206 research outputs found
Spectral Separation Coefficients for digital GNSS receivers
Publication in the conference proceedings of EUSIPCO, Florence, Italy, 200
QoS-aware offloading policies for serverless functions in the Cloud-to-Edge continuum
Function-as-a-Service (FaaS) paradigm is increasingly attractive to bring the benefits of serverless computing to the edge of the network, besides traditional Cloud data centers. However, FaaS adoption in the emerging Cloud-to-Edge Continuum is challenging, mostly due to geographical distribution and heterogeneous resource availability. This emerging landscape calls for effective strategies to trade off low latency at the edge of the network with Cloud resource richness, taking into account the needs of different functions and users. In this paper, we present QoS-aware offloading policies for serverless functions running in the Cloud-to-Edge continuum. We consider heterogeneous functions and service classes, and aim to maximize utility given a monetary budget for resource usage. Specifically, we introduce a two-level approach, where (i) FaaS nodes rely on a randomized policy to schedule every incoming request according to a set of probability values, and (ii) periodically, a linear programming model is solved to determine the probabilities to use for scheduling. We show by extensive simulation that our approach outperforms alternative approaches in terms of generated utility across multiple scenarios. Moreover, we demonstrate that our solution is computationally efficient and can be adopted in large-scale systems. We also demonstrate the functionality of our approach through a proof-of-concept experiment on an open-source FaaS framework
Relationship Between Heart Rate Recovery After Exercise and Maximal Oxygen Uptake in Sedentary Patients with Type 2 Diabetes
AIMS: Heart rate recovery after exercise (HRR) is an estimate of autonomic modulation of the heart, and has been
shown to be inversely associated with type 2 diabetes. Type 2 diabetes is associated with decreased maximal
oxygen consumption (VO2max). Aim of our study was to assess the relationship between HRR and VO2max in
sedentary patients with type 2 diabetes.
METHODS: Maximal exercise testing to determine VO2max (ml ∙ Kg-1 ∙ min-1) was performed in 16 sedentary
patients with type 2 diabetes (DP) and in 16 age-matched sedentary healthy controls (HS). HRR (bpm) 2 min after
cessation of the exercise was recorded. Simple linear regression was used to assess the relations between HRR
and VO2max.
RESULTS: VO2max and HRR were significantly lower in DP compared to HS (P = 0.002 and P = 0.008
respectively). A correlation between HRR and VO2max has been found, stronger in DP (r = 0.672, P = 0.004) than
HS (r = 0.620, P = 0.01).
CONCLUSIONS: Our study suggests that regular physical activity aimed to improve the levels of VO2max in
subjects with diabetes may improve the HRR and reduce the risk of cardiovascular events
Quantifying the effect of demixing approaches on directed connectivity estimated between reconstructed EEG sources
Electrical activity recorded on the scalp using electroencephalography (EEG) results from the mixing of signals originating from different regions of the brain as well as from artifactual sources. In order to investigate the role of distinct brain areas in a given experiment, the signal recorded on the sensors is typically projected back into the brain (source reconstruction) using algorithms that address the so-called EEG inverse problem. Once the activity of sources located inside of the brain has been reconstructed, it is often desirable to study the statistical dependencies among them, in particular to quantify directional dynamical interactions between brain areas. Unfortunately, even when performing source reconstruction, the superposition of signals that is due to the propagation of activity from sources to sensors cannot be completely undone, resulting in potentially biased estimates of directional functional connectivity. Here we perform a set of simulations involving interacting sources to quantify source connectivity estimation performance as a function of the location of the sources, their distance to each other, the noise level, the source reconstruction algorithm, and the connectivity estimator. The generated source activity was projected onto the scalp and projected back to the cortical level using two source reconstruction algorithms, linearly constrained minimum variance beamforming and Exact' low-resolution tomography (eLORETA). In source space, directed connectivity was estimated using multi-variate Granger causality and time-reversed Granger causality, and compared with the imposed ground truth. Our results demonstrate that all considered factors significantly affect the connectivity estimation performance
Relationship between heart rate variability and repeated sprint exercise in young soccer players
Aim: The sport of soccer is characterized by neuromuscular performance resulting in short bursts interspersed by brief recovery periods over an extended period of time. Several studies suggest that the cardiac autonomic nervous system (ANS) assessed by heart rate variability (HRV) may provide useful information regarding the functional adaptations to training stimulus. Although HRV has often been associated with aerobic power and cardiovascular fitness, the influence of sympathovagal balance on neuromuscular performance in young athletes is not well assessed.
