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The effect of variable temperatures (10–50 ºC) on photosynthesis and chlorophyll fluorescence in Conocarpus lancifolius was evaluated. Additionally, the ability of the species to synthesize heat-shock proteins (HSPs) to protect against high temperatures, and malondialdehyde (MDA) as a by-product of lipid peroxidation was investigated. Plants at 10 ºC showed virtually no measurable growth, leaf discoloration and a few brown lesions, while high temperatures (40 and 50 ºC) promoted growth and lateral branch development. Chlorophyll content index, photochemical efficiency (Fv/Fm) of PS II, electron transport rate and photosynthetic rate declined with decreasing temperature but increased significantly at higher temperatures. Heat-shock protein (HSP 70 kDa) was produced at temperatures 30–50 ºC and an additional 90 kDa protein was also produced at 50 ºC. Increase in the efficiency of excitation energy captured by the open PS II reaction centers (Fv/Fm) increased linearly (P B 0.05) with the accumulation of HSP 70 at higher temperatures. However, at low temperatures the concentration of MDA increased significantly, indicating lipid peroxidation due to oxidative stress. The production and accumulation of HSP 70 and 90 kDa coupled with increased electron transport rate and photochemical efficiency can be used to assess survival, growth capacity and to some extent the tolerance of C. lancifolius to elevated temperatures.
Efficacy of ivermectin against cattle warbles was studied in an endemic area of Pakistan. A total of 229 cattle of three breeds and different ages were divided into two groups; treated and untreated control. Treated group was given ivermectin s/c at the rate of 200 µg/kg body weight during the 1st week of September. None of the treated animal developed warbles. Warbles were seen in 23,8% of untreated control animals. Statistically non-significant differences were seen amongst different breeds and age groups. The seasonality of warbles is discussed.
The contamination of soil and water with heavy metals is one of the major environmental problems in the world. Oil and gas exploration and production activities contaminate the environment with heavy metals. In this study, heavy metal concentration was assessed in drilling waste discharges of different oil and gas wells at Khyber Pakhtunkhwa (KP), Pakistan. Moreover, the concentration of heavy metals in the soil surrounding the drilling waste discharges was determined. The representative samples were collected from seven oil and gas drilling waste discharges and the surrounding soil. The collected samples were analyzed for selected heavy metals (Ba, Pb Cr, Cd, Zn, Mn, and Ni) by atomic absorption spectrometric standard methods. Analysis showed that oil and gas well drilling operation waste is enriched with determined heavy metals. The high concentration of heavy metals, particularly Ba and Pb, was also found in the surrounding soil samples. In particular, Ba concentration varied from 1050 to 4168 mg/kg soil. Statistical correlational analysis depicted a common origin of the heavy metals in the soil of the study area, potentially the drilling waste discharges from oil and gas wells. The concentration of heavy metals in oil and gas well drilling waste discharge high, and also affects surrounding soils.
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