Reorganization of 3D genome architecture provides insights into pathogenesis of early fatty liver disease in laying hens

Background Fatty liver disease causes huge economic losses in the poultry industry due to its high occurrence and lethality rate.Three-dimensional(3D)chromatin architecture takes part in disease processing by regulating tran-scriptional reprogramming.The study is carried out to investigate the alterations of hepatic 3D genome and H3K27ac profiling in early fatty liver(FLS)and reveal their effect on hepatic transcriptional reprogramming in laying hens.Results Results show that FLS model is constructed with obvious phenotypes including hepatic visible lipid deposi-tion as well as higher total triglyceride and cholesterol in serum.A/B compartment switching,topologically associat-ing domain(TAD)and chromatin loop changes are identified by high-throughput/resolution chromosome conforma-tion capture(HiC)technology.Targeted genes of these alternations in hepatic 3D genome organization significantly enrich pathways related to lipid metabolism and hepatic damage.H3K27ac differential peaks and differential expres-sion genes(DEGs)identified through RNA-seq analysis are also enriched in these pathways.Notably,certain DEGs are found to correspond with changes in 3D chromatin structure and H3K27ac binding in their promoters.DNA motif analysis reveals that candidate transcription factors are implicated in regulating transcriptional reprogram-ming.Furthermore,disturbed folate metabolism is observed,as evidenced by lower folate levels and altered enzyme expression.Conclusion Our findings establish a link between transcriptional reprogramming changes and 3D chromatin struc-ture variations during early FLS formation,which provides candidate transcription factors and folate as targets for FLS prevention or treatment.

c-myb is involved in CML progression and is a therapeutic target in the zebrafish CML model

Background:Despite the success of tyrosine kinase inhibitors in chronic myeloid leukemia(CML)therapy,CML still faces the challenges of drug resistance and progression to blast crisis.Twenty-five percent of patients have imatinib resistance and treatment difficulties due to heterogeneity after progression,but little is known about the mechanism.A key transcription factor in hematopoiesis,MYB,has been reported to increase abnormally in several types of aggressive blood disorders including CML.Methods:This study used a zebrafish model to explore the relationship between BCR/ABL1 and c-myb in CML progression.A CML zebrafish model was crossed with a c-myb hyperactivity transgenic line.Results:It was found that both exogenous BCR/ABL1 and c-myb could up-regulate the expression of neutrophil-related genes.More seriously,neutrophil accumulation was observed when BCR/ABL1 was combined with c-myb overexpression.Further studies showed that c-myb may be one of the downstream targets of BCR/ABL1 and the effect of BCR/ABL1 on neutrophils was c-myb dependent.Taking advantage of this inheritable in vivo model,it was shown that a combination of imatinib and flavopiridol,a cyclin-dependent kinase inhibitor targeting MYB,could more effectively alleviate the aggressive phenotype of the double transgene line.Conclusion:In summary,this study suggests that c-myb acts downstream of BCR/ABL1 and is involved in CML progression and is therefore a risk factor and a valuable target for the treatment of CML progression.The model used in the study could be helpful in high-throughput drug screening in CML transformation.

Adjusting phosphate feeding regimen according to daily rhythm increases eggshell quality via enhancing medullary bone remodeling in laying hens

Background Body phosphorus metabolism exhibits a circadian rhythm over the 24-h daily cycle.The egg laying behavior makes laying hens a very special model for investigating phosphorus circadian rhythms.There is lack of information about the impact of adjusting phosphate feeding regimen according to daily rhythm on the phosphorus homeostasis and bone remodeling of laying hens.Methods and results Two experiments were conducted.In Exp.1,Hy-Line Brown laying hens(n=45)were sampled according the oviposition cycle(at 0,6,12,and 18 h post-oviposition,and at the next oviposition,respectively;n=9 at each time point).Diurnal rhythms of body calcium/phosphorus ingestions and excretions,serum calcium/phosphorus levels,oviduct uterus calcium transporter expressions,and medullary bone(MB)remodeling were illustrated.In Exp.2,two diets with different phosphorus levels(0.32%and 0.14%non-phytate phosphorus(NPP),respectively)were alternately presented to the laying hens.Briefly,four phosphorus feeding regimens in total(each included 6 replicates of 5 hens):(1)fed 0.32%NPP at both 09:00 and 17:00;(2)fed 0.32%NPP at 09:00 and 0.14%NPP at 17:00;(3)fed 0.14%NPP at 09:00 and 0.32%NPP at 17:00;(4)fed 0.14%NPP at both 09:00 and 17:00.As a result,the regimen fed 0.14%NPP at 09:00 and 0.32%NPP at 17:00,which was designed to strengthen intrinsic phosphate circadian rhythms according to the findings in Exp.1,enhanced(P<0.05)MB remodeling(indicated by histological images,serum markers and bone mineralization gene expressions),elevated(P<0.05)oviduct uterus calcium transportation(indicated by transient receptor potential vanilloid 6 protein expression),and subsequently increased(P<0.05)eggshell thickness,eggshell strength,egg specific gravity and eggshell index in laying hens.Conclusions These results underscore the importance of manipulating the sequence of daily phosphorus ingestion,instead of simply controlling dietary phosphate concentrations,in modifying the bone remodeling process.Body phosphorus rhythms will need to be maintained during the daily eggshell calcification cycle.

