Hybrid Research Articles

Metabolomic, lipidomic and transcriptomic reveal meat quality differences among hybrid, indigenous and commercial broiler

With the improvement in living standards, breeders need to improve meat quality to meet consumers' demands. Hybrid (HB), indigenous (IB), and commercial broiler (CB) are the most essential components in consumer market. However, the difference in meat quality and underlying mechanism remains unclear. Our study found that HB showed significant differences in meat-quality performance compared with IB and CB, especially in breast muscle's shear force and meat color. Furthermore, metabolomic, lipidomic, and RNA-seq were performed to screen the critical molecular networks contributing to the performance difference. Most differentially expressed metabolites (DEMs) were significantly associated with shear force and a∗value and enriched in lipid metabolism-related pathways. The lipidomic analysis detected many differentially expressed lipids (DELs), especially between HB and CB. Most showed a positive association with a∗ and b∗ value and a negative association with shear force. RNA-seq analysis screened 275 and 497 differentially expressed genes (DEGs) in HB compared with IB and CB, and they were also highly associated with metabolism pathways and meat-quality performance. Finally, integrative analysis was conducted to screen the core DEMs, DELs and DEGs contributing to meat-quality performance. Our findings provided knowledge for molecular markers to facilitate the selection of chicken meat quality.

The comparison between different types of constructed wetlands for biochemical oxygen demand removal efficiency

This research shows efficiency of constructed wetlands (CWs) to purify waste water in the case of Biochemical Oxygen Demand (BOD). CWs such as surface flow (SF), subsurface flow (SSF), and hybrid (HYB) systems have been compared to provide an analysis about which system has better performance for BOD removal efficiency. Data were collected from different scientific articles and from all over the world. Meta-analysis technique was employed to aggregate data from scientific sources, facilitating hypothesis testing, and comparisons between different types of CWs. All the systems of CWs show satisfactory removal efficiency. HYB systems are shown to be the most efficient. One-way analysis of variance (ANOVA) has been applied to analyze differences between respective CWs using R software. It shows that there is a statistically significant difference between different types of CWs. Post-hoc Tukey?s Honestly Significant Different (HSD) analysis demonstrates a statistically significant difference between SF and HYB systems in the case of BOD removal efficiency. Also, Post-hoc Tukey?s HSD shows statistically significant difference between SSF and SF CWs. On the other hand, Post-hoc Tukey?s HSD does not show statistically significant difference between HYB and SSF CWs. The significant reduction rates for BOD removal efficiency, demonstrates that CWs can be used to diminish this kind of pollution.

Performance enhancement of PbS quantum dot solar cells employing a hybrid solid-state ligand exchange protocol

In this work, a hybrid (HB) solid-state ligand exchange strategy was developed for PbS quantum dots (QDs) films, incorporating a synergistic utilization of the popular inorganic ligand tetrabutylammonium iodide (TBAI) and the organic short bidentate linker 1, 2-Ethanedithiol (EDT) in a two-stage process. The two-stage process consisted of a primary solid-state ligand treatment with TBAI in a controlled manner followed by a second-stage ligand treatment with EDT. We could achieve an optimal iodine/EDT ligand passivation ratio for the QDs films by controlling the TBAI ligand treatment time. The method integrates the benefits of both the ligands and resolves the intrinsic incompleteness of the solid-state TBAI ligand exchange. The QDs films thus created have an optimal surface coverage and reduced inter-dot spacing due to an improved QDs close packing. This in turn led to lesser recombination routes due to reduced mid-bandgap trap states and an improved charge transport property through an enhanced electronic coupling between the QDs. A power conversion efficiency of 8.2 % has been achieved in the device with an optimized TBAI /EDT ligand passivation ratio for the QDs films with an EDT hole transport layer.

Comparison of long- and short-read metagenomic assembly for low-abundance species and resistance genes.

