Determinants of Import Demand for Crude Oil in Pakistan

This study analyzes determinants of import demand for crude oil in Pakistan. For this purpose, Co- integration technique has been used to estimates long run relationship between crude oil import demand and its determinants; GDP per capita, price of crude oil, real effective exchange rate, and electricity production from oil sources. This import demand of crude oil function empirically tested for Pakistan. Results show that import demand elasticity of crude oil with respect to its different determinants is different. The import demand of crude oil is affected positively and significantly by GDP per capita and electricity production from oil sources. Price and real effective exchange rate have negative and significant impact on crude oil import demand in Pakistan. This study provides guidelines for macroeconomic policymakers in order to formulate comprehensive and appropriate import policy for crude oil

Enhancing water stress tolerance of bread wheat during seed germination and seedling emergence: caffeine-induced modulation of antioxidative defense mechanisms

Better crop stand establishment, a function of rapid and uniform seedling emergence, depends on the activities of germination-related enzymes, which is problematic when there is insufficient soil moisture. Different ways are in practice for counteracting this problem, including seed priming with different chemicals, which are considered helpful in obtaining better crop stand establishment to some extent through improved seed germination and seedling emergence. In this growth room experiment, caffeine was used as a seed priming agent to improve germination under moisture scarcity. Polyethylene glycol-8000 (18%) was added to Hoagland’s nutrient solution to create drought stress (−0.65 MPa). The experiment was arranged in a completely randomized design (CRD), having four replications of each treatment. A newly developed wheat genotype SB-1 was used for the experimentation. Different doses of caffeine, i.e., 4 ppm, 8 ppm, 12 ppm, and 16 ppm, including no soaking and water soaking, were used as seed priming treatments. Water deficit caused oxidative stress and adversely affected the seed germination, seedling vigor, activities of germination enzymes, photosynthetic pigments, and antioxidative defense mechanism in roots and shoots of seedlings. Caffeine seed priming ameliorated the negative effects of water deficit on seed germination and seedling vigor, which was attributed to the reduction in lipid peroxidation and improvement in the activities of germination-related enzymes like glucosidase, amylase, and protease. Conclusively, seed priming with 12 ppm caffeine outperformed the other treatments and hence is recommended for better crop stand establishment under conditions of soil moisture deficit

Sources of Type I Interferons in Infectious Immunity: Plasmacytoid Dendritic Cells Not Always in the Driver's Seat

Type I Interferons (IFNs) are hallmark cytokines produced in immune responses to all classes of pathogens. Type I IFNs can influence dendritic cell (DC) activation, maturation, migration, and survival, but also directly enhance natural killer (NK) and T/B cell activity, thus orchestrating various innate and adaptive immune effector functions. Therefore, type I IFNs have long been considered essential in the host defense against virus infections. More recently, it has become clear that depending on the type of virus and the course of infection, production of type I IFN can also lead to immunopathology or immunosuppression. Similarly, in bacterial infections type I IFN production is often associated with detrimental effects for the host. Although most cells in the body are thought to be able to produce type I IFN, plasmacytoid DCs (pDCs) have been termed the natural “IFN producing cells” due to their unique molecular adaptations to nucleic acid sensing and ability to produce high amounts of type I IFN. Findings from mouse reporter strains and depletion experiments in in vivo infection models have brought new insights and established that the role of pDCs in type I IFN production in vivo is less important than assumed. Production of type I IFN, especially the early synthesized IFNβ, is rather realized by a variety of cell types and cannot be mainly attributed to pDCs. Indeed, the cell populations responsible for type I IFN production vary with the type of pathogen, its tissue tropism, and the route of infection. In this review, we summarize recent findings from in vivo models on the cellular source of type I IFN in different infectious settings, ranging from virus, bacteria, and fungi to eukaryotic parasites. The implications from these findings for the development of new vaccination and therapeutic designs targeting the respectively defined cell types are discussed