Dietary oregano aqueous extract improves growth performance and intestinal health of broilers through modulating gut microbial compositions

Background Intestinal health plays a pivotal role in broiler chicken growth.Oregano aqueous extract(OAE)effec-tively exerts anti-inflammatory and antibacterial effects.However,the protective effects of OAE on intestinal health in broilers and the underlying mechanism remain unclear.This study aimed to investigate the potential effects of OAE on growth performance,the gut microbiota and intestinal health.A total of 8401-d-old male and female broilers(Arbor Acres)were randomly allocated into 6 groups as follows:basal diet(Con),Con+antibiotics(Anti,colistin sulfate 7 g/kg,roxarsone 35 g/kg),Con+400,500,600 and 700 mg/kg OAE(OAE400,OAE500,OAE600 and OAE700).Subse-quently,fermentation in vitro together with oral administration trials were carried out to further assess the function of OAE on intestinal health of broilers.Results Dietary 700 mg/kg OAE supplementation resulted in an increase(P<0.05)in body weight and a decrease(P<0.05)in feed conversion ratio when compared with the control during d 22 to 42 of the trial.OAE addition resulted in lower(P<0.05)jejunal crypt depth and mRNA expression of IL-4 and IL-10 at d 42.In addition,dietary OAE addition increased the abundance of Firmicutes(P=0.087)and Lactobacillus(P<0.05)in the cecum,and increased(P<0.05)the content of acetic acid and butyric acid.In the in vitro fermentation test,OAE significantly increased(P<0.05)the abundance of Lactobacillus,decreased(P<0.05)the abundance of unspecified_Enterobacteriaceae,and increased the content of acetic acid(P<0.05).In the oral administration trial,higher(P<0.05)IL-4 expression was found in broilers when oral inoculation with oregano fermentation microorganisms at d 42.And SIgA content in the ileum was significantly increased(P=0.073)when giving OAE fermentation supernatant.Conclusions Dietary OAE addition could maintain intestinal health and improve growth performance through enhancing intestinal mucosal immunity and barrier function mediated by gut microbiota changes.

Research and Application of Log Defect Detection and Visualization System Based on Dry Coupling Ultrasonic Method

In order to optimize the wood internal quality detection and evaluation system and improve the comprehensive utilization rate of wood,this paper invented a set of log internal defect detection and visualization system by using the ultrasonic dry coupling agent method.The detection and visualization analysis of internal log defects were realized through log specimen test.The main conclusions show that the accuracy,reliability and practicability of the system for detecting the internal defects of log specimens have been effectively verified.The system can make the edge of the detected image smooth by interpolation algorithm,and the edge detection algorithm can be used to detect and reflect the location of internal defects of logs accurately.The content mentioned above has good application value for meeting the requirement of increasing demand for wood resources and improving the automation level of wood nondestructive testing instruments.

