Showing papers by "Muhammad Irfan published in 2009"

Gossypium arboreum GHSP26 enhances drought tolerance in Gossypium hirsutum.

Abstract: Heat-shock proteins (HSP) are molecular chaperones for protein molecules. These proteins play an important role in protein-protein interactions such as, folding and assisting in the establishment of proper protein conformation and prevention of unwanted protein aggregation. A small HSP gene GHSP26 present in Gossypium arboreum responds to dehydration. In the present study, an attempt was made to overcome the problem of drought stress in cotton. A cDNA of GHSP26 was isolated from G. arboreum, cloned in plant expression vector, pCAMBIA-1301 driven by the cauliflower mosaic virus 35S promoter and introduced into Gossypium hirsutum. The integration and expression studies of putative transgenic plants were performed through GUS assay; PCR from genomic DNA, and quantitative real-time PCR analysis. Transgenic cotton plants showed an enhanced drought tolerance, suggesting that GHSP26 may play a role in plant responsiveness to drought.

Functional analysis of cotton small heat shock protein promoter region in response to abiotic stresses in tobacco using Agrobacterium-mediated transient assay

Abstract: The cotton (Gossypium arboreum) stress-related gene GHSP26 responds to dehydration. To elucidate its stress tolerant mechanism at the transcriptional level, we isolated and characterized the promoter region (PGHSP26, −2,831 bp) flanking the 5′ GHSP26 coding region from the genomic DNA. A series of PGHSP26 deletion derivatives was created for the identification of the upstream region of the gene required for the promoter activity. Each deletion construct was analyzed by agrobacterium mediated transient transformation in tobacco leaves after treatment with abscissic acid (ABA), heavy metals and dehydration. Promoter fragments of 716 bp or longer showed two-fold or greater induction after each treatment. These findings further our understanding of the regulation of GHSP26 expression and provide a new drought-inducible promoter system in transgenic plants.

Isolation and functional analysis of cotton universal stress protein promoter in response to phytohormones and abiotic stresses

Abstract: The 949 bp promoter fragment upstream from the translation initiation site of the GUSP gene encoding a universal stress protein was isolated from the genomic DNA of Gossypium arboream. Some putative cis-acting elements involved in stress responses including E-box, ABRE, DPBF-box, and MYB-core elements were found in the promoter region. In an Agrobacterium-mediated transient expression assay, strong activation of the GUSP full promoter region occurred in tobacco leaves following dehydration, abscisic acid, salt, heavy metal, gibberellic acid and dark treatments. Deletion analysis of the promoter revealed that the dehydration, abscisic acid and salt responses were affected by the deletion between -208 and -949 bp and showed 2-4-fold induction. However, in response to dark, gibberellic acid and heavy metals the induction was only 2-fold. This is an important study as no report of this universal stress protein promoter is available in literature.

Usability evaluation of e-learning applications, A case study of It’s Learning from a student’s perspective

Abstract: The basic purpose of e-learning applications is to deliver knowledge, share information and help learners in their learning activities in an effective and efficient way by involving advanced electronic technologies. Usability of e-learning applications is of great significance because their success depends upon basic usability principles. The criteria for judging the success can be defined by user satisfaction level after the user’s interaction with interface of e-learning system. In this research report we present the results of a usability evaluation of an e-learning system. Appropriate use of usability evaluation methods according to given scenarios is an important aspect of this report. Both end-users and usability experts participated in our study, during which we used different methods for usability evaluation of specific e-learning platform It’s Learning. The authors give recommendations for the improvement of It’s Learning after validating the results of methods used for usability evaluation. Moreover, the authors discuss the areas of e-learning with relation to usability where future could be more beneficial to learners by involving and adopting new technologies.

