469 research outputs found
Effective Capacity in Broadcast Channels with Arbitrary Inputs
We consider a broadcast scenario where one transmitter communicates with two
receivers under quality-of-service constraints. The transmitter initially
employs superposition coding strategies with arbitrarily distributed signals
and sends data to both receivers. Regarding the channel state conditions, the
receivers perform successive interference cancellation to decode their own
data. We express the effective capacity region that provides the maximum
allowable sustainable data arrival rate region at the transmitter buffer or
buffers. Given an average transmission power limit, we provide a two-step
approach to obtain the optimal power allocation policies that maximize the
effective capacity region. Then, we characterize the optimal decoding regions
at the receivers in the space spanned by the channel fading power values. We
finally substantiate our results with numerical presentations.Comment: This paper will appear in 14th International Conference on
Wired&Wireless Internet Communications (WWIC
Reducing Discomfort While Measuring Crown-Heel Length in Neonates
To assess the degree of discomfort caused by length measurement in neonates, performed with one or both lower limbs extended, on the first and second day after birth, with either one or both lower limbs extended.
METHODS: Healthy full-term neonates were systematically sampled during the months of February and March 2004. Crown-heel length was measured, using a 1-mm precision neonatometer, at approximately 8 h and 32 h after birth, with one and both lower limbs extended. The Neonatal Facial Coding System was used to assess discomfort during measurements. Data were analysed by parametric and non-parametric tests as appropriate.
RESULTS: Whatever the measurement technique, discomfort scores are significantly higher during the length measurement than at baseline. Whenever length measurements are performed, discomfort scores are significantly higher when extending both lower limbs rather than one lower limb (p < 0.006). The measured length is greater with one lower limb extended; however, the difference decreases over time, being 0.19 cm (95% CI 0.1-0.3; p < 0.001) at approximately 32 h of age. No significant differences in length were found between measurements at approximately 8 or 32 h, regardless of the technique used. The best correlation between length measurements with one or both lower limbs extended was observed at approximately 32 h after birth (r = 0.98).
CONCLUSION: Measuring crown-heel length is a distressful procedure for the neonate. Measurements with one lower limb extended result in less discomfort than when both lower limbs are extended, without decreasing the accuracy
Adaptive nonlinear interference suppressor for cognitive radio applications
To utilize the radio frequency spectrum efficiently a Cognitive Radio (CR) can operate as a secondary user in a frequency band which is licensed to a primary user. To this end, the CR must sense the spectrum continuously to find empty frequency channels for its transmission. The transmitted signal by the local transmitter of the CR, however, induces a strong local interference in the local receiver of the CR. Hence a half-duplex transceiver is used where the transmit and sense operations are done in separate time slots. The time-slotted operation though, reduces the throughput of the CR. This paper proposes application of an adaptive Nonlinear Interference Suppressor (NIS) to suppress this strong local interference to enable simultaneous transmit and sense. We present experimental results of a transceiver testbed that uses an implementation of the NIS, fabricated in 140 nm CMOS technology. These experiments show that the NIS can substantially suppress the local interference with low complexity and power consumption
IPS in supported housing:Fidelity and employment outcomes over a 4 year period
Background: People with severe mental illness have difficulties finding and maintaining competitive employment. This is particularly so for those living in supported housing who, by definition, have significant day-to-day support needs: in the Netherlands only 3 to 5% of people with serious mental health problems who live in supported housing are competitively employed. To support these people in finding and maintaining competitive employment, Individual Placement, and Support (IPS) was introduced within supported housing services in the Netherlands in 2015. As this is the first country that broadly implemented IPS in supported housing settings, this paper will focus on the first results regarding feasibility and effects on employment in clients of IPS in this sector. Methods: We investigated the feasibility and employment outcomes of delivering IPS in supported housing services using fidelity assessments and quarterly employment outcomes on IPS program level within eight supported housing organizations, and compared these with 21 mental health treatment organizations in the Netherlands over a 4 year period. We investigated possible reasons for our findings and their implications through qualitative evaluations of the IPS fidelity assessors' notes and additional focus groups with IPS specialists and coordinators from supported housing services and fidelity assessors. Results: The overall fidelity scores indicated reasonable implementation of the IPS model within both supported housing services and mental health services. However, there were differences between services with regard to specific fidelity items; mental health treatment organizations scored higher for team integration, whereas supported housing services scored higher for rapid job search and caseload size, diversity of jobs, and employers. Our qualitative data suggested that the difference in team integration between the two sectors was due to differences in their organizational and financial structures, as well as in the specific needs of their clients. Conversely, supported housing services had better connections with employers which facilitated more rapid job searching and greater diversity in employment opportunities. The average total client employment rate did not significantly differ; and was 25.8% per quarter in supported housing services and 29.6% in mental health treatment services. Conclusion: Implementing IPS in supported housing settings is both feasible and effective
The participatory turn in radioactive waste management:Deliberation and the social-technical divide