Recent technological and computational advances have made metagenomic assembly a viable approach to achieving high-resolution views of complex microbial communities. In previous benchmarking, short-read (SR) metagenomic assemblers had the highest accuracy, long-read (LR) assemblers generated the most contiguous sequences and hybrid (HY) assemblers balanced length and accuracy. However, no assessments have specifically compared the performance of these assemblers on low-abundance species, which include clinically relevant organisms in the gut. We generated semi-synthetic LR and SR datasets by spiking small and increasing amounts of Escherichia coli isolate reads into fecal metagenomes and, using different assemblers, examined E. coli contigs and the presence of antibiotic resistance genes (ARGs). For ARG assembly, although SR assemblers recovered more ARGs with high accuracy, even at low coverages, LR assemblies allowed for the placement of ARGs within longer, E. coli-specific contigs, thus pinpointing their taxonomic origin. HY assemblies identified resistance genes with high accuracy and had lower contiguity than LR assemblies. Each assembler type's strengths were maintained even when our isolate was spiked in with a competing strain, which fragmented and reduced the accuracy of all assemblies. For strain characterization and determining gene context, LR assembly is optimal, while for base-accurate gene identification, SR assemblers outperform other options. HY assembly offers contiguity and base accuracy, but requires generating data on multiple platforms, and may suffer high misassembly rates when strain diversity exists. Our results highlight the trade-offs associated with each approach for recovering low-abundance taxa, and that the optimal approach is goal-dependent.

Classification of seismic activity at the Lazufre Volcanic System, based on 2011 to 2012 data

The Lazufre Volcanic System (LVS), on the border of northern Chile and Argentina, is an active complex of two volcanoes, Lastarria to the north and Cordón del Azufre to the south. The LVS is not regularly monitored with any scientific equipment despite being recognized as a top ten volcanic hazard in Argentina by the Observatorio Argentino de Vigilancia Volcánica of the Servicio Geológico y Minero Argentino. The system has shown unusual inflation signatures observed in InSAR but the level of seismic activity and its spatial and temporal distribution were unknown due to the lack of a permanent local seismic network. The PLUTONS Project deployed eight broadband seismic stations throughout the LVS between November 2011 and March 2013. This study shows event locations and types from November 2011 through March 2012. We analyze 591 seismic events within 20 km of Lastarria. Most events cluster tightly beneath Lastarria and almost no activity is observed beneath Cordón del Azufre or the primary inflation center. All events are reviewed manually, and located using a velocity model that assimilates prior studies and accounts for hypocenters within the edifice up to 5 km above sea level. More than 90% of the resulting hypocenters are shallower than 10 km below sea level. The waveforms have characteristics similar to those observed at many other volcanoes, suggesting five classes of events: volcano-tectonic (VT), long-period 1 (LP1), long period 2 (LP2), hybrid (HY), and unknown (X). Frequency-magnitude analysis reveals distinct b-values ranging from 1.2 for VT events to 2.5 for LP1 events. Based on the spatial distribution of events and the b-values, we infer that seismic activity is driven mainly by movement of fluids and gases associated with the regional magma zones and inflation centers. The seismic activity is energetic at times, and quieter at others, suggesting the presence of episodic magmatic and/or hydrothermal activity, focused at Lastarria. Our findings indicate that the previously observed inflation signals are indeed volcanic in origin. These results also demonstrate the potential for success of a future seismic monitoring system and provide a framework for interpreting the subsequent observations, both of which are critical to assessing the volcanic risk of the northern Chile-Argentina region.

Three-dimensional direct numerical simulations of two interfering side-by-side circular cylinders at intermediate spacing ratios

Side-by-side arranged circular cylinders show fierce interferences when they are not far apart. In this paper, we present the vibration response and wake characteristics of two elastically mounted circular cylinders in a side-by-side arrangement through three-dimensional direct numerical simulations (3-D DNS). The Reynolds number is Re = 500 and two center-to-center spacings (s) of 2.0D and 2.5D are considered where D is the diameter of the two cylinders. We found that with the increasing reduced velocity, the responses of both s/D cases can be divided into three different regions, which are named desynchronization region (DS), initial branch (IB), and lower branch (LB), with the former being further divided into two subregions (DS-I and DS-II). The vibration, hydrodynamic forces, and spectral features in each region are discussed in detail. According to the characteristics of cylinder oscillation and vortex dynamics, six types of wake patterns are identified, with the deflected (DF) and flip-flopping (FF) patterns at s/D = 2.0 while in-phase (IP), anti-phase (AP), in-/anti-phase (I/AP), and hybrid (HB) patterns at both s/D = 2.0 and 2.5. Furthermore, we investigated the wake three-dimensionality through the evolution of vortical structures, and the statistics and development of the enstrophies. It was observed that the presence of the streamwise vortices modifies the strength and spanwise coherence of the spanwise vortices. Finally, flow physics for the interactions of the two cylinders at different regions is elucidated.