Fluctuation-induced conductivity of five planar Cu0.5Tl0.5Ba2Ca4−xMgxCu5O14−δ (x = 1, 2) superconductors

Abstract: Excess conductivities of polycrystalline, as-prepared and oxygen post annealed Mg doped samples have been studied from the resistivity versus temperature data. The logarithmic plots of excess conductivity versus reduced temperatures [ ( T - T c mf ) / T c mf ] show two cross-over temperatures with three exponents. Except for the as-prepared sample with x = 1 all the samples have shown a distinct cross-over from two-dimensional to three-dimensional conductivity in accordance with the 2D, 3D Aslamazov–Larkin equations. Interlayer-coupling strength estimated by using Lawrence–Doniach equations has been observed to increase with higher Mg doping and post-annealing. The improved properties with the higher Mg concentration might be arising from the reduction of the anisotropy along the c-axis. The oxygen post-annealing seems to improve carrier concentration in the conducting CuO2 planes that may be responsible for 2D–3D cross-over of the excess conductivity.

Enhanced three-dimensional excess conductivity in Be-doped Cu0.5Tl0.5Ba2Ca3−xBexCu4O12−δ(x=0,0.5,0.75,1.0,1.25,1.5) superconductors

Abstract: We report the enhanced fluctuation-induced conductivity of Be-doped Cu0.5Tl0.5Ba2Ca3−xBex Cu4O12−δ (x=0,0.5,0.75,1.0,1.25,1.5) samples. The analysis has been done with partial substitution of Be in place of Ca. In each case excess conductivity has been analyzed and we tried to make a fit with the Aslamasov–Larkin (AL) and Lawrence–Doniach equations. It is observed that our data fit well with the three-dimensional (3D) AL equation, and a crossover from two dimensions to three dimensions has been found in our samples. We have also employed this transition to estimate the Josephson coupling strength in our samples. This interlayer coupling strength J, which controls the superconducting transition, has been found to improve with increased Be content. The Ginzburg–Landau coherence lengths ξc(0) for all cases have also been calculated. The Fourier transform infrared spectroscopy (FTIR) absorption measurements also provide a clue for the enhanced 3D fluctuations. The higher electronegativity, as well as smaller ...

Fluctuation-Induced Conductivity of Cu0.5Tl0.5Ba2Ca2Cu2M1O10−δ (M = Si, Sn, Ge) Superconductors

Abstract: Fluctuation-induced conductivity of Cu0.5Tl0.5Ba2Ca2Cu2M1O10−δ (M = Si, Sn, Ge) superconductors has been studied from the resistivity vs. temperature data. The logarithmic plots of excess conductivity (Δσ) vs. reduced temperatures [e=(T−T )/T ] show two crossover temperatures with three exponents. A distinct crossover from two-dimensional to three-dimensional conductivity in accordance with the 2D, 3D Aslamazov–Larkin equations has been observed in all the samples. Another crossover from 2D to 0D fluctuations has also been witnessed. FIC data analysis has been found to be quite useful in explaining the superconducting properties of the samples. Si and Sn doped samples have shown almost similar characteristics, while in Ge doped sample diverse behavior is observed.

Implementation of GA in Designing Control System for Paraplegic Walking Movement using Walker

Abstract: Due to the complex nature of the humanoid model structure and unavailability of its mathematical model, the model of humanoid structure is developed and then simulated in MSC Visual Nastran to find the dynamics of humanoid model walk with walker and the reference trajectories for normal walk are obtained. Further estimation of the joint torques and the development of a controller to control the movement of the humanoid model with walker is being done. To guide the humanoid model according to the reference trajectories, the controllers are designed. Genetic Algorithm (GA) is employed to optimize the PID controller's parameters so that the developed model follows the reference trajectories.

Business ethics: myths and current approaches business ethics: myths and current approaches business ethics: myths and current approaches business ethics: myths and current approaches business ethics: myths and current approaches

Abstract: This paper is basically a review paper and discusses business ethics in the context of myth and its current approaches. Most of business people think that business has nothing to do with ethics, but the business is there just to strive for more and more profit. The duties and responsibilities towards the society are not clear, so they are striving for much profit and ignoring the ethical standards. The current approaches in this regard elaborate that without considering the current environment, the flow of business, establishing good relationship and ignoring the ethical standards the business will loose its image and will not be able to survive.