A systematic review and meta-analysis of heart rate variability in COPD

Background: Chronic obstructive pulmonary disease (COPD) is associated with disruption in autonomic nervous control of the heart rhythm. We present here quantitative evidence of the reduction in HRV measures as well as the challenges to clinical application of HRV in COPD clinics. Method: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we search in June 2022 Medline and Embase databases for studies reporting HRV in COPD patients using relevant medical subject headings (MeSH) terms. The quality of included studies was assessed using the modified version of the Newcastle–Ottawa Scale (NOS). Descriptive data were extracted, while standardized mean difference was computed for changes in HRV due to COPD. Leave-one-out sensitivity test was performed to assess exaggerated effect size and funnel plots to assess publication bias. Results: The databases search yielded 512 studies, of which we included 27 that met the inclusion criteria. The majority of the studies (73%) had a low risk of bias and included a total of 839 COPD patients. Although there were high between-studies heterogeneity, HRV time and frequency domains were significantly reduced in COPD patients compared with controls. Sensitivity test showed no exaggerated effect sizes and the funnel plot showed general low publication bias. Conclusion: COPD is associated with autonomic nervous dysfunction as measured by HRV. Both sympathetic and parasympathetic cardiac modulation were decreased, but there is still a predominance of sympathetic activity. There is high variability in the HRV measurement methodology, which affects clinical applicability

Secondary users selection and sparse narrow-band interference mitigation in cognitive radio networks

Spectrum scarcity is a critical problem that may reduce the effectiveness of wireless technologies and services. To address this problem, different spectrum management techniques have been proposed in the literature such as overlay cognitive radio (CR) where the unlicensed users can share the same spectrum with the licensed users. The main challenges in overlay CR networks are the identification and detection of the Primary User (PU) signals in a multi-source narrow-band interference (NBI) scenario. Therefore, in this paper, we investigate the performance of an orthogonal frequency division multiplexing (OFDM) overlay CR network with Secondary Users (SUs) and subcarriers selection schemes. Three approaches for SUs and subcarriers Selection named Direct, Distributed and Incremental selection techniques are proposed in this paper to increase the expected signal to interference and noise ratio based on full or partial knowledge of the channel state information (CSI). We also show that Distributed selection techniques provide all the SUs equal chances to be selected without affecting the selection diversity gain. General as well as simplified outage probability expressions are derived and extensive simulations are conducted to evaluate the performance of the proposed techniques and support the theoretical derivations. To accommodate more SUs, a new approach for asynchronous NBI estimation and mitigation in CR networks is investigated. Without any prior knowledge of the NBI characteristics and based on sparse signal recovery theory, the proposed approach allows the PU to exploit the sparsity of the SUs interference to recover it and approach the interference-free limit over practical ranges of NBI power levels.This publication was made possible by NPRP grant 6-070-2-024 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

Secondary users selection and sparse narrow-band interference mitigation in cognitive radio networks

International audienceSpectrum scarcity is a critical problem that may reduce the effectiveness of wireless technologies and services. To address this problem, different spectrum management techniques have been proposed in the literature such as overlay cognitive radio (CR) where the unlicensed users can share the same spectrum with the licensed users. The main challenges in overlay CR networks are the identification and detection of the Primary User (PU) signals in a multi-source narrow-band interference (NBI) scenario. Therefore, in this paper, we investigate the performance of an orthogonal frequency division multiplexing (OFDM) overlay CR network with Secondary Users (SUs) and subcarriers selection schemes. Three approaches for SUs and subcarriers Selection named Direct, Distributed and Incremental selection techniques are proposed in this paper to increase the expected signal to interference and noise ratio based on full or partial knowledge of the channel state information (CSI). We also show that Distributed selection techniques provide all the SUs equal chances to be selected without affecting the selection diversity gain. General as well as simplified outage probability expressions are derived and extensive simulations are conducted to evaluate the performance of the proposed techniques and support the theoretical derivations. To accommodate more SUs, a new approach for asynchronous NBI estimation and mitigation in CR networks is investigated. Without any prior knowledge of the NBI characteristics and based on sparse signal recovery theory, the proposed approach allows the PU to exploit the sparsity of the SUs interference to recover it and approach the interference-free limit over practical ranges of NBI power levels

PTNet: An efficient and green data center network

International audienceIn recent years, data centers have witnessed an exponential growth for hosting hundreds of thousands of servers as well as to accommodating a very large demand for resources. To fulfill the required level of demand, some approaches tackled network aspects so to host a huge number of servers while others focused on delivering rapid services to the clients by minimizing the path length between any two servers. In general, network devices are often designed to achieve 1:1 oversubscription. Alternatively, in a realistic data center environment, the average utilization of a network could vary between 5% and 25%, and thus the energy consumed by idle devices is wasted. This paper proposes a new parameterizable data center topology, called PTNet. PTNet offers a gradual scalability that interconnects small to large networks covering different ranges of sizes. This new interconnection network provides also a small path length between any two servers even in large sized data centers. PTNet does not only reduce path length and latency, it also uses a power-aware routing algorithm which saves up to 40% of energy with an acceptable computation time. In comparison to existing solutions (e.g. Flatnet, BCube, DCell and Fat-tree), PTNet shows substantial improvements in terms of capacity, robustness, cost-effectiveness and power efficiency: this improvement reaches up to 50% in some cases. (C) 2017 Elsevier Inc. All rights reserved

