Search Results (14)

Nano-/microplastics (NMPs) accumulation in agricultural soils has become a growing environmental concern due to its negative impacts on soil health, crop productivity, and food safety. Biochar has gained considerable attention as a sustainable soil amendment capable of improving soil quality and mitigating emerging pollutants. This review examines the role of biochar and modified biochar in reducing the mobility, bioavailability, and plant uptake of NMPs through adsorption, aggregation, and immobilization mechanisms. In addition, biochar improves soil fertility by enhancing nutrient retention, water holding capacity, soil structure, and microbial activity, while also contributing to climate change mitigation through carbon sequestration. However, certain biochars may negatively affect saline–alkaline soils because of their high pH and salinity. Generally, biochar application offers multiple environmental benefits, including soil restoration, pollutant mitigation, and enhanced agricultural sustainability. This review synthesizes recent advances in understanding the mechanisms by which biochar influences NMPs behavior in soil–plant systems and highlights current knowledge gaps and future research directions needed to support its effective application in sustainable agriculture. Full article

Due to growing water demands and changing hydro-meteorological variables brought on by climate change, drought is becoming an increasingly serious climate concern. The Al-Baha region of Saudi Arabia is the subject of this study because it is susceptible to both agricultural and meteorological droughts. This study investigates how climate change affects patterns of drought in Al-Baha by analyzing four drought indices (Agricultural Standardized Precipitation Index (aSPI), the Standardized Precipitation Index (SPI), the Rainfall Deficiency Index (RDI), and the Effective Reconnaissance Drought Index (eRDI)) for the years 1991–2022. Analysis of rainfall data was carried out to classify drought events according to their duration, frequency, and severity. Results showed that severe droughts occurred in 2009, 2010, 2012, 2016, and 2022, with 2010 being the worst year. Results also indicated a notable decrease in precipitation, which has resulted in extended dry spells. Several indices indicate that this tendency has significant ramifications for agriculture, particularly in areas where farming is a major economic activity. In addition, the possible occurrence of hydrological drought was also observed based on the negative values for the Reservoir Storage Index (RSI) in Al-Baha. Projections for the future under two Representative Concentration Pathways (RCPs) showed notable variations in temperature and precipitation. Both the RCP4.5 (low emission) and the RCP8.5 (high emission) projection scenarios indicate that drought conditions will likely worsen further. Depending on the emission scenario, it is projected to show a temperature increase of 1–2 °C, whereas the variability in precipitation projections indicates significant uncertainty, with a reduction change in the range of 1.2–27% between 2050 and 2100. The findings highlight the urgent need for proactive adaptation strategies, effective water resource management, and the development of sophisticated drought prediction tools. Addressing these challenges is crucial for sustaining agriculture and managing water scarcity in Saudi Arabia in the face of increasing drought risk. Full article

The tomato is a vital component of agriculture and is the second-most important vegetable globally. Maintaining a high tomato production requires both water quality and quantity. Water-scarce regions like Saudi Arabia still lack an understanding of the impact of deficit irrigation and the use of a blend of saline and freshwater, especially their nuanced impact across growth stages. The purpose of this study was to evaluate the effects of six different irrigation amounts: full irrigation with 100% ET_c (FI), regulated deficit irrigation with 60% ET_c (DI), and deficit irrigation with 60% ET_c, except for the initial (DI-int), development (DI-dev), mid-season (DI-mid), and late-season (DI-lat) stages. This was performed with three different water qualities: fresh (FW), saline (SW), and fresh-saline blend (1:1) (MW) water. FW and MW enhanced the growth, physiology, morphology, yield, and quality, while SW had the lowest values. DI reduced these parameters and lowered yields by 13.7%, significantly improving water use efficiency (WUE) by 44% and fruit quality. DI-mid or DI-lat slightly improved yields while remarkably decreasing WUE and fruit quality. DI outperforms deficit irrigation in all growth stages except one, and countries with limited freshwater resources can benefit from a mix of fresh and saline water with a 60% ET_c deficit irrigation, resulting in greater water savings. Full article

The impacts of regulated deficit irrigation (RDI) and partial root zone drying irrigation (PRD) on water productivity (WP), crop water response factor (Ky), and yield of tomato crop (Solanum lycopersicum) were explored in this study using fresh (0.9 dS m⁻¹) and saline (3.6 dS m⁻¹) water under greenhouse conditions. RDI had four ETc (crop evapotranspiration) levels, i.e., 40, 60, 80, and 100%. PRD adopted 100% ETc for all treatments with changes in its application time (first, second, third, and fourth growth stages). Biochar pyrolyzed at 450–500 °C and added at rate of 4%. The results revealed that the Ky ranged between 0.21 and 0.37, indicating that tomato can tolerate a shortage of irrigation water. The highest value of WP (191 kg m⁻³) was found in 40% ETc using fresh water with biochar. The highest yield (20.0 kg m⁻²) was obtained with the application of 100% ETc with fresh water and biochar. Biochar application did not result in favorable yields with saline water due to its high salinity (7.8 dS m⁻¹). The use of PRD in the fourth stage with biochar and fresh water led to the highest yield (20.6 kg m⁻²). Finally, this study recommends the application of biochar only when fresh irrigation water is available in adequate amounts. Full article