The aim of this study was to assess the influence of the autonomic system on the performance of repeated sprints, involving predominantly muscular power and anaerobic metabolism, in young soccer players.
Method: Twelve young soccer players, selected for the Sicilian Regional Representative of the Italian Football Federation, mean age 15 years, were recruited. Resting HRV was measured and indices of power spectral analysis (ratio LF/HF) were calculated to evaluate the sympathovagal balance. To assess the state of physical fitness of subjects, VO2max was determined by maximal graded treadmill test. Finally, the athletes performed 10 maximal all-out 6-sec cycling sprints (RS), interspersed with 30-sec of passive recovery, to measure the peak power (PP) represented by the highest value recorded during a single sprint, and the average of the values of maximum power (AP) recorded during all sprints.
Results: On the basis of their VO2max (56.22 ± 3.93 ml/Kg/min), all subjects showed good levels of physical fitness. HRV index (LF/HF = 1.31 ± 0.74) showed an inverse correlation with PP (14.05 ± 0.89 W/Kg; r = -0.709, P = 0.01), and with AP (12.82 ± 0.88 W/Kg; r = -0.606, P = 0.04).
Conclusion: Our study shows that a low ratio LF/HF, which reflects a parasympathetic predominance in the ANS balance, is associated with a better anaerobic contribution to performance resulting in higher values of PP and AP during brief repeated maximal cycling sprints. The assessment of resting HRV before exercise may be useful for performance monitoring of young soccer players
Real-Time Particle Radiography by Means of Scintillating Fibers Tracker and Residual Range Detectors
In this chapter, a detailed description of the construction and the procedure for the measurement of performances of a charged particle imaging system is given. Such a system can be realized by the combined use of a position sensitive detector and a residual range detector. The position sensitive detector is made up of two superimposed and right-angled planes, each of which subsists of two layers of pre-aligned and juxtaposed scintillating fibers. The selected 500 μm square section fibers are optically coupled to two silicon photomultiplier arrays adopting a channel reduction system patented by the Istituto Nazionale di Fisica Nucleare. The residual range detector consists of 60 parallel layers of the same fibers used in the position detector, each of which is optically coupled to a channel of silicon photomultiplier array by means of two wavelength-shifting fibers. The sensitive area of both detectors is 90 × 90 mm2. The performance of the prototypes was tested in different facilities with protons and carbon ions at energy up to about 250 MeV and rate up to about 109 particles per second. The comparison between simulations and measurements confirms the validity of this system. Based on the results, a future development is a real-time radiography system exploiting high-intensity pencil beams and real-time treatment plan verification
Activity of Tagetes minuta Linnaeus (Asteraceae) essential oil against L3 Anisakis larvae type 1
Abstract Objective To evaluate in vitro effects of Tagetes minuta L. essential oil (TEO) on L3 Anisakis larvae type 1. Methods In order to evaluate the potential use of Tagetes minuta essential oil against L3 Anisakis larvae three different media were tested: 1) a saline solution (SS); 2) an industrial marinating solution (MS); 3) sunflower seeds oil (SO). For each media and concentrations of TEO (0.1%, 0.5%, 1.0% and 5.0% v/v), 20 parasites were introduced into plastic Petri dishes (diameter 90 mm) and maintained at room temperature. As controls, larvae were maintained without TEO under identical experimental conditions in SS, MS and SO. A total of 900 larvae were tested. The normalized mean viability, LT100, LT50 and the percentage of inactivation at 24 h were calculated. Results In vitro tests revealed a complete inactivation of parasites in saline solution after 2 h with 5% and 1% of TEO. In marinating solution, a complete inactivation of parasites was observed after 4 h at all concentrations used. A slower activity for all TEO concentration was reported in SO. Conclusions The results obtained, showing a strong activity against Anisakis larvae, confirm TEO as a larvicidal agent in the treatment of human anisakidosis and in the industrial marinating process
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