National policies for long-term management of radioactive waste have for decades been driven by technical experts. The pursuit of these technocratic policies led in many countries to conflict with affected communities. Since the late 1990s, however, there has been a turn to more participatory approaches. This participatory turn reflects widespread acknowledgement in the discourse of policy actors and implementing organisations of the importance of social aspects of radioactive waste management and the need to involve citizens and their representatives in the process. This appears to be an important move towards democratisation of this particular field of technological decision making but, despite these developments, technical aspects are still most often brought into the public arena only after technical experts have defined the āproblemā and decided upon a āsolutionā. This maintains a notional divide between the treatment of technical and social aspects of radioactive waste management and raises pressing questions about the kind of choice affected communities are given if they are not able to debate fully the technical options. The article aims to contribute to better understanding and addressing this situation by exploring the complex entanglement of the social and the technical in radioactive waste management policy and practice, analysing the contingent configurations that emerge as sociotechnical combinations. Drawing upon empirical examples from four countries that have taken the participatory turn - Belgium, Slovenia, Sweden and the United Kingdom ā the article describes the different ways in which sociotechnical combinations have been constructed, and discusses their implications for future practice
Achievable rates optimization for broadcast channels using finite size constellations under transmission constraints
Selective digestive and oropharyngeal decontamination in medical and surgical ICU patients:individual patient data meta-analysis
Objectives: Selective digestive decontamination (SDD) and selective oropharyngeal decontamination (SOD) improved intensive care unit (ICU), hospital and 28-day survival in ICUs with low levels of antibiotic resistance. Yet it is unclear whether the effect differs between medical and surgical ICU patients.& para;& para;Methods: In an individual patient data meta-analysis, we systematically searched PubMed and included all randomized controlled studies published since 2000. We performed a two-stage meta-analysis with separate logistic regression models per study and per outcome (hospital survival and ICU survival) and subsequent pooling of main and interaction effects.& para;& para;Results: Six studies, all performed in countries with low levels of antibiotic resistance, yielded 16 528 hospital admissions and 17 884 ICU admissions for complete case analysis. Compared to standard care or placebo, the pooled adjusted odds ratios for hospital mortality was 0.82 (95% confidence interval (CI) 0.72-0.93) for SDD and 0.84 (95% CI 0.73-0.97) for SOD. Compared to SOD, the adjusted odds ratio for hospital mortality was 0.90 (95% CI 0.82-0.97) for SDD. The effects on hospital mortality were not modified by type of ICU admission (p values for interaction terms were 0.66 for SDD and control, 0.87 for SOD and control and 0.47 for SDD and SOD). Similar results were found for ICU mortality.& para;& para;Conclusions: In ICUs with low levels of antibiotic resistance, the effectiveness of SDD and SOD was not modified by type of ICU admission. SDD and SOD improved hospital and ICU survival compared to standard care in both patient populations, with SDD being more effective than SOD. (C) 2017 The Author(s). Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases
Associations of early changes in lung ultrasound aeration scores and mortality in invasively ventilated patients: a post hoc analysis
Background: Lung ultrasound (LUS) in an emerging technique used in the intensive care unit (ICU). The derivative LUS aeration score has been shown to have associations with mortality in invasively ventilated patients. This study assessed the predictive value of baseline and early changes in LUS aeration scores in critically ill invasively ventilated patients with and without ARDS (Acute Respiratory Distress Syndrome) on 30- and 90-day mortality. Methods: This is a post hoc analysis of a multicenter prospective observational cohort study, which included patients admitted to the ICU with an expected duration of ventilation for at least 24 h. We restricted participation to patients who underwent a 12-region LUS exam at baseline and had the primary endpoint (30-day mortality) available. Logistic regression was used to analyze the primary and secondary endpoints. The analysis was performed for the complete patient cohort and for predefined subgroups (ARDS and no ARDS). Results: A total of 442 patients were included, of whom 245 had a second LUS exam. The baseline LUS aeration score was not associated with mortality (1.02 (95% CI: 0.99 ā 1.06), p = 0.143). This finding was not different in patients with and in patients without ARDS. Early deterioration of the LUS score was associated with mortality (2.09 (95% CI: 1.01 ā 4.3), p = 0.046) in patients without ARDS, but not in patients with ARDS or in the complete patient cohort. Conclusion: In this cohort of critically ill invasively ventilated patients, the baseline LUS aeration score was not associated with 30- and 90-day mortality. An early change in the LUS aeration score was associated with mortality, but only in patients without ARDS. Trial registration: ClinicalTrials.gov, ID NCT04482621
High Early Fluid Input After Aneurysmal Subarachnoid Hemorrhage: Combined Report of Association With Delayed Cerebral Ischemia and Feasibility of Cardiac OutputāGuided Fluid Restriction
Background: Guidelines on the management of aneurysmal subarachnoid hemorrhage (aSAH) recommend euvolemia, whereas hypervolemia may cause harm. We investigated whether high early fluid input is associated with delayed cerebral ischemia (DCI), and if fluid input can be safely decreased using transpulmonary thermodilution (TPT). Methods: We retrospectively included aSAH patients treated at an academic intensive care unit (2007-2011; cohort 1) or managed with TPT (2011-2013; cohort 2). Local guidelines recommended fluid input of 3 L daily. More fluids were administered when daily fluid balance fell below +500 mL. In cohort 2, fluid input in high-risk patients was guided by cardiac output measured by TPT per a strict protocol. Associations of fluid input and balance with DCI were analyzed with multivariable logistic regression (cohort 1), and changes in hemodynamic indices after institution of TPT assessed with linear mixed models (cohort 2). Results: Cumulative fluid input 0 to 72 hours after admission was associated with DCI in cohort 1 (n=223; odds ratio [OR] 1.19/L; 95% confidence interval 1.07-1.32), whereas cumulative fluid balance was not. In cohort 2 (23 patients), using TPT fluid input could be decreased from 6.0 Ā± 1.0 L before to 3.4 Ā± 0.3 L; P =.012), while preload parameters and consciousness remained stable. Conclusion: High early fluid input was associated with DCI. Invasive hemodynamic monitoring was feasible to reduce fluid input while maintaining preload. These results indicate that fluid loading beyond a normal preload occurs, may increase DCI risk, and can be minimized with TPT
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