Spatial analysis of rangeland's vegetation intensity as related to selected physical soil variables over ABQAIQ municipality of Saudi Arabia

Through most of the natural rangelands of Saudi Arabia, overgrazing, sand drifting, and off-road vehicles driving are almost the major contributing factors that lead to vegetation damage and land degradation in natural landscapes. The current study aimed at examining the dynamic nature of Abqaiq rangelands' vegetation, generating a vegetation intensity map, and investigating possible impacts caused by the spatial variability of obtained soil texture, sand content (%), and the derived available water capacity (DAW capacity (%)) on the intensity distribution of vegetation cover. Ordinal-nominal correlation type and spatial autocorrelation processes were adopted throughout the study to analyze the spatial correspondences as well as the interrelated patterns of the given variables. The resultant correlation between vegetation and soil texture (ordinal versus nominal variables) has yielded a significant (p-value < 0.001) relevancies, where, silt loam texture class, in particular, has proven to have the most correlated values to the most intensive vegetation habitats, where 5%, 35%, and 28% of the silt loam class were occupied by 80%, 60%, and 40% of vegetation intensities, respectively. Whereas, for the continuous variables, correlation outcomes have achieved a substantial negative spatial autocorrelation concerning vegetation intensity and sand content percentage, revealing a total absence of green biomass over the sandy soils. Additionally, vegetation intensity versus DAW capacity percentage significantly yielded a positive autocorrelation, revealing a high clustering of green biomass cover that associates with high clustering of high-water capacity soils. The autocorrelation strength identifier (Morn's I), produced an approximate value of 0.3 with a pseudo p-value of 0.001, for both relationships. The findings of this study would help researchers and relative authorities to grasp the reasons, consequences and behaviors of rangeland flora, considering Abqaiq's area as an example.     

Immunoinformatics Driven Prediction of Multiepitopic Vaccine Against Klebsiella pneumoniae and Mycobacterium tuberculosis Coinfection and Its Validation via In Silico Expression

International Journal of Peptide Research and Therapeutics - Klebsiella pneumoniae and Mycobacterium tuberculosis coinfection is one of the most lethal combinations that has been becoming frequent...     

Modeling the structure of the frameshift-stimulatory pseudoknot in SARS-CoV-2 reveals multiple possible conformers

The coronavirus causing the COVID-19 pandemic, SARS-CoV-2, uses −1 programmed ribosomal frameshifting (−1 PRF) to control the relative expression of viral proteins. As modulating −1 PRF can inhibit viral replication, the RNA pseudoknot stimulating −1 PRF may be a fruitful target for therapeutics treating COVID-19. We modeled the unusual 3-stem structure of the stimulatory pseudoknot of SARS-CoV-2 computationally, using multiple blind structural prediction tools followed by μs-long molecular dynamics simulations. The results were compared for consistency with nuclease-protection assays and single-molecule force spectroscopy measurements of the SARS-CoV-1 pseudoknot, to determine the most likely conformations. We found several possible conformations for the SARS-CoV-2 pseudoknot, all having an extended stem 3 but with different packing of stems 1 and 2. Several conformations featured rarely-seen threading of a single strand through junctions formed between two helices. These structural models may help interpret future experiments and support efforts to discover ligands inhibiting −1 PRF in SARS-CoV-2.     

New Pyrano-4H-benzo[g]chromene-5,10-diones with Antiparasitic and Antioxidant Activities

New pyranonaphthoquinone derivatives were synthesized and investigated for their activity against Trypanosoma brucei, Leishmania major, and Toxoplasma gondii parasites. The pentafluorophenyl derivative was efficacious against T. brucei with single digit micromolar EC₅₀ values and against T. gondii with even sub-micromolar values. The 3-chloro-4,5-dimethoxyphenyl derivative showed an activity against amastigotes of Leishmania major parasites comparable to that of amphotericin B. In addition, antioxidant activities were observed for the bromophenyl derivatives, and their redox behavior was studied by cyclovoltammetry. Anti-parasitic and antioxidative activities of the new naphthoquinone derivatives appear uncorrelated.     