A review on thermal analysis of hybrid greenhouse solar dryer (HGSD)

The objective of the paper is to present the modifications done in hy brid gr eenhouse solar dryers to make them more efficient. As hy brid dryers we re developed to ov ercome the various limitations of other types of solar dryers. Due to modifications in dryers, the effect on various heat transfer parameters like heat transfer coefficient, drying time, drying efficiency, etc. is studied and also encapsulated in the paper. It is found that in most of the hybrid dryers, the maximum temperature of the drying chamber is around 65–80°C. This shows the suitability of a hybrid dryer for drying high moisture crops. Also, the drying time for most of the crops is around 2–3 days, which shows the faster moisture removal rate inside the hybrid dryers. According to the literature studied, the maximum drying efficiency of a hybrid dryer is reported by about 35%. The paper also encapsulates the various relations/equations used by different researchers to carry out the thermal modeling and heat transfer analysis of greenhouse dryers.

Enhancing surface integrity of titanium alloy through hybrid surface modification (HSM) treatments

The current study investigates the development of a novel hybrid surface modification (HSM) technique to improve the surface integrity of Ti–6Al–4V alloy. The approach combines the mechanical shot peening (SP) and the deposition by Physical Vapour Deposition (PVD) of a tungsten-doped diamond-like carbon coating (WC/C) on Ti–6Al–4V surfaces. The mechanical shot peening induced high surface roughness increasing the metallurgical bonding sites for the PVD deposition, whereas mainly the grain growth during the deposition, was successfully eliminated. The mechanical SP process induced the high strain lattice misorientations evident for increasing the dislocation density in the crystalline structure. The Electron Backscatter Diffraction (EBSD) results suggest that subjecting the SP specimens to a temperature of 240 °C for more than 3 h during coating deposition, results in a reduction of dislocation densities, presumably as a result of dislocation annihilation by heat-activated dislocation mobilisation. Hence, the presented Grain Orientation Spread maps suggest that some degree of macro and micro stress relaxation may have occurred during the coating deposition treatment. Further, the Raman spectroscopy confirms the existence of beneficial compressive residual stresses on both PVD and hybrid (HY) coated surfaces. Comparatively, the HY surfaces show a high hardness of 12.08 GPa and high elasticity indices (H/E ratios) of 0.1.

Fully Automated 3-D Ultrasound Segmentation of the Placenta, Amniotic Fluid, and Fetus for Early Pregnancy Assessment.

Volumetric placental measurement using 3-D ultrasound has proven clinical utility in predicting adverse pregnancy outcomes. However, this metric cannot currently be employed as part of a screening test due to a lack of robust and real-time segmentation tools. We present a multiclass (MC) convolutional neural network (CNN) developed to segment the placenta, amniotic fluid, and fetus. The ground-truth data set consisted of 2093 labeled placental volumes augmented by 300 volumes with placenta, amniotic fluid, and fetus annotated. A two-pathway, hybrid (HB) model using transfer learning, a modified loss function, and exponential average weighting was developed and demonstrated the best performance for placental segmentation (PS), achieving a Dice similarity coefficient (DSC) of 0.84- and 0.38-mm average Hausdorff distances (HDAV). The use of a dual-pathway architecture improved the PS by 0.03 DSC and reduced HDAV by 0.27 mm compared with a naïve MC model. The incorporation of exponential weighting produced a further small improvement in DSC by 0.01 and a reduction of HDAV by 0.44 mm. Per volume inference using the FCNN took 7-8 s. This method should enable clinically relevant morphometric measurements (such as volume and total surface area) to be automatically generated for the placenta, amniotic fluid, and fetus. The ready availability of such metrics makes a population-based screening test for adverse pregnancy outcomes possible.

