Existence of Mild Solutions for Semilinear Impulsive Functional Mixed Integro-differential Equations with Nonlocal Conditions

In this paper, we prove the existence, uniqueness and continuous dependence of initial data on mild solutions of first order semilinear functional impulsive mixed integro-differential equations with nonlocal condition in general Banach spaces. The results are obtained by using the semigroup theory and Banach contraction theorem

Factors and Impact of Risk Management Practice on success of Construction Projects of Housing Developers, Kathmandu, Nepal

Risk Management is set of activities concerned with identifying the root causes of risks and to trace their consequences through the comprehensive and systematic way of identifying, analysing and responding to risks to achieve the project objectives. The use of risk management is essential from the early stages of a project, where major decisions such as selection of site, construction methods and procurement methods can be influenced. This research is conducted to identify significant factors of risk and the impact of Risk Management Practice on success of construction projects of Housing Developers in Kathmandu Valley. It was revealed that housing developers of Kathmandu valley are quite aware regarding Risk Management (more than 80%) and are practising it in their project  someway (more than 65%) whereas only 45% of the developers are practicing using formal techniques . Risk factors related to time overrun, cost overrun, quality, project scope, design and specification, contract, finance and economy, health safety and environment, organisation and leadership were found to be the ten significant factors. These ten risks are taken as success criteria for hypothesis testing. Out of thirty three hypothesis testing to find impact, only 6 hypotheses were not accepted and impact was not seen. For the remaining twenty seven hypotheses, significant impact was found to exist between the variables. Those 27 hypotheses are Risk Identification, Risk Assessment and Risk Response on Project Success, Scope well defined, Technical Specifications  Compliance, Planned budget, Quality, Time, Contractual Risks, Financial and economic Risks, Safety, Health and Environmental Risks, Leadership Risk and Organizational Risk.Thus from this study, it can be said that significant impact exists between risk management practice and success of projects for the housing projects in Kathmandu valley. And thus from this study, it can be said that significant impact exists between risk management practise and success of projects for the housing projects in Kathmandu valley

Insertion of a small peptide of six amino acids into the β7–β8 loop of the p51 subunit of HIV-1 reverse transcriptase perturbs the heterodimer and affects its activities

BACKGROUND: HIV-1 RT is a heterodimeric enzyme, comprising of the p66 and p51 subunits. Earlier, we have shown that the β7-β8 loop of p51 is a key structural element for RT dimerization (Pandey et al., Biochemistry 40: 9505, 2001). Deletion or alanine substitution of four amino acid residues of this loop in the p51 subunit severely impaired DNA binding and catalytic activities of the enzyme. To further examine the role of this loop in HIV-1 RT, we have increased its size such that the six amino acids loop sequences are repeated in tandem and examined its impact on the dimerization process and catalytic function of the enzyme. RESULTS: The polymerase and the RNase H activities of HIV-1 RT carrying insertion in the β7-β8 loop of both the subunits (p66(INS)/p51(INS)) were severely impaired with substantial loss of DNA binding ability. These enzymatic activities were restored when the mutant p66(INS) subunit was dimerized with the wild type p51. Glycerol gradient sedimentation analysis revealed that the mutant p51(INS) subunit was unable to form stable dimer either with the wild type p66 or mutant p66(INS). Furthermore, the p66(INS)/p66(INS) mutant sedimented as a monomeric species, suggesting its inability to form stable homodimer. CONCLUSION: The data presented herein indicates that any perturbation in the β7-β8 loop of the p51 subunit of HIV-1 RT affects the dimerization process resulting in substantial loss of DNA binding ability and catalytic function of the enzyme