Biochemistry of Nitric Oxide

Nitric oxide (NO) a free radical having both cytoprotective as well as tumor promoting agent is formed from l-arginine by converting it to l-citrulline via nitric oxide synthase enzymes. The reaction product of nitric oxide with superoxide generates potent oxidizing agent, peroxynitrite which is the main mediator of tissue and cellular injury. Peroxynitrite is reactive towards many biomolecules which includes amino acids, nucleic acid bases; metal containing compounds, etc. NO metabolites may play a key role in mediating many of the genotoxic/carcinogenic effects as DNA damage, protein or lipid modification, etc. The basic reactions of nitric oxide can be divided as direct effect of the radical where it alone plays a role in either damaging or protecting the cell milieu and an indirect effect in which the byproducts of nitric oxide formed by convergence of two independent radical generating pathways play the role in biological reactions which mainly involve oxidative and nitrosative stress. Nitric oxide is also capable of directly interacting with mitochondria through inhibition of respiration or by permeability transition. Reaction of nitric oxide with metal ions include its direct interaction with the metals or with oxo complexes thereby reducing them to lower valent state. Excessive production of nitric oxide can be studied by inhibiting the synthetic pathway of nitric oxide using both selective or specific nitric oxide synthase inhibitor or non-selective nitric oxide synthase inhibitor with respect to isoforms of nitric oxide.     

Awareness about plagiarism amongst university students in Pakistan

Research is an original and systematic investigation undertaken to discover new facts and information about a phenomenon. However a variety of empirical and ethical issues are on the rise in academia, especially plagiarism is quickly becoming part of global educational and research culture. More and more students and researchers are turning to the Internet for cooked solutions and shortcuts for writing assignments, research papers and thesis. The purpose of this paper is to highlight the seriousness of plagiarism amongst graduate and post graduate students of Pakistan. It also explores the university students’ level of awareness of plagiarism. A total of 365 graduate and post graduate students of randomly selected public and private sector universities participated in this exploratory empirical study. A self-reported questionnaire survey was used for collection of primary data. Findings revealed that there was a low level of awareness about plagiarism and university plagiarism policies and processes amongst the students. Findings also revealed that many respondents did not understand what plagiarism is? A significant number of students have fairly admitted that they have intentionally plagiarized written materials. Based on the findings of the study this paper puts forward recommendations to create awareness amongst the students regarding plagiarism, plagiarism policies and provides statistical evidences for formulation of policies and guidelines to combat plagiarism in institutions of higher learning in Pakistan. Furthermore, the paper submits recommendations to minimize the plagiarism based on the authors’ experiences.     

Instructional management of a private and a government secondary school principal in Northern Pakistan

This study investigated the instructional management of a private and a government secondary school principal in the Gigit-Baltistan region of Northern Pakistan. The study used the following lenses to examine the instructional behavior of the two principals: supervisory techniques, professional development activities, curriculum enrichment, and the availability of instructional resources. A comparison between the levels of engagement of the private and public school principals for the promotion of instructional matter suggests that the private school principal spent more time than the government principal on the development of instructional practices in his school. The study maintains that variables, such as structural processes, personal disposition of principals, and staff characteristics, led the two subjects to deal with their instructional responsibility differently.     

New insights on the utilization of ultrasonicated mustard seed cake: chemical composition and antagonistic potential for root-knot nematode,Meloidogyne javanica

This study focused, for the first time, on the effect of ultrasonic features on the extraction efficiency of secondary metabolites in mustard seed cake(MSC). The nematostatic potential of sonicated seed cake was examined against the second-stage juveniles(J2 s) of root-knot nematode, Meloidogyne javanica. The results show that a 35 ppm(parts per million) concentration of a sonicated extract(SE) sample of MSC caused 65% J2 s mortality at 18 h exposure period in vitro. It also significantly suppressed the root-knot index(RKI=0.94) in tomato roots. The lethal concentration values for SE were 51.76, 29.79, and 13.34 ppm,respectively, at 6, 12, and 18 h of the exposure period, and the lethal concentration values for the non-sonicated extract(NSE)sample were 116.95, 76.38, and 55.59 ppm, respectively, at similar exposure time. Sinapine and gluconapin were identified as the major compounds in ultrasonic-assisted MSC. Because of the high extraction efficiency of metabolites in the SE, all treatments of SE were shown to be antagonistic to J2 s. Thus, this study of ultrasonication activity-based profiling of MSC may help generate target-based compounds at a scale relevant to the control of disease caused by nematodes in economic crops.     

Extraction of DNA suitable for PCR applications from mature leaves of Mangifera indica L.

