Dynamic Evolution and Correlation between Metabolites and Microorganisms during Manufacturing Process and Storage of Fu Brick Tea

Fu brick tea (FBT) is one of the major brands of dark tea. Microbial fermentation is considered the key step in the development of the special characteristics of FBT. The systemic corelationship of the microbiome and metabolomics during manufacture of Fu brick tea is not fully understood. In this study, we comprehensively explored the microbiome and metabolite dynamic evolution during the FBT manufacturing processes, and revealed decisive factors for the quality and safety of FBT based on the grouped methods of metabolomics combined with biochemical measurements, microbiome sequencing combined with quantitative polymerase chain reaction (PCR), and multiplex analysis. Both the microbiome and quantitative PCR showed that fungi displayed concentrated distribution characteristics in the primary dark tea samples, while bacterial richness increased during the flowering processes and ripening period. All microorganism species, as well as dominant fungi and bacteria, were identified in the distinct processes periods. A total of 178 metabolites were identified, and 34 of them were characterized as critical metabolites responsible for metabolic changes caused by the corresponding processes. Metabolic analysis showed that most metabolites were decreased during the FBT manufacturing processes, with the exception of gallic acid. Multivariate analysis verified that the critical metabolites were correlated with specific dominant microbial species. All the top fungal species except unclassified_g_ Aspergillus showed positive correlations with six critical metabolites (L-The, epigallocatechin (EGC), Gln, tea polyphenol (TP), tea polysaccharides (TPs) and caffeine). Five of the top bacteria species (Cronobacter, Klebsiella, Pantoea, Pluralibacter, and unclassified_ f_Entero-bacteriaceae) showed positive correlations with epigallocatechins and tea polyphenols, while the other 11 top bacterial species correlated negatively with all the critical metabolites. The content of amino acids, tea polyphenols, tea polysaccharides, and flavonoids was reduced during microbial fermentation. In conclusion, our results reveal that microbial composition is the critical factor in changing the metabolic profile of FBT. This discovery provides a theoretical basis for improving the quality of FBT and enhancing its safety

Coal dust explosibility meter evaluation and recommendations for application

"This report details the results of a NIOSH investigation on the ability of the Coal Dust Explosibility Meter (CDEM) to accurately predict the explosibility of samples of coal and rock dust mixtures collected from underground coal mines in the U.S. The CDEM, which gives instantaneous results in real time, represents a new way for miners and operators to assess the relative hazard of dust accumulations in their mines and the effectiveness of their rock dusting practices. The CDEM was developed by the National Institute for Occupational Safety and Health (NIOSH) and successfully underwent national and international peer review. The intention of the device is to assist mine operators in complying with the Mine Safety and Health Administration (MSHA) final rule 30 CFR* 75.403, requiring that the incombustible content of combined coal dust, rock dust, and other dust be at least 80% in underground areas of bituminous coal mines. As a final step towards commercialization of the CDEM, and to evaluate the performance of the device as a potential compliance tool, NIOSH undertook an extensive cooperative study with MSHA. This study, completed in 2009-2010, involved field use of the CDEM within MSHA's 10 bituminous coal districts. As part of their routine dust compliance surveys in these districts, MSHA inspectors collected sample coal and rock dust mixtures, field testing these samples for explosibility with the CDEM. Samples were then sent to the MSHA National Air and Dust Laboratory at Mt. Hope, WV, for parallel testing, first using a drying oven to determine the moisture followed by the traditional low temperature ashing (LTA) method. The LTA method determines explosibility of a coal and rock dust sample in a laboratory by heating the mixture to burn off the combustible material. The results, when combined with the moisture, are reported as total incombustible content (TIC). If the TIC is . 80%, the sample is deemed to be nonexplosible and compliant with 30 CFR 75.403. In the field component of this study, MSHA's use of the CDEM indicated that 30% (175) of the 591 samples collected were explosible. NIOSH was able to obtain and remeasure 297 samples, and 97% of those identified by the CDEM as being explosible (27% of samples) or nonexplosible (73% of samples) correlated with the results of the subsequent lab analysis using the LTA method. Of the remaining 3% where there were differences between the field and laboratory methods, subsequent NIOSH evaluation attributed these differences to the variability (incomplete mixing, inadequate drying of the sample, the particle size of the rock dust and/or coal dust) of the samples being analyzed, the retained moisture in those samples, and the inherent ash in the coal. In considering these results and comparing the CDEM field measurements to the LTA laboratory measurements, it is important to understand the fundamental distinctions between the two methods. The determination of TIC by the LTA method is not itself a direct measure of explosibility, but a surrogate that calculates a single parameter associated with full-scale experimental results. This method is not based on particle size and treats all particles equally regardless of the size. In contrast, the CDEM utilizes a different approach, using optical reflectance to determine the ratio of rock dust to coal dust in a mixture, with full-scale experiments on flame propagation having already demonstrated the effects of varying the coal dust particle sizes and incombustible concentrations on the explosible vs. nonexplosible dust mixtures. A final important distinction between the two methods is that the CDEM offers real-time measurements of the explosion propagation hazard within a coal mine entry, allowing for immediate identification and mitigation of the problem, while the results from the traditional LTA method are not known for days or weeks after a sample is collected, allowing for the deficiency in rock dust to continue. The conclusions of this study strongly support the field use of the CDEM to measure the explosibility of coal and rock dust mixtures, to more effectively improve the onsite adequacy of rock dusting for explosion prevention. Mine operators could use the CDEM on a regular basis to ensure that their rock dusting practices are achieving inertization requirements and meeting the intent of 30 CFR 75.403. MSHA inspectors could use the CDEM as a tool to immediately identify onsite explosibility hazards and initiate corrective action. A critical issue to both the LTA and the CDEM analysis methods is that the results are dependent on representative samples being collected for analysis." - NIOSHTIC-2Executive summary -- Introduction -- Background on coal dust and explosibility testing -- CDEM 0peration -- Comparison of laboratory results and CDEM results -- Joint study between NIOSH and MSHA -- Results and discussion -- GREEN measurements -- RED/YELLOW measurements -- Conclusions from the NIOSH study -- Commercial CDEM development -- Calibration and programming of the commercial CDEM -- Commercial CDEM changes based on potential customer concerns -- The Commercial CDEM as a verification and compliance tool -- NIOSH recommendations -- Acknowledgments -- References -- APPENDIX A: CDEM design -- APPENDIX B: CDEM training -- APPENDIX C: Prototype CDEM calibration and testing procedures used in the joint study -- APPENDIX D: Particle size effect -- APPENDIX E: MSHA inspector questions and commentsMarcia L. Harris, Michael J. Sapko, Floyd D. Varley, and Eric S. Weiss"August 2012."Also available via the World Wide Web.Includes bibliographical references (p. 25-26)

