Vegetation greening has long been acknowledged,but recent studies have pointed out that vegetation greening is possibly stalled or even reversed.However,detailed analyses about greening reversal or increased browning ...Vegetation greening has long been acknowledged,but recent studies have pointed out that vegetation greening is possibly stalled or even reversed.However,detailed analyses about greening reversal or increased browning of vegetation remain scarce.In this study,we utilized the normalized difference vegetation index(NDVI)as an indicator of vegetation to investigate the trends of vegetation greening and browning(monotonic,interruption,and reversal)through the breaks for the additive season and trend(BFAST)method across China’s drylands from 1982 to 2022.It also reveals the impacts of ecological restoration programs(ERPs)and climate change on these vegetation trends.We find that the vegetation displays an obvious pattern of east-greening and west-browning in China’s drylands.Greening trends mainly exhibits monotonic greening(29.8%)and greening with setback(36.8%),whereas browning shows a greening to browning reversal(19.2%).The increase rate of greening to browning reversal is 0.0342/yr,which is apparently greater than that of greening with setback,0.0078/yr.This research highlights that,under the background of widespread vegetation greening,vegetation browning is pro-gressively increasing due to the effects of climate change.Furthermore,the ERPs have significantly increased vegetation coverage,with the increase rate in 2000-2022 being twice as much as that of 1982-1999 in reveg-etation regions.Vegetation browning in southwestern Qingzang Plateau is primarily driven by adverse climatic factors and anthropogenic disturbances,which offset the efforts of ERPs.展开更多
Background Necrotic enteritis(NE)is a major enteric disease in poultry,yet effective mitigation strategies remain elusive.Deoxycholic acid(DCA)and butyrate,two major metabolites derived from the intestinal microbiota,...Background Necrotic enteritis(NE)is a major enteric disease in poultry,yet effective mitigation strategies remain elusive.Deoxycholic acid(DCA)and butyrate,two major metabolites derived from the intestinal microbiota,have independently been shown to induce host defense peptide(HDP)synthesis.However,the potential synergy between these two compounds remains unexplored.Methods To investigate the possible synergistic effect between DCA and butyrate in regulating HDP synthesis and barrier function,we treated chicken HD11 macrophage cells and jejunal explants with DCA and sodium butyrate(NaB),either individually or in combination,for 24 h.Subsequently,we performed RNA isolation and reverse transcrip-tion-quantitative PCR to analyze HDP genes as well as the major genes associated with barrier function.To further determine the synergy between DCA and NaB in enhancing NE resistance,we conducted two independent trials with Cobb broiler chicks.In each trial,the diet was supplemented with DCA or NaB on the day-of-hatch,followed by NE induction through sequential challenges with Eimeria maxima and Clostridium perfringens on d 10 and 14,respectively.We recorded animal mortality after infection and assessed intestinal lesions on d 17.The impact of DCA and NaB on the microbiota in the ileum and cecum was evaluated through bacterial 16S rRNA gene sequencing.Results We found that the combination of DCA and NaB synergistically induced multiple HDP genes in both chicken HD11 cells and jejunal explants.Additionally,the gene for claudin-1,a major tight junction protein,also exhibited synergistic induction in response to DCA and NaB.Furthermore,dietary supplementation with a combination of 0.75 g/kg DCA and 1 g/kg NaB led to a significant improvement in animal survival and a reduction in intestinal lesions compared to either compound alone in a chicken model of NE.Notably,the cecal microbiota of NE-infected chickens showed a marked decrease in SCFA-producing bacteria such as Bacteroides,Faecalibacterium,and Cuneatibacter,with lactobacilli becoming the most dominant species.However,supplementation with DCA and NaB largely restored the intestinal microbiota to healthy levels.Conclusions DCA synergizes with NaB to induce HDP and claudin-1 expression and enhance NE resistance,with potential for further development as cost-effective antibiotic alternatives.展开更多
Background:Intestinal microbiota plays a key role in nutrient digestion and utilization with a profound impact on feed efficiency of livestock animals.However,the intestinal microbes that are critically involved in fe...Background:Intestinal microbiota plays a key role in nutrient digestion and utilization with a profound impact on feed efficiency of livestock animals.However,the intestinal microbes that are critically involved in feed efficiency remain elusive.Methods:To identify intestinal bacteria associated with residual feed intake(RFI)in chickens,male Cobb broiler chicks were individually housed from day 14 to day 35.Individual RFI values were calculated for 56 chickens.Luminal contents were collected from the ileum,cecum,and cloaca of each animal on day 35.Bacterial DNA was isolated and subjected to 16S rRNA gene sequencing.Intestinal microbiota was classified to the feature level using Deblur and QIIME 2.High and low RFI groups were formed by selecting 15 and 17 chickens with the most extreme RFI values for subsequent LEfSe comparison of the difference in the microbiota.Spearman correlation analysis was further performed to identify correlations between the intestinal microbiota composition and RFI.Results:No significant difference in evenness,richness,and overall diversity of the microbiota in the ileum,cecum,or cloaca was observed between high and low RFI chickens.However,LEfSe analysis revealed a number of bacterial features being differentially enriched in either high or low RFI chickens.Spearman correlation analysis further identified many differentially enriched bacterial features to be significantly correlated with RFI(P<0.05).Importantly,not all short-chain fatty acid(SCFA)producers showed a positive association with RFI.While two novel members of Oscillibacter and Butyricicoccus were more abundant in low-RFI,high-efficiency chickens,several other SCFA producers such as Subdoligranulum variabile and two related Peptostreptococcaceae members were negatively associated with feed efficiency.Moreover,a few closely-related Lachnospiraceae family members showed a positive correlation with feed efficiency,while others of the same family displayed an opposite relationship.Conclusions:Our results highlight the complexity of the intestinal microbiota and a need to differentiate the bacteria to the species,subspecies,and even strain levels in order to reveal their true association with feed efficiency.Identification of RFI-associated bacteria provides important leads to manipulate the intestinal microbiota for improving production efficiency,profitability,and sustainability of poultry production.展开更多
