196,033 research outputs found
Respiratory variation in aortic blood peak velocity and caudal vena cava diameter can predict fluid responsiveness in anaesthetised and mechanically ventilated dogs
No full textBACKGROUND AND M&MS:
Dynamic preload indices, such as systolic pressure variation (SPV), aortic flow peak velocity variation (ΔVpeak) and distensibility index of the caudal vena cava (CVCDI), are reliable indices for predicting fluid responsiveness in humans. This study aimed to investigate the ability of these indices to predict fluid response in 24 healthy dogs undergoing general anaesthesia and mechanical ventilation. Aortic flow peak velocity variation (∆Vpeak), CVCDI, and SPV were calculated before volume expansion (5mL/kg bolus of lactated Ringer's solution). The aortic velocity time integral (VTI) was measured before and after volume expansion as a surrogate of stroke volume. Dogs were considered responders (n=9) when the VTI increase was ≥15% and non-responders (n=15) when the increase was <15%.
RESULTS AND CONCLUSIONS:
Before volume expansion, ΔVpeak, CVCDI and SPV were higher in responders than in non-responders (P=0.0009, P=0.0003, and P=0.0271, respectively). Receiver operating characteristic (ROC) curves were plotted for the three indices. The areas under the ROC curves for SPV, ΔVpeak, and CVCDI were 0.91 (CI 0.73-0.99; P=0.0001), 0.95 (CI 0.77-1; P=0.0001), and 0.78 (CI 0.56-0.92; P=0.015), respectively. The best cut-offs were 6.7% for SPV (sensitivity, 77.78%; specificity, 93.33%), 9.4% for ΔVpeak (sensitivity, 88.89%; specificity, 100%), and 24% for CVCDI (sensitivity, 77.78%; specificity, 73.33). In conclusion, ΔVpeak, CVCDI, and SPV are reliable predictors of fluid responsiveness in healthy dogs undergoing general anaesthesia and mechanical ventilation
Preemption-aware planning on Big-Data systems
No full textRecent developments in Big Data frameworks are moving towards reservation based approaches as a mean to manage the increasingly complex mix of computations, whereas preemption techniques are employed to meet strict jobs deadlines. Within this work we propose and evaluate a new planning algorithm in the context of reservation based scheduling. Our approach is able to achieve high cluster utilization while minimizing the need for preemption that causes system overheads and planning mispredictions
METODO PER REALIZZARE UN DISPOSITIVO HARDWARE PER ESEGUIRE OPERAZIONI DEFINITE DA UN CODICE SOFTWARE DI ALTO LIVELLO
No full textAutomated design space exploration and roofline analysis for FPGA-based hls applications
No full textThe growing interest in FPGA-based solutions for accelerating compute demanding algorithms is pushing the need for new tools and methods to improve productivity. In this work, we propose a methodology to support designers in generating optimal FPGA hardware implementations using High-Level Synthesis (HLS). First, we propose an automated roofline model generation that operates directly on a C/C++ description of the algorithm. The approach enables fast evaluation of the operational intensity of the target function and visualizes the main bottlenecks of the current HLS implementation, providing guidance on how to improve it. Second, we integrate it with a Design Space Exploration (DSE) methodology for quickly evaluating different HLS directives to identify an optimal implementation
Haemodynamic changes during propofol induction in dogs: New findings and approach of monitoring
No full textAbstract Background Propofol is one of the most widely used injectable anaesthetic agents in veterinary practice. Cardiovascular effects related to propofol use in dogs remain less well defined. The main objective of this study was to evaluate the haemodynamic changes during induction of general anaesthesia with propofol in healthy dogs, by a beat-to-beat continuous monitoring. All dogs were premedicated with intramuscular acepromazine (0.015 mg/kg) and methadone (0.15 mg/kg). Transthoracic echocardiography was used to measure the velocity time integral (VTI) of the left ventricular outflow tract. A syringe driver, programmed to deliver propofol 5 mg/kg over 30 s followed by a continuous infusion of 25 mg/kg/h, was used to induce and maintain anaesthesia. From the initiation of propofol administration, heart rate (HR) and mean invasive arterial blood pressure (MAP) were recorded every 5 s for 300 s, while aortic blood flow was continuously recorded and stored for 300 S. maximum cardiovascular depression was defined the lowest MAP (MAP_Tpeak) recorded during the monitored interval. VTI and VTI*HR were calculated at 0, 30, 90, 120, 150 and 300 s post administration of propofol, and at MAP_Tpeak. Haemodynamic effects of propofol in relation to plasma and biophase concentrations were also evaluated by pharmacokinetics simulation. Results The median (range) HR was significantly higher (p = 0.006) at the moment of maximum hemodynamic depression (Tpeak) [105(70–148) bpm] compared with pre-induction values (T0) [65(50–120) bpm]. The median (range) MAP was significantly lower (p < 0.001) at Tpeak [61(51–69) mmHg] compared with T0 [88(72–97) mmHg]. The median (range) VTI and VTI*HR were similar at the two time points [11.9(8.1–17.3) vs 13,3(9,4-16,5) cm, and 1172(806–1554) vs 1002(630–1159) cm*bpm, respectively]. Conclusions Induction of anaesthesia with propofol causes a drop of arterial pressure in healthy dogs, however cardiac output is well maintained by compensatory chronotropic response. The magnitude of MAP_Tpeak may be strictly related with propofol plasma concentration
Diversity and inclusion: Buzzword or real value?
