Effect of Extraction Method and Solvent Power on Polyphenol and Flavonoid Levels in Hyphaene Thebaica L Mart (Arecaceae) (Doum) Fruit, and its Antioxidant and Antibacterial Activities

Purpose: To evaluate the influence of extraction method and solvent type on extractable polyphenols and flavonoids in Doum Hyphaene Thebaica L. Mart. (Arecaceae) fruit, as well as to examine the antioxidant and antibacterial activities of the fruit extracts.Methods: The extraction procedures were performed separately in an ultrasonic bath or shaking water bath for 30 min (70 °C for ethanol and 60 °C for methanol) at agitation speed of 50 Hz and 70 rpm, respectively. The antioxidant potential of the extracts was investigated using â-carotene bleaching, 2,2- diphenylpicrylhydrazyl (DPPH) and reducing power ability assays. In vitro antibacterial activity of the extracts against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella typhi was assessed using agar disc diffusion assay.Results: Total polyphenol content (TPC) and total flavonoid content (TFC), as well as antioxidant capacity were maximized using methanol as the extraction solvent, particularly with the ultrasonic method. The half  maximal inhibitory concentration (IC50) values of the methanol/ultrasonic (MU), methanol/water bath (MW), ethanol/ultrasonic (EU), and   ethanol/water bath (EW) extracts in the DPPH assay were 107.6 126.7, 172.7, and 196.3 ìg/mL, respectively. The extracts showed strong antibacterial activity against Staphylococcus aureus and Salmonella typhi, while MU extract inhibited the growth of all pathogenic bacteria used in this study.Conclusion: The antioxidant and antibacterial activities of Doum fruit extracts are significantly affected by the type of extracting solvent and equipment used. The findings further demonstrate that MU extract had stronger antioxidant and antibacterial activity than the other extracts.Keywords: Doum fruit, Hyphaene thebaica, Ultrasonic extraction, Antioxidant, Phenolic, Flavonoid, Antibacteria

Identification of soil heavy metal sources and improvement in spatial mapping based on soil spectral information: A case study in northwest China

In a sewage irrigation area of northwest China, 52 topsoil samples were collected to measure the contents of arsenic (As), chromium (Cr), copper (Cu), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn). To identify their sources, multivariate statistics and geostatistics were applied to separate pedogenic elements (As and Mn) from anthropogenic elements (Cr, Cu, Hg, Ni, Pb and Zn). The accumulation of soil Hg was mainly attributed to long-term sewage irrigation, whereas Cr, Ni and Zn were mainly from industrial activities and dust deposition. In addition to the impacts of industry and dust, traffic-related factors were the main sources of Pb and Cu contamination. Based on the relationships of heavy metals with various soil properties and reflectance spectra, co-kriging (CK) was used to improve the interpolation of heavy metals. Comparatively, soil spectra were more suitable as covariates due to their ease and low-cost of collecting as features.</p

iDO: Compiler-Directed Failure Atomicity for Nonvolatile Memory

This paper presents iDO, a compiler-directed approach to failure atomicity with nonvolatile memory. Unlike most prior work, which instruments each store of persistent data for redo or undo logging, the iDO compiler identifies idempotent instruction sequences, whose re-execution is guaranteed to be side-effect-free, thereby eliminating the need to log every persistent store. Using an extension of prior work on JUSTDO logging, the compiler then arranges, during recovery from failure, to back up each thread to the beginning of the current idempotent region and re-execute to the end of the current failure-Atomic section. This extension transforms JUSTDO logging from a technique of value only on hypothetical future machines with nonvolatile caches into a technique that also significantly outperforms state-of-The art lock-based persistence mechanisms on current hardware during normal execution, while preserving very fast recovery times