Background:The emergence of antimicrobial resistance has necessitated the development of effective alternatives to antibiotics for livestock and poultry production.This study investigated a possible synergy between bu...Background:The emergence of antimicrobial resistance has necessitated the development of effective alternatives to antibiotics for livestock and poultry production.This study investigated a possible synergy between butyrate and forskolin(a natural labdane diterpene)in enhancing innate host defense,barrier function,disease resistance,growth performance,and meat quality of broilers.Methods:The expressions of representative genes involved in host defense(AvBD9 and AvBD10),barrier function(MUC2,CLDN1,and TJP1),and inflammation(IL-1β)were measured in chicken HD11 macrophages in response to butyrate and forskolin in the presence or absence of bacterial lipopolysaccharides(LPS).Intestinal lesions and the Clostridium perfringens titers were also assessed in C.perfringens-challenged chickens fed butyrate and forskolincontaining Coleus forskohlii(CF)extract individually or in combination.Furthermore,growth performance and carcass characteristics were evaluated in broilers supplemented with butyrate and the CF extract for 42 d.Results:Butyrate and forskolin synergistically induced the expressions of AvBD9,AvBD10,and MUC2 in chicken HD11 cells(P<0.05)and the synergy was maintained in the presence of LPS.Butyrate and forskolin also suppressed LPS-induced IL-1βgene expression in HD11 cells in a synergistic manner(P<0.05).The two compounds significantly reduced the intestinal lesions of C.perfringens-challenged chickens when combined(P<0.05),but not individually.Furthermore,butyrate in combination with forskolin-containing CF extract had no influence on weight gain,but significantly reduced feed intake(P<0.05)with a strong tendency to improve feed efficiency(P=0.07)in a 42-d feeding trial.Desirably,the butyrate/forskolin combination significantly decreased abdominal fat deposition(P=0.01)with no impact on the carcass yield,breast meat color,drip loss,or pH of d-42 broilers.Conclusions:Butyrate and forskolin has potential to be developed as novel antibiotic alternatives to improve disease resistance,feed efficiency,and carcass composition of broilers.展开更多
Cathelicidins are a major family of antimicrobial peptides present in vertebrate animals with potent microbicidal and immunomodulatory activities. Four cathelicidins, namely fowlicidins 1 to 3 and cathelicidin B1, hav...Cathelicidins are a major family of antimicrobial peptides present in vertebrate animals with potent microbicidal and immunomodulatory activities. Four cathelicidins, namely fowlicidins 1 to 3 and cathelicidin B1, have been identified in chickens. As a first step to understand their role in early innate host defense of chickens, we examined the tissue and developmental expression patterns of all four cathelicidins. Real-time PCR revealed an abundant expression of four cathelicidins throughout the gastrointestinal, respiratory, and urogenital tracts as well as in all primary and secondary immune organs of chickens. Fowlicidins 1 to 3 exhibited a similar tissue expression pattern with the highest expression in the bone marrow and lung, while cathelicidin B1 was synthesized most abundantly in the bursa of Fabricius. Additionally, a tissue-specific regulatory pattern was evident for all four cathelicidins during the first 28 days after hatching. The expression of fowlicidins 1 to 3 showed an age-dependent increase both in the cecal tonsil and lung, whereas all four cathelicidins were peaked in the bursa on day 4 after hatching, with a gradual decline by day 28. An abrupt augmentation in the expression of fowlicidins 1 to 3 was also observed in the cecum on day 28, while the highest expression of cathelicidin B1 was seen in both the lung and cecal tonsil on day 14. Collectively, the presence of cathelicidins in a broad range of tissues and their largely enhanced expression during development are suggestive of their potential important role in early host defense and disease resistance of chickens.展开更多
Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are...Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are known for their broad-spectrum antimicrobial and immunomodulatory capabilities.Enhancing the synthesis of endogenous HDPs represents a promising antibiotic alternative strategy to disease control and prevention.Methods:To identify natural products with an ability to stimulate the synthesis of endogenous HDPs,we performed a high-throughput screening of 1261 natural products using a newly-established stable luciferase reporter cell line known as IPEC-J2/pBD3-luc.The ability of the hit compounds to induce HDP genes in porcine IPEC-J2 intestinal epithelial cells,3D4/31 macrophages,and jejunal explants were verified using RT-qPCR.Augmentation of the antibacterial activity of porcine 3D4/31 macrophages against a Gram-negative bacterium(enterotoxigenic E.coli)and a Gram-positive bacterium(Staphylococcus aureus)were further confirmed with four selected HDP-inducing compounds.Results:A total of 48 natural products with a minimum Z-score of 2.0 were identified after high-throughput screening,with 21 compounds giving at least 2-fold increase in luciferase activity in a follow-up dose-response experiment.Xanthohumol and deoxyshikonin were further found to be the most potent in inducing pBD3 mRNA expression,showing a minimum 10-fold increase in IPEC-J2,3D4/31 cells,and jejunal explants.Other compounds such as isorhapontigenin and calycosin also enhanced pBD3 mRNA expression by at least 10-fold in both IPEC-J2 cells and jejunal explants,but not 3D4/31 cells.In addition to pBD3,other porcine HDP genes such as pBD2,PG1-5,and pEP2C were induced to different magnitudes by xanthohumol,deoxyshikonin,isorhapontigenin,and calycosin,although clear gene-and cell type-specific patterns of regulation were observed.Desirably,these four compounds had a minimum effect on the expression of several representative inflammatory cytokine genes.Furthermore,when used at HDP-inducing concentrations,these compounds showed no obvious direct antibacterial activity,but significantly augmented the antibacterial activity of 3D4/31 macrophages(P<0.05)against both Gram-negative and Gram-positive bacteria.Conclusions:Our results indicate that these newly-identified natural HDP-inducing compounds have the potential to be developed as novel alternatives to antibiotics for prophylactic and therapeutic treatment of infectious diseases in livestock production.展开更多
