Niacin alters the ruminal microbial composition of cattle under high-concentrate condition

To understand the effects of niacin on the ruminal microbial ecology of cattle under high-concentrate diet condition, Illumina MiSeq sequencing technology was used. Three cattle with rumen cannula were used in a 3 x 3 Latin-square design trial. Three diets were fed to these cattle during 3 periods for 3 days, respectively: high-forage diet(HF; forage-to-concentrate ratio = 80:20), high-concentrate diet(HC;forage-to-concentrate ratio=20:80), and HC supplemented with 800 mg/kg niacin(HCN). Ruminal pH was measured before feeding and every 2 h after initiating feeding. Ruminal fluid was sampled at the end of each period for microbial DNA extraction. Overall, our findings revealed that subacute ruminal acidosis(SARA) was induced and the a-diversity of ruminal bacterial community decreased in the cattle of HC group. Adding niacin in HC could relieve the symptoms of SARA in the cattle but the ruminal pH value and the Shannon index of ruminal bacterial community of HCN group were still lower than those of HF group. Whatever the diet was, the ruminal bacterial community of cattle was dominated by Bacteroidetes,Firmicutes and Proteobacteria. High-concentrate diet significantly increased the abundance of Prevotella,and decreased the abundance of Paraprevotella, Sporobacter, Ruminococcus and Treponema than HF.Compared with HC, HCN had a trend to decrease the percentage of Prevotella, and to increase the abundance of Succiniclasticum, Acetivibrio and Treponema. Increasing concentrate ratio could decrease ruminal pH value, and change the ruminal microbial composition. Adding niacin in HC could increase the ruminal pH value, alter the ruminal microbial composition.

NICFS:a file system based on persistent memory and SmartNIC

Emergence of new hardware,including persistent memory and smart network interface card(SmartNIC),has brought new opportunities to file system design.In this paper,we design and implement a new file system named NICFS based on persistent memory and SmartNIC.We divide the file system into two parts:the front end and the back end.In the front end,data writes are appended to the persistent memory in a log-structured way,leveraging the fast persistence advantage of persistent memory.In the back end,the data in logs are fetched,processed,and patched to files in the background,leveraging the processing capacity of SmartNIC.Evaluation results show that NICFS outperforms Ext4 by about 21%/10%and about 19%/50%on large and small reads/writes,respectively.

Insight analysis of the cross-sensitization of multiple fish parvalbumins via the Th1/Th2 immunological balance and cytokine release from the perspective of safe consumption of fish

Objectives:Parvalbumin(PV)is the primary allergen found in fish and is highly conserved.According to some studies,some patients with fish allergy are allergic to only one species of fish but are tolerant to others;however,the underlying mechanism has not been identified.Materials and Methods:The cross-reactivity of these seven fish parvalbumins based on turbot PV-treated mice was determined using BALB/c mouse and RBL-2H3 cell models.Meanwhile,immunoinformatic tools were used to assess cross-reactivity.Results:The results indicated that the seven species of fishes(turbot,large yellow croaker,sea bass,grass carp,common carp,conger eel and Japanese eel)studied exhibited varying degrees of cross-reactivity,with the highest cross-reactivity being between turbot and bass and the lowest being between turbot and conger eel.The bioinformatics analysis revealed that the sequence homology of parvalbumin between conger eel and turbot was the lowest,which may account for the conger eel and turbot cross-reaction being so limited.Parvalbumin was a potent cross-reactive allergen found in turbot,large yellow croaker,sea bass,grass carp,common carp,conger eel and Japanese eel,and the cross-reactivity between conger eel and turbot parvalbumin was the weakest.Conclusion:This study demonstrated that the cross-reactivity between conger eel PV and turbot PV was the weakest.

Relationship between physicochemical properties and microbial structural distribution of Chinese-style and Salami fermented sausages

This study insightfully analyzed the relationship between chemical composition change,volatile flavor compounds(VFCs)and microbial structural distribution of Chinese-style(CFS)and Salami fermented sausages(WFS)during their fermentation processes(FP).The results showed pH,acid and peroxide values of CFS were higher than WFS during whole FP(38 d).At the end of fermentation(38 days),the pH value of CFS and WFS were 5.70±0.01 and 5.43±0.01,respectively.The acid value was 9.89±0.38 and 6.29±0.28 mg/g,respectively.The peroxide value was 0.21±0.01 and 0.14±0.01 g/100g,respectively.During 0-13 d,moisture contents of CFS were higher than WFS,while opposite in 14-38 d.Nitrite contents of WFS were higher than CFS.The total free-amino acid contents of CFS were significantly lower than WFS(p<0.05).The six groups of main VFCs in the two sausages were aldehydes,acids,alcohols,esters,ketones and hydrocarbons,respectively,and the contents of ketone in CFS were higher than WFS.However,the bacterial abundance in CFS increased gradually,while that in WFS’s increased firstly and then decreased.The abundances and diversities of fungi in WFS were higher than CFS.In brief,microbial structural distribution formed an obvious impact on the chemical composition quality of fermented sausages,the above results provided data support for the production improvement of Chinese-style and Salami fermented sausages.