A Transmissive X-ray Polarimeter Design For Hard X-ray Focusing Telescopes

The X-ray Timing and Polarization (XTP) is a mission concept for a future space borne X-ray observatory and is currently selected for early phase study. We present a new design of X-ray polarimeter based on the time projection gas chamber. The polarimeter, placed above the focal plane, has an additional rear window that allows hard X-rays to penetrate (a transmission of nearly 80% at 6 keV) through it and reach the detector on the focal plane. Such a design is to compensate the low detection efficiency of gas detectors, at a low cost of sensitivity, and can maximize the science return of multilayer hard X-ray telescopes without the risk of moving focal plane instruments. The sensitivity in terms of minimum detectable polarization, based on current instrument configuration, is expected to be 3% for a 1mCrab source given an observing time of 10^5 s. We present preliminary test results, including photoelectron tracks and modulation curves, using a test chamber and polarized X-ray sources in the lab

In-Orbit Instrument Performance Study and Calibration for POLAR Polarization Measurements

POLAR is a compact space-borne detector designed to perform reliable measurements of the polarization for transient sources like Gamma-Ray Bursts in the energy range 50-500keV. The instrument works based on the Compton Scattering principle with the plastic scintillators as the main detection material along with the multi-anode photomultiplier tube. POLAR has been launched successfully onboard the Chinese space laboratory TG-2 on 15th September, 2016. In order to reliably reconstruct the polarization information a highly detailed understanding of the instrument is required for both data analysis and Monte Carlo studies. For this purpose a full study of the in-orbit performance was performed in order to obtain the instrument calibration parameters such as noise, pedestal, gain nonlinearity of the electronics, threshold, crosstalk and gain, as well as the effect of temperature on the above parameters. Furthermore the relationship between gain and high voltage of the multi-anode photomultiplier tube has been studied and the errors on all measurement values are presented. Finally the typical systematic error on polarization measurements of Gamma-Ray Bursts due to the measurement error of the calibration parameters are estimated using Monte Carlo simulations.Comment: 43 pages, 30 figures, 1 table; Preprint accepted by NIM

Influence of the Earth on the background and the sensitivity of the GRM and ECLAIRs instruments aboard the Chinese-French mission SVOM

SVOM (Space-based multi-band astronomical Variable Object Monitor) is a future Chinese-French satellite mission which is dedicated to Gamma-Ray Burst (GRB) studies. Its anti-solar pointing strategy makes the Earth cross the field of view of its payload every orbit. In this paper, we present the variations of the gamma-ray background of the two high energy instruments aboard SVOM, the Gamma-Ray Monitor (GRM) and ECLAIRs, as a function of the Earth position. We conclude with an estimate of the Earth influence on their sensitivity and their GRB detection capability.Comment: 24 pages, 15 figures, accepted for publication in Experimental Astronom

Comparison of broiler performance, carcass yields and intestinal microflora when fed diets containing transgenic (Mon-40-3-2) and conventional soybean meal

This study was conducted to analyze the effects of transgenic glyphosate-tolerant soybeans on the performance, carcass yields and intestinal microflora of broiler chickens. Three hundred and sixty oneday- old Abor Aerec broilers were randomly divided into two dietary treatments, adding genetically modified (GM) glyphosate-tolerant soybean meal or conventional soybean meal, respectively. Broiler body weight and feed intake were recorded at regular intervals (day 0, 21 and 42). Chickens were slaughtered at day 42 for carcass yield measurement and sampling. Diversity of the ileum and cecum microflora was determined by denaturing gradient gel electrophoresis (DGGE) technique and DNA sequencing. No treatment differences (P > 0.05) were detected among dietary treatments for any measured performance and carcass parameters. The microbial population in ileum and cecum also had no significant difference between the two treatments (P>0.05). The similarity of the total ileum and cecum microflora between the two treatments was about 62 and 58%, respectively. The DNA-DGGE electrophoresis pattern bands of intestine microbe were divided into two groups because of the different diet. Fifteen DGGE DNA bands were identified, of which five of them were identified as known bacteria. The current study showed that there were no adverse effects of the transgenic soybean meal on the intestinal microflora of broilers.Key words: Broiler, glyphosate-tolerant soybean meal, intestinal microbiota, feed safety

In vitro and in vivo antibacterial efficacy of bacteriophage combined with tigecycline against carbapenem-resistant Klebsiella pneumoniae and characterization of phage resistant mutants

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged as a critical global public health threat, characterized by high infection rates, elevated mortality, and limited therapeutic options. In this study, we isolated and characterized a novel bacteriophage (phage), designated as HZJ31, which exhibited potent lytic activity against CRKP strains. Phylogenetic and genomic analyses revealed that phage HZJ31 belongs to the order Caudovirales and lacks virulence factors, antibiotic resistance genes, and lysogeny-related elements, supporting its suitability for therapeutic applications. Phage HZJ31 exhibits remarkable anti-biofilm activity by preventing biofilm formation and disrupting established biofilms, with bacterial reduction rates exceeding 70% (P<0.05). In combination with Tigecycline, it significantly enhanced bactericidal efficacy, delayed the emergence of phage resistant mutants, and improved survival rates in Galleria mellonella larvae infection models. Compared to the bacterial-infected group, which had 80% larval mortality at 96 h, treatment with HZJ31 or TGC alone led to 50% and 60% survival, while their combination improved survival to 70% (P < 0.05). Notably, the phage-resistant mutant, which emerged due to capsule loss, resulted in reduced growth and virulence, while regaining sensitivity to certain antibiotics (such as gentamicin), indicating a fitness cost associated with phage resistance. Collectively, these findings provide valuable insights into phage-antibiotic synergy and underscore the promising clinical potential of phage HZJ31 as a therapeutic agent against CRKP infections

Multiple-Crop Human Mesh Recovery with Contrastive Learning and Camera Consistency in A Single Image

We tackle the problem of single-image Human Mesh Recovery (HMR). Previous approaches are mostly based on a single crop. In this paper, we shift the single-crop HMR to a novel multiple-crop HMR paradigm. Cropping a human from image multiple times by shifting and scaling the original bounding box is feasible in practice, easy to implement, and incurs neglectable cost, but immediately enriches available visual details. With multiple crops as input, we manage to leverage the relation among these crops to extract discriminative features and reduce camera ambiguity. Specifically, (1) we incorporate a contrastive learning scheme to enhance the similarity between features extracted from crops of the same human. (2) We also propose a crop-aware fusion scheme to fuse the features of multiple crops for regressing the target mesh. (3) We compute local cameras for all the input crops and build a camera-consistency loss between the local cameras, which reward us with less ambiguous cameras. Based on the above innovations, our proposed method outperforms previous approaches as demonstrated by the extensive experiments