Acute myeloid leukemia (AML) is one of the cancers that grow most aggressively. The challenges in AML management are huge, despite many treatment options. Mutations in FLT3 tyrosine kinase receptors make the currently available therapies less responsive. Therefore, there is a need to find new lead molecules that can specifically target mutated FLT3 to block growth factor signaling and inhibit AML cell proliferation. Our previous studies on FLT3-mutated AML cells demonstrated that β-elemene and compound 5a showed strong inhibition of proliferation by blocking the mutated FLT3 receptor and altering the key apoptotic genes responsible for apoptosis. Furthermore, we hypothesized that both β-elemene and compound 5a could be therapeutically effective. Therefore, combining these drugs against mutated FLT3 cells could be promising. In this context, dose–matrix combination-based cellular inhibition analyses, cell morphology studies and profiling of 43 different apoptotic protein targets via combinatorial treatment were performed. Our studies provide strong evidence for the hypothesis that β-elemene and compound 5a combination considerably increased the therapeutic potential of both compounds by enhancing the activation of several key targets implicated in AML cell death. Full article

Groundwater depletion coupled with climate change, increasing temperature, and decreasing precipitation, has led to groundwater quality deterioration and diminishing groundwater quantity, subsequently affecting agricultural productivity in arid environments. The groundwater of the Al-Baha region, Saudi Arabia is located in unconfined shallow aquifers and responds quickly to climate change. The Al-Baha region is facing an increase in temperature and a substantial decrease in precipitation. Over the 24-year period from 1995 to 2019, average temperatures increased by 1.1 °C–1.6 °C, while rainfall decreased by 24–41%. Consequently, this study aimed at investigating the influence of climate change on soil salinity and pomegranate productivity. To achieve this goal, a hundred and fifteen samples of soil and groundwater were collected from different locations in the Al-Baha region. Furthermore, the SALTMED model was calibrated using the salinities of 50 groundwater samples, which are used as irrigation water, and climatic data from the year 2020. The model was then validated using 65 irrigation water salinities and climatic data from the year 2020. Pomegranate fruit yield was used as the main variable for calibration and validation. After successful calibration and validation, the SALTMED model was run using ‘what if’ scenarios for the years 2044, 2068, and 2092. It is assumed that the temperature will increase, while the annual rainfall will decrease in upcoming decades. Consequently, the groundwater salinities will reach 1.44, 2.59, and 4.67 dS m⁻¹ for the years 2044, 2068, and 2092, respectively. The results revealed that the soil salinities will increase by 113%, 300%, and 675%, respectively, compared with the average soil salinity of the year 2020 (2.22 dS m⁻¹). Furthermore, the pomegranate tree productivity in the Al-Baha region will decrease significantly (24.0%, 36.6%, and 41.6%) in the predicted three years due to deterioration of groundwater quality and increasing temperatures. Interventions by the regional authorities to minimize the impact of climate change on crop and fruit productivity and groundwater deterioration in the Al-Baha region should be planned and carried out as soon as possible. The method used in this investigation can be utilized in similar ecosystems worldwide. Full article

The coronavirus pandemic (COVID-19) is disrupting the entire world; its rapid global spread threatens to affect millions of people. Accurate and timely diagnosis of COVID-19 is essential to control the spread and alleviate risk. Due to the promising results achieved by integrating machine learning (ML), particularly deep learning (DL), in automating the multiple disease diagnosis process. In the current study, a model based on deep learning was proposed for the automated diagnosis of COVID-19 using chest X-ray images (CXR) and clinical data of the patient. The aim of this study is to investigate the effects of integrating clinical patient data with the CXR for automated COVID-19 diagnosis. The proposed model used data collected from King Fahad University Hospital, Dammam, KSA, which consists of 270 patient records. The experiments were carried out first with clinical data, second with the CXR, and finally with clinical data and CXR. The fusion technique was used to combine the clinical features and features extracted from images. The study found that integrating clinical data with the CXR improves diagnostic accuracy. Using the clinical data and the CXR, the model achieved an accuracy of 0.970, a recall of 0.986, a precision of 0.978, and an F-score of 0.982. Further validation was performed by comparing the performance of the proposed system with the diagnosis of an expert. Additionally, the results have shown that the proposed system can be used as a tool that can help the doctors in COVID-19 diagnosis. Full article

