ABSTRACT
Assessing the impacts of climate change and land-use change is of critical importance, particularly for urbanized catchments. In this study, a novel framework was used to examine and quantify these impacts on the runoff in six catchments in Southeast Queensland, Australia. For each catchment, temporal variations in impervious areas were derived from six satellite images using a sub-pixel classification technique and incorporated into the SIMHYD hydrological model. This model was satisfactorily calibrated and validated with daily runoff observations (0.63 ≤ Nash-Sutcliffe efficiency coefficient ≤ 0.94, percent bias ≤ ±18 %) and was used to produce baseline runoff for 1986-2005 in these six catchments. The projected population increase was used to predict future imperviousness based on the linear relationship between the two. The projected rainfall and evapotranspiration were derived from the ensemble means of the eight general circulation models. Catchment runoff was projected under two climate change scenarios (RCP4.5 and 8.5), three urbanization scenarios (low, medium, and high), and six combined scenarios for two future periods (2026-2045 and 2046-2065). Comparing with the baseline, it was found that (1) climate change alone would lead to a -3.8 % to -17.6 % reduction in runoff among the six catchments, for all scenarios and both future periods; (2) a 11.8 % to 78 % increase in runoff was projected under the three urbanization scenarios, and (3) a decrease in runoff due to climate change would moderate the increase in runoff caused by urbanization. For example, the combined effect would be a 54 % increase in runoff, with a -17.2 % decrease due to climate change and 78 % increase due to urbanization. Overall, runoff in the six catchments may be significantly affected by urban expansion. From this study, decision makers could gain a better understanding of the relative importance of the effects of climate and land-use change, which can be applied when developing future long-term water management plans at the catchment scale.
Subject(s)
Urbanization , Water Movements , Queensland , Climate Change , AustraliaABSTRACT
Background: Heat Shock Proteins (HSPs) elicit humoral and cellular immune responses. Due to their high sequence homology, they can be developed as a new immunogen for cross prophylactic and vaccination effects against infectious agents such as Enteropathogenic and Enterohemorrhagic Escherichia coli (EPEC and EHEC). This study aimed to evaluate the immunogenicity and cross-protective efficacy of rGroEL of Salmonella typhi (S. typhi) encapsulated in poly lactic-co-glycolic acid (PLGA) nanoparticles against EPEC and EHEC. Methods: Recombinant GroEL was expressed in Escherichia coli (E. coli) and purified using Ni-NTA affinity chromatography. The protein was encapsulated in PLGA by the double emulsion method, and the nanoparticles were characterized physicochemically. BALB/c mice were immunized, and the efficacy of the protein to elicit immune responses was assessed. Results: Over-expression in E. coli led to corresponding 64.5 kDa protein bands in Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). Non-aggregated nanoparticles had a spherical shape with a mean diameter of 194.3±3 nm and encapsulation efficiency of 89.5±2.5%. Antibody isotyping revealed that GroEL immunization induced both IgG1 and IgG2a antibodies. Moreover, immunization of the mice with recombinant GroEL protein conferred 80 and 60% protection against lethal infections by EPEC and EHEC, respectively. Furthermore, organ burden studies revealed a significant reduction in infection in the immunized mice compared to the non-immunized ones. Passive immunization with anti-GroEL sera also protected 50% of the mice against the lethal doses of EHEC and EPEC strains. Conclusion: The findings indicated that immunization of the mice with recombinant GroEL of S. typhi elicited cross-protection against other bacterial infections. This represented the immense potential of GroEL to be developed as a single vaccine against multiple pathogens.
ABSTRACT
Pepper is mostly produced in greenhouses and fields in spring up to the end of summer. The reproductive stage coincides with high temperature of summer, which causes flowers to drop, leading to reduction in the yield, Se as a beneficial element can improved some stress indices. Control randomized design experiment was conducted to investigate the effect(s) of Se on heat stresses of pepper in control environment. Se in three concentrations of SeCl2 (4 (Se1), 6 (Se2) and 8 (Se3) mg L-1) was used at 35 ± 2 °C for 4 h a day, matching the high afternoon temperature. Growth, photosynthesis traits (Photosynthesis rate, transpiration and stomatal conductance), flower dropping and antioxidant changes were all measured. Results showed that Se1 decreased deleterious effects of heat stresses on vegetative traits (fresh and dry weight of fruit). Including dry weight of shoot, fresh and dry weight of root, and reproductive growth, such as Fresh weight and dry weight of fruit, flowers and fruit number. Photosynthesis rate, fruit antioxidant and phenol improved with the application of Se to heat stresses. POD and SOD activity increased, and MDA content decreased with Se application at the high temperature. Se also improved the P and S uptake. Generally, using 4 and 6 mg L-1 of Se could improve growth and physiological and phytochemical parameters of pepper and decrease the flower dropping at high temperature.