Background:Intestinal microbiota is critical for maintaining animal health and homeostasis.However,involvement of the fungal community,also known as the mycobiota,in animal health and disease is poorly understood.This...Background:Intestinal microbiota is critical for maintaining animal health and homeostasis.However,involvement of the fungal community,also known as the mycobiota,in animal health and disease is poorly understood.This study was aimed to examine the association between the intestinal mycobiota and the severity of necrotic enteritis(NE),an economically significant poultry disease.Methods:A total of 90 day-of-hatch Cobb broilers were infected with Eimeria maxima on d 10,followed by an oral challenge with C.perfringens on d 14 to induce NE,while another 10 broilers were served as mock-infected controls.On d 17,the lesions in the jejunum were scored,and the ileal digesta were subjected to DNA isolation and real-time PCR quantification of total bacterial and fungi populations.Internal transcribed spacer 2(ITS2)amplicon sequencing was also performed to profile the ileal mycobiota composition.Changes in the ileal mycobiota in response to NE were investigated.Spearman correlation analysis was further conducted to identify the correlations between relative abundances of individual ileal fungi and the severity of NE.Results:While the total bacterial population in the ileum was increased by 2-to 3-fold in NE chickens,the total fungal population was progressively declined in more exacerbated NE,with the most severely infected chickens showing a nearly 50-fold reduction relative to mock-infected controls.Richness of the ileal mycobiota also tended to reduce in chickens with NE(P=0.06).Compositionally,among 30 most abundant fungal amplicon sequence variants(ASVs),11 were diminished and 7 were enriched(P<0.05),while 12 remained largely unchanged in NEafflicted chickens(P>0.05).Multiple Wallemia and Aspergillus species were markedly diminished in NE(P<0.05)and also showed a significant negative correlation with NE severity(P<0.05).Conclusions:Dysbiosis of the ileal mycobiota is induced evidently by NE and the extent of the dysbiosis is positively correlated with disease severity.These findings suggest a possible role of the intestinal mycobiota in NE pathogenesis and highlight the mycobiota as a new potential target for NE mitigation in poultry.展开更多
Background: The growth rate often varies among individual broilers of the same breed under a common management condition. To investigate whether a variation in the growth rate is associated with a difference in hormo...Background: The growth rate often varies among individual broilers of the same breed under a common management condition. To investigate whether a variation in the growth rate is associated with a difference in hormone levels and myogenic gene expression profile in broilers, a feeding trial was conducted with 10,000 newly hatched Ross 308 chicks in a commercial production facility under standard management. At 38 d of age,30 fast-, 30 medium-, and 30 slow-growing broilers were selected among 600 healthy male individuals. The levels of insulin-like growth factor-1(IGF-1), triiodothyronine(T3), thyroxine(T4), and growth hormone in the serum or breast muscle were assayed by ELISA or RIA kits, and the expression levels of several representative pro-and anti-myogenic genes in the breast muscle were also measured by real-time PCR.Results: Results showed that both absolute and relative weights of the breast muscle were in linear positive correlations with the body weight of broilers(P 〈 0.001). Fast-growing broilers had higher concentrations of IGF-1 than slow-growing broilers(P 〈 0.05) in both the serum and breast muscle. The serum concentration of T3 was significantly higher in fast-growing birds than in slow-growing birds(P 〈 0.05). However, no difference was observed in growth hormone or T4 concentration among three groups of birds. Additionally, a decreased expression of an anti-myogenic gene(myostatin) and increased expressions of pro-myogenic genes such as myogenic differentiation factor 1, myogenin, muscle regulatory factor 4, myogenic factor 5, IGF-1, and myocyte enhancer factor 2B, C, and D were observed in fast-growing broilers(P 〈 0.05), relative to slow-growing broilers.Conclusions: Collectively, these findings suggested that the growth rate is linked to the hormone and myogenic gene expression levels in broiler chickens. Some of these parameters such as serum concentrations of IGF-1 and T3 could be employed to breed for enhanced growth.展开更多
Acne conglobata(AC),perifolliculitis capitis abscedens et suffodiens(PCAS)and hidradenitis suppurativa(HS)are uncommon refractory chronic,inflammatory,scarring diseases but cause serious damage to the quality of life....Acne conglobata(AC),perifolliculitis capitis abscedens et suffodiens(PCAS)and hidradenitis suppurativa(HS)are uncommon refractory chronic,inflammatory,scarring diseases but cause serious damage to the quality of life.These three diseases are associated with follicular occlusion.Several studies indicated topical 5-aminolevulinic acid photodynamic therapy(ALA-PDT)improved follicular occlusion besides acne treatment.So we attempted to apply ALA-PDT to medicine resistant AC,PCAS and HS.Topical ALA-PDT was applied to 10 patients with AC,seven patients with PCAS and three patients with HS for more than three sessions.All the patients completed the dermatology life quality index(DLQI)questionnaire and were assessed for the efficacy at the baseline and on two weeks after each treatment.Adverse effects were recorded at each visit.The results showed 25.5%(5/20,two cases of AC and three cases of PCAS)of patients achieved excellent improvement after three sessions of PDT and another 60.0%(12/20,eight cases of AC and four cases of PCAS)of patients achieved good improvement.15.0%(3/20,three cases of HS)got poor response(<20%lesions clearance).Anotherfive cases(three cases of AC and two cases of PCAS)also achieved excellent response after 5–7 sessions of PDT.We also found that papular/nodular,cyst/abscess showed higher clearance rate than sinus/¯stula(88.5%,86.1%versus 11.1%).DLQI was reduced after three sessions of PDT in AC and PCAS patients rather than HS patients.5-ALA-PDT could improve refractory AC and PCAS but could not lead to improvement in late stage of HS.The e±cacy increased with more treatment sessions.展开更多
Under global warming, seasonal snow takes faster melting rate than before, which greatly changes the hydro-logical cycle. In this study, by targeting three typical seasonal snow-covered land types (i.e., open shrublan...Under global warming, seasonal snow takes faster melting rate than before, which greatly changes the hydro-logical cycle. In this study, by targeting three typical seasonal snow-covered land types (i.e., open shrubland,evergreen needleleaf forest and mixed forest) in the Northern Hemisphere, the start of growing season (SGS) hasbeen found obviously advanced in the past years, greatly contributed by the faster melting rate of seasonal snow.It is manifested that significantly positive correlation has been found between SGS and May snow depth for openshrubs, March and April snow depth for evergreen needleleaf forests and March snow depth for mixed forests.However, such close association is not appeared in all the climate conditions of same vegetation. In the future,as the rate of melting snow becomes faster in the high emission of greenhouse gasses than the current situation,continuously advanced SGS will accelerate the change of vegetation distribution in the Northern Hemisphere.These findings offer insights into understanding the effect from seasonal snow on vegetation and promote thesustainable utilization of regional vegetation in the Northern Hemisphere.展开更多
