SJTU-AISPEECH System for VoxCeleb Speaker Recognition Challenge 2022

This report describes the SJTU-AISPEECH system for the Voxceleb Speaker Recognition Challenge 2022. For track1, we implemented two kinds of systems, the online system and the offline system. Different ResNet-based backbones and loss functions are explored. Our final fusion system achieved 3rd place in track1. For track3, we implemented statistic adaptation and jointly training based domain adaptation. In the jointly training based domain adaptation, we jointly trained the source and target domain dataset with different training objectives to do the domain adaptation. We explored two different training objectives for target domain data, self-supervised learning based angular proto-typical loss and semi-supervised learning based classification loss with estimated pseudo labels. Besides, we used the dynamic loss-gate and label correction (DLG-LC) strategy to improve the quality of pseudo labels when the target domain objective is a classification loss. Our final fusion system achieved 4th place (very close to 3rd place, relatively less than 1%) in track3.Comment: System description of VoxSRC 202

Single Shot Thermal Momentum Imaging for High Brightness Photoinjector Cathode

In state of the art photoinjector electron sources, cathode performancedetermines the lower limit of achievable beam emittance. Measuring the intrinsic emittance at the photocathodes in electron guns is of vital importance for improving the injectors. Traditional methods, like solenoid scan, pepper-pot, need multi-shots and are time-consuming, therefore suffers from machine stability. Here we propose a new method, named thermal momentum imaging. By tuning the gun solenoid focusing, the electrons’ transverse momentum at cathode is imaged to a downstream screen. The new method enables a single shot measurement of cathode intrinsic emittance by measuring the beam spot size. Several experiments have been done at Photo Injector Test facility at DESY,Zeuthen site (PITZ) with CsTe cathode#661.1. Measurements of cathodeintrinsic emittance, transverse thermal momentum spectra, cathode intrinsicemittance map and its correlation with surface electric field are presented

DEVELOPMENT OF A COMPACT C-BAND PHOTOCATHODE RF GUN*

Abstract A C-band photocathode RF gun for a compact electron diffraction facility is developed at Tsinghua University, which is designed to work at the frequency of 5.712GHz. This paper presents the physics and structure design of this C-band RF gun, and the comparison of beam dynamics of S-band and C-band photoinjectors. New design features will be adopted in this gun, including the optimized cavity length and elliptical iris, which are helpful to achieve better compression, lower emittance and larger mode separation

Lactobacillus delbrueckii Ameliorates Intestinal Integrity and Antioxidant Ability in Weaned Piglets after a Lipopolysaccharide Challenge

This study was conducted to evaluate the effect of dietary supplementation with Lactobacillus delbrueckii (LAB) on intestinal morphology, barrier function, immune response, and antioxidant capacity in weaned piglets challenged with lipopolysaccharide (LPS). A total of 36 two-line crossbred (Landrace × large Yorkshire) weaned piglets (28 days old) were divided into three groups: (1) nonchallenged control (CON); (2) LPS-challenged control (LPS); and (3) LAB+LPS treatment (0.2% LAB+LPS). Compared to the LPS piglets, the LAB+LPS piglets improved intestinal morphology, indicated by greater (P<0.05) villus height in the duodenum and ileum; villus height : crypt depth ratio in the duodenum, jejunum, and ileum, as well as decreased (P<0.05) crypt depth in the jejunum and ileum; and better intestinal barrier function, indicated by upregulated (P<0.05) mRNA expression of tight junction proteins in the intestinal mucosa. Moreover, compared to the LPS piglets, LAB significantly decreased (P<0.05) concentrations of TNF-α and IL-1β in the small intestine and increased (P<0.05) IL-10 levels in the jejunum and ileum. Additionally, LAB increased (P<0.05) T-AOC activities of the colon, GSH concentrations of the jejunum, and mRNA expression of CAT and Cu/Zn-SOD, while reduced (P<0.05) MDA concentrations in the jejunum and ileum in LPS-changed piglets. Collectively, our results indicate that supplementation of LAB improved intestinal integrity and immune response and alleviated intestinal oxidative damage in LPS-challenged piglets

h5bench: A unified benchmark suite for evaluating HDF5 I/O performance on pre‐exascale platforms

Parallel I/O is a critical technique for moving data between compute and storage subsystems of supercomputers. With massive amounts of data produced or consumed by compute nodes, high-performant parallel I/O is essential. I/O benchmarks play an important role in this process; however, there is a scarcity of I/O benchmarks representative of current workloads on HPC systems. Toward creating representative I/O kernels from real-world applications, we have created h5bench, a set of I/O kernels that exercise hierarchical data format version 5 (HDF5) I/O on parallel file systems in numerous dimensions. Our focus on HDF5 is due to the parallel I/O library's heavy usage in various scientific applications running on supercomputing systems. The various tests benchmarked in the h5bench&nbsp;suite include I/O operations (read and write), data locality (arrays of basic data types and arrays of structures), array dimensionality (one-dimensional arrays, two-dimensional meshes, three-dimensional cubes), I/O modes (synchronous and asynchronous). In this paper, we present the observed performance of h5bench&nbsp;executed along several of these dimensions on existing supercomputers (Cori and Summit) and pre-exascale platforms (Perlmutter, Theta, and Polaris). h5bench&nbsp;measurements can be used to identify performance bottlenecks and their root causes and evaluate I/O optimizations. As the I/O patterns of h5bench&nbsp;are diverse and capture the I/O behaviors of various HPC applications, this study will be helpful to the broader supercomputing and I/O community

Plasmids Expressing shRNAs Specific to the Nucleocapsid Gene Inhibit the Replication of Porcine Deltacoronavirus In Vivo

Porcine deltacoronavirus (PDCoV) is a novel enteric coronavirus and is becoming one of the major causative agents of diarrhea in pig herds in recent years. To date, there are no commercial vaccines or antiviral pharmaceutical agents available to control PDCoV infection. Therefore, developing a reliable strategy against PDCoV is urgently needed. In this study, to observe the antiviral activity of RNA interference (RNAi), four short hairpin RNAs (shRNAs) specific to the nucleocapsid (N) gene of PDCoV were designed and tested in vitro. Of these, a double-shRNA-expression vector, designated as pSil-double-shRNA-N1, was the most effectively expressed, and the inhibition of PDCoV replication was then further evaluated in neonatal piglets. Our preliminary results reveal that plasmid-based double-shRNA-expression targeting the N gene of PDCoV can significantly protect LLC-PK1 cells and piglets from pathological lesions induced by PDCoV. Our study could benefit the investigation of the specific functions of viral genes related to PDCoV infection and offer a possible methodology of RNAi-based therapeutics for PDCoV infection