193 research outputs found

    Experimental validation of a reinforcement learning based approach for a service-wise optimisation of heterogeneous wireless sensor networks

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    Due to their constrained nature, wireless sensor networks (WSNs) are often optimised for a specific application domain, for example by designing a custom medium access control protocol. However, when several WSNs are located in close proximity to one another, the performance of the individual networks can be negatively affected as a result of unexpected protocol interactions. The performance impact of this 'protocol interference' depends on the exact set of protocols and (network) services used. This paper therefore proposes an optimisation approach that uses self-learning techniques to automatically learn the optimal combination of services and/or protocols in each individual network. We introduce tools capable of discovering this optimal set of services and protocols for any given set of co-located heterogeneous sensor networks. These tools eliminate the need for manual reconfiguration while only requiring minimal a priori knowledge about the network. A continuous re-evaluation of the decision process provides resilience to volatile networking conditions in case of highly dynamic environments. The methodology is experimentally evaluated in a large scale testbed using both single- and multihop scenarios, showing a clear decrease in end-to-end delay and an increase in reliability of almost 25 %

    Vehicular communication management framework : a flexible hybrid connectivity platform for CCAM services

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    In the upcoming decade and beyond, the Cooperative, Connected and Automated Mobility (CCAM) initiative will play a huge role in increasing road safety, traffic efficiency and comfort of driving in Europe. While several individual vehicular wireless communication technologies exist, there is still a lack of real flexible and modular platforms that can support the need for hybrid communication. In this paper, we propose a novel vehicular communication management framework (CAMINO), which incorporates flexible support for both short-range direct and long-range cellular technologies and offers built-in Cooperative Intelligent Transport Systems' (C-ITS) services for experimental validation in real-life settings. Moreover, integration with vehicle and infrastructure sensors/actuators and external services is enabled using a Distributed Uniform Streaming (DUST) framework. The framework is implemented and evaluated in the Smart Highway test site for two targeted use cases, proofing the functional operation in realistic environments. The flexibility and the modular architecture of the hybrid CAMINO framework offers valuable research potential in the field of vehicular communications and CCAM services and can enable cross-technology vehicular connectivity

    Установка для исследования характеристик теплообменного аппарата

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    Приведено обоснование актуальности применения методов интенсификации теплообмена. Спроектирована экспериментальная установка для исследования характеристик теплообменного аппарата. Средствами вычислительной гидродинамики проведено экспериментальное исследование теплоотдачи и гидравлического сопротивления в трубах с проволочными винтовыми вставками и вставками пропеллерного типа. Проведен анализ полученных экспериментальных данных. Получены критериальные зависимости.The substantiation of the relevance of the application of heat exchange intensification methods is given. The experimental installation for research the characteristics of the heat exchanger is designed. With the help of computational fluid dynamics, an experimental study of heat transfer and hydraulic resistance in pipes with wire helical inserts and propeller-type inserts was carried out. The obtained experimental data are analyzed. Criterial dependencies are obtained

    A genomic resource for the sedentary semi-endoparasitic reniform nematode, Rotylenchulus reniformis Linford & Oliveira.

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    The reniform nematode (Rotylenchulus reniformis) is a sedentary semi-endoparasitic species that is pathogenic on many row crops, fruits, and vegetables. Here, the authors present a draft genome assembly of R. reniformis using small- and large-insert libraries sequenced on the Illumina GAIIx and MiSeq platforms. The reniform nematode (Rotylenchulus reniformis) is a sedentary semi-endoparasitic species that is pathogenic on many row crops, fruits, and vegetables. Here, the authors present a draft genome assembly of R. reniformis using small- and large-insert libraries sequenced on the Illumina GAIIx and MiSeq platforms

    Efficacy and Safety Analyses of Recombinant Factor VIIa in Severe Post-Partum Hemorrhage

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    Background: Despite a range of available treatments, it is still sometimes challenging to treat patients with severe post-partum hemorrhage (sPPH). Objective: This study evaluated the efficacy and safety of recombinant activated factor VIIa (rFVIIa) in sPPH management. Methods: An open-label, multi-center, randomized controlled trial (RCT; NCT00370877) and four observational studies (OS; OS-1 (NCT04723979), OS-2, OS-3, and OS-4) were analyzed regarding efficacy (need for subsequent invasive procedures, including uterine compression sutures, uterine or iliac artery ligations, arterial embolization, or hysterectomy) and safety (incidence of thromboembolic events (TE) and maternal mortality) of rFVIIa for sPPH. The RCT, and OS-1 and OS-2, included a control group of women who did not receive rFVIIa (with propensity score-matching used in OS-1 and OS-2), whereas OS-3 and OS-4 provided descriptive data for rFVIIa-exposed women only. Results: A total of 446 women exposed to rFVIIa and 1717 non-exposed controls were included. In the RCT, fewer rFVIIa-exposed women (50% [21/42]) had an invasive procedure versus non-exposed women (91% [38/42]; odds ratio: 0.11; 95% confidence interval: 0.03–0.35). In OS-1, more rFVIIa-exposed women (58% [22/38]) had an invasive procedure versus non-exposed women (35% [13.3/38]; odds ratio: 2.46; 95% confidence interval: 1.06–5.99). In OS-2, 17% (3/18) of rFVIIa-exposed women and 32% (5.6/17.8) of non-exposed women had an invasive procedure (odds ratio: 0.33; 95% confidence interval: 0.03–1.75). Across all included women, TEs occurred in 1.5% (0.2% arterial and 1.2% venous) of rFVIIa-exposed women and 1.6% (0.2% arterial and 1.4% venous) of non-exposed women with available data. Conclusions: The positive treatment effect of rFVIIa on the RCT was not confirmed in the OS. However, the safety analysis did not show any increased incidence of TEs with rFVIIa treatment