A physics-based approach to modeling real-fuel combustion chemistry – VII. Relationship between speciation measurement and reaction model accuracy

The HyChem ( hy brid chem istry) approach has been proposed recently for modeling high-temperature combustion of real, multicomponent fuels. The approach combines lumped reaction steps for fuel thermal and oxidative pyrolysis with detailed chemistry for oxidation of the resulting pyrolysis products. The 14 independent model parameters in the lumped reaction steps are determined by matching the time histories of key pyrolysis products of the fuel, obtained notably from the Stanford shock tube and laser diagnostics facilities, and from flow reactor experiments. The prediction accuracy of HyChem model depends on the availability of the speciation data and their accuracy. In the present work, we carry out comprehensive Monte Carlo analysis of model predictions with respect to species measurement using the Jet A HyChem model as the test case. We assess the impact of the measured fuel pyrolysis products, including ethylene (C 2 H 4 ), methane (CH 4 ), propene (C 3 H 6 ), iso -butene ( i -C 4 H 8 ), 1-butene (1-C 4 H 8 ), benzene (C 6 H 6 ), and toluene (C 7 H 8 ) on HyChem predictions using ignition delay time and laminar flame speed as test cases. The results show that the speciation data are necessary to obtain reliable predictions for the laminar flame speed and ignition delay time at and above 1200 K. Additional measurement targets (e.g., CO and CH 2 O) are proposed for future HyChem model development, especially in improving model predictions for ignition delay time.

Plant resistance and leaf chemical characteristic jointly shape phyllosphere bacterial community.

Phyllosphere bacteria have an important role in plant growth and resistance to pathogen infection and are partially influenced by plant genotype and leaf environment. How plant resistance to pathogens and leaf chemical characteristics shape the phyllosphere bacterial communities is unclear. In this study, the phyllosphere bacterial communities of maize hybrids with various resistance to Setosphaeria turcica were compared using the high-throughput sequencing and large-scale culturing methods. The results showed that Shannon and Simpson indices of phyllosphere bacterial communities were markedly higher in the highly resistant hybrid (HR) compared with the susceptible one. Hierarchical clustering analysis, unweighted UniFrac principal component analysis (PCoA) and the analysis of similarities (ANOSIM) demonstrated that the phyllosphere bacterial communities were significantly distinct between resistant and susceptible hybrids. The redundancy analysis (RDA) demonstrated that leaf chemical characteristics, including nitrogen and phosphorus concentration, and disease resistance play an important role in shaping the phyllosphere bacterial community. Linear discriminant effect size (LEfSe) analysis indicated that Bacillus, Pseudomonas and Tumebacillus were the biomarker species in the phyllosphere of HR. Biocontrol bacteria against S. turcica (such as Pseudomonas and Bacillus) were isolated from the phyllosphere of HR by large-scale culturing. The work contributes to understanding of the phyllosphere bacterial community assembly and provides a new clue to screening for strong biocontrol bacteria from HR and to facilitating future breeding efforts for enhancing disease resistance.

Immobilization of Low-Cost Alternative Vegetable Peroxidase (Raphanus sativus L. peroxidase): Choice of Support/Technique and Characterization.

In the present work the radish (Raphanus sativus L.) was used as the low-cost alternative source of peroxidase. The enzyme was immobilized in different supports: coconut fiber (CF), calcium alginate microspheres (CAMs) and silica SBA-15/albumin hybrid (HB). Physical adsorption (PA) and covalent binding (CB) as immobilization techniques were evaluated. Immobilized biocatalysts (IBs) obtained were physicochemical and morphologically characterized by SEM, FTIR and TGA. Also, optimum pH/temperature and operational stability were determined. For all supports, the immobilization by covalent binding provided the higher immobilization efficiencies—immobilization yield (IY%) of 89.99 ± 0.38% and 77.74 ± 0.42% for HB and CF, respectively. For CAMs the activity recovery (AR) was of 11.83 ± 0.68%. All IBs showed optimum pH at 6.0. Regarding optimum temperature of the biocatalysts, HB-CB and CAM-CB maintained the original optimum temperature of the free enzyme (40 °C). HB-CB showed higher operational stability, maintaining around 65% of the initial activity after four consecutive cycles. SEM, FTIR and TGA results suggest the enzyme presence on the IBs. Radish peroxidase immobilized on HB support by covalent binding is promising in future biotechnological applications.

