0000000000214982
AUTHOR
Ahmed H. Alfarhan
showing 10 related works from this author
Prediction models based on soil properties for evaluating the uptake of eight heavy metals by tomato plant (Lycopersicon esculentum Mill.) grown in a…
2021
The aim of this study is to design de novo prediction models in order to gauge the likely uptake of eight heavy metals (Al, Cr, Cu, Fe, Mn, Ni, Pb and Zn) by Lycopersicon esculentum, the tomato plant. Uptake was assessed within the plant’s root, stem, leaf and fruit tissues, respectively. The plant was cultivated in soil amended by different application rates of sewage sludge, i.e. 0, 10, 20, 30 and 40 g/kg. The roots exhibited markedly elevated heavy metal concentrations compared to the above-ground plant components, with the exception of the quantity of Ni in the leaves. Apart from Al, Fe and Mn, a bioconcentration factor >1 was identified for all heavy metals. Excluding Ni in the leaves,…
Ecotoxicological Effects of Ibuprofen on Plant Growth of Vigna unguiculata L.
2020
Despite the prevalence of the common pharmaceutical ibuprofen (IBU) in water and sediments worldwide, the effects of IBU on plants are largely unknown. This study was designed to assess the ecotoxicological effects of emerging pharmaceutical pollutant IBU on plant growth and development in a series of toxicity experiments using cowpea (Vigna unguiculata). Plant growth parameters (morphological and physicochemical) were investigated under a series of IBU concentrations (0, 400, 800, 1200, 1600, 2000 ppm IBU). IBU exposure reduced the shoot and root lengths, fresh and dry weights, leaf area, and chlorophyll a and b, carotenoid, total chlorophyll, mineral (K and Mg), glutathione reductase, and…
Target vs non-target analysis to determine pesticide residues in fruits from Saudi Arabia and influence in potential risk associated with exposure
2017
The occurrence of pesticide residues in fruits was determined by a target method for 62 analytes and a wide scope screening method against a database of 500 pesticides. Limits of quantification (LOQs) were from 0.5 to 6.3 μg kg−1 for the target method and from 0.5 to 119 μg kg−1 for the non-target. Thirty samples: dates, apples, oranges, tangerines, lemons and grapefruits were selected because their high consumption, except lemons and grapefruits that were to cover all citrus fruits. Using the target method, 15 compounds (mostly insecticides and fungicides) out of 62 pesticides (organophosphorus, carbamates, pyrethroids, chloroacetanilides, triazines, triazoles, imidazoles, etc.) were detec…
Nano- and microplastic analysis: Focus on their occurrence in freshwater ecosystems and remediation technologies
2019
Plastic pollution is a global problem since 2016 when its production reached 322 million tonnes, excluding fibers. Daily discharges of microplastics (MPs, defined as <5 mm in size) are estimated in the range of 50,000 up to 15 million particles, whereas no information on nanoplastic (NP, <100 nm) release is available yet. Different processes further degraded these materials producing more MPs and NPs. This review attempts to fill the void of information on the state-of-art analysis of MPs and NPs (recently identified as emerging contaminants) and provides a critical overview on modern instrumentation, newly developed workflows, and promising techniques for their characterization (Raman and …
Distribution of soil organic carbon in Wadi Al-Thulaima, Saudi Arabia: A hyper-arid habitat altered by wastewater reuse
2018
The carbon cycle is being altered as a result of human-induced changes in the Earth's system. Therefore, ecosystems such as wetlands, authentic CO2 sinks, are becoming especially important. Little information exits on the soil organic carbon (SOC) stock for the middle east-countries man-made wetlands making wadis permanent with the outflow of wastewater treatment plants. This paper presents the vertical distribution of SOC content, soil bulk density (SBD) and SOC density in soil of vegetated and bare sites in Wadi Al-Thulaima, one of the artificial wetlands in central Saudi Arabia. The mean distribution of SBD in the vegetated and bare sites increased significantly with depth. Inversely, th…
Effect of the conversion of mangroves into shrimp farms on carbon stock in the sediment along the southern Red Sea coast, Saudi Arabia
2019
The conservation of coastal ecosystems and specially mangroves ‘‘blue carbon’’ is receiving more attention as consequence of their recognition as high ecosystem carbon stocks and for the fact that these areas are undergoing land conversion. The aim of the present study is to evaluate the impact of land use changes due to conversion of mangroves to shrimp farms on the bulk density (SBD), organic carbon (SOC) concentration, and SOC stock in the sediments along the southern Saudi Arabian Red Sea coast. Shrimp farms and mangrove locations showed significant (P < 0.001) differences in SBD with high mean values in the sediments of shrimp farms. Shrimp farms and mangrove locations showed significa…
Biomonitoring potential of the native aquatic plant Typha domingensis by predicting trace metals accumulation in the Egyptian Lake Burullus.
2020
The ability of the native emergent macrophytes Typha domingensis for monitoring pollution with trace metals in Egyptian Lake Burullus was investigated through developing regression models for predicting their concentrations in the plant tissues. Plant samples (above-ground shoot and below-ground root and rhizome) as well as sediment samples were collected monthly during one growing season and analyzed. The association of trace metals concentration with several sediment characteristics (pH, organic matter, clay and silt) was also studied using the simple linear correlation coefficient (r). The concentration of some trace metals was significantly proportional to its values in the sediment suc…
Experimental conditions improving in-solution target enrichment for ancient DNA.
2016
High-throughput sequencing has dramatically fostered ancient DNA research in recent years. Shotgun sequencing, however, does not necessarily appear as the best-suited approach due to the extensive contamination of samples with exogenous environmental microbial DNA. DNA capture-enrichment methods represent cost-effective alternatives that increase the sequencing focus on the endogenous fraction, whether it is from mitochondrial or nuclear genomes, or parts thereof. Here, we explored experimental parameters that could impact the efficacy of MYbaits in-solution capture assays of ~5000 nuclear loci or the whole genome. We found that varying quantities of the starting probes had only moderate ef…
Uptake prediction of nine heavy metals by Eichhornia crassipes grown in irrigation canals: A biomonitoring approach
2021
The principal objective of this study is to generate mathematical regression equations that facilitate the estimation of the extent to which Eichhornia crassipes (C. Mart.) Solms, water hyacinth, absorbs heavy metals (HMs) into four plant organs (laminae, petioles, roots, and stolons). This study considers the absorption of nine HMs (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), and the E. crassipes evaluated in this study were located in three irrigation canals in the North Nile Delta in Egypt, with sampling being conducted in both monospecific and homogenous E. crassipes. Samples of both E. crassipes and water were collected on a monthly basis during one growing season. Analysis of the water s…
Tracking Five Millennia of Horse Management with Extensive Ancient Genome Time Series
2019
Summary Horse domestication revolutionized warfare and accelerated travel, trade, and the geographic expansion of languages. Here, we present the largest DNA time series for a non-human organism to date, including genome-scale data from 149 ancient animals and 129 ancient genomes (≥1-fold coverage), 87 of which are new. This extensive dataset allows us to assess the modern legacy of past equestrian civilizations. We find that two extinct horse lineages existed during early domestication, one at the far western (Iberia) and the other at the far eastern range (Siberia) of Eurasia. None of these contributed significantly to modern diversity. We show that the influence of Persian-related horse …