An optimized predication execution for SIMD extensions

Vector processing is a widely used technique to improve performance and energy efficiency in modern processors. Most of them rely on predication to support divergence control. However, performance and energy consumption in predicated instructions are usually independent on the number of true values in a mask. This means that the efficiency of the system becomes sub-optimal as vector length increases. In this work we propose the Optimized Predication Execution (OPE) technique. OPE delays the execution of sparse masked vector instructions sharing the same PC, extracts their active elements and creates a new dense instruction with a higher mask density. After executing such dense instruction, results are restored to the original sparse instructions. Our approach improves performance by up to 25% and reduces dynamic energy consumption by up to 43% on real applications with predication.This work has been partially supported by the RoMoL ERC Advanced Grant (GA 321253), the European HiPEAC Network of Excellence and the Spanish Government (contract TIN2015-65316-P). A. Barredo has been supported by the Spanish Government under Formación del Personal Investigador fellowship number BES-2017-080635. M. Moretó has been partially supported by the Spanish Ministry of Economy, Industry and Competitiveness under Ramon y Cajal fellowship number RYC-2016-21104.Peer ReviewedPostprint (author's final draft

The analysis of meiosis of the B genome of common wheat.

6 p.Two intervarietal hybrids of common wheat, Triticum aestivum L., are meiotically analyzed using the C-banding staining method. The C-banding pattern of nine meiotic chromosomes (4A, 7A, and the seven of the B genome) permitted their unequivocal recognition at first metaphase plates. The pairing frequency of each B-genome chromosome arm was scored. Data on the pairing frequency of the arms, separately considered, are applied to calculate expected pairing of whole chromosomes and whole genomes. The application of mathematical models to predict the genome pairing using either equal or different frequencies per chromosome arm is discussed.Key words: meiotic analysis, Triticum aestivum L., C-banding

Stencil codes on a vector length agnostic architecture

Data-level parallelism is frequently ignored or underutilized. Achieved through vector/SIMD capabilities, it can provide substantial performance improvements on top of widely used techniques such as thread-level parallelism. However, manual vectorization is a tedious and costly process that needs to be repeated for each specific instruction set or register size. In addition, automatic compiler vectorization is susceptible to code complexity, and usually limited due to data and control dependencies. To address some these issues, Arm recently released a new vector ISA, the Scalable Vector Extension (SVE), which is Vector-Length Agnostic (VLA). VLA enables the generation of binary files that run regardless of the physical vector register length. In this paper we leverage the main characteristics of SVE to implement and optimize stencil computations, ubiquitous in scientific computing. We show that SVE enables easy deployment of textbook optimizations like loop unrolling, loop fusion, load trading or data reuse. Our detailed simulations using vector lengths ranging from 128 to 2,048 bits show that these optimizations can lead to performance improvements over straight-forward vectorized code of up to 56.6% for 2,048 bit vectors. In addition, we show that certain optimizations can hurt performance due to a reduction in arithmetic intensity, and provide insight useful for compiler optimizers.This work has been partially supported by the European HiPEAC Network of Excellence, by the Spanish Ministry of Economy and Competitiveness (contract TIN2015-65316-P), and by the Generalitat de Catalunya (contracts 2017-SGR-1328 and 2017-SGR-1414). The Mont-Blanc project receives funding from the EUs H2020 Framework Programme (H2020/2014-2020) under grant agreements no. 671697 and no. 779877. M. Moreto has been partially supported by the Spanish Ministry of Economy, Industry and Competitiveness under Ramon y Cajal fellowship number RYC-2016-21104. Finally, A. Armejach has been partially supported by the Spanish Ministry of Economy, Industry and Competitiveness under Juan de la Cierva postdoctoral fellowship number FJCI-2015-24753.Peer ReviewedPostprint (author's final draft

Phase II clinical trial of nab-paclitaxel plus gemcitabine in elderly patients with previously untreated locally advanced or metastatic pancreatic adenocarcinoma: the BIBABRAX study