No full textThe STEM field is characterized by a strong gender gap, both in Business and in Academia. Previous studies showed how the gender gap presents some peculiarities: women result to publish less than men across all disciplines, and this is the reason why this publication gap is often referred to as 'productivity puzzle'. Strongly believing that gender should not influence the choice of the career to pursue, recent literature in organization has paid greater attention to gender related issues, analyzing the role played by team heterogeneity on performance. Such studies often obtained controversial outcomes, suggesting that the relationship between group heterogeneity and performance is a complex phenomenon. The dynamics taking place within working groups have been vastly studied in organizational psychology, showing that factors shaping group members' behavior are various. In this context, the working environment results to be a crucial factor. For these reasons, in this study we investigated the impact of heterogeneity on academic teams performance, taking into account gender representation in the overall working environment. More specifically, we evaluated the impact of diversity on the research conducted at the Dipartimento di Elettronica, Informazione e Biotecnologia of Politecnico di Milano, the first awarded technical university in Italy and at NECST Laboratory, a laboratory inside the Dipartimento di Elettronica, Informazione e Biotecnologia. Data are available for scientific paper published between 1965 and 2018. In this paper we studied the transformations occurred inside Dipartimento di Elettronica, Informazione e Biotecnologia in terms of gender representation between 1965 and 2018, taking into account teams characteristics, research outcomes and productivity puzzle. The results obtained showed how in both cases the impact of heterogeneity varied according to perceived value of diversity. Heterogeneity per se does not account for a boost in performance. Gender heterogeneity leads to an increase in performance only when also inclusion is achieved
The Importance of Being X-Drop: High Performance Genome Alignment on Reconfigurable Hardware
No full textPairwise sequence alignment accounts for the majority of key genome analysis applications' runtime. Because of the quadratic time complexity of exact alignment algorithms, the community is moving away from exact algorithms in favor of heuristics that only compute high-quality results. However, the state of the art lacks hardware-accelerated versions of these heuristic algorithms as the vast majority of the available solutions still rely on implementing exact alignment algorithms. Moreover, hardware-based implementations lack high-level APIs that can simplify their integration in commonly used genomic pipelines, hindering their applicability in real-world scenarios. In this context, we present the first high-performance FPGA implementation of the popular X-drop heuristic alignment algorithm and provide an easy-to-use API for its integration. On a Xilinx Alveo U280, our FPGA design achieves up to 5 speed-up over SeqAn, the state-of-the-art software version of the algorithm, running on two Intel Xeon processors using 80 CPU threads. Moreover, our design is also 3.45 faster than ksw2, a state-of-the-art vectorized alignment algorithm that performs a similar heuristic to the one employed in the X-drop algorithm. Finally, our implementation also outperforms LOGAN, a recently published GPU implementation of X-drop running on an Nvidia Tesla V100, by a factor of 1.5
HLS Support for Polymorphic Parallel Memories
No full textThe importance of High-Level Languages in abstracting machine language to enhance productivity has been proved in many sectors, and has recently encouraged the spread of reconfigurable hardware for general purpose computing. At the same time, Field Programmable Gate Arrays (FPGAs) become popular for data-intensive applications, because they promise customized hardware accelerators and achieve high-performance with low power consumption. However, taking advantage of parallel accesses to the local memories of FPGAs remains difficult, as it currently requires application re-engineering. A solution to this challenge is PolyMem, an easy-to-use parallel memory. In this work, we investigate the implementation, integration, and performance of PolyMem for HLS applications. To this end, we present a novel open-source implementation of PolyMem, optimized for the Xilinx Design Suite. We further demonstrate the use of PolyMem for three different case studies, implemented using both the Vivado workflow with a Virtex-7 VC707, and the SDx workflow with a Kintex Ultrascale 3 ADM-PCIE. Finally, we provide a thorough empirical analysis of these three cases studies in terms of latency, hardware resources, and productivity. Our results demonstrate that PolyMem delivers the expected performance, while enhancing productivity at the cost of a small increase in resources
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
- …