Prevalence of Nomophobia and Its Association with Academic Performance Among Physiotherapy Students in Saudi Arabia: A Cross- Sectional Survey

BACKGROUND: Nomophobia is common among students in many healthcare disciplines, and its association with academic performance has been explore before. However, there is no available data on its prevalence and association with academic performance among undergraduate physiotherapy (PT) students in Saudi Arabia. METHODS: Between 22 December 2022 and 30 January 2023, a cross-sectional survey was conducted by dissemination using an online platform (Survey Monkey). RESULTS: In total, 806 PT students, with males accounting for 494 (61%), responded to the survey. The prevalence of nomophobia among PT students was 98.4% (793). The mean (±SD) of the total NMP-Q items scores was 49 (± 17), indicating a mild level of nomophobia. Female PT students had significantly higher nomophobia scores than the males (47 (39– 65); 44 (38– 52); (p < 0.001)). Non-smokers had significant higher nomophobia scores than smokers (46 (38– 61); 44 (38– 49); (p = 0.004)). Regarding grade point averages (GPA), the students with a GPA of less than 3.49 had the highest nomophobia score (51 (43– 74); p < 0.001)). Concerning the stage of their studies, bridging students had the highest nomophobia score (51 (34– 76); p = 0.023)). Regarding academic warnings, those who reported no academic warnings had the highest nomophobia score (46 (42– 50); p = 0.023)). Finally, regarding study hours, the students who spent ≥ five hours studying per week had the highest nomophobia score (54 (42– 68); p < 0.001)). CONCLUSION: Nomophobia is common among PT students, with the majority experiencing a mild level. Being female, non-smoker, and having a higher academic performance were risk factors associated with higher nomophobia levels

Physiotherapists’ attitudes, and barriers of delivering cardiopulmonary rehabilitation for patients with heart failure in Saudi Arabia: a cross-sectional study

Background: Cardiopulmonary rehabilitation (CR) is an effective management approach for heart failure (HF) patients and is delivered by multidisciplinary teams including physiotherapists (PTs). PT attitudes about delivering CR and barriers that might affect referral have not been explored. Thus, this study is aimed to explore PT attitudes about delivering CR programs to patients with HF and identify factors and barriers that might affect referral decisions. Methods: A cross-sectional online survey was disseminated to all PTs in Saudi Arabia between 19 February and 27 June, 2022. The characteristics of the respondents were described using descriptive statistics. Percentages and frequencies were used to report categorical variables. Results: Overall, 553 PTs, 289 (52.30%) male and 264 (47.70%) females, completed the online survey. Of these, 360 (65.1%) strongly agreed that CR would improve patients’ physical fitness and 334 (60.4%) strongly agreed that CR would reduce breathlessness in patients with HF. The majority of PTs (321, 58%) strongly agreed that CR would improve HF patients’ palpitation and fatigue. Out of 553 PTs, 349 (63.1%) strongly agreed that CR would improve patients’ ability to perform daily activities. A hospital-supervised program was the preferred mode of delivering CR programs by 499 (90.20%) of the respondents. Apart from the exercise component, stress management was perceived by 455 (82.30%) as an essential component of CR programs. The most common patient-related factor that strongly influenced referral decisions was “fatigue related to disease” (42%). A lack of CR centers was reported by 59.90% as the most common referring barrier. Conclusion: PTs perceived CR as a successful strategy for patients with HF. Although a supervised hospital-based program with stress management as an essential component aside from the exercise component was perceived as the preferred mode of delivery, CR was lacking, which caused a significant barrier to CR referral from the PTs’ perspective

Needs assessment for the establishment of master's degree programs in respiratory care in the Kingdom of Saudi Arabia

Background: Despite recent advancements in the respiratory care (RC) profession, no single institution in the Kingdom of Saudi Arabia (KSA) offers a master's degree program in RC. Methods: A nationwide and validated survey was used to explore the current needs and interests in establishing RC master’s degree programs in the KSA. The process included representatives from the healthcare industry, universities, and professional societies. Results: A total of 1250 stakeholders across the KSA completed the survey. The sample includes 722 (58%) males, 504 (40%) respiratory therapists, 547 (44%) students, 138 (11%) leaders, and 61 (5%) were academic respondents. Most respondents were from Central 491 (39%) and Eastern 307 (25%) regions, with 1003 (80%) of the total sample worked or studied in governmental sectors. 574 (82%) of the leaders and RTs had Bachelor degree and 430 (61%) of them had 1-5 years working experience. According to 80% of the employers and employees, only 0-5% of the RTs in their organization had a master's degree. The calculated mean % of the agreement (agree/strongly agree) on the needs was 83% in all needs’ assessment items, which shows a great support for establishing a master’s in RC to meet the personal, professional and society needs. The mean % of the agreement for the level of interests among all participants was 86%, indicating a great level of interests in establishing a master degree in RC. The agreement % on the needs assessment and level of interests in establishing a master degree in RC in KSA were ≥80% in each stakeholder group. Conclusion: There are obvious needs and interests in establishing master’s degree programs in RC in the KSA. A master's degree in RC should be established to address the growing needs for advanced RC services throughout the nation and enhance RC research