreps. [Ed.note: URL outdated. Use http://www.bu.edu/cs/research/technical-reports/ or http://hdl.handle.net/2144/1455 in this repository to access the reports.]Cisco Systems; InfoLibria; Measurement Factory Inc; Voler

Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017

A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1–70.8) million) to 6.4% (58.3 (47.6–70.7) million), but is predicted to remain above the World Health Organization’s Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8–38.5) million) in 2000 to 6.0% (55.5 (44.8–67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

Severe COVID19 Patients and a 3D Airway Tissue Model of SARS-CoV-2 Infection Express High Levels of Airway Mucins and Associated Immunomodulatory Long Noncoding RNAs

Background: Respiratory epithelial cells (RECs) lining the upper airways are primary entry-point for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent for coronavirus disease 2019 (COVID19). Managing the overwhelming inflammatory response and mucus hypersecretion are among the major challenges faced in achieving effective treatment. The present study analyzes the acute inflammatory and mucous responses following SARS-CoV-2 infection. Methods: Nasal swabs from COVID19 patients with mild and severe pathologies were analyzed for the expression of viral RNA (vRNA) for nucleocapsid (N) and spike (S) proteins, viral entry regulating host factors (ACE-2 and TMPRSS-2), epithelial inflammatory factors (IL-6, ICAM-1 and CXCL-8), respiratory mucins (MUC1, 2, 4, 5AC, 5B, 7, 16 and 19), mucin regulatory transcription factors (SPDEF and FOXA3) and select long noncoding RNAs (lncRNAs) by qRT-PCR. Sub-cellular localization and association of lncRNAs and SARS-CoV-2 vRNA was depicted by Dual-fluorescence in situ hybridization (FISH), and immunostaining for epithelial cell markers. A 3D in-vitro cell culture model was developed using primary human RECs differentiated on transwells at air-liquid interface and were infected with a SARS-CoV-2 clinical isolate (USA-WI1/2020) via apical as well as basal regions. Samples were collected at 0, 1, 4, 24 and 48 h post-infection (p.i.) and the expression of aforementioned factors were analyzed in cell lysates and media. Results: Severely affected patients showed significantly higher expression of IL-6, ICAM-1, and CXCL-8 along with the respiratory mucins, MUC4, 5AC, 16, and 19 and the transcriptional regulators, SPDEF and FOXA3 compared to the mild COVID19 patients. Our recently identified novel lncRNAs, LASI (lncRNA on antisense strand to ICAM-1), and TOSL (TNFAIP3-opposite strand lncRNA) were significantly higher in severe patients whereas NEAT1 and MALAT1 levels were lower as were the ACE2 and TMPRSS2. SARS-CoV-2 clinical isolate productively infected 3D human REC model with highest expression of SARS-CoV-2 N vRNA at 24 h p.i., and showed increased expression of inflammatory factors and LASI and TOSL at 1 h p.i. The dual-FISH staining of LASI and SARS-CoV-2 N1 vRNA validated that both the transcripts were enriched in nuclear/perinuclear region of RECs and, club cells and MUC5AC+ cells of severe COVID19.Conclusions: Together, these data indicate that severely infected COVID19 patients are impacted by high respiratory mucin expression and the associated airway inflammation. Interestingly, the lncRNAs, LASI and TOSL showed associated increased expression suggesting a possible role for these innate immunomodulators in SARS-CoV-2 induced innate airway mucosal responses

Performance evaluation of Bluetooth low energy technology under interference

Abstract In this chapter, the focus is on analytical and experimental performance evaluation of the Bluetooth Low Energy (BLE) technology. Studies have been conducted in indoor case relevant to healthcare and medical scenarios. Performance of the recently developed BLE 5 coded technique is compared to BLE 4 that is currently the most popular wireless technology in commercial healthcare and medical solutions. The improved version of BLE may continue the popularity of BLE usage in those application scenarios, and in addition it may enable novel Internet of Things (IoT) solutions. The main objective of this work was to explore the packet error rate (PER) of BLE communication under ZigBee interference, since it is envisaged, that coexistence problems may arise with the further growth of number of the different IoT devices deployed. In this chapter, we first develop an analytical model to characterize the PER of BLE link with varying distance to interfering nodes. Then we conduct a series of practical measurements using the Nordic Semiconductor nRF52840 chipset, which supports the new BLE 5 coded features. Our results show that ZigBee interference is very harmful for BLE communication when operating at the same frequency band, i.e., assuming worst-case scenario. The proposed model can be used to evaluate PER of BLE in various interference scenarios to get insight of communication reliability which is very important specifically for healthcare and medical applications

Performance comparison of near-field focused and conventional phased antenna arrays at 140 GHz

Abstract The future high frequency systems require very high antenna gains to cope with the large channel losses. In order to obtain large gain and flexible beamforming, large antenna arrays are often considered. With hundreds or thousands of antenna elements, transmit energy is highly concentrated on the target. However, large numbers of antenna elements make the antennas very large compared with the wavelength. Therefore, it is likely for the user to be in the near field of the array. In this region, the maximum antenna gain is obtained by focusing the energy on the desired locations. The downside is a need to know the exact locations of the radios. This paper focuses on analysis of the traditional linear phase beam steering and near field focusing beam steering and the impact of the user location uncertainty on the achievable antenna gain. The uncertainty in the user location can arise, for instance, due to user mobility. The results show that the near field focusing gives superior gain in the near field of the antenna array, but is more sensitive to the user location information than the linear phase beam steering