In a very shocking symbol, animation art leads us to the continuing social and philosophical problems. With its unique hypothetical language as the human spirit and emotional material carrier, animation art passes var...In a very shocking symbol, animation art leads us to the continuing social and philosophical problems. With its unique hypothetical language as the human spirit and emotional material carrier, animation art passes various social messages to people. The value of animation art lies in the certain form of expression to convey characteristics of the content and spirit, which is the core issues that Chinese animation industry worthy of attention and research. Animation art as a cultural transmission symbols, bears culture spreading. The combination of cultural heritage and the new animation language means is an important way for animation art to direct towards the life of road. At the same time, let the excellent national culture and art forms combine with modem advanced technology and make innovation and creativity. Only in this way can China's animation talent with a new, unique appearance presented to the audience and occupy an important seat in the world animation art.展开更多
Traditionally, antibiotics are included in animal feed at subtherapeutic levels for growth promotion and disease prevention.However, recent links between in-feed antibiotics and a rise in antibiotic-resistant pathogen...Traditionally, antibiotics are included in animal feed at subtherapeutic levels for growth promotion and disease prevention.However, recent links between in-feed antibiotics and a rise in antibiotic-resistant pathogens have led to a ban of all antibiotics in livestock production by the European Union in January 2006 and a removal of medically important antibiotics in animal feeds in the United States in January 2017.An urgent need arises for antibiotic alternatives capable of maintaining animal health and productivity without triggering antimicrobial resistance.Host defense peptides(HDP) are a critical component of the animal innate immune system with direct antimicrobial and immunomodulatory activities.While in-feed supplementation of recombinant or synthetic HDP appears to be effective in maintaining animal performance and alleviating clinical symptoms in the context of disease, dietary modulation of the synthesis of endogenous host defense peptides has emerged as a cost-effective,antibiotic-alternative approach to disease control and prevention.Several different classes of smallmolecule compounds have been found capable of promoting HDP synthesis.Among the most efficacious compounds are butyrate and vitamin D.Moreover, butyrate and vitamin D synergize with each other in enhancing HDP synthesis.This review will focus on the regulation of HDP synthesis by butyrate and vitamin D in humans, chickens, pigs, and cattle and argue for potential application of HDP-inducing compounds in antibiotic-free livestock production.展开更多
East Asian dust(EAD) exerts considerable impacts on the energy balance and climate/climate change of the earth system through its influence on solar and terrestrial radiation, cloud properties, and precipitation eff...East Asian dust(EAD) exerts considerable impacts on the energy balance and climate/climate change of the earth system through its influence on solar and terrestrial radiation, cloud properties, and precipitation efficiency. Providing an accurate description of the life cycle and climate effects of EAD is therefore critical to better understanding of climate change and socioeconomic development in East Asia and even worldwide. Dust modeling has undergone substantial development since the late 1990 s, associated with improved understanding of the role of EAD in the earth system. Here, we review the achievements and progress made in recent decades in terms of dust modeling research,including dust emissions, long-range transport, radiative forcing(RF), and climate effects of dust particles over East Asia. Numerous efforts in dust/EAD modeling have been directed towards furnishing more sophisticated physical and chemical processes into the models on higher spatial resolutions. Meanwhile, more systematic observations and more advanced retrieval methods for instruments that address EAD related science issues have made it possible to evaluate model results and quantify the role of EAD in the earth system, and to further reduce the uncertainties in EAD simulations. Though much progress has been made, large discrepancies and knowledge gaps still exist among EAD simulations. The deficiencies and limitations that pertain to the performance of the EAD simulations referred to in the present study are also discussed.展开更多
Extreme snow loads can collapse roofs.This load is calculated based on the ground snow load(that is,the snow water equivalent on the ground).However,snow water equivalent(SWE) measurements are unavailable for most sit...Extreme snow loads can collapse roofs.This load is calculated based on the ground snow load(that is,the snow water equivalent on the ground).However,snow water equivalent(SWE) measurements are unavailable for most sites,while the ground snow depth is frequently measured and recorded.A new simple practical algorithm was proposed in this study to evaluate the SWE by utilizing ground snow depth,precipitation data,wind speed,and air temperature.For the evaluation,the precipitation was clas sified as snowfall or rainfall according to the air temperature,the snowfall or rainfall was then corrected for measurement error that is mainly caused by wind-induced undercatch,and the effect of snow water loss was considered.The developed algorithm was applied and validated using data from57 meteorological stations located in the northeastern region of China.The annual maximum SWE obtained based on the proposed algorithm was compared with that obtained from the actual SWE measurements.The return period values of the annual maximum ground snow load were estimated and compared to those obtained according to the procedure suggested by the Chinese structural design code.The comparison indicated that the use of the proposed algorithm leads to a good estimated SWE or ground snow load.Its use allowed the estimation of the ground snow load for sites without SWE measurement and facilitated snow hazard mapping.展开更多
Summary What is already known about this topic?The association of diabetes mellitus(DM)with both increased risk of tuberculosis(TB)and unfavorable treatment outcomes has been identified by many studies(1).However,epid...Summary What is already known about this topic?The association of diabetes mellitus(DM)with both increased risk of tuberculosis(TB)and unfavorable treatment outcomes has been identified by many studies(1).However,epidemic data for TB cases in DM patients is absent in China.What is added by this report?This current population-based prospective cohort study,conducted in ten counties located in eastern,central,and western China during 2013–2015,revealed a high prevalence and incidence of TB in known DM patients.Most TB cases were captured by active case-finding and a much higher presence of being asymptomatic among TB/DM patients was obtained.What are the implications for public health practice?Active case-finding should be carried out in DM patients and populations at high risk for developing TB.A TB symptom screening-based case-finding strategy is not enough;chest radiography check should be done once a year for these patients.展开更多
基金supported by the National Natural Science Foundation of China(Grants No.41991231,42041004,and 41888101)the China University Research Talents Recruitment Program(111 project,Grant No.B13045).
