Volatile components of Camellia sinensis inhibit growth and biofilm formation of oral streptococci in vitro

This study aimed to evaluate the efficacy of semi fermented and non fermented Camellia sinensis extracts (Black and Green tea) and comparison between them against Streptococcus mutans ATCC 25175, S. mitis ATCC 9811 and S. sanguis ATCC 10556 that are responsible for dental caries and bacteremias following dental manipulations. Minimum inhibitory concentrations of both tea extracts were assessed by Well diffusion and Broth dilution methods and examination of cell adherence (Biofilm inhibitory concentrations) was observed on glass slides under phase contrast microscope and colony counts from glass beads. Concentration of 1 mg mL(-1) of semi fermented tea extract was completely biofilm inhibitor but biofilm formation by these bacteria was seen 7 days after treatment with 1 mg mL(-1) of non fermented Camellia sinensis on glass beads and BIC for oral streptococci treated with this extract was 1.5, 2.5 mg mL(-1) of semi fermented and 3 mg mL(-1) of non fermented extracts had bactericidal effect on these bacteria. Semi fermented and non fermented Camellia sinensis extracts were able to prevent growth of oral streptococci. Therefore dental caries significantly reduce and the efficiency of semi fermented tea was higher due to rich content of volatile components rather than non fermented extracts.     

Antioxidant and Antiproliferative Activity of <Emphasis Type="Italic">Diospyros lotus</Emphasis> L. Extract and Isolated Compounds

The object of the study was to determine the chemical composition of Diospyros lotus L. extract and their antioxidant and antiproliferative properties. Eight compounds were isolated from D. lotus and identified as gallic acid, methylgallate, ellagic acid, kaempferol, quercetin, myricetin, myricetin 3-O-β-glucuronide, and myricetin-3-O-α-rhamnoside. D. lotus extract tested in different in vitro systems (DPPH, ABTS, FRAP, and Fe²⁺ chelating activity assay) showed significant antioxidant activity. The potential antiproliferative properties of D. lotus extract and isolated compounds against nine human cancer cell lines such as COR-L23, CaCo-2, C32, ACHN, A375, A549, Huh-7D12, MCF-7, and LNCaP were investigated in vitro by SRB assay. D. lotus extract demonstrated the highest inhibitory activity against COR-L23 with an IC₅₀ value of 12.2 μg/ml. Among identified hydrolysable tannins, ellagic acid evidenced strong antiproliferative activity against both C32 and A375 cells with IC₅₀ values of 0.8 and 4.1 μg/ml, respectively. Interesting results were observed, also, with gallic acid that showed the highest cytotoxic activity against CaCo-2 (IC₅₀ 2.6 μg/ml). Overall, the results of this study suggest that D. lotus displays a good antioxidant activity and has antiproliferative effects. Both activities are related to identified phenolic compounds.     

Modeling of maximum dry density and optimum moisture content of stabilized soil using artificial neural networks

This study considers the use of artificial neural networks (ANNs) to predict the maximum dry density (MDD) and optimum moisture content (OMC) of soil‐stabilizer mix. Multilayer perceptron (MLP), one of the most widely used ANN architectures in the literature, is utilized to construct comprehensive and accurate models relating the MDD and OMC of stabilized soil to the properties of natural soil such as particle‐size distribution, plasticity, linear shrinkage, and the type and quantity of stabilizing additives. Five ANN models are constructed using different combinations of the input parameters. Two separate sets of ANN prediction models, one for MDD and the other for OMC, and also a combined ANN model for multiple outputs are developed using the potentially influential input parameters. Relative‐importance values of various inputs of the models are calculated to determine the significance of each of the predictor variables to MDD and OMC. Inferring the most relevant input parameters based on Garson's algorithm, modified ANN models are separately developed for MDD and OMC. The modified ANN models are utilized to introduce explicit formulations of MDD and OMC. A parametric study is also conducted to evaluate the sensitivity of MDD and OMC due to the variation of the most influencing input parameters. A comprehensive set of data including a wide range of soil types obtained from the previously published stabilization test results is used for training and testing the prediction models. The performance of ANN‐based models is subsequently analyzed and compared in detail. The results demonstrate that the accuracy of the proposed models is satisfactory as compared to the experimental results.     

Characterizing Zebra Chip Symptom Severity and Identifying Spectral Signatures Associated with ‘<Emphasis Type="Italic">Candidatus</Emphasis> Liberibacter solanacearum’-Infected Potato Tubers