Intestinal toxicity of deoxynivalenol is limited by supplementation with Lactobacillus plantarum JM113 and consequentially altered gut microbiota in broiler chickens

Background: Limited research has focused on the effect of Lactobacillus on the intestinal toxicity of deoxynivalenol(DON).The present study was conducted to investigate the role of Lactobacillus plantarum(L.plantarum) JM113 in protecting against the intestinal toxicity caused by DON.Methods: A total of 144 one-day-old healthy Arbor Acres broilers were randomly distributed into 3 treatments,including the CON(basal diet),the DON(extra 10 mg/kg deoxynivalenol),and the DL(extra 1 × 109 CFU/kg L.plantarum JM113 based on DON group) treatments.The growth performance,organ indexes,intestinal morphology,pancreatic digestive enzymes,intestinal secreted immunoglobulin A(sIgA),jejunal transcriptome,and intestinal microbiota were evaluated.Results: Compared with the CON and DL groups,the DON supplementation altered intestinal morphology,especially in duodenum and jejunum,where villi were shorter and crypts were deeper(P < 0.05).Meanwhile,the significantly decreased mRNA expression of jejunal claudin-1 and occludin(P < 0.05),ileal rBAT and jejunal GLUT1 of 21-day-old broilers(P < 0.05),as well as duodenal PepT1 and ileal rBAT of 42-day-old broilers were identified in the DON group.Moreover,supplementation with L.plantarum JM113 could increase duodenal expression of IL-10 and IL-12 of 21-dayold broilers,ileal s IgA of 42-day-old broilers,and the bursa of Fabricius index of 21-day-old broilers.Further jejunal transcriptome proved that the genes related to the intestinal absorption and metabolism were significantly reduced in the DON group but a significant increase when supplemented with extra L.plantarum JM113.Furthermore,the bacteria related to nutrient utilization,including the Proteobacteria,Escherichia,Cc-115(P < 0.05),Lactobacillus and Prevotella(P < 0.1) were all decreased in the DON group.By contrast,supplementation with L.plantarum JM113 increased the relative abundance of beneficial bacterium,including the Bacteroidetes,Roseburia,Anaerofustis,Anaerostipe,and Ruminococcus bromi(P < 0.05).Specifically,the increased abundance of bacteria in the DL group could be proved by the significantly increased caecal content of propionic acid,n-Butyric acid,and total short-chain fatty acid.Conclusions: L.plantarum JM113 enhanced the digestion,absorption,and metabolic functions of the gut when challenged with DON by reducing the injury to intestinal barriers and by increasing the abundance of beneficial bacterium.

Lactobacillus reuteri-derived extracellular vesicles maintain intestinal immune homeostasis against lipopolysaccharideinduced inflammatory responses in broilers

Background:Lactobacillus reuteri strains are widely used as probiotics to prevent and treat inflammatory bowel disease by modulating the host’s immune system.However,the underlying mechanisms by which they communicate with the host have not been clearly understood.Bacterial extracellular vesicles(EVs)have been considered as important mediators of host-pathogen interactions,but their potential role in commensals-host crosstalk has not been widely studied.Here,we investigated the regulatory actions of EVs produced by L.reuteri BBC3,a gut-associated commensal bacterium of Black-Bone chicken,in the development of lipopolysaccharide(LPS)-induced intestinal inflammation in a chicken model using both in vivo and in vitro experiments.Results:L.reuteri BBC3 produced nano-scale membrane vesicles with the size range of 60-250 nm.Biochemical and proteomic analyses showed that L.reuteri BBC3-derived EVs(LrEVs)carried DNA,RNA and several bioactive proteins previously described as mediators of other probiotics’beneficial effects such as glucosyltransferase,serine protease and elongation factor Tu.In vivo broiler experiments showed that administration of LrEVs exerted similar effects as L.reuteri BBC3 in attenuating LPS-induced inflammation by improving growth performance,reducing mortality and decreasing intestinal injury.LrEVs suppressed the LPS-induced expression of pro-inflammatory genes(TNF-α,IL-1β,IL-6,IL-17 and IL-8),and improved the expression of anti-inflammatory genes(IL-10 and TGF-β)in the jejunum.LrEVs could be internalized by chicken macrophages.In vitro pretreatment with LrEVs reduced the gene expression of TNF-α,IL-1βand IL-6 by suppressing the NF-κB activity,and enhanced the gene expression of IL-10 and TGF-βin LPS-activated chicken macrophages.Additionally,LrEVs could inhibit Th1-and Th17-mediated inflammatory responses and enhance the immunoregulatory cells-mediated immunosuppression in splenic lymphocytes of LPS-challenged chickens through the activation of macrophages.Finally,we revealed that the reduced content of both vesicular proteins and nucleic acids attenuated the suppression of LrEVs on LPS-induced inflammatory responses in ex vivo experiments,suggesting that they are essential for the LrEVs-mediated immunoregulation.Conclusions:We revealed that LrEVs participated in maintaining intestinal immune homeostasis against LPSinduced inflammatory responses in a chicken model.Our findings provide mechanistic insight into how commensal and probiotic Lactobacillus species modulate the host’s immune system in pathogens-induced inflammation.