文摘Vegetation greening has long been acknowledged,but recent studies have pointed out that vegetation greening is possibly stalled or even reversed.However,detailed analyses about greening reversal or increased browning of vegetation remain scarce.In this study,we utilized the normalized difference vegetation index(NDVI)as an indicator of vegetation to investigate the trends of vegetation greening and browning(monotonic,interruption,and reversal)through the breaks for the additive season and trend(BFAST)method across China’s drylands from 1982 to 2022.It also reveals the impacts of ecological restoration programs(ERPs)and climate change on these vegetation trends.We find that the vegetation displays an obvious pattern of east-greening and west-browning in China’s drylands.Greening trends mainly exhibits monotonic greening(29.8%)and greening with setback(36.8%),whereas browning shows a greening to browning reversal(19.2%).The increase rate of greening to browning reversal is 0.0342/yr,which is apparently greater than that of greening with setback,0.0078/yr.This research highlights that,under the background of widespread vegetation greening,vegetation browning is pro-gressively increasing due to the effects of climate change.Furthermore,the ERPs have significantly increased vegetation coverage,with the increase rate in 2000-2022 being twice as much as that of 1982-1999 in reveg-etation regions.Vegetation browning in southwestern Qingzang Plateau is primarily driven by adverse climatic factors and anthropogenic disturbances,which offset the efforts of ERPs.
基金supported by the USDA National Institute of Food and Agriculture grants (2020-67016-31619 and 2023-67015-39095)the Ralph F. and Leila W. Boulware Endowment Fund+1 种基金Oklahoma Agricultural Experiment Station Project H-3112supported by a USDA National Institute of Food and Agriculture Predoctoral Fellowship grant (2021-67034-35184)
文摘Background Necrotic enteritis(NE)is a major enteric disease in poultry,yet effective mitigation strategies remain elusive.Deoxycholic acid(DCA)and butyrate,two major metabolites derived from the intestinal microbiota,have independently been shown to induce host defense peptide(HDP)synthesis.However,the potential synergy between these two compounds remains unexplored.Methods To investigate the possible synergistic effect between DCA and butyrate in regulating HDP synthesis and barrier function,we treated chicken HD11 macrophage cells and jejunal explants with DCA and sodium butyrate(NaB),either individually or in combination,for 24 h.Subsequently,we performed RNA isolation and reverse transcrip-tion-quantitative PCR to analyze HDP genes as well as the major genes associated with barrier function.To further determine the synergy between DCA and NaB in enhancing NE resistance,we conducted two independent trials with Cobb broiler chicks.In each trial,the diet was supplemented with DCA or NaB on the day-of-hatch,followed by NE induction through sequential challenges with Eimeria maxima and Clostridium perfringens on d 10 and 14,respectively.We recorded animal mortality after infection and assessed intestinal lesions on d 17.The impact of DCA and NaB on the microbiota in the ileum and cecum was evaluated through bacterial 16S rRNA gene sequencing.Results We found that the combination of DCA and NaB synergistically induced multiple HDP genes in both chicken HD11 cells and jejunal explants.Additionally,the gene for claudin-1,a major tight junction protein,also exhibited synergistic induction in response to DCA and NaB.Furthermore,dietary supplementation with a combination of 0.75 g/kg DCA and 1 g/kg NaB led to a significant improvement in animal survival and a reduction in intestinal lesions compared to either compound alone in a chicken model of NE.Notably,the cecal microbiota of NE-infected chickens showed a marked decrease in SCFA-producing bacteria such as Bacteroides,Faecalibacterium,and Cuneatibacter,with lactobacilli becoming the most dominant species.However,supplementation with DCA and NaB largely restored the intestinal microbiota to healthy levels.Conclusions DCA synergizes with NaB to induce HDP and claudin-1 expression and enhance NE resistance,with potential for further development as cost-effective antibiotic alternatives.
基金This work was supported by the USDA National Institute of Food and Agriculture(grant no.2018-68003-27462)the Ralph F.and Leila W.Boulware Endowment Fund,and Oklahoma Agricultural Experiment Station Project H-3025K.A.R.was supported by a USDA-NIFA Predoctoral Fellowship grant(2018-67011-28041).
文摘Background:Intestinal microbiota plays a key role in nutrient digestion and utilization with a profound impact on feed efficiency of livestock animals.However,the intestinal microbes that are critically involved in feed efficiency remain elusive.Methods:To identify intestinal bacteria associated with residual feed intake(RFI)in chickens,male Cobb broiler chicks were individually housed from day 14 to day 35.Individual RFI values were calculated for 56 chickens.Luminal contents were collected from the ileum,cecum,and cloaca of each animal on day 35.Bacterial DNA was isolated and subjected to 16S rRNA gene sequencing.Intestinal microbiota was classified to the feature level using Deblur and QIIME 2.High and low RFI groups were formed by selecting 15 and 17 chickens with the most extreme RFI values for subsequent LEfSe comparison of the difference in the microbiota.Spearman correlation analysis was further performed to identify correlations between the intestinal microbiota composition and RFI.Results:No significant difference in evenness,richness,and overall diversity of the microbiota in the ileum,cecum,or cloaca was observed between high and low RFI chickens.However,LEfSe analysis revealed a number of bacterial features being differentially enriched in either high or low RFI chickens.Spearman correlation analysis further identified many differentially enriched bacterial features to be significantly correlated with RFI(P<0.05).Importantly,not all short-chain fatty acid(SCFA)producers showed a positive association with RFI.While two novel members of Oscillibacter and Butyricicoccus were more abundant in low-RFI,high-efficiency chickens,several other SCFA producers such as Subdoligranulum variabile and two related Peptostreptococcaceae members were negatively associated with feed efficiency.Moreover,a few closely-related Lachnospiraceae family members showed a positive correlation with feed efficiency,while others of the same family displayed an opposite relationship.Conclusions:Our results highlight the complexity of the intestinal microbiota and a need to differentiate the bacteria to the species,subspecies,and even strain levels in order to reveal their true association with feed efficiency.Identification of RFI-associated bacteria provides important leads to manipulate the intestinal microbiota for improving production efficiency,profitability,and sustainability of poultry production.
