Archives-October 2011

Nardostachys jatamansi DC is used by Mary to anoint Jesuss feet and mentioned Holy Quran and Bible besides evolutionary ideas in Ayurveda. The plant abounds in sesquiterpenes predominantly; jatamansone and nardostachone. The plant has demonstrated several pharmacological activities including hepatoprotective, cardio protective and hypolipidemic and antifungal. The significant effect is on the central nervous system, as diverse pharmacological actions, ranging from sedative to nootropic have been reported. Animal and clinical research with jatamansone, the active principle of the plant, has justified hypno-sedative claim of Ayurveda. The review summarizes, phytochemical and pharmacological investigations carried out on the plant.

Human cytomegalovirus (HCMV), a ubiquitous and opportunistic pathogen, is a member of the Herpesviridae family of viruses. Infection with HCMV is generally asymptomatic, but naïve or immunosuppressed individuals, such as neonates, AIDS patients, and transplant recipients, often manifest serious disease. In the present work, MHC class-I, MHC class-II and B-cell epitopes for the envelope glycoprotein B (gB) of HCMV were predicted using the ProPred1, MHC2Pred and ABCpred servers respectively. The 3D structures of predicted epitopes were modeled using the HHpred server. In order to find the most relevant epitopes among all predicted T-cell epitopes, protein-protein docking was carried out for MHC-I and MHC-II receptors respectively. The energy score for every docked complex was calculated using the Hex 6.0 program. The lower energy score reveals higher binding affinity towards the receptor. It was found that the epitopes ‘YLFKRMIDL’ and ‘KYGDVVGVN’ possess highest binding affinity for MHC-I and MHC-II receptors respectively. For B-cell, the peptide ‘HVTSSEAVSHRANETI’ was highest ranked epitope. These predicted epitopes might be promising candidates for vaccine design against HCMV.

Mefenamic acid, an anti-inflammatory drug, exhibits poor water solubility, dissolution and flow properties. Thus, the aim of the present study was to improve the solubility and dissolution rate of Mefenamic acid by preparing crystals by freeze drying technique. Mefenamic acid crystals were prepared by freeze drying using THF, isopropyl acetate and water as solvents system to enhance solubility and dissolution rate. The prepared crystals containing Mefenamic acid were evaluated for in vitro dissolution and solubility. The prepared formulations were characterized by scanning electron microscopy, differential scanning calorimeter, X-ray diffraction and Fourier transform infrared spectroscopy. Dissolution profile of the freeze dried crystals was compared with its recrystallized sample and pure sample. The samples were stored in stability chamber to investigate their physical stability Freeze dried crystals exhibited decreased crystallinity and the solubility and dissolution of the mefenamic acid crystals were significant improved compared with its recrystallized and pure sample of mefenamic acid. In stability test, the release profile of the freeze dried crystals was almost unchanged as compared with the freshly prepared freeze dried crystals stored at 40 ⁰C and 75% relative humidity for 90 days. Hence this technique can be used for formulation of tablets of mefenamic acid by direct compression with directly compressible tablet excipients.

Power system performance is a?ected by dynamic characteristics of hydraulic governor-turbines during and following any disturbance, such as occurrence of a fault, loss of a transmission line, a rapid change of load or hydraulic transients. Accurate modeling of hydraulic governor-turbines is essential to characterize and diagnose the system response during an emergency. In this paper, the identification/development and implementation of hydraulic systems in power plants via literature survey and computer based simulations have been described and it has been analyzed with comparing different models. This article examines the responses of different models through simulation in MATLAB/SIMULINK. The results obtained provide an insight into the interaction between electrical and hydraulic system of hydro power plant governed by di?erent governor settings, so that the system may remain unaffected during any disturbance.

The wave propagation in an infinite, homogeneous transversely isotropic solid cylinder of elliptic inner and outer cross-section immersed in a fluid is studied using the Fourier expansion collocation method, within the framework of the linearized, three-dimensional theory of elasticity. The equation of motion of solid and fluid are respectively formulated using the constitutive equations of a transversely isotropic cylinder and the constitutive equation of an inviscid fluid. Three displacement potentional functions are introduced to uncouple the equation of motion. The frequency equations of longitudinal and flexural (symmetric and antisymmetric) modes are analyzed numerically for an elliptic cross-sectional transversely isotropic solid cylinder of elliptic inner and outer cross-section immersed in a fluid. To compare the model with the existing literature, the results of a fluid-loaded transversely isotropic cylinder are obtained and they are compared with the results of Berlinear and Solecki (1996). It shows very good degree of agreement. The computed non-dimensional wave numbers are presented in the form of dispersion curves for the material zinc.