Simulating `Complex' Problems with Quantum Monte Carlo

We present a new quantum Monte Carlo algorithm suitable for generically complex problems, such as systems coupled to external magnetic fields or anyons in two spatial dimensions. We find that the choice of gauge plays a nontrivial role, and can be used to reduce statistical noise in the simulation. Furthermore, it is found that noise can be greatly reduced by approximate cancellations between the phases of the (gauge dependent) statistical flux and the external magnetic flux.Comment: Revtex, 11 pages. 3 postscript files for figures attache

Critical Exponents for Three-Dimensional Superfluid--Bose-Glass Phase Transition

The critical phenomenon of the zero temperature superfluid--Bose-glass phase transition for hard-core bosons on a three-dimensional disordered lattice is studied using a quantum real-space renormalization-group method. The correlation-length exponent $\nu$ and the dynamic exponent z are computed. The critical exponent z is found to be 2.5 for compressible states and 1.3 for incompressible states. The exponent $\nu$ is shown to be insensitive to z as that in the two-dimensional case, and has value roughly equal to 1.Comment: 11 pages, REVTE

Research Progress on Inhibition of Recrystallization of Ice Cream Crystals

Ice cream has the characteristic of thermodynamic instability. During processing, storage, transportation, and sales, temperature fluctuations cause recrystallization of ice crystals and then increase the average size of ice crystals, which leads to rough texture and poor taste of ice cream. Therefore, inhibiting the recrystallization of ice crystals in ice cream is the key to ensure the quality of ice cream. This paper reviews the formation mechanism and research progress of supercooling, nucleation, growth and recrystallization of ice crystals during freezing. The inhibitory effects of emulsifiers, stabilizers, sweeteners, and proteins in ice cream raw materials on ice crystal recrystallization are introduced in detail. Meanwhile, it also list the contents of freezing technologies such as ultrasonic assisted freezing, magnetic field assisted freezing, high-pressure assisted freezing, and electric field assisted freezing to inhibit ice cream recrystallization. The development direction of that is prospected, which provides a theoretical reference for adapting to the trend of online sales, developing new ice cream products and solving the problem of its crystal recrystallization

A Gaussian Theory of Superfluid--Bose-Glass Phase Transition

We show that gaussian quantum fluctuations, even if infinitesimal, are sufficient to destroy the superfluidity of a disordered boson system in 1D and 2D. The critical disorder is thus finite no matter how small the repulsion is between particles. Within the gaussian approximation, we study the nature of the elementary excitations, including their density of states and mobility edge transition. We give the gaussian exponent $\eta$ at criticality in 1D and show that its ratio to $\eta$ of the pure system is universal.Comment: Revtex 3.0, 11 pages (4 figures will be sent through airmail upon request

Transcriptome and functional analysis revealed the intervention of brassinosteroid in regulation of cold induced early flowering in tobacco

Cold environmental conditions may often lead to the early flowering of plants, and the mechanism by cold-induced flowering remains poorly understood. Microscopy analysis in this study demonstrated that cold conditioning led to early flower bud differentiation in two tobacco strains and an Agilent Tobacco Gene Expression microarray was adapted for transcriptomic analysis on the stem tips of cold treated tobacco to gain insight into the molecular process underlying flowering in tobacco. The transcriptomic analysis showed that cold treatment of two flue-cured tobacco varieties (Xingyan 1 and YunYan 85) yielded 4176 and 5773 genes that were differentially expressed, respectively, with 2623 being commonly detected. Functional distribution revealed that the differentially expressed genes (DEGs) were mainly enriched in protein metabolism, RNA, stress, transport, and secondary metabolism. Genes involved in secondary metabolism, cell wall, and redox were nearly all up-regulated in response to the cold conditioning. Further analysis demonstrated that the central genes related to brassinosteroid biosynthetic pathway, circadian system, and flowering pathway were significantly enhanced in the cold treated tobacco. Phytochemical measurement and qRT-PCR revealed an increased accumulation of brassinolide and a decreased expression of the flowering locus c gene. Furthermore, we found that overexpression of NtBRI1 could induce early flowering in tobacco under normal condition. And low-temperature-induced early flowering in NtBRI1 overexpression plants were similar to that of normal condition. Consistently, low-temperature-induced early flowering is partially suppressed in NtBRI1 mutant. Together, the results suggest that cold could induce early flowering of tobacco by activating brassinosteroid signaling