基金supported by the USDA National Institute of Food and Agriculture (grant no. 2018–68003-27462 and 2020–67016-31619)Oklahoma Center for the Advancement of Science and Technology (grant no. AR19–027)+2 种基金Boulware Endowment FundOklahoma Agricultural Experiment Station Project H-3112supported by the USDA-NIFA Predoctoral Fellowship grant 2018–67011-28041
文摘Background:The emergence of antimicrobial resistance has necessitated the development of effective alternatives to antibiotics for livestock and poultry production.This study investigated a possible synergy between butyrate and forskolin(a natural labdane diterpene)in enhancing innate host defense,barrier function,disease resistance,growth performance,and meat quality of broilers.Methods:The expressions of representative genes involved in host defense(AvBD9 and AvBD10),barrier function(MUC2,CLDN1,and TJP1),and inflammation(IL-1β)were measured in chicken HD11 macrophages in response to butyrate and forskolin in the presence or absence of bacterial lipopolysaccharides(LPS).Intestinal lesions and the Clostridium perfringens titers were also assessed in C.perfringens-challenged chickens fed butyrate and forskolincontaining Coleus forskohlii(CF)extract individually or in combination.Furthermore,growth performance and carcass characteristics were evaluated in broilers supplemented with butyrate and the CF extract for 42 d.Results:Butyrate and forskolin synergistically induced the expressions of AvBD9,AvBD10,and MUC2 in chicken HD11 cells(P<0.05)and the synergy was maintained in the presence of LPS.Butyrate and forskolin also suppressed LPS-induced IL-1βgene expression in HD11 cells in a synergistic manner(P<0.05).The two compounds significantly reduced the intestinal lesions of C.perfringens-challenged chickens when combined(P<0.05),but not individually.Furthermore,butyrate in combination with forskolin-containing CF extract had no influence on weight gain,but significantly reduced feed intake(P<0.05)with a strong tendency to improve feed efficiency(P=0.07)in a 42-d feeding trial.Desirably,the butyrate/forskolin combination significantly decreased abdominal fat deposition(P=0.01)with no impact on the carcass yield,breast meat color,drip loss,or pH of d-42 broilers.Conclusions:Butyrate and forskolin has potential to be developed as novel antibiotic alternatives to improve disease resistance,feed efficiency,and carcass composition of broilers.
基金supported by a United States Department of Agriculture grant2008-35204-04544Oklahoma Center for the Advancement of Science and Technology grants HR07-113, and AR07.2-087, and Oklahoma Agricultural Experiment Station project H-2811
文摘Cathelicidins are a major family of antimicrobial peptides present in vertebrate animals with potent microbicidal and immunomodulatory activities. Four cathelicidins, namely fowlicidins 1 to 3 and cathelicidin B1, have been identified in chickens. As a first step to understand their role in early innate host defense of chickens, we examined the tissue and developmental expression patterns of all four cathelicidins. Real-time PCR revealed an abundant expression of four cathelicidins throughout the gastrointestinal, respiratory, and urogenital tracts as well as in all primary and secondary immune organs of chickens. Fowlicidins 1 to 3 exhibited a similar tissue expression pattern with the highest expression in the bone marrow and lung, while cathelicidin B1 was synthesized most abundantly in the bursa of Fabricius. Additionally, a tissue-specific regulatory pattern was evident for all four cathelicidins during the first 28 days after hatching. The expression of fowlicidins 1 to 3 showed an age-dependent increase both in the cecal tonsil and lung, whereas all four cathelicidins were peaked in the bursa on day 4 after hatching, with a gradual decline by day 28. An abrupt augmentation in the expression of fowlicidins 1 to 3 was also observed in the cecum on day 28, while the highest expression of cathelicidin B1 was seen in both the lung and cecal tonsil on day 14. Collectively, the presence of cathelicidins in a broad range of tissues and their largely enhanced expression during development are suggestive of their potential important role in early host defense and disease resistance of chickens.
基金supported by the National Natural Science Foundation of China(31972576)the Beijing Natural Science Foundation(6202004)+2 种基金the Special Program on Science and Technology Innovation Capacity Building of BAAFS(KJCX20180414 and KJCX201914)the USDA National Institute of Food and Agriculture(2018-68003-27462 and 2018-33610-28252)the Oklahoma Center for the Advancement of Science and Technology(AR19-27)。
文摘Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are known for their broad-spectrum antimicrobial and immunomodulatory capabilities.Enhancing the synthesis of endogenous HDPs represents a promising antibiotic alternative strategy to disease control and prevention.Methods:To identify natural products with an ability to stimulate the synthesis of endogenous HDPs,we performed a high-throughput screening of 1261 natural products using a newly-established stable luciferase reporter cell line known as IPEC-J2/pBD3-luc.The ability of the hit compounds to induce HDP genes in porcine IPEC-J2 intestinal epithelial cells,3D4/31 macrophages,and jejunal explants were verified using RT-qPCR.Augmentation of the antibacterial activity of porcine 3D4/31 macrophages against a Gram-negative bacterium(enterotoxigenic E.coli)and a Gram-positive bacterium(Staphylococcus aureus)were further confirmed with four selected HDP-inducing compounds.Results:A total of 48 natural products with a minimum Z-score of 2.0 were identified after high-throughput screening,with 21 compounds giving at least 2-fold increase in luciferase activity in a follow-up dose-response experiment.Xanthohumol and deoxyshikonin were further found to be the most potent in inducing pBD3 mRNA expression,showing a minimum 10-fold increase in IPEC-J2,3D4/31 cells,and jejunal explants.Other compounds such as isorhapontigenin and calycosin also enhanced pBD3 mRNA expression by at least 10-fold in both IPEC-J2 cells and jejunal explants,but not 3D4/31 cells.In addition to pBD3,other porcine HDP genes such as pBD2,PG1-5,and pEP2C were induced to different magnitudes by xanthohumol,deoxyshikonin,isorhapontigenin,and calycosin,although clear gene-and cell type-specific patterns of regulation were observed.Desirably,these four compounds had a minimum effect on the expression of several representative inflammatory cytokine genes.Furthermore,when used at HDP-inducing concentrations,these compounds showed no obvious direct antibacterial activity,but significantly augmented the antibacterial activity of 3D4/31 macrophages(P<0.05)against both Gram-negative and Gram-positive bacteria.Conclusions:Our results indicate that these newly-identified natural HDP-inducing compounds have the potential to be developed as novel alternatives to antibiotics for prophylactic and therapeutic treatment of infectious diseases in livestock production.