Changes in the gut microbiota mediate the differential regulatory effects of two glucose oxidases produced by Aspergillus niger and Penicillium amagasakiense on the meat quality and growth performance of broilers

Background: Glucose oxidase(GOD), an aerobic dehydrogenase, has been used as an antibiotic substitute in feed.A study was conducted to evaluate the differential effects of 2 different GODs fermented by Aspergillus niger or Penicillium amagasakiense on caecal microbiota and to further illuminate the potential roles of changes in the gut microbiota in regulating the growth performance and meat quality of broiler chickens.Results: A total of 420 one-day-old healthy Arbor Acres broilers were randomly assigned to 4 treatments: the control group,the antibiotic growth promoter(AGP) supplementation group, and the GOD-A and GOD-P(GODs produced by A. niger and P. amagasakiense, respectively) groups. As a result, supplementation with GOD produced by P. amagasakiense could significantly improve the average daily weight gain and average daily feed intake of broilers before 21 days of age by significantly increasing the enzymatic activities of jejunal amylase and those of ileal amylase, chymotrypsin, and lipase in21-day-old broilers and could increase the enzymatic activities of duodenal amylase, jejunal amylase and lipase, and ileal chymotrypsin and lipase in 42-day-old broilers. Meanwhile, compared with AGP treatment, supplementation with GOD produced by P. amagasakiense significantly decreased the L value of 21-day-old broilers and the Δp H and L* value of 42-day-old broilers, while supplementation with GOD produced by A. niger significantly increased the p H24 hvalue of 21-day-old and 42-day-old broilers by reducing plasma malondialdehyde content. By using 16 S r RNA sequencing, we found that the beneficial bacteria and microbiota in broilers were not disturbed but were improved by GOD supplementation compared with ADP treatment, including the genera Eubacterium and Christensenel a and the species uncultured_Eubacterium_sp,Clostridium_asparagiforme, and uncultured_Christensenel a_sp, which were positively related to the improved intestinal digestive enzymatic activities, growth performance, and meat quality of broilers.Conclusion: The altered gut microbiota induced by supplementation with glucose oxidase produced by P. amagasakiense mediate better regulatory effects on the meat quality and growth performance of broilers than that induced by supplementation with glucose oxidase produced by A. niger.

Status and distribution changes of the endangered Green Peafowl (Pavo muticus) in China over the past three decades (1990s-2017)

Background： Understanding the changes in population dynamics, including demographics, distribution and threats is essential for species status assessing.The endangered Green Peafowl （Povo muticus） has experienced sharp population declines and d stribution range diminishing both in China and Southeast Asia. Field population surveys have not been conducted in China since the 1990s, which hindered conservation planning and decision-making.Methods： With interview and line transects methods, we figured out the population and distribution changes of Green Peafowl across its historical ranges over the past three decades in China during 2014-2017.Results： The Green Peafowl once habituated in 54 counties in China. Nearly 60% of the distribution counties were lost in the past three decades, with the left 22 counties distributed in central, southern and western Yunnan, SW China. Population decrease detected in all distribution areas except for Shuangbai and Xinping county where more than 60% of the total population is located. Only about 30% of the former bird population were recorded with the same interviewing method as 20 years ago.Three birds, 1 carcass, 6 calls and 12 footprints were detected along the 865 km line transects, indicating extremely low encounter rate of Green Peafowl in field. Sharp decreases in flock sizes were also detected, from 8-20 birds per flock in the 1990s to 3-5 birds at present. Poaching and habitat conversion are two widespread and long-lasting threats, while poison tion affect regional population＇s survival. Large flocks of 18 ng caused mortality in the past and hydropower construc -27 birds were discovered in the field, which increases our confidence of population recovery of this endangered pheasant in China.Conclusions： Only interviewed bird number and counts based on line transects were presented in this study, without further population estimation due to limitation of the data sets. Although the actual population of this cryptic bird must be underestimated, dramatic population declines and distribution concentrations of the endangered Green Peafowl occurred over the past 30 years in China undoubtedly.