Impact of Political Setups on Foreign Direct Investment in Pakistan

This paper analyses the impact of different political setups on foreign direct investment (FDI) in Pakistan and examines whether different political setups has any effect on FDI. The time series data from the period 1971-2018 is used. Ordinary least square regression model is run to check the significance of the data and relationship between dependent and independent variables. Gross domestic product, gross capital formation, inflation rate, indirect taxes, exchange rate, trade openness and dummy variable for dictatorship or autocratic regime in Pakistan are taken as an independent variables and FDI as dependent variable. The results of study indicate that in the long run GDP is the major determinant of FDI in Pakistan and is followed by gross capital formation or domestic investment and inflation. The results also indicate that during dictatorship or imperialistic regimes there are less FDI into Pakistan

Sugar alcohols-induced oxidative metabolism in cotton callus culture

Sugar alcohols (mannitol and sorbitol) may cause oxidative damage in plants if used in higher concentration. Our present experiment was undertaken to study physiological and metabolic responses in cotton (Gossypium hirsutum L.) callus against mannitol and sorbitol higher doses. Both markedly declined mean values of relative fresh weight growth rates with the increase in their concentration intensities. The overall protein and malonaldehyde (MDA) contents increased in the stressed-shocked cells. Also, the mean values of various antioxidants such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and calalase (CAT) quantitatively improved over their respective controls. As a whole, MDA contents were higher in magnitude than that of different antioxidant enzymes. Also values of relative increase in case of POD were higher as compared to SOD showing the ability of cotton callus culture to scavenge H2O2 produced as a result of the activity of SOD. Our results show that both agents caused greater damage to the membranous structure in comparison to less activation of the antioxidants. As a whole, the overall change regarding fresh weight growth rates was less after 14-day stress regime, while the mean values of the antioxidant enzymes activities were lower after the 28-day stress period. Such decrease conveys the message that less reactive oxygen species (ROS) might have been produced.Keywords: Antioxidants, callus culture, Gossypium hirsutum L., osmotic stress, sugar alcoholsAfrican Journal of Biotechnology Vol. 12(17), pp. 2191-220

Modulation of Cd carriers by innovative nanocomposite (Ca+Mg) and Cd-resistance microbes (Bacillus pumilus): a mechanistic approach to enhance growth and yield of rice (Oryza sativa L.)

Cadmium (Cd) is a well-known pollutant in agricultural soil, affecting human health through the food chain. To combat this issue, Ca + Mg (25 mg L−1) nanocomposite and Bacillus pumilus, either alone or combined, were applied to rice plants under Cd (5 mg kg−1, 10 mg kg−1) contamination. In our study, growth and yield traits demonstrated the beneficial influence of Ca + Mg and B. pumilus application in improving rice defense mechanism by reducing Cd stress. Combined Ca + Mg and B. pumilus application increased SPAD (15), total chlorophyll (18), chlorophyll a (11), chlorophyll b (22), and carotenoids (21%) with Cd (10 mg kg−1), compared to the application alone. Combined Ca + Mg and B. pumilus application significantly regulated MDA (15), H2O2 (13), EL (10), and O2•– (24%) in shoots under Cd (10 mg kg−1), compared to the application alone. Cd (10 mg kg−1) increased the POD (22), SOD (21), APX (12), and CAT (13%) in shoots with combined Ca + Mg and B. pumilus application, compared to the application alone. Combined Ca + Mg and B. pumilus application significantly reduced Cd accumulation in roots (22), shoots (13), and grains (20%) under Cd (10 mg kg−1), compared to the application alone. Consequently, the combined application of Ca + Mg and B. pumilus is a sustainable solution to enhance crop production under Cd stress

Optimization of exogenous CeO2 nanoparticles on Pak choi (Brassica rapa L. var. chinensis) to alleviate arsenic stress

