Pakistan is vulnerable to climate change, and extreme climatic conditions are threatening food security. This study examines the effects of climate change (e.g., maximum temperature, minimum temperature, rainfall, relative humidity, and the sunshine) on the major crops of Pakistan (e.g., wheat, rice, maize, and sugarcane). The methods of feasible generalized least square (FGLS) and heteroscedasticity and autocorrelation (HAC) consistent standard error were employed using time series data for the period 1989 to 2015. The results of the study reveal that maximum temperature adversely affects wheat production, while the effect of minimum temperature is positive and significant for all crops. Rainfall effect towards the yield of a selected crop is negative, except for wheat. To cope with and mitigate the adverse effects of climate change, there is a need for the development of heat- and drought-resistant high-yielding varieties to ensure food security in the country.

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Solvent accessible surface area (SASA) of proteins has always been considered as a decisive factor in protein folding and stability studies. It is defined as the surface characterized around a protein by a hypothetical centre of a solvent sphere with the van der Waals contact surface of the molecule. Based on SASA values, amino acid residues of a protein can be classified as buried or exposed. There are various types of SASAs starting from relative solvent accessibility to absolute surface areas. Direct estimation of accurate SASAs of folded proteins experimentally at the atomic level is not possible. However, the SASA of a native protein can be estimated computationally from the atomic coordinates. Similarly, various simulation methods are available to compute the SASA of a protein in its unfolded state. In efforts to estimate the changes in SASA related to the protein folding, a number of the unfolded state models have been proposed. In this review, we have summarized different algorithms and computational tools for SASA estimations. Furthermore, online resources for SASA calculations and representations have also been discussed in detail. This review will be useful for protein chemists and biologists for the accurate measurements of SASA and its subsequent applications for the calculation of various biophysical and thermodynamic properties of proteins.

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BackgroundParrotiopsis jacquemontiana (Decne) Rehder. is locally used for skin infections and in wound healing. In this study we have evaluated methanol extract of its leaves and derived fractions against the clinical multi-drug resistant bacterial strains.MethodsP. jacquemontiana leaves powder extracted with 95% methanol (PJM) and fractionated in escalating polarity of solvents; n-hexane (PJH), chloroform (PJC), ethyl acetate (PJE), n-butanol (PJB) and the remaining as aqueous fraction (PJA). Clinical as well as environmental 19 bacterial strains and 8 fungal strains were screened for minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC). Preliminary phytochemical investigation for various phytochemical classes was also carried out.ResultsPJM contained the coumarins, phenols, flavonoids, tannins, alkaloids, glycosides, saponins, sterols, phlobatannins, steroids, phytosterols, triterpenoids, acids, quinones, proteins, vitamin C, betacyanins, oils and resins while anthraquinones, phytosteroids, carbohydrates and anthocyanins were not detected. Disc diffusion assay (1 mg/disc) indicated the sensitivity of all the MDR strains of bacteria with PJM, PJE and PJB, while no inhibition was recorded with PJA. PJH and PJC inhibited the growth of all the strains of Staphylococcus aureus, Pseudomonas aeruginosa and Coagulase negative staphylococci used in this study. Maximum zone of inhibition (35.5 ± 1.32 mm) was obtained with PJM against Staphylococcus lugdenesis MDR (6197). Comparatively lower MIC (8-64 μg/ml) and MBC (32-256 μg/ml) values were recorded for PJM and PJE. In case of fungal strains only PJM, PJE and PJB markedly inhibited the growth and lower MIC (8-128 μg/ml) and MFC (32-512 μg/ml) values were determined for PJM and PJE.ConclusionThe remarkable inhibition of various bacterial and fungal strains at low doses of the extract/fractions suggested the strong antibacterial, antifungal and anti-candidal potential of P. jacquemontiana leaves.