Analysis of UHF-band sea clutter reflectivity at low grazing angles in offshore waters of the Yellow Sea

ABSTRACT Reflectivity is an important characteristic of sea clutter that depends on the parameters of the radar and the environment. This paper presents reflectivity measurements of UHF-band horizontal polarized sea clutter based upon data collected in the offshore waters of the Yellow Sea of China at low grazing angles. During the experiment, the oceanic and meteorological conditions were recorded by the Datawell Waverider 4 and Lufft WS700-UMB on the sea surface. The factors that affect the reflectivity acquisition are analysed and the selective median filtering method in average Doppler power spectrum is presented to remove the effect of ground clutter from the sidelobes of the antenna beam pattern and the normalized reflectivity of the sea surface is computed. The applicability of the four classical reflectivity empirical models to the datasets is analysed. The results show that the Hybrid (HYB) and Technology Service Corporation (TSC) models are suitable while the Georgia Institute of Technology (GIT) and Naval Research Laboratory (NRL) models are unsuitable for the UHF-band horizontal polarized sea clutter in the offshore waters of the Yellow Sea of China.

Intermediate-term clinical and radiographic outcomes with less invasive adult spinal deformity surgery: patients with a minimum follow-up of 4 years

Little information exists regarding longer-term outcomes with minimally invasive spine surgery (MISS), particularly regarding long-segment and deformity procedures. We aimed to evaluate intermediate-term outcomes of MISS for adult spinal deformity (ASD). This retrospective review of a prospectively collected multicenter database examined outcomes at 4 or more years following circumferential MIS (cMIS) or hybrid (HYB) surgery for ASD. A total of 53 patients at 8 academic centers satisfied the following inclusion criteria: age >18years and coronal Cobb > 20°, pelvic incidence-lumbar lordosis (PI-LL) > 10°, or sagittal vertical axis (SVA) > 5cm. Radiographic outcomes demonstrated improvements of PI-LL from 16.8° preoperatively to 10.8° and coronal Cobb angle from 38° preoperatively to 18.2° at 4years. The incidence of complications over the follow-up period was 56.6%. A total of 21 (39.6%) patients underwent reoperation in the thoracolumbar spine, most commonly for adjacent level disease or proximal junctional kyphosis, which occurred in 11 (20.8%) patients. Mean Oswestry Disability Index (ODI) at baseline and years 1 through 4 were 49.9, 33.1, 30.2, 32.7, and 35.0, respectively. The percentage of patients meeting minimal clinically important difference (MCID) (defined as 12% or more from baseline) decreased over time, with leg pain reduction more durable than back pain reduction. Intermediate-term clinical and radiographic improvement following MISS for ASD is sustained, but extent of improvement lessens over time. Outcome variability exists within a subset of patients not meeting MCID, which increases over time after year two. Loss of improvement over time was more notable in back than leg pain. However, average ODI improvement meets MCID at 4years after MIS ASD surgery.

A hybrid model for estimation of pore size from ortho-positronium lifetimes in porous materials

The present paper proposes a novel model for estimating the free-volume size of porous materials based on the analysis of various experimental ortho-positronium (o-Ps) lifetime data. The model is derived by combining the semi-classical (SE) physics model, which works in the region of large pores (pore size R> 1 nm), with the conventional Tao-Eldrup (TE) model, which is applicable only for the small-pore region (R< 1 nm). Thus, the proposed model, called the hybrid (HYB) model, is able to smoothly connect the o-Ps lifetimes in the two regions of the pore. Moreover, by introducing the o-Ps diffusion probability parameter (D), the HYB model has reproduced quite well the experimental o-Ps lifetimes in the whole region of pore sizes. It is even in a better agreement with the experimental data than the most up-to-date rectangular TE (RTE) and Tokyo models. In particular, by adjusting the value of D, the HYB model can also describe very well the two defined sets of experimental o-Ps lifetimes in the pores with spherical and channel geometries. The merit of the present model, in comparison with the previously proposed ones, is that it is applicable for the pore size in the universal range of 0.2−400 nm for most of porous materials with different geometries.