    Association between duration of early empiric antibiotics and necrotizing enterocolitis and late-onset sepsis in preterm infants:a multicenter cohort study

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    The threshold to initiate empiric antibiotics for suspicion of early-onset sepsis (EOS) is low in preterm infants. Antibiotics’ effects on short-term outcomes have recently been debated. We aimed at exploring the extent of early empiric antibiotic exposure (EEAE) in preterm infants and the association between the duration of EEAE with necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) within different EEAE groups. EEAE practice for suspicion of EOS was evaluated in all included infants (gestational age 72 h). Infants with EEAE ≤ 72 h had a lower incidence of NEC compared to both infants without EEAE (adjusted odds ratio (aOR) 0.39; 95% confidence interval (CI) [0.19–0.80]; p = 0.01) and with prolonged EEAE (> 72 h) (aOR [95%CI]: 0.58 [0.35–0.96]; p = 0.03). With every additional day of EEAE, LOS incidence decreased (aOR [95%CI]: 0.90 [0.85–0.97]; p = 0.003). Conclusion: Almost 90% of preterm infants who have negative blood culture results in the first 72 h of life are exposed to EEAE under suspicion of EOS. One-fourth has prolonged EEAE. Duration of EEAE was differently associated with NEC and LOS incidence. The effects of antibiotics, and potentially induced microbial dysbiosis related to development of NEC and LOS, should further be explored.What is Known:• Preterm infants often receive antibiotics empirically directly after birth for suspicion of early-onset sepsis.• The effects of the duration of early empirical antibiotic exposure on the risk for necrotizing enterocolitis and late-onset sepsis are debated.What is New:• Almost 90% of preterm infants with a gestational age below 30 weeks are exposed to antibiotics empirically after birth despite negative culture results. In a quarter of these culture-negative infants, empirical antibiotics are prolonged.• A short course of empirical antibiotics (≤72h) is associated with decreased odds for necrotizing enterocolitis compared to both prolonged (>72h) or no empirical antibiotics after birth. Furthermore, every additional day of empirical antibiotic exposure is associated with decreased risk for late-onset sepsis in the first month of life

    Clinical and radiological outcome of conservative vs. surgical treatment of atraumatic degenerative rotator cuff rupture: design of a randomized controlled trial

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    Background: Subacromial impingement syndrome is a frequently observed disorder in orthopedic practice. Lasting symptoms and impairment may occur when a subsequent atraumatic rotator cuff rupture is also present. However, degenerative ruptures of the rotator cuff can also be observed in asymptomatic elderly individuals. Treatment of these symptomatic degenerative ruptures may be conservative or surgical. Acceptable results are reported for both treatment modalities. No evidence-based level-1 studies have been conducted so far to compare these treatment modalities. The objective of this study is to determine whether there is a difference in outcome between surgical reconstruction and conservative treatment of a degenerative atraumatic rotator cuff tendon rupture. Methods/Design: A randomized controlled trial will be conducted. Patients aged between 45 and 75 with a symptomatic atraumatic rotator cuff rupture as diagnosed by MRI will be included. Exclusion criteria are traumatic rotator cuff rupture, frozen shoulder and diabetes mellitus. Patients will be randomized into two groups. Conservative treatment includes physical therapy according to a standardized protocol, NSAIDs and, if indicated, subacromial infiltration with a local anesthetic and corticosteroids. Surgical reconstruction is performed under general anesthesia in combination with an interscalenus plexus block. An acromioplasty with reconstruction of the rotator cuff tendon is performed, as described by Rockwood et al. Measurements take place preoperatively and 6 weeks, 3 months, 6 months and 1 year postoperatively. The primary outcome measure is the Constant score. Secondary measures include both disease-specific and generic outcome measures, and an economic evaluation. Additionally, one year after inclusion a second MRI will be taken of all patients in order to determine whether extent and localization of the rupture as well as the amount of fatty degeneration are prognostic factors. Discussion: Both surgical as conservative treatment of a symptomatic atraumatic rotator cuff tendon rupture is used in current practice. There is a lack of level-1 studies comparing surgical vs. conservative treatment. This randomized controlled trial has been designed to determine whether the surgical treatment of a degenerative atraumatic rotator cuff tendon rupture may lead to a better functional and radiological outcome than conservative treatment after one year of follow-up
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