基金supported by the USDA National Institute of Food and Agriculture (grant no. 2018–68003-27462 and 2018–67011-28041)the Ralph F. and Leila W. Boulware Endowment FundOklahoma Agricultural Experiment Station Project H-3112。
文摘Background:Intestinal microbiota is critical for maintaining animal health and homeostasis.However,involvement of the fungal community,also known as the mycobiota,in animal health and disease is poorly understood.This study was aimed to examine the association between the intestinal mycobiota and the severity of necrotic enteritis(NE),an economically significant poultry disease.Methods:A total of 90 day-of-hatch Cobb broilers were infected with Eimeria maxima on d 10,followed by an oral challenge with C.perfringens on d 14 to induce NE,while another 10 broilers were served as mock-infected controls.On d 17,the lesions in the jejunum were scored,and the ileal digesta were subjected to DNA isolation and real-time PCR quantification of total bacterial and fungi populations.Internal transcribed spacer 2(ITS2)amplicon sequencing was also performed to profile the ileal mycobiota composition.Changes in the ileal mycobiota in response to NE were investigated.Spearman correlation analysis was further conducted to identify the correlations between relative abundances of individual ileal fungi and the severity of NE.Results:While the total bacterial population in the ileum was increased by 2-to 3-fold in NE chickens,the total fungal population was progressively declined in more exacerbated NE,with the most severely infected chickens showing a nearly 50-fold reduction relative to mock-infected controls.Richness of the ileal mycobiota also tended to reduce in chickens with NE(P=0.06).Compositionally,among 30 most abundant fungal amplicon sequence variants(ASVs),11 were diminished and 7 were enriched(P<0.05),while 12 remained largely unchanged in NEafflicted chickens(P>0.05).Multiple Wallemia and Aspergillus species were markedly diminished in NE(P<0.05)and also showed a significant negative correlation with NE severity(P<0.05).Conclusions:Dysbiosis of the ileal mycobiota is induced evidently by NE and the extent of the dysbiosis is positively correlated with disease severity.These findings suggest a possible role of the intestinal mycobiota in NE pathogenesis and highlight the mycobiota as a new potential target for NE mitigation in poultry.
基金supported by the Special Fund for Public Projects of Zhejiang Province(2016C32073)International Cooperation Program of Zhejiang Academy of Agricultural Sciences
文摘Background: The growth rate often varies among individual broilers of the same breed under a common management condition. To investigate whether a variation in the growth rate is associated with a difference in hormone levels and myogenic gene expression profile in broilers, a feeding trial was conducted with 10,000 newly hatched Ross 308 chicks in a commercial production facility under standard management. At 38 d of age,30 fast-, 30 medium-, and 30 slow-growing broilers were selected among 600 healthy male individuals. The levels of insulin-like growth factor-1(IGF-1), triiodothyronine(T3), thyroxine(T4), and growth hormone in the serum or breast muscle were assayed by ELISA or RIA kits, and the expression levels of several representative pro-and anti-myogenic genes in the breast muscle were also measured by real-time PCR.Results: Results showed that both absolute and relative weights of the breast muscle were in linear positive correlations with the body weight of broilers(P 〈 0.001). Fast-growing broilers had higher concentrations of IGF-1 than slow-growing broilers(P 〈 0.05) in both the serum and breast muscle. The serum concentration of T3 was significantly higher in fast-growing birds than in slow-growing birds(P 〈 0.05). However, no difference was observed in growth hormone or T4 concentration among three groups of birds. Additionally, a decreased expression of an anti-myogenic gene(myostatin) and increased expressions of pro-myogenic genes such as myogenic differentiation factor 1, myogenin, muscle regulatory factor 4, myogenic factor 5, IGF-1, and myocyte enhancer factor 2B, C, and D were observed in fast-growing broilers(P 〈 0.05), relative to slow-growing broilers.Conclusions: Collectively, these findings suggested that the growth rate is linked to the hormone and myogenic gene expression levels in broiler chickens. Some of these parameters such as serum concentrations of IGF-1 and T3 could be employed to breed for enhanced growth.
基金This work was supported by grants from the National Natural Science Foundation of China (81402585)Advanced Suitable Technology Popularization Project of Shanghai Health System (2013SY007)the Natural Science Foundation of Shanghai Municipal Commission of Health and Family Planning (20144Y0216).
文摘Acne conglobata(AC),perifolliculitis capitis abscedens et suffodiens(PCAS)and hidradenitis suppurativa(HS)are uncommon refractory chronic,inflammatory,scarring diseases but cause serious damage to the quality of life.These three diseases are associated with follicular occlusion.Several studies indicated topical 5-aminolevulinic acid photodynamic therapy(ALA-PDT)improved follicular occlusion besides acne treatment.So we attempted to apply ALA-PDT to medicine resistant AC,PCAS and HS.Topical ALA-PDT was applied to 10 patients with AC,seven patients with PCAS and three patients with HS for more than three sessions.All the patients completed the dermatology life quality index(DLQI)questionnaire and were assessed for the efficacy at the baseline and on two weeks after each treatment.Adverse effects were recorded at each visit.The results showed 25.5%(5/20,two cases of AC and three cases of PCAS)of patients achieved excellent improvement after three sessions of PDT and another 60.0%(12/20,eight cases of AC and four cases of PCAS)of patients achieved good improvement.15.0%(3/20,three cases of HS)got poor response(<20%lesions clearance).Anotherfive cases(three cases of AC and two cases of PCAS)also achieved excellent response after 5–7 sessions of PDT.We also found that papular/nodular,cyst/abscess showed higher clearance rate than sinus/¯stula(88.5%,86.1%versus 11.1%).DLQI was reduced after three sessions of PDT in AC and PCAS patients rather than HS patients.5-ALA-PDT could improve refractory AC and PCAS but could not lead to improvement in late stage of HS.The e±cacy increased with more treatment sessions.
基金This work is supported by the National Natural Science Foundation of China(Grant No.42041004 and 41991231)the“Innovation Star”Project for Outstanding Postgraduates of Gansu Province(Grant No.2022CXZX-107)the Central Universities(Grant No.lzujbky-2019-kb30).
文摘Under global warming, seasonal snow takes faster melting rate than before, which greatly changes the hydro-logical cycle. In this study, by targeting three typical seasonal snow-covered land types (i.e., open shrubland,evergreen needleleaf forest and mixed forest) in the Northern Hemisphere, the start of growing season (SGS) hasbeen found obviously advanced in the past years, greatly contributed by the faster melting rate of seasonal snow.It is manifested that significantly positive correlation has been found between SGS and May snow depth for openshrubs, March and April snow depth for evergreen needleleaf forests and March snow depth for mixed forests.However, such close association is not appeared in all the climate conditions of same vegetation. In the future,as the rate of melting snow becomes faster in the high emission of greenhouse gasses than the current situation,continuously advanced SGS will accelerate the change of vegetation distribution in the Northern Hemisphere.These findings offer insights into understanding the effect from seasonal snow on vegetation and promote thesustainable utilization of regional vegetation in the Northern Hemisphere.
