Microbial shelf life of chub-packaged ground beef from four large U.S. processing plants

Ten pound chubs of coarsely ground beef of two different lean:fat specifications (73:27 and 81:19) were stored at three temperatures (34, 38 or 45 ÌŠF) to monitor the effects of storage temperature on microbial condition of the product. Ground beef from four U.S. plants was tested (2 trials each), and microbial analyses were conducted on storage days 0, 6, 10, 14, and 18 using seven different media to estimate counts of total aerobic and anaerobic, lactic acid bacteria (LAB), and Gram-negative bacteria. Bacterial counts for a given culture medium were similar among plants and meat types. At day 10, total mi crobial counts from chubs stored at 38 or 45 ÌŠF were approximately 8 log10 CFU/g, whereas total counts from chubs stored at 34 ÌŠF were approximately 4.5 log 10 CFU/g (4 log=10,000, CFU is colony forming units). Regardless of storage temperature and meat type, LAB predominated. Growth of gram-negative enteric bacteria was delayed in chubs stored at 34 ÌŠF throughout the 18 day study, whereas counts increased in chubs stored at 38 or 45 ÌŠ F

Performance of CFRP strengthened concrete beam subjected to cyclic temperature

The use of Carbon Fiber Reinforced Polymers (CFRP) for strengthening of structurally deficient reinforced concrete structures is widely gaining appeal. There are many applications in outdoor structures such as bridges. These structures are directly exposed to the environment. Epoxy adhesive used to create the bond between CFRP and concrete is very sensitive to the elevated temperature. It is important to explore the behavior of CFRP strengthened concrete structures under long term exposure to cyclic temperature because of the direct exposure of these structures even for the daily temperature fluctuations. A numerical model was developed to simulate the behavior of CFRP strengthened concrete beam subjected to four point bending. Initially, the composite beam was analysed to evaluate the short term performance and validated with experimental results. Then, the simulations were extended to determine the deterioration of load bearing capacity of the beam under long term exposure to cyclic temperature

Microbial shelf life of chub-packaged ground beef from four large U.S. processing plants

Ten pound chubs of coarsely ground beef of two different lean:fat specifications (73:27 and 81:19) were stored at three temperatures (34, 38 or 45 ̊F) to monitor the effects of storage temperature on microbial condition of the product. Ground beef from four U.S. plants was tested (2 trials each), and microbial analyses were conducted on storage days 0, 6, 10, 14, and 18 using seven different media to estimate counts of total aerobic and anaerobic, lactic acid bacteria (LAB), and Gram-negative bacteria. Bacterial counts for a given culture medium were similar among plants and meat types. At day 10, total mi crobial counts from chubs stored at 38 or 45 ̊F were approximately 8 log10 CFU/g, whereas total counts from chubs stored at 34 ̊F were approximately 4.5 log 10 CFU/g (4 log=10,000, CFU is colony forming units). Regardless of storage temperature and meat type, LAB predominated. Growth of gram-negative enteric bacteria was delayed in chubs stored at 34 ̊F throughout the 18 day study, whereas counts increased in chubs stored at 38 or 45 ̊ F

Protonation-dependent sequencing of 5-formylcytidine in RNA.

Chemical modification of cytidine in non-coding RNAs plays a key role in regulating translation and disease. However, the distribution and dynamics of many of these modifications remains unknown due to a lack of sensitive site-specific sequencing technologies. Here we report a protonation-dependent sequencing reaction for detection of 5-formylcytidine (5fC) and 5-carboxycytidine (5caC) in RNA. First, we evaluate how protonation combined with electron withdrawing substituents alters the molecular orbital energies and reduction of modified cytidine nucleosides, highlighting 5fC and 5caC as reactive species. Next, we apply this reaction to detect these modifications in synthetic oligonucleotides as well as endogenous human tRNA. Finally, we demonstrate the utility of our method to characterize a patient-derived model of 5fC-deficiency, where it enables facile monitoring of both pathogenic loss and exogenous rescue of NSUN3-dependent 5fC within the wobble base of human mitochondrial tRNAMet . These studies showcase the ability of protonation to enhance the reactivity and sensitive detection of 5fC in RNA, and provide a molecular foundation for applying optimized sequencing reactions to better understand the role of oxidized RNA cytidine nucleobases in disease