An Improved SASS Model for Sea Clutter Reflectivity at Ku-band

The typical models, namely, Hybrid (HYB) model, Technology Service Corporation (TSC) model, and Naval Research Laboratory (NRL) model, reveal a large deviation at medium and high grazing angles that leads to an inaccurate prediction of sea clutter backscattering coefficient, owing to a limitation of the measured Nathanson data. An improved model for sea clutter reflectivity is proposed as a function of grazing angle, azimuth direction, radar polarization and wind speed, based on the SEASAT-A Satellite Scatterometer (SASS) model with sufficient measured data at Ku-band. To deal with the redundant structure of SASS model, the improved SASS model is developed to simplify the calculation of mean backscatter coefficients of sea clutter. In addition, the design algorithm of the improved SASS model, as well as the model usage method is presented. The reliability of the improved SASS model is proved by comparisons with Nathanson models and measured sea clutter data.

P427 A hybrid approach of handling missing data in inflammatory bowel disease (IBD) trials: results from VISIBLE 1 and VARSITY

Abstract Background Missing data is common in IBD trials. Depending on the volume and nature of missing data, it can reduce statistical power for detecting treatment difference, introduce potential bias and invalidate conclusions. Non-responder imputation (NRI), where patients (patients) with missing data are considered treatment failures, is widely used to handle missing data for dichotomous efficacy endpoints in IBD trials. However, it does not consider the mechanisms leading to missing data and can potentially underestimate the treatment effect. We proposed a hybrid (HI) approach combining NRI and multiple imputation (MI) as an alternative to NRI in the analyses of two phase 3 trials of vedolizumab (VDZ) in patients with moderate-to-severe UC – VISIBLE 11 and VARSITY2. Methods VISIBLE 1 and VARSITY assessed efficacy using dichotomous endpoints based on complete Mayo score. Full methodologies reported previously.1,2 Our proposed HI approach is aimed at imputing missing Mayo scores, instead of imputing the missing dichotomous efficacy endpoint. To assess the impact of dropouts for different missing data mechanisms (categorised as ‘missing not at random [MNAR]’ and ‘missing at random [MAR]’, HI was implemented as a potential sensitivity analysis, where dropouts owing to safety or lack of efficacy were imputed using NRI (assuming MNAR) and other missing data were imputed using MI (assuming MAR). For MI, each component of the Mayo score was imputed via a multivariate stepwise approach using a fully conditional specification ordinal logistic method. Missing baseline scores were imputed using baseline characteristics data. Missing scores from each subsequent visit were imputed using all previous visits in a stepwise fashion. Fifty imputation datasets were computed for each component of Mayo score. The complete Mayo score and relevant efficacy endpoints were derived subsequently. The analysis was performed within each imputed dataset to determine treatment difference, 95% CI and p-value, which were then combined via Rubin’s rules3. Results Tables 1 and 2 show a comparison of efficacy in the two studies using the primary NRI analysis vs. the alternative HI approach for handling missing data. Conclusion HI and NRI approaches can provide consistent efficacy analyses in IBD trials. The HI approach can serve as a useful sensitivity analysis to assess the impact of dropouts under different missing data mechanisms and evaluate the robustness of efficacy conclusions. Reference

Exploratory study on simple hybrid or pre-stressed steel-glass I-beams under short-term bending – Part 1: Experiments

Due to glass intrinsic brittleness and unpredictable failure behaviour, several research studies are focused on the development of safe design concepts for structural elements, component details or composite systems. In this regard, the paper aims at assessing the bending performance of a relatively novel composite solutions for glass beams, and namely presents major experimental outcomes from full-scale bending tests performed on I-shaped hybrid (HB) steel-glass beams. In accordance with earlier literature efforts, such a design concept embodies additional steel flanges to traditional glass web, and thus can provide relevant ductility to the so assembled composite systems. Even further redundancy and ductility capacities can then be obtained by introducing in the so-assembled HB beams an external pre-stressing system of cables (PSHB). Key aspects of the design concept are however represented by detailing choices, as well as to the assembly strategies, and multiple aspects should be properly taken into account. Major experimental outcomes and comparative behaviours are hence discussed in the paper, based on a series of four full-scale prototypes, with a focus on the observed global deformations, measured strains and qualitative distribution of crack patterns.