[Purpose] To evaluate the health-related quality of life (HRQoL), global health status (GHS), and deterioration-free survival of an elderly population (> 70 years) with unresectable locally advanced (LAPC) or metastatic pancreatic cancer (mPC) treated with nab-paclitaxel in combination with gemcitabine.[Methods] In this open-label, single-arm, multicenter, phase II trial, patients received 4-week cycles of intravenous (i.v.) nab-paclitaxel at a dose of 125 mg/m2, followed by i.v. injections of gemcitabine at a dose of 1000 mg/m2 on days 1, 8 and 15 until disease progression or unacceptable toxicity was observed. The primary outcome was the HRQoL (deterioration-free rate at 3 months as evaluated with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30.[Results] Eighty patients (median age: 74.6 years) were enrolled (56 with mPC, 24 with LAPC). The percentage of patients who had not experienced deterioration at 3 months was 54.3% (95% CI 41.6–67.0%). The median (interquartile range) time until definite deterioration was 1.6 (1.1–3.7) months. The objective response rate and clinical benefit rate were achieved by 11 (13.8%, 95% CI 6.2–21.3%) and 54 patients (67.5%, 95% CI 57.2–77.8%), respectively. The median overall survival was 9.2 months (95% CI 6.9–11.5), and the median progression-free survival was 7.2 months (95% CI 5.8–8.5). Only fatigue and neutropenia demonstrated a grade 3–4 toxicity incidence > 20%.[Conclusions] Our study confirms the clinical benefit of the combination of nab-paclitaxel and gemcitabine in an elderly population with pancreatic cancer in terms of improved survival and clinical response. However, we were unable to confirm a benefit in terms of quality-of-life.The BIBABRAX study was funded by Celgene. Medical writing assistance in the preparation of this paper was provided by Apices with financial support from Celgene.Peer reviewe

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Usos del e‐learning en las Universidades Andaluzas: estado de la situación y análisis de buenas prácticas. (Resumen ejecutivo).

Secretaría General de Universidades, Investigación y Tecnología P07-SE-J.0267

Usos del e-learning en las Universidades Andaluzas: Estado de la situación y análisis de buenas prácticas. (Versión completa)

Secretaría General de Universidades, Investigación y Tecnología P07-SE-J.0267

Inter-Rater Variability in the Evaluation of Lung Ultrasound in Videos Acquired from COVID-19 Patients

12 páginas, 7 figuras, 1 tablaLung ultrasound (LUS) allows for the detection of a series of manifestations of COVID-19, such as B-lines and consolidations. The objective of this work was to study the inter-rater reliability (IRR) when detecting signs associated with COVID-19 in the LUS, as well as the performance of the test in a longitudinal or transverse orientation. Thirty-three physicians with advanced experience in LUS independently evaluated ultrasound videos previously acquired using the ULTRACOV system on 20 patients with confirmed COVID-19. For each patient, 24 videos of 3 s were acquired (using 12 positions with the probe in longitudinal and transverse orientations). The physicians had no information about the patients or other previous evaluations. The score assigned to each acquisition followed the convention applied in previous studies. A substantial IRR was found in the cases of normal LUS (κ = 0.74), with only a fair IRR for the presence of individual B-lines (κ = 0.36) and for confluent B-lines occupying 50% (κ = 0.50). No statistically significant differences between the longitudinal and transverse scans were found. The IRR for LUS of COVID-19 patients may benefit from more standardized clinical protocols.This research was partially funded by CDTI (Spanish acronym: Centre for Industrial Tech- nological Development), funding number COI-20201153. Partially supported by the Google Cloud Research Credits program with the funding number GCP19980904, by the project RTI2018-099118- A-I00 founded by MCIU/AEI/FEDER UE and by the European Commission–NextGenerationEU, through CSIC’s Global Health Platform (PTI Salud Global)

Predictors of Response to Exclusive Enteral Nutrition in Newly Diagnosed Crohn´s Disease in Children: PRESENCE Study from SEGHNP

Exclusive enteral nutrition (EEN) has been shown to be more effective than corticosteroids in achieving mucosal healing in children with Crohn´s disease (CD) without the adverse effects of these drugs. The aims of this study were to determine the efficacy of EEN in terms of inducing clinical remission in children newly diagnosed with CD, to describe the predictive factors of response to EEN and the need for treatment with biological agents during the first 12 months of the disease. We conducted an observational retrospective multicentre study that included paediatric patients newly diagnosed with CD between 2014–2016 who underwent EEN. Two hundred and twenty-two patients (140 males) from 35 paediatric centres were included, with a mean age at diagnosis of 11.6 ± 2.5 years. The median EEN duration was 8 weeks (IQR 6.6–8.5), and 184 of the patients (83%) achieved clinical remission (weighted paediatric Crohn’s Disease activity index [wPCDAI] 15 mg/L and ileal involvement tended to respond better to EEN. EEN administered for 6–8 weeks is effective for inducing clinical remission. Due to the high response rate in our series, EEN should be used as the first-line therapy in luminal paediatric Crohn’s disease regardless of the location of disease and disease activityS