Optimal deadlock avoidance Petri net supervisors for automated manufacturing systems

Deadlock avoidance problems are investigated for automated manufacturing systems with flexible routings. Based on the Petri net models of the systems, this paper proposes, for the first time, the concept of perfect maximal resourcetransition circuits and their saturated states. The concept facilitates the development of system liveness characterization and deadlock avoidance Petri net supervisors. Deadlock is characterized as some perfect maximal resource-transition circuits reaching their saturated states. For a large class of manufacturing systems, which do not contain center resources, the optimal deadlock avoidance Petri net supervisors are presented. For a general manufacturing system, a method is proposed for reducing the system Petri net model so that the reduced model does not contain center resources and, hence, has optimal deadlock avoidance Petri net supervisor. The controlled reduced Petri net model can then be used as the liveness supervisor of the system.

Evaluation of human epidermal growth factor receptor 2 status of breast cancer using preoperative multidetector computed tomography with deep learning and handcrafted radiomics features

Objective:To evaluate the human epidermal growth factor receptor 2(HER2)status in patients with breast cancer using multidetector computed tomography(MDCT)-based handcrafted and deep radiomics features.Methods:This retrospective study enrolled 339 female patients(primary cohort,n=177;validation cohort,n=162)with pathologically confirmed invasive breast cancer.Handcrafted and deep radiomics features were extracted from the MDCT images during the arterial phase.After the feature selection procedures,handcrafted and deep radiomics signatures and the combined model were built using multivariate logistic regression analysis.Performance was assessed by measures of discrimination,calibration,and clinical usefulness in the primary cohort and validated in the validation cohort.Results:The handcrafted radiomics signature had a discriminative ability with a C-index of 0.739[95%confidence interval(95%CI):0.661-0.818]in the primary cohort and 0.695(95%CI:0.609-0.781)in the validation cohort.The deep radiomics signature also had a discriminative ability with a C-index of 0.760(95%CI:0.690-0.831)in the primary cohort and 0.777(95%CI:0.696-0.857)in the validation cohort.The combined model,which incorporated both the handcrafted and deep radiomics signatures,showed good discriminative ability with a C-index of 0.829(95%CI:0.767-0.890)in the primary cohort and 0.809(95%CI:0.740-0.879)in the validation cohort.Conclusions:Handcrafted and deep radiomics features from MDCT images were associated with HER2 status in patients with breast cancer.Thus,these features could provide complementary aid for the radiological evaluation of HER2 status in breast cancer.

A Hybrid Electrode of Co_3O_4@PPy Core/Shell Nanosheet Arrays for High-Performance Supercapacitors

Herein, combining solverthermal route and electrodeposition, we grew unique hybrid nanosheet arrays consisting of Co_3O_4 nanosheet as a core, PPy as a shell. Benefiting from the PPy as conducting polymer improving an electron transport rate as well as synergistic effects from such a core/shell structure, a hybrid electrode made of the Co_3O_4@PPy core/shell nanosheet arrays exhibits a large areal capacitance of 2.11 F cm-2at the current density of 2 m A cm^(-2), a *4-fold enhancement compared with the pristine Co_3O_4electrode; furthermore, this hybrid electrode also displays good rate capability(*65 % retention of the initial capacitance from 2 to 20 m A cm^(-2)) and superior cycling performance(*85.5 % capacitance retention after 5000 cycles). In addition, the equivalent series resistance value of the Co_3O_4@PPy hybrid electrode(0.238 X) is significantly lower than that of the pristine Co_3O_4electrode(0.319 X). These results imply that the Co_3O_4@PPy hybrid composites have a potential for fabricating next-generation energy storage and conversion devices.

Numerical simulation of spatial distributions of mining-induced stress and fracture fields for three coal mining layouts

In this study, the spatial distributions of stress and fracture fields for three typical underground coal mining layouts, Le, non-pillar mining （NM）, top-coal caving mining （TCM） and protective coal-seam mining （PCM）, are modeled using discrete element software UDEC, The numerical results show that different mining layouts can lead to different mining-induced stress fields, resulting in diverse fracture fields, For the PCM, the mining influenced area in front of the mining faces is the largest, and the stress concentration factor in front of the mining faces is the lowest, The spatial shapes of the mining-induced fracture fields under NM, TCM and PCM differ, and they are characterized by trapezoidal, triangular and tower shapes, respectively, The fractal dimensions of mining-induced fractures of the three mining layouts decrease in the order of PCM, TCM and NM, It is also shown that the PCM can result in a better gas control effect in coal mines with high outburst potential, The numerical results are expected to provide a basis for understanding of mining-induced gas seepage fields and provide a reference for high- efficiency coal mining,