AhSpMV: An Autotuning Hybrid Computing Scheme for SpMV on the Sunway Architecture

The prevalence of the Internet of Things (IoT) and the explosion of available information on the Web have led to an enormous amount of widely available IoT data sets with sparsity. Sparse matrix–vector multiplication (SpMV) is one of the most essential algorithms in various kinds of IoT applications. This article designs an autotuning hybrid computing scheme for SpMV, named ahSpMV, on the powerful and unique architecture of Sunway TaihuLight supercomputer, to combine the advantages of the heterogeneous parallel Sunway architecture and the Hybrid (HYB) sparse matrix format and optimize the SpMV’s performance. First, we propose a heterogeneous parallelization design for ahSpMV based on the heterogeneous manycore architecture of the SW26010 of Sunway TaihuLight and the hybrid feature of the HYB format. Second, we propose several optimization techniques for computation and communication of ahSpMV, to fully utilize the computing power of Sunway. Third, we analyze the execution time of ahSpMV on Sunway. Fourth, based on the performance analysis, we propose an autotuning scheme for ahSpMV to set the proper parameter for the HYB format. We evaluate ahSpMV’s performance on the Sunway architecture. The result analysis indicates that ahSpMV has obvious performance improvement over parallel SpMV based on other related sparse matrix formats. The optimization techniques and the autotuning scheme for ahSpMV also yield expected optimization effects. Moreover, the experimental results illustrate that ahSpMV has good scalability on the Sunway architecture.

252. Incidence of PJK with pedicle screws at upper instrumented vertebrae in posterior spinal fusion for adolescent idiopathic scoliosis

BACKGROUND CONTEXT Posterior spinal fusion (PSF) using all-pedicle screw constructs has become the standard surgical treatment for adolescent idiopathic scoliosis (AIS). However, some studies have shown that all-pedicle screw constructs or the use of pedicle screws at the upper instrumented vertebrae (UIV) increases the incidence of proximal junctional kyphosis (PJK). The purpose of this study is to examine the impact of different instrumentation types on the incidence of PJK following PSF for AIS. PURPOSE To determine if all-pedicle screw constructs increase the incidence of PJK following PSF for AIS, as pedicle screw placement at the UIV may violate the supra-adjacent facet capsules. STUDY DESIGN/SETTING Longitudinal cohort study. PATIENT SAMPLE Multicenter database of surgically treated AIS. OUTCOME MEASURES PJA. METHODS A multicenter database of surgically treated AIS was used. A stratified random sampling was done to obtain a representative sample from all curve types. Patients were included if they underwent PSF, and if immediate postoperative and final follow-up radiographs were available. The patients were grouped by instrumentation type: all-pedicle screw (PS), hook at UIV with distal all-pedicle screw (HT), and hybrid (HB). PJA was measured as the angle between UIV and UIV+2 on lateral full-length standing radiographs immediately postoperative and at the final follow-up. PJK was defined as PJA ≥ 10° or PJA progression of ≥ 10° at the final follow-up. RESULTS The PS, HT and HB groups included 128, 111 and 106 patients, respectively. There was no difference in baseline demographic and radiographic characteristics among the groups. Fifteen cases (4.3%) developed PJK at the latest follow-up (average 2.2 years). PJK was more common in the PS group (p CONCLUSIONS The incidence of PJK following PSF for AIS was 4.3% and was more common in an all-pedicle screw constructs compared to hybrid or UIV-hook distal pedicle screw constructs. Using hooks at UIV might be a treatment strategy to limit PJK. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.