Arsenic (As) is a regulated hazardous substance that persists in the environment, causing issues related to environmental health, agriculture, and food safety. Cerium oxide nanoparticles (CeO2 NPs) are emerging sustainable solutions for alleviating heavy metal stress. However, their effectiveness and optimization for foliar application in reducing As stress, especially in Pak choi, has not been reported yet. Hence, this study aims to examine the effects of foliar application of CeO2 NPs (75,000,000, 150,000,000, and 300,000,000 ng/L) on the growth, nutrient availability, and antioxidant enzymatic activities of Pak choi plants under As stress. The findings showed that foliar application of 75,000,000 ng/L CeO2 NPs significantly increased shoot length (77.32%), root length (80.98%), and number of leaves (80.23%) as compared to control without NPs. The lowest dose of CeO2 NPs (75,000,000 ng/L) increased antioxidant enzyme activities such as peroxidase (86.10%), superoxide dismutase (81.48%), and catalase (52.07%), while significantly reducing malondialdehyde (44.02%), hydrogen peroxide (34.20%), and electrolyte leakage (43.53%). Furthermore, foliar application of 75,000,000 ng/L CeO2 NPs significantly increased the content of zinc (81.02%), copper (56.99%), iron (88.04%), manganese (68.37%), magnesium (76.83%), calcium (61.16%), and potassium (84.91%) in leaves when compared to control without NPs. The same trend was observed for shoot and root nutrient concentrations. Most importantly, 75,000,000 ng/L CeO2 NPs foliar application significantly reduced shoot As (45.11%) and root As (20.89%) concentration compared to control, providing a reassuring indication of their potential to reduce As concentration in plants. Our study’s findings are of utmost importance as they indicate that lower concentrations of foliar-applied CeO2 NPs can be more effective in enhancing crop nutrition and reducing heavy metals than higher concentrations. This article is intended to present critical issues of As contamination in agricultural soils, which imposes substantial risks to crop productivity and food security

Heavy Metal Toxicity in Plants: An Overview on Tolerance Mechanisms and Management Strategies

Heavy metals are one of the factors that pollute the environment and significantly affect soil fertility, plant physiology, development, and productivity. The tolerance of plants to toxicity depends on the species and tissue, element type, and duration of exposure to stress. Some special signal molecules such as nitric oxide (NO), hydrogen peroxide (H2O2), beneficial ions, hyperaccumulating plants, stress hormones, nanoparticles, organic compounds, and microbial applications can be recommended to alleviate the stress effects caused by toxic heavy metals in plants. Induction of other promising techniques like seed priming, active involvement of plant growth regulator, use of osmoprotectants, successful plant microbes’ crosstalk and recent utilization of nanoparticles are worth using strategies in mitigation of heavy metal stress in plants. These practices effectively regulate the activities of antioxidant enzymes for the alleviation of stress in plants, creditably improving the plant tolerance via preserving cell homeostasis and amending the adversative effects of heavy metal stress in plants. These inventive strategies offer an enriched understanding of how to boost crop productivity under heavy metal stress in order to decrease the risk to global food security

Zinc fortification and alleviation of cadmium stress by application of lysine chelated zinc on different varieties of wheat and rice in cadmium stressed soil

Sustainable and cost-effective methods are required to increase the food production and decrease the toxic effects of heavy metals. Most of the agriculture land is contaminated with cadmium (Cd). The present study was designed to minimize the toxic effect of Cd stress (0, 10 and 20 mg kg1-) on tolerant and sensitive varieties of wheat (Punjab-2011; Sammar) and rice (Kisan Basmati; Chenab) under Zn-lysine (Zn-lys) application as foliar spray (0, 12.5 and 25 mM) and seed priming (0, 3 and 6 ppm). Remarkable decrease was observed in plant growth, physiology and biochemistry as well as increase in Cd uptake, roots to shoots and grains of both crops. Cd significantly reduced the root and shoot lengths, root and shoot dry weights, transpiration rate, photosynthetic rate, stomatal conductance and water use efficiency as well as chlorophyll contents associated with enhanced electrolyte leakage (EL), malondialdehyde (MDA) and H2O2 and Cd uptake in different plant parts including grains of both crop varieties. The foliar application of Zn-lys (0, 12.5 and 25 mM) ameliorated the toxic effect of Cd on growth and physiology associated with decrease in EL, MDA and H2O2 and improved the activities of SOD, POD, CAT and APX enzymes with decreasing Cd uptake in tolerant varieties of wheat and rice as compared to seed priming. Furthermore, it has been investigated that the foliar application of Zn-lys is effective to improve quality of wheat and rice tolerant varieties (Punjab-2011 and Chenab) under Cd contamination soils