Good quality deoxyribonucleic acid (DNA) is the pre-requisite for its downstream applications. The presence of high concentrations of polysaccharides, polyphenols, proteins, and other secondary me- tabolites in mango leaves poses problem in getting good quality DNA fit for polymerase chain reaction (PCR) applications. The problem is exacerbated when DNA is extracted from mature mango leaves. A reliable and modified protocol based on the cetyl- trimethylammonium bromide (CTAB) method for DNA extraction from mature mango leaves is described here. High concentrations of inert salt were used to remove polysaccharides; Polyvinylpyrrolidone (PVP) and β-mercaptoethanol were employed to manage phenolic compounds. Extended chloroform-isoamyl alcohol treatment followed by RNase treatment yielded 950?1050 μg of good quality DNA, free of protein and RNA. The problems of DNA degradation,contamination, and low yield due to irreversible binding of phenolic compounds and coprecipitation of polysaccharides with DNA were avoided by this method. The DNA isolated by the modified method showed good PCR amplification using simple se- quence repeat (SSR) primers. This modified protocol can also be used to extract DNA from other woody plants having similar problems.     

Can more become less? Effects of an intensive assessment environment on students’ learning performance

Online interactive systems offer the beguiling prospect of an improved environment for learning at minimum extra cost. We have developed online interactive tutorials that adapt the learning environment to the current learning status of each individual student. These Adaptive Tutorials (ATs) modify the tasks given to each student according to their previous responses. Feedback, assessment and remediation are also adapted. Over a three-year period we progressively blended ATs into notoriously challenging courses in introductory Engineering Mechanics. We assessed the impact of this initiative by reviewing three lines of data: (i) the built-in diagnostics of the system, (ii) changes in student grades from year-to-year and (iii) supplementary surveys. Generally, students liked the new blended system and grades improved. Detailed analysis revealed nuances in the measures of student learning, such as differences between high-performing and low-performing students. With these insights we are able to further adapt the system to meet the learning needs of our students.     

Oxygen free radical modified DNA: Implications in the etiopathogenesis of Systemic lupus erythematosus

The present study was designed to probe the possible role of singlet oxygen and superoxide anion radical modified DNA in the etiopathogenesis of Systemic lupus erythematosus. These species were generated by the exposure of riboflavin to 365 nm UV light. Modified DNA showed single strand breaks, hyperchromicity at 260nm and decrease in Tm. The modified DNA induced high titer antibodies in experimental animals. The antibodies showed reactivity with various nucleic acid polymers, a property commonly associated with Systemic lupus erythematosus anti-DNA autoantibodies. Systemic lupus erythematosus sera showed preferential binding of modified DNA over native DNA in direct binding and competitive binding solid phase immunoassays and band shift assays. The results suggest for the possible involvement of the singlet- superoxide modified DNA as a potential trigger for anti- DNA autoantibody production in SLE and thus in the etiopathogenesis of the disease.     

Oxidatively Damaged DNA: A Possible Antigenic Stimulus for Cancer Autoantibodies

Reactive oxygen species (ROS) are cytotoxic at higher concentration resulting in cell death, mutations, chromosomal aberrations or carcinogenesis. In this study DNA was modified by singlet oxygen and superoxide anion radicals generated by illumination of riboflavin under 365 nm UV-light. The modified DNA induced high titre antibodies in experimental animals. In enzyme immunoassay, serum antibodies from cancer patients (n = 34) showed a higher recognition of the modified DNA, as compared to the native form. This was further confirmed by the gel-shift assay. Immune IgG were used as a probe to detect oxidative lesions in the DNA of cancer patients. DNA isolated from lymphocytes of cancer patients proved to be an appreciable inhibitor of the experimentally induced antibodies against the ROS-DNA. This indicates the presence of oxidative lesions in the DNA obtained from cancer patients. The results show that ROS induced oxidative damage to DNA in cancer patients generate neo-epitopes that are alien for the immune system, resulting in autoantibody formation.     

Information Seeking Anxiety: Background,Research, and Implications

This research aims to provide an analytic and critical review of research on information seeking anxiety (ISA) with a view to inform the information professionals, especially those engaged in information literacy instructions about the existing situation. This study established the background of the proposed phenomenon, provided integrated analysis of the available research, and discussed the theoretical and practical implications of ISA on information services, especially information literacy instruction. Although the results from previous studies were not comparable, directly due to varied geographical contexts and research methods, it was nevertheless possible to draw some common conclusions regarding the users’ anxiety related to information seeking tasks. This review overwhelmingly indicated the manifestation and prevalence of ISA among students in the digital environment. Some personal and academics variables of students appear to be correlated with ISA. The results of reviewed studies indicated the necessity for a need-based information literacy curriculum for alleviation of anxiety related to students’ information-seeking tasks.