Water management and irrigation conservation in calcareous sandy soil are of significant importance for sustaining agricultural production, especially in arid and semi-arid region that facing scarcity of water resources. The changes in hydro-physical characteristics of calcareous sand soil were investigated after date palm waste-derived biochar application in column trials. Significance of pyrolysis temperature (300 °C, 500 °C, and 700 °C), particle size [<0.5 mm (D_0.5), 0.5–1 mm (D₁), and 1–2 mm (D₂)], and application rate (1%, 2.5%, and 5%) were studied. Variations in infiltration rate, intermittent evaporation, and saturated hydraulic conductivity as a function of aforementioned factors were investigated. After amending the top 10-cm soil layer with different biochar and application rates, the columns were subjected to six wetting and drying cycles by applying 25 cm³ tap water per week over a 6-week period. Overall, biochar application resulted in decreased saturated hydraulic conductivity, while improved cumulative evaporation. Specifically, biochar produced at 300 °C and 500 °C demonstrated 10.2% and 13.3% higher cumulative evaporation, respectively., whereas, biochar produced at 700 °C with 5% application rate resulted in decreased cumulative evaporation. Cumulative evaporation increased by 5.0%, 7.7% and, 7.8% for D_0.5, D₁ and D₂ (mm) on average, respectively, as compared with the untreated soil. Thus, biochar with particle size 0.5–1 mm significantly improved hydro-physical properties when applied at 1%. Generally, using biochar produced at medium temperature and small particle size with appropriate application rates could improve the soil hydro-physical properties. Full article

In Saudi Arabia, more than 335,000 tons of cow manure is produced every year from dairy farming. However, the produced cow manure is usually added to the agricultural soils as raw or composted manure; significant nitrogen losses occur during the storage, handling, and application of the raw manure. The recovery of ammonia from cow manure through thermochemical treatments is a promising technique to obtain concentrated nitrogen fertilizer and reducing nitrogen losses from raw manure. However, the byproduct effluents from the recovery process are characterized by different chemical properties from the original raw manure; thus, its impact as soil amendments on the soil carbon and nitrogen dynamics is unknown. Therefore, a 90-day incubation experiment was conducted to study the impact of these effluents on CO₂ efflux, organic C, microbial biomass C, available NH₄⁺, and NO₃⁻ when added to agricultural soil. In addition to the two types of effluents (produced at pH 9 and pH 12), raw cow manure (CM), composted cow manure (CMC), cow manure biochar (CMB), and control were used for comparison. The application of CM resulted in a considerable increase in soil available nitrogen and CO₂ efflux, compared to other treatments. Cow manure biochar showed the lowest CO₂ efflux. Cumulative CO₂ effluxes of cow manure effluents were lower than CM; this is possibly due to the relatively high C:N ratio of manure effluent. The content of P, Fe, Cu, Zn, and Mn decreased as incubation time increased. Soil microbial biomass C for soil treated with cow manure effluents (pH 12 and 7) was significantly higher than the rest of the soil amendments and control. Full article

Pregnant women are susceptible to COVID-19 complications due to gestation-related physiological changes. We aimed to evaluate the level of maternal knowledge, perception, and practice during the pandemic. A cross-sectional study was conducted during the Malaysian Movement Control Order (MCO) between April and June 2020. A self-administered electronic questionnaire that included the knowledge and practice domains was distributed. A newly designed set of questions was used to evaluate (1) women’s perception of MCO and (2) maternal experience, which was subdivided into clinical care provision and maternal anxiety. The survey response rate was 93% with the final number for analysis of 415. The majority of women (95%) demonstrated an adequate level of knowledge on COVID-19, whilst 99% had a good practice. We found that tertiary education (p < 0.001), employment status (p = 0.03), higher household income (p < 0.001), and multiple sources of information (p < 0.001) were independent predictors of adequate maternal knowledge on COVID-19. Women with adequate knowledge also reported a more positive perception of MCO (p < 0.001) and better obstetric care experience (p = 0.037), as did those of Malay ethnicity. Younger (p < 0.001) and nulliparous (p = 0.01) women demonstrated greater anxiety levels. The majority of our women reported good practice and adequate knowledge, which contributed to a positive perception of MCO and better maternal obstetric experience. First-time mothers may benefit from extra support and reassurance during the pandemic to alleviate maternal anxiety. Full article

