Diversity of lactic acid bacteria from Hussuwa, a traditional African fermented sorghum food

The diversity of lactic acid bacteria associated with Hussuwa fermentation, a Sudanese fermented sorghum food, was studied using a polyphasic taxonomical approach. Predominant strains could be well characterised based on a combination of phenotypic tests and genotypic methods such as ARDRA, rep-PCR and RAPD-PCR, as well as 16S rRNA gene sequencing of representative strains. Thus, the majority (128 of 220, 58.3%) of strains exhibited phenotypic properties typical of heterofermentative lactobacilli and of these, 100 strains were characterised more closely using the genotyping methods. The majority (97/100) strains could be characterised as Lactobacillus fermentum strains. Seventy-two of 220 strains (32.7%) showed phenotypic properties that are characteristic of pediococci. Of 41 selected strains investigated by genotyping techniques, 38 (92.7%) could be characterised as Pediococcus acidilactici strains, while three (7.3%) could be characterised as Pediococcus pentosaceus strains. The Hussuwa fermentation thus appears to be dominated by L. fermentum strains and P. acidilactici strains. For this reason, we selected representative and predominant strains as potential starter cultures for Hussuwa fermentation. These strains, L. fermentum strains BFE 2442 and BFE 2282 and P. acidilactici strain BFE 2300, were shown on the basis of RAPD-PCR fingerprinting to predominate in a model fermentation when used as starter cultures inoculated at 1 × 10⁶ CFU/g and to lower the pH of the fermentation to below pH 4.0 within 48 h. These cultures should be studied for further development as starter preparations in pilot scale studies in actual field fermentations.     

The traditional fermented milk products of the Sudan

Primary human hepatocytes contain a full complement of human drug-metabolizing enzymes and therefore represent a relevant experimental system for the evaluation of pharmacokinetic drug-drug interaction potential in human. In this study, the cytochrome P450 (CYP) induction potential of pantoprazole (PAN) was evaluated and compared to two other proton pump inhibitors (PPIs), omeprazole (OM) and lansoprazole (LAN). Primary human hepatocytes from three donors were studied. The hepatocytes were cultured for 3 days, followed by treatment for 3 days with the PPIs at 2, 5 and 10 microM. Two other known CYP inducers, 3-methylcholanthrene at 1 microM and rifampin at 50 microM, were also evaluated. Induction potentials of these chemicals for CYP1A and CYP3A were evaluated by isozyme activity and isozyme content. 7-Ethoxyresorufin-O-deethylase and testosterone 6beta-hydroxylase activities were used as endpoints for CYP1A and CYP3A, respectively. Isozyme protein contents of CYP1A and CYP3A were evaluated via Western blotting. The results showed that for CYP1A induction, the rank ordering in induction potential was consistently OM > LAN > PAN. CYP3A induction by the PPI's were observed in two of the three hepatocyte cultures, with no apparent differences in induction potency for the three compounds. Our results on CYP1A induction suggest that PAN has a lower drug-drug interaction potential than OM and LAN.     

Assess deep learning models for Egyptian exchange prediction using nonlinear artificial neural networks

Neural Computing and Applications - Financial analysis of the stock market using the historical data is the exigent demand in business and academia. This work explores the efficiency of three deep...     

Biochemical and microbiological studies on kawal,a meat substitute derived by fermentation of cassia obtusifolia leaves

Biochemical and microbiological changes during the fermentation of leaves of the tropical legume, Cassia obtusifolia, in the preparation of the traditional Sudanese food, kawal, are reported. The microflora during fermentation were dominated by two bacteria, Bacillus subtilis and Propionibacterium sp. Other species present included Lactobacillus plantarum, Staphylococcus sciuri and two yeasts. No marked inter-special successional pattern was observed during fermentation. Sun-dried kawal possessed a mean crude protein content of 26.2% indicating negligible loss of N during fermentation. The overall chemical score of kawal protein was 73 with lysine as the most limiting amino acid. The main fermentation products were volatile fatty acids (VFA) principally n-butyric and acetic acids although propionic and isobutyric acids were also present. Total VFA content averaged 15% at the end of fermentation but fell to 10% during sun-drying. Lactic acid concentrations remained low throughout fermentation, the final product containing only 0.2% of this compound. Accumulation of ammonia-N closely paralleled VFA formation and similarly declined sharply in concentration during sun-drying. The major alcohols formed during fermentation were n-propanol and n-butanol which attained a maximum combined concentration of 3% although disappearing during the drying process. The insignificant change in pH during fermentation was ascribed to the buffering effect of the high calcium content of the leaves. Changes in chemical composition noted during sun-drying indicated that this process involved not only dehydration but secondary microbial action.     

Logistic regression in large rare events and imbalanced data: A performance comparison of prior correction and weighting methods

The purpose of this study is to use the truncated Newton method in prior correction logistic regression (LR). A regularization term is added to prior correction LR to improve its performance, which results in the truncated‐regularized prior correction algorithm. The performance of this algorithm is compared with that of weighted LR and the regular LR methods for large imbalanced binary class data sets. The results, based on the KDD99 intrusion detection data set, and 6 other data sets at both the prior correction and the weighted LRs have the same computational efficiency when the truncated Newton method is used in both of them. A higher discriminative performance, however, resulted from weighting, which exceeded both the prior correction and the regular LR on nearly all the data sets. From this study, we conclude that weighting outperforms both the regular and prior correction LR models in most data sets and it is the method of choice when LR is used to evaluate imbalanced and rare event data.     

Solving the inverse problem of electrocardiography using a Duncan and Horn formulation of the Kalman filter

Numeric regularization methods most often used to solve the ill-posed inverse problem of electrocardiography are spatial and ignore the temporal nature of the problem. In this paper, a Kalman filter reformulation incorporated temporal information to regularize the inverse problem, and was applied to reconstruct left ventricular endocardial electrograms based on cavitary electrograms measured by a noncontact, multielectrode probe. These results were validated against in situ electrograms measured with an integrated, multielectrode basket-catheter. A three-dimensional, probe-endocardium model was determined from multiplane fluoroscopic images. The boundary element method was applied to solve the boundary value problem and determine a linear relationship between endocardial and probe potentials. The Duncan and Horn formulation of the Kalman filter was employed and was compared to the commonly used zero- and first-order Tikhonov spatial regularization as well as the Twomey temporal regularization method. Endocardial electrograms were reconstructed during both sinus and paced rhythms. The Paige and Saunders solution of the Duncan and Horn formulation reconstructed endocardial electrograms at an amplitude relative error of 13% (potential amplitude) which was superior to solutions obtained with zero-order Tikhonov (relative error, 31%), first-order Tikhonov (relative error, 19%), and Twomey regularization (relative error, 44%). Likewise, activation time error in the inverse solution using the Duncan and Horn formulation (2.9 ms) was smaller than that of zero-order Tikhonov (4.8 ms), first-order Tikhonov (5.4 ms), and Twomey regularization (5.8 ms). Therefore, temporal regularization based on the Duncan and Horn formulation of the Kalman filter improves the solution of the inverse problem of electrocardiography.