Effects of different energy levels in low-protein diet on liver lipid metabolism in the late-phase laying hens through the gut-liver axis

Background The energy/protein imbalance in a low-protein diet induces lipid metabolism disorders in late-phase laying hens.Reducing energy levels in the low-protein diet to adjust the energy-to-protein ratio may improve fat deposition,but this also decreases the laying performance of hens.This study investigated the mechanism by which different energy levels in the low-protein diet influences liver lipid metabolism in late-phase laying hens through the enterohepatic axis to guide feed optimization and nutrition strategies.A total of 288 laying hens were randomly allocated to the normal-energy and normal-protein diet group(positive control:CK)or 1 of 3 groups:lowenergy and low-protein diet(LL),normal-energy and low-protein diet(NL),and high-energy and low-protein diet(HL)groups.The energy-to-protein ratios of the CK,LL,NL,and HL diets were 0.67,0.74,0.77,and 0.80,respectively.Results Compared with the CK group,egg quality deteriorated with increasing energy intake in late-phase laying hens fed low-protein diet.Hens fed LL,NL,and HL diets had significantly higher triglyceride,total cholesterol,acetylCo A carboxylase,and fatty acid synthase levels,but significantly lower hepatic lipase levels compared with the CK group.Liver transcriptome sequencing revealed that genes involved in fatty acid beta-oxidation(ACOX1,HADHA,EHHADH,and ACAA1)were downregulated,whereas genes related to fatty acid synthesis(SCD,FASN,and ACACA)were upregulated in LL group compared with the CK group.Comparison of the cecal microbiome showed that in hens fed an LL diet,Lactobacillus and Desulfovibrio were enriched,whereas riboflavin metabolism was suppressed.Cecal metabolites that were most significantly affected by the LL diet included several vitamins,such as riboflavin(vitamin B2),pantethine(vitamin B5 derivative),pyridoxine(vitamin B6),and 4-pyridoxic acid.Conclusion A lipid metabolism disorder due to deficiencies of vitamin B2 and pantethine originating from the metabolism of the cecal microbiome may be the underlying reason for fat accumulation in the liver of late-phase laying hens fed an LL diet.Based on the present study,we propose that targeting vitamin B2 and pantethine(vitamin B5 derivative)might be an effective strategy for improving lipid metabolism in late-phase laying hens fed a low-protein diet.

SURFACE IMBALANCE ENERGY CALCULATED AND ANALYZED WITH THE DATA OF EBEX-2000

Mainly.three methods have been developed to calculate turbulence heat flux.They are eddy covariance method,Bowen ratio/energy balance method and aerodynamic method.In this paper, all the three methods have been used to calculate sensible heat flux,latent heat flux and imbalance energy near the surface with the experiment data of EBEX-2000.Then comparisons of the three methods and some possible explanations of the surface imbalance energy are given.

Discussion on Calculation Methods of Sensible Heat Flux during GAME/Tibet in 1998

Based on previous research on sensible heat flux, we investigate it from different aspects using GAME/Tibet data measured during 6 June–13 September, 1998. This work consists of the derivation of the surface heat flux equation, analysis on counter-gradient heat transference, comparison between two different methods to compute the sensible heat flux, and investigation on the calculation scheme of sensible heat flux in the Simple Biosphere model 2 (SiB2) with relevant simulation. By improving two previous formulations, an integrated formulation for calculating surface heat flux is given. Secondly, using the measured data, the counter-gradient heat flux is clarified, leading to the fact that buoyancy plays an important role in the sensible heat transfer process. It is concluded that (1) energy imbalance is a common phenomenon resulting from the use of the traditional closure scheme on the heterogeneous underlying surface because the measured ensemble heat fluxes by eddy correlation contain the effect of nonlocal parcel movements; and (2) nonlocal parcel movement deserves more attention in any future heat flux study.

Mechanism of cancer-induced fatigue

Cancer related fatigue(CRF)is one of the most common and painful reactions in cancer patients.Due to the negative effects of cancer itself and long-term treatment,patients often feel continuous burnout,fatigue and powerlessness in both mental and physical aspects.Fatigue related to cancer and cancer treatment will affect the physical and mental health of cancer patients for a long time and continuously,and it is hard to be relieved through rest.Nowadays,most of the researches focus on the clinical manifestations of patients with cancer,such as pain,nausea and vomiting,weight loss and so on.The fatigue feeling of cancer patients is often one of the most easily overlooked pain symptoms in the treatment process.The influence of CRF on cancer patients may be one of the reasons for reducing the survival time of cancer patients.This paper aims to summarize and explore the pathogenesis of cancer-related fatigue,in order to analyze the related factors of cancer-related fatigue from multi-dimensional and multi-angle,and provide reference for its comprehensive treatment in clinic.

Modification of the land surface energy balance relationship by introducing vertical sensible heat advection and soil heat storage over the Loess Plateau

Little is known about the surface energy balance problem for a complex underlying surface.Taking data from the Loess Plateau Land-surface Processes Experiment(LOPEX) and investigating the characteristics of the surface energy balance over a complex underlying surface,this paper calculates the soil heat storage and vertical sensible heat advection,analyzes their contributions to the surface energy imbalance,and discusses the mechanism by which the vertical velocity and temperature gradient in the surface layer affect the vertical sensible heat advection transfer.We found that the vertical velocity in the surface layer provides the necessary dynamic power for vertical sensible heat advection,and a relatively strong temperature gradient is the energy source generating vertical sensible heat advection.Under an ascending condition,the effect of vertical sensible heat advection on the surface energy budget is more obvious.It is also found that when the soil heat storage term and the vertical sensible heat advection term are added to the energy balance equation,the imbalance significantly improves.The peak of average diurnal residuals decreases from 125.1 to 41.5 W m-2,the daily average absolute value of residuals falls from 59.0 to 26.4 W m-2,and the surface energy balance closure increases from 78.4% to 94.0%.