Zebra chip (ZC) disease has been a threat to the US potato industry for nearly two decades. ZC is associated with the bacteria ‘Candidatus Liberibacter solanacearum’ (Lso), which is transmitted by the potato psyllid, Bactericera cockerelli (?ulc) (Hemiptera: Triozidae). ZC reduces yield and quality, due to discoloration of the tuber tissue. Symptom severity is affected by the time of infection and early-season infections express relatively higher degrees of ZC. Although tubers infected late in the growing season, i.e. within 2 weeks of harvest, express minimal to no symptoms, they may proceed to express ZC symptoms following storage. Currently, visualization of ZC symptoms in tubers is used by processors to estimate the percentage of ZC-affected tubers in truckloads of potatoes. This approach, however, is time consuming and relies on evaluations of a small sample size. Thus, it is likely to fail in detecting the asymptomatic late infections. Using several potato genotypes infected at different times during the growing season, this study was set to determine if visible and near infrared spectrometry, and infrared thermal imaging, can be used to distinguish ZC-affected tubers, and to predict the severity of ZC symptoms. The subjective symptom score categorization, commonly used in ZC studies, corresponded with the percentage of the symptomatic area in the tubers sliced at the solon attachment end. The percentage of symptomatic area was also correlated with Lso titer. Reflectance effectively distinguished infected and uninfected tubers with high accuracy; the combined wavelengths 468, 582, 680 and 720-nm were the most effective in predicting symptom severity. Near infrared (NIR) and infrared (IR) thermal imaging failed to distinguish tubers based on Lso infection status after storage. The quantitative measure of ZC severity, and the effectiveness of some visual wavelengths in detecting ZC may help to facilitate selection assays for ZC resistance. While in our study infrared imaging did not appear to be effective in distinguishing Lso- affected tubers after storage, additional studies with field harvested tubers are still needed to evaluate the effectiveness of VIS, NIR and IR spectrometry in screening for ZC.     

Qualitative and quantitative studies of the inferior olivary complex in the water buffalo (Buballus bubalis)

The shape and neuronal number of the inferior olivary complex (IOC) were determined in the water buffalo (Buballus bubalis). The configuration and interrelations of the IOC compartments were ascertained by investigating serial sections through the whole rostro-caudal extent of the IOC. Nissl-stained celloidin sections of six water buffalo's brainstems were used. The IOC in the water buffalo consisted of three major nuclei and four small cell groups. The medial accessory olivary nucleus (MAO) had the longest rostro-caudal extent as well as the highest number of neurons (98,000 +/- 3,000). Although the total area of the principal olivary nucleus (PO) was smaller than the area of the dorsal accessory olivary nucleus (DAO), the PO had the second largest neuronal number. The total number of neurons on both sides of the IOC was 210,000 +/- 7,000 cells. The average neuronal density was 3,000 cells/mm3. Although the size of the PO relatively increases while the size of MAO decreases with the development of the cerebellar hemispheres, the IOC in most mammals maintains a similar structure except for the higher primates and marsupials. The water buffalo IOC showed morphological similarities to the almost all mammalian IOC including rats as follow; the main part of the MAO consists of three subgroups (a, b and c), the DAO is Boomerang-shaped while the PO is a simple U-shaped structure.     

Effects of Holding Temperatures on the Development of Zebra Chip Symptoms, ‘<Emphasis Type="Italic">Candidatus</Emphasis> Liberibacter Solanacearum’ Titers,and Phenolic Levels in ‘Red La Soda’ and ‘Russet Norkotah’ Tubers

‘Candidatus Liberibacter solanacearum’ (Lso) is the putative causal agent of zebra chip disease (ZC). Late season Lso-infected potatoes that are known to be asymptomatic at harvest may continue to develop symptoms by the time of shipment to consumers. This study observed symptom development, Lso titer changes, and changes in symptom-associated phenolic compounds in Lso-infected yet asymptomatic tubers placed at different holding temperatures. ZC symptoms present in freshly-sliced tubers were more severe in ‘Red La Soda’ or ‘Russet Norkotah’ tubers held at 3 °C than at 6 °C or 9 °C. However, Lso titers showed considerable variability in both cultivars over time and at these holding temperatures. Phenolic compound levels, known to be associated with ZC symptom severity, in tubers kept at 3 °C were greater than those kept at 6 °C or 9 °C and increased over time. These results demonstrate that ZC could develop in tubers kept in cold storage, with those kept at 3 °C having more ZC development than those kept at 6 °C or 9 °C.     

The effects of ghrelin on ovary histology in Barbus sharpeyi

Ghrelin is expressed in key cells of the female reproductive organ in several species of fishes. It has a role in the control of fertility. In the present study, the histological effect of ghrelin on 48 female Barbus sharpeyi was tested. Twenty-four hours later, microscopic observations and histometric counting was done. The results indicated that ghrelin can increase the number of mature ovarian follicles and sexual maturation and reduce the average oocyte diameter.     

Trichogramma evanescens West. (Hym., Trichogrammatidae) as an egg parasitoid of Grape MothLobesia botrana (Den. & Schiff.) (Lep., Tortricidae)

The adaptation of the primary internal parasitoid,Trichogramma evanescens (Westw.), as an egg parasitoid ofLobesia botrana (Den. & Schiff.) was the first report in Alexandria region, Egypt. The life-span of this parasitoid on eggs ofL. botrana andSitotroga cerealella Ol. was investigated. The duration from egg to adult, longevity of adult stage, sex-ratio and total life cycle each of the two hosts were recorded. The ovipositional periods of mated females ofT. evanescens on egg ofL. botrana at 27±2c^o and 75±2% R.H. were studied. Also, percentages of parasitism byT. evanescens ranged from 22%–64% on the eggs ofL. botrana. Therefore, this parasitoid was very efficient as a biocontrol agent against the most serious grape pestL. botrana in Egypt.