Insecticide resistance in dengue vectors from hotspots in Selangor,Malaysia

BackgroundIn Malaysia, dengue remains a top priority disease and usage of insecticides is the main method for dengue vector control. Limited baseline insecticide resistance data in dengue hotspots has prompted us to conduct this study. The present study reports the use of a map on the insecticide susceptibility status of Aedes aegypti and Aedes albopictus to provide a quick visualization and overview of the distribution of insecticide resistance.Method and resultsThe insecticide resistance status of Aedes populations collected from 24 dengue hotspot areas from the period of December 2018 until June 2019 was proactively monitored using the World Health Organization standard protocol for adult and larval susceptibility testing was conducted, together with elucidation of the mechanisms involved in observed resistance. For resistance monitoring, susceptibility to three adulticides (permethrin, deltamethrin, and malathion) was tested, as well as susceptibility to the larvicide, temephos. Data showed significant resistance to both deltamethrin and permethrin (pyrethroid insecticides), and to malathion (organophosphate insecticide) in all sampled Aedes aegypti populations, while variable resistance patterns were found in the sampled Aedes albopictus populations. Temephos resistance was observed when larvae were tested using the diagnostic dosage of 0.012mg/L but not at the operational dosage of 1mg/L for both species.ConclusionThe present study highlights evidence of a potential threat to the effectiveness of insecticides currently used in dengue vector control, and the urgent requirement for insecticide resistance management to be integrated into the National Dengue Control Program.     

Stakeholders’ attitudes to outdoor residual spraying technique for dengue control in Malaysia: A PLS-SEM approach

Outdoor Residual Spraying (ORS) technique is a complementary preventive measure for dengue. The alarming number of dengue cases in Malaysia requires an alternative method to control dengue besides the traditional method such as fogging. However, the introduction of new technologies depends on social acceptance. Therefore, this study was important to determine the factors that influence stakeholders’ attitudes towards the ORS and the moderating factor. A validated instrument was used to randomly interview 399 respondents representing two stakeholder groups which consist of scientists, and the public in Klang Valley, Malaysia. The findings revealed that the stakeholders claimed to have a high degree of religiosity, a high level of trust in the key players, perceived ORS as having high benefits, and displayed highly positive attitudes towards the ORS. The attitudes model towards the ORS model was developed using the SmartPLS software version. The perceived benefit was endorsed as the most important direct predictor of attitudes towards the ORS (ß = 0.618, P<0.001), followed by trust in the key players (ß = 0.151, P<0.001). It is also interesting to note that religiosity served as a moderator for the association between perceived benefit (ß = 0.075, P = 0.024) and perceived risk (ß = 0.114, P = 0.006) with attitudes towards the ORS. The identified predictor factors of stakeholders’ attitudes toward the ORS and the moderating factor can serve as indicators for social acceptance of ORS in developing countries. These indicators can help the policymakers in decision making to implement this technique.     

Green tea (Camellia sinesis) ameliorates female Schistosoma mansoni-induced changes in the liver of Balb/C mice

This study was designed to assess the effect of green tea, an aqueous extract of Camellia sinensis, on the oxidative stress, antioxidant defense system and liver pathology of Schistosoma mansoni-infected mice. Green tea at concentration of 3% (w/v) was given orally to treated mice as sole source of drinking water from the end of the 4th week to the end of 10th week post-infection; untreated mice were allowed to drink normal water. The data of the studied S. mansoni-infected mice exhibited a suppression of hepatic total antioxidant capacity, superoxide dismutase (SOD), catalase (CAT) activity and glutathione content. The liver lipid peroxidation was deleteriously elevated in S. mansoni-infected mice. The hepatic total protein content, AST and ALT activities were profoundly decreased in the S. mansoni-infected mice. Most hepatocytes were damaged and showed abnormal microscopic appearance with aggressive necrosis. Both total protein and glycogen levels have been greatly reduced as indicated by histochemical examination. The treatment of S. mansoni-infected mice with green tea succeeded to suppress oxidative stress by decreasing the lipid peroxides but failed to significantly enhance the antioxidant defense system and deteriorated changes owing to liver damage and necrosis. In consistence with biochemical data, histopathological and histochemical data indicated that treatment of S. mansoni-infected mice with green tea could ameliorate hepatocytes thus reduce cellular necrosis and partially restore both total protein and glycogen levels. Thus, the study concluded that the green tea suppresses the oxidative stress through its constituent with free radicals scavenging properties rather than through the endogenous antioxidant defense system.     

Effect of sewage water on mineral nutritive potential of six fodder species grown under semiarid conditions

Investigation was performed to assess the effect of different sewage water treatments on the metal status of different fodder species consumed by ruminants under semi-arid conditions. Five samples each of six fodder species viz., Trifolium alexandrinum, Cichorium intybus, Avena sativa, Medicago polymorpha, Brassica campestris and Medicago sativa were collected from three fields irrigated with canal water, mix water (canal water and sewage water) and sewage water, respectively. Fodder samples were analyzed to determine the Mg, Co and Zn concentrations in shoots. Higher values of these metals were found in fodder species irrigated with sewage water relatively. Mg and Zn concentrations in all the fodder species were found to be below the critical level among all treatments. Whereas, concentrations of Co in the different fodder species were significantly different (p < 0.05) and above the critical level. Consequently, ruminants feeding on these fodder species need continued mineral supplementation of Zn and Mg elements to prevent diseases caused by the deficiency of these elements, and to support optimum animal productivity.