In this study, waste olive leaves and branches were pyrolyzed to produced biochar, and their impacts on physical and chemical properties of a sandy soil were evaluated. Pyrolytic temperatures of 300 °C, 400 °C, and 500 °C were used for biochar production. After evaluating the physio-chemical properties, the produced biochars were added to the top 10 cm layer of the soil at rates of 0%, 1%, 3%, and 5% in a column experiment at 25 °C. Biochar was mixed with a sandy soil into the top 10 cm of the columns. For all treatments, cumulative evaporation was reduced; however, treatments with 5% biochar prepared at the highest temperatures showed the highest impact. The available water contents were increased by 153.33% and 151.11% when olive branch-derived biochar and olive leaves-derived biochars produced at 500 °C were applied at 5% rate, respectively. No impact of available water was observed for 1% biochar contribution. Biochar application decreased both cumulative infiltration and infiltration rate. Biochar pyrolyzed at 500 °C most intensely improved hydro-physical properties of a sandy soil. However, its application as a soil supplement in arid environments should be adopted with constraints due to its high pH (9.69 and 9.29 for biochar pyrolyzed at the highest temperatures) and salinity (up to electrical conductivity = 5.07 dS m⁻¹). However, the salinity of biochar prepared from olive branches (5%, pyrolyzed at 500 °C) was low (0.79 dS m⁻¹); therefore, it can be used safely as a supplement in saline and acidic soils, but with restriction in alkaline soils. Full article

Fifty-four groundwater samples were collected from Hamra Alasad in Al-Madinah City. The chemical and microbial characteristics of the samples were analyzed and compared with their respective standards. The results revealed that 90.7% of the samples showed higher amounts of NO₃. However, 59.3% of the samples were found unfit for irrigation purposes due to a high salinity hazard. Most of the groundwater samples were highly saline, yet no sodicity hazards were anticipated as predicted by sodium adsorption ratio (SAR). Generally, the soluble cations and anions, dissolved salts, boron, and NO₃⁻ exceeded the maximum permissible limits for drinking water in most of the samples; however, Pb, Cd, As, Zn, Cu, Ni, Co, Fe, Mn, and Cr were within the permissible limits. Furthermore, 42.6%, 24.1%, 18.5%, 14.8%, 1.9%, and 37.0% of the samples were infected by a total coliforms group, fecal coliform, Escherichia coli, Staphylococcus sp., Salmonella sp., and Shigilla sp., respectively. The water quality index revealed that 3.7% of the samples were good for drinking (class II), and 9.3% were very poor (class IV). The remaining samples were unfit for drinking (class V) due to high salinity and/or microbial contamination. Durov and Piper diagrams revealed that the majority of water samples were of the calcium sulfate–chloride type. Overall, 87% of water samples were inappropriate for drinking purposes, while 77.8% were unsuitable for irrigation. Full article

The peristaltic flow of velocity second slip boundary conditions and inclined magnetic field of Jeffrey fluid by means of heat and mass transfer in asymmetric channel was inspected in the present study. Leading equations described the existing flow were then simplified under lubrication approach. Therefore, exact solutions of stream function, concentration and temperature were deduced. Further, the numerical solutions of pressure rise and pressure gradient were computed using Mathematica software. Furthermore, the effect of the second slip parameter was argued via graphs. It has been depicted that this kind of slip is mandatory and very imperative to foresee the physical model. On the other hand, false results will be obtained. Full article

Synthetic polymers, such as polyacrylamide (PAM), and biochar are generally used as soil amendments to improve soil properties. This paper explores a laboratory column experiment conducted to investigate the effects of biochar (pyrolysis at 400–450 °C) and polymers, with different application rates, on the hydro-physical properties of sandy soil. The experiment evaluated four rates each of biochar (0.0% (C), 2% (B₁), 4% (B₂), 6% (B₃) and 8% (B₄)) and polymers (0.0% (C), 0.2% (P₁), 0.4% (P₂), 0.6% (P₃), and 0.8%(P₄)), as well as a mixture of them. The infiltration rate decreased significantly when a mixture of biochar and polymers was adopted. B₁ showed a decrease of 32.73% while a mixture of 8% (B₄) and (0.8%) P₄ exhibited a decrease of 57.31%. The polymers increased the infiltration rate at low concentrations (P₁ and P₂) and reduced it at high concentrations (P₃ and P₄). The cumulative evaporation decreased significantly for most treatments. B₁ recorded the highest decrease in cumulative evaporation with a percentage decrease of 31.9%. The highest decrease in hydraulic conductivity (Ks) was for B₁. However, the mixture of B₄ and P₄ resulted in the highest increase in soil moisture content at field capacity compared to the control and other treatments. P₄ and the mixture of B₂ and P₂ showed significant (p < 0.05) increases in the percentage of stable aggregate (SA) in fraction size (0.25–0.125 mm). Although the mixture of B₄ and P₄ had the highest increase in soil moisture content, this study recommends using the B₁ treatment on sandy soil in arid environments due to its strong hydro-physical properties and affordability. Full article