A novel apidaecin Api-PR19 synergizes with the gut microbial community to maintain intestinal health and promote growth performance of broilers

Background: Antibiotic growth promoters(AGPs) have been used as growth promoters to maintain animal intestinal health and improve feed efficiency in broilers by inhibiting pathogen proliferation. In view of the growing emergence of antibiotic-resistant pathogen strains and drug residue issues, novel treatments are increasingly required. This study aimed to compare two antimicrobial approaches for managing pathogen infection and maintaining animal intestinal health in broilers by supplying Apidaecin Api-PR19 and AGPs over 42 d of a feeding trial.Results: Compared with the broilers that were only fed a corn-soybean basal diet(CON group), supplementation with Api-PR19 and AGP(respectively named the ABP and AGP groups) both increased the feed conversion efficiency. When compared with the AGP group, Api-PR19 supplementation could significantly increase the organ index of the bursa of fabricius and subtype H9 antibody level in broiler chickens. Moreover, when compared with the CON group, the intestinal villus height, intestinal nutrient transport, and intestinal s Ig A content were all increased in the Api-PR19 group, while AGP supplementation was harmful to the intestinal villus height and intestinal nutrient transport. By assessing the antibacterial effect of Api-PR19 and antibiotics in vitro and in vivo, we found that Api-PR19 and antibiotics both inhibited the growth of pathogens, including Escherichia coli and Campylobacter jejuni. Furthermore, by using 16 S r RNA gene sequencing, the beneficial bacteria and microbiota in broilers were not disturbed but improved by apidaecin Api-PR19, including the genera of Eubacterium and Christensenella and the species of uncultured_Eubacterium_sp, Clostridium_asparagiforme, and uncultured_Christensenella_sp, which were positively related to improved intestinal development, absorption, and immune function.Conclusion: Apidaecin Api-PR19 treatment could combat pathogen infection and had little negative impact on beneficial bacteria in the gut compared to antibiotic treatment, subsequently improving intestinal development,absorption, and immune function.

Joint state and parameter estimation in particle filtering and stochastic optimization

In this paper, an adaptive estimation algorithm is proposed for non-linear dynamic systems with unknown static parameters based on combination of particle filtering and Simultaneous Perturbation Stochastic Approxi- mation （SPSA） technique. The estimations of parameters are obtained by maximum-likelihood estimation and sampling within particle filtering framework, and the SPSA is used for stochastic optimization and to approximate the gradient of the cost function. The proposed algorithm achieves combined estimation of dynamic state and static parameters of nonlinear systems. Simulation result demonstrates the feasibilitv and efficiency of the proposed algorithm

Integration Interval Determination and Decision Threshold Optimization for Improved TRPC-UWB Communication Systems

Integration interval and decision threshold issues were investigated for improved transmitted reference pulse cluster （iTRPC-） ultra-wideband （UWB） systems. Our analysis shows that the bit error rate （BER） performance of iTRPC-UWB systems can be significantly improved via integration interval determination （IID） and decision threshold optimization. For this purpose, two modifications can be made at the autocorrelation receiver as follows. Firstly, the liD processing is performed for autocorrelation operation to capture multi-path energy as much as possible. Secondly, adaptive decision threshold （ADT） instead of zero decision threshold （ZDT）, is used as estimated optimal decision threshold for symbol detection. Performance of iTRPCUWB systems using liD and ADT was evaluated in realistic IEEE 802.15.4a UWB channel models and the simulation results demonstrated our theoretical analysis.

Low-Density Parity-Check Codes for Noncoherent UWB Communication Systems

In order to guarantee reliable data transmission, powerful channel coding techniques are usually required in noncoherent ultra-wideband(UWB) communication systems. Accordingly, several forward error correction(FEC) codes, such as Reed-Solomon and convolutional codes have been used in noncoherent UWB systems to improve the bit error rate(BER) performance. In this paper, low-density parity-check(LDPC) codes are further studied as more powerful FEC candidates for noncoherent UWB systems. Two LDPC codes and the corresponding decoding procedures are presented for noncoherent UWB systems. Moreover, performance comparison between the LDPC codes and other FEC codes are provided for three major noncoherent UWB communication systems, namely, noncoherent pulse position modulation(NC-PPM), transmitted reference(TR) and transmitted reference pulse cluster(TRPC). Both theoretical analysis and simulation results show that the two investigated LDPC codes outperform other existing FEC codes with limited penalty in terms of complexity and therefore they are promising FEC candidates for noncoherent UWB systems with low-cost and low-power consumption.

