Incidence, Molecular Detection, and Partial Nucleotide Sequencing of Some Viruses Causing Fig Mosaic Disease (FMD) on Fig Plants in Egypt.

Fig mosaic disease (FMD) is a viral disease that poses a significant danger to Egypt's fig-producing economy. During the two growing seasons 2017 and 2018, fig leaves and fruits displaying a variety of symptoms linked with fig mosaic disease (FMD) were collected and differentiated from the most famous fig-growing governorates in Egypt, Mersa Matruh, Ismailia, and Giza. Symptomatic samples were tested for the presence of fig mosaic virus (FMV), fig leaf mottle-associated virus 1 (FLMaV-1), fig leaf mottle-associated virus 2 (FLMaV-2), fig mild mottle-associated virus (FMMaV), fig latent virus 1 (FLV-1), fig fleck-associated virus (FFkaV), and fig cryptic virus (FCV) using reverse transcription-polymerase chain reaction (RT-PCR) with specific primers. Three viruses were detected in mixed infections and showed positive results. FMV was detected with infection rate 49% followed by FLMaV-2 with infection rate 21.8% and FLMaV-1 with infection rate 10.9%, respectively, whereas all tested samples were negative for the other viruses. According to the sequence and phylogenetic analysis, the Egyptian FMV isolate was closely related to other FMV isolates, particularly the Argentina ones (Acc. No. KP796424), with 99% identity. While FLMaV-1 showed more than 98% identity with reference isolate FLMaV-1 (Acc. No. LN873219), on the other hand, the isolate of FLMaV-2 showed 100% identity with reference FLMaV-2 isolate (Acc. No. FJ473383) based on phylogenetic analysis. Because fig output in Egypt is expanding, our findings suggest that greater attention should be paid to improving the phytosanitary condition of fig trees in Egypt.

Determination of acid dissociation constants of Alizarin Red S, Methyl Orange, Bromothymol Blue and Bromophenol Blue using a digital camera.

Acid dissociation constants (pK a) are important parameters for the characterization of organic and inorganic compounds. They play a crucial role in different physical, chemical, and biological studies. Herein, we introduce a new approach for the determination of acid dissociation constant based on digital image analysis using a low-cost, precise, accurate, sensitive, and portable home-made, camera-based platform. Digital images of Alizarin Red S, Bromophenol Blue, Bromothymol Blue, and Methyl Orange solutions were captured at various pH values. The captured images were analysed to obtain the RGB (Red, Green, and Blue) colour intensities that are used to calculate the RGB colour absorbances. The pK a values were calculated from the RGB colour absorbance-pH relationship using graphical and mathematical methods, and with the aid of DATAN software. For the four studied dyes, the results obtained from digital image analysis were in excellent agreement with the data of sophisticated spectrophotometers and the previously reported literature data.

Digital imaging devices as sensors for iron determination.

Portable, sensitive and cost-effective sensors represent an unmet need, especially in resource-limited settings and locally deprived communities. Digital imaging devices can fill the gap. Thus, we have tested a desktop scanner, a digital camera and a smartphone to determine iron using three standard colour reactions. Images of reacting solutions were analysed to obtain the RGB (red, green and blue) non-uniform colour space parameters. To improve the calibration linearity, sensitivity, and detection limit, we converted the RGB intensities into six uniform colour space values and two colour differences attributes. The converted signals surpassed the RGB signals and compared well with reference spectrophotometric signals. The simplicity and sensitivity of this approach make digital imaging devices as excellent competitors to field-monitoring instruments and sophisticated spectrophotometers. Our approach was successfully applied to the assessment of iron in Nile river water, soils, plant materials and meat and liver samples.

The Yxy colour space parameters as novel signalling tools for digital imaging sensors in the analytical laboratory.

Digital imaging devices can be promising, sensitive, and cost-effective chemical sensors for resource-limited settings. Three model colour reactions of iron were used and monitored using a simple platform consisting only of a camera, a cuvette, and a white paper diffuser. A desktop scanner and a mobile phone camera were also used as imaging devices. Captured images were analysed to obtain the RGB intensities (red, green, blue) and were further converted into the corresponding signals of the grayscale, CMY (cyan, magenta, yellow), XYZ (Y: luminance, XZ: chromaticity plane values) and Yxy colour spaces (Y: luminance, xy: chrominance values) analytical signals. The elegant procedure utilizing the Yxy signals surpassed those based on RGB, grayscale, CMY and tristimulus XYZ data regarding the calibration graph linearity and detection limit and compare well with those data obtained from a sophisticated spectrophotometer for assessing iron in complex environmental samples. The simplicity, sensitivity and cost effectiveness of the approach make it suitable for poorly equipped laboratories and locally deprived communities.