文摘In a very shocking symbol, animation art leads us to the continuing social and philosophical problems. With its unique hypothetical language as the human spirit and emotional material carrier, animation art passes various social messages to people. The value of animation art lies in the certain form of expression to convey characteristics of the content and spirit, which is the core issues that Chinese animation industry worthy of attention and research. Animation art as a cultural transmission symbols, bears culture spreading. The combination of cultural heritage and the new animation language means is an important way for animation art to direct towards the life of road. At the same time, let the excellent national culture and art forms combine with modem advanced technology and make innovation and creativity. Only in this way can China's animation talent with a new, unique appearance presented to the audience and occupy an important seat in the world animation art.
基金supported in part by Oklahoma Center for the Advancement of Science and Technology grants(AR12.2-077,HR12-051,and AR15.049)Oklahoma Agricultural Experiment Station Project(H-3025)+1 种基金National Science Foundation of China grant(31528018)supported by a USDA-NIFA National Needs Fellowship grant(2013-38420-20500)
文摘Traditionally, antibiotics are included in animal feed at subtherapeutic levels for growth promotion and disease prevention.However, recent links between in-feed antibiotics and a rise in antibiotic-resistant pathogens have led to a ban of all antibiotics in livestock production by the European Union in January 2006 and a removal of medically important antibiotics in animal feeds in the United States in January 2017.An urgent need arises for antibiotic alternatives capable of maintaining animal health and productivity without triggering antimicrobial resistance.Host defense peptides(HDP) are a critical component of the animal innate immune system with direct antimicrobial and immunomodulatory activities.While in-feed supplementation of recombinant or synthetic HDP appears to be effective in maintaining animal performance and alleviating clinical symptoms in the context of disease, dietary modulation of the synthesis of endogenous host defense peptides has emerged as a cost-effective,antibiotic-alternative approach to disease control and prevention.Several different classes of smallmolecule compounds have been found capable of promoting HDP synthesis.Among the most efficacious compounds are butyrate and vitamin D.Moreover, butyrate and vitamin D synergize with each other in enhancing HDP synthesis.This review will focus on the regulation of HDP synthesis by butyrate and vitamin D in humans, chickens, pigs, and cattle and argue for potential application of HDP-inducing compounds in antibiotic-free livestock production.
基金National Natural Science Foundation of China(41405003 and 41521004)supported by the Office of Science,U.S.Department of Energy(DOE),as part of its Regional and Global Climate Modeling ProgramThe Pacific Northwest National Laboratory is operated for the DOE by the Battelle Memorial Institute under contract DE-AC05-76RL01830
文摘East Asian dust(EAD) exerts considerable impacts on the energy balance and climate/climate change of the earth system through its influence on solar and terrestrial radiation, cloud properties, and precipitation efficiency. Providing an accurate description of the life cycle and climate effects of EAD is therefore critical to better understanding of climate change and socioeconomic development in East Asia and even worldwide. Dust modeling has undergone substantial development since the late 1990 s, associated with improved understanding of the role of EAD in the earth system. Here, we review the achievements and progress made in recent decades in terms of dust modeling research,including dust emissions, long-range transport, radiative forcing(RF), and climate effects of dust particles over East Asia. Numerous efforts in dust/EAD modeling have been directed towards furnishing more sophisticated physical and chemical processes into the models on higher spatial resolutions. Meanwhile, more systematic observations and more advanced retrieval methods for instruments that address EAD related science issues have made it possible to evaluate model results and quantify the role of EAD in the earth system, and to further reduce the uncertainties in EAD simulations. Though much progress has been made, large discrepancies and knowledge gaps still exist among EAD simulations. The deficiencies and limitations that pertain to the performance of the EAD simulations referred to in the present study are also discussed.
基金Financial support from the National Natural Science Foundation of China(Grant Nos.51808169 and 51927813)the Fundamental Research Funds for the Central Universities(Grant No.HIT.NSRIF.2020083)are gratefully acknowledged.
文摘Extreme snow loads can collapse roofs.This load is calculated based on the ground snow load(that is,the snow water equivalent on the ground).However,snow water equivalent(SWE) measurements are unavailable for most sites,while the ground snow depth is frequently measured and recorded.A new simple practical algorithm was proposed in this study to evaluate the SWE by utilizing ground snow depth,precipitation data,wind speed,and air temperature.For the evaluation,the precipitation was clas sified as snowfall or rainfall according to the air temperature,the snowfall or rainfall was then corrected for measurement error that is mainly caused by wind-induced undercatch,and the effect of snow water loss was considered.The developed algorithm was applied and validated using data from57 meteorological stations located in the northeastern region of China.The annual maximum SWE obtained based on the proposed algorithm was compared with that obtained from the actual SWE measurements.The return period values of the annual maximum ground snow load were estimated and compared to those obtained according to the procedure suggested by the Chinese structural design code.The comparison indicated that the use of the proposed algorithm leads to a good estimated SWE or ground snow load.Its use allowed the estimation of the ground snow load for sites without SWE measurement and facilitated snow hazard mapping.
基金Supported by the National Twelfth Five-Year Mega-Scientific Projects of Infectious Diseases in China(Grant Number 2013ZX10003-004-001).
文摘Summary What is already known about this topic?The association of diabetes mellitus(DM)with both increased risk of tuberculosis(TB)and unfavorable treatment outcomes has been identified by many studies(1).However,epidemic data for TB cases in DM patients is absent in China.What is added by this report?This current population-based prospective cohort study,conducted in ten counties located in eastern,central,and western China during 2013–2015,revealed a high prevalence and incidence of TB in known DM patients.Most TB cases were captured by active case-finding and a much higher presence of being asymptomatic among TB/DM patients was obtained.What are the implications for public health practice?Active case-finding should be carried out in DM patients and populations at high risk for developing TB.A TB symptom screening-based case-finding strategy is not enough;chest radiography check should be done once a year for these patients.