Effect of in ovo folic acid injection on hepatic IGF2 expression and embryo growth of broilers

Background： Insulin-like factor 2（IGF2） plays an important role in embryonic growth process by modulating intermediary metabolism and cell proliferation. Folic acid is involved in one carbon metabolism and contributes to DNA methylation which is related to gene expression. The purpose of this study was to explore whether folic acid could regulate IGF2 expression via epigenetic mechanism and further promote embryonic growth of new-hatched broilers.Methods： In the present study, 360 fertile eggs were selected and randomly assigned to four treatments. On11 embryonic day of incubation（E11）, 0, 50, 100 and 150 μg folic acid were injected into eggs respectively.After hatched, growth performance of broilers were calculated. Hepatic IGF2 expression, methylation level and chromatin structure of promoter region were analyzed.Results： Results have showed that IGF2 expression was up-regulated in 150 μg folic acid group（P 〈 0.05） and other two dose of folic acid did not affect gene expression（P 〉 0.05）. Meanwhile, methylation level of IGF2 promoter were lower in 100 and 150 μg groups, which was consistent with lower expression of DNA methyltransferase1（DNMT1）（P 〈 0.05）. What＇s more, chromatin looseness of IGF2 promoter was higher in 150 μg group than control group（P 〈 0.05）. Further, birth weight（BW）, liver and bursa index of new-hatched chickens in 150 μg folic acid group were higher than the other groups（P 〈 0.05）. There were positive correlations between hepatic IGF2 expression and BW and organs index（P 〈 0.05）.Conclusion： In conclusion, our data have demonstrated that 150 μg folic acid injection on E11 could up-regulate IGF2 expression by modulating DNA hypomethylation and improving chromatin accessibility in the gene promoter region,and ulteriorly facilitate embryonic growth and organ development of broilers.

青年幼师入职焦虑压力源分析及其对策研究

随着学前教育规模的扩大和发展速度的加快,青年幼师已经成为当今学前教育的主干力量。青年幼师面临着社会身份转化、人际交往能力不足、所学知识无法灵活运用、事实与想象落差较大等问题,使得青年幼师在入职初期出现了各种入职焦虑的状况,影响了正常教学工作的开展和教师自我认同的实现。尝试从青年幼师教学授课恐惧、职业关系处理失当等焦虑表现当中分析造成焦虑的压力源,并从教师自身、幼儿园、社会、国家教育行政机关、高等教育机构等五个方面提出相关的应对策略。

Exploring the effectiveness of in ovo feeding of vitamin C based on the embryonic vitamin C synthesis and absorption in broiler chickens

Background:Many researches about in ovo feeding(IOF)of vitamin C(VC)are gradually carried out to explore physiological development in chicken,but little studies focus on VC synthesis capacity of the embryo itself,the selection of injection site and the effectiveness of IOF of VC.This study aims to explore the above problems.Results:Kidney and yolk sac were the main organs for VC synthesis and L-gulonolactone oxidase(GLO)expression was lower during pre-hatch development than that during post-hatch development.Sodium-dependent vitamin C transporter 1(SVCT1)expression was increased continuously in yolk sac from embryonic age 19(E19)to post-hatch day 1(D1)and in intestine(duodenum,jejunum and ileum)from E17 to D1.Plasma VC content was higher at D1 than that at D21 and D42.IOF of VC significantly reduced GLO expression in liver,kidney and yolk sac as well as SVCT1 expression in duodenum,jejunum and ileum,but increased the VC content in plasma,brain,kidney and liver.In addition,IOF of VC obviously reduced the embryonic morality and increased the hatchability under heat stress.Conclusions:This study suggested that IOF of VC at E11 in yolk was effective for embryonic VC supplementation.These findings provide a theoretical reference about the method of embryonic VC supplementation and effective methodology on embryonic VC nutrition in broiler chickens.