This article examines the potentials for developing health-based tourism in the state of Perak. The discussion begins on the distribution of hot springs frequented for various ailment treatments in Perak. The second part of the paper identifies and analyses challenges and opportunities for potential development of health based tourism in the state. Lastly, it discusses issues associated with developing policies promoting tour sites. Current global trends in tourism activities leads into increased domestic trips for short distance tourism. The fast changing lifestyles among state residents help increase awareness and concern for health care activities that utilise natural resources uniquely available in different hot spring parks. This situation increased competitiveness among tour locations. Each individual hot springs has the potential to market its own strengths and uniqueness by promoting the local content either based on natural resources or man-made physical attractions. In this context, marketing strategies must identify and emphasise strengths and characteristics of each location to stimulate increase in tourist return. Quality issues are also one of the main attractions to be considered in future global tourism policies. Using SWOT analysis, factors influencing site selection and priority development strategies based on place consumerism factual information, consumer perceptions and capacity of place, and future potential hot springs in Perak state as a health tourism destination will be evaluated and discussed.

The main chemical used for the gold mining is Mercury. It is widely considered to be among the highest priority environmental pollutants of great concern to the world. Concerns about mercury are based on its effect both on ecosystems and human health. Mercury levels in various foodstuffs were determined by instrumental neutron activation analysis (INAA). High level of Hg was found in all the foodstuffs collected from mining areas. Generally, Hg concentration in foodstuffs ranged from Capsicum sp <0.01 to 69 µg/kg > Xanthosoma sagittifolium <0.01 to 67µg/kg, Nbelmoschus esculentus <0.01 to 67 µg/kg > Colocasia esculentus <0.01 to 66 µg/kg > Manihot esculentus <0.01 to 65 µg/kg , Musa paradisiacal <0.01 to 65 µg/kg , leaves of Xanthosoma sagittifolium, <0.01 to 65 µg/kg > Solanum melongena <0.01 to 63 µg/kg, > Lycopersicum esculentus <0.01 to 54 µg/kg. Most of the values far exceed the WHO recommended values of Hg in foodstuffs, 20ngHg per gram fresh weight. This is not surprising because of the large amount of mercury the illegal miners add in order to be sure that they have all amalgamated available gold. Hg levels should be carefully monitored in the Wassa west district in Ghana.

Plants respond with changes in their pattern of gene expression and protein products when exposed to low temperatures. Thus ability to adapt has an impact on the distribution and survival of the plant, and on crop yields. Many species of tropical or subtropical origin are injured or killed by nonfreezing low temperatures, and exhibit various symptoms of chilling injury such as chlorosis, necrosis, or growth retardation. In contrast, chilling-tolerant species are able to grow at such cold temperatures. Conventional breeding methods have met with limited success in improving the cold tolerance of important crop plants involving inter-specific or inter-generic hybridization. Recent full-genome transcript profiling studies, in combination with mutational and transgenic plant analyses, have provided a snapshot of the complex transcriptional network that operates under cold stress. The changes in expression of hundreds of genes in response to cold temperatures are followed by increases in the levels of hundreds of metabolites, some of which are known to have protective effects against the damaging effects of cold stress. Various low temperature-inducible genes have been isolated from plants. Most appear to be involved in tolerance to cold stress and the expression of some of them is regulated by C-repeat/dehydration-responsive element binding (CBF/DREB1) transcription factors. Genetic analysis has revealed important roles for cellular metabolic signals, and for RNA splicing, export and secondary structure unwinding, in regulating cold-responsive gene expression and chilling and freezing tolerance. Numerous physiological and molecular changes occur during cold acclimation which reveals that the cold resistance is more complex than perceived and involves more than one pathway. The findings summarized in this review have shown potential practical applications for breeding cold tolerance in crop and horticultural plants suitable to temperate geographical locations.

Micro Electro Mechanical System (MEMS) controlled electromagnetic micro power generator was designed with basic cantilever structure using comsol software. This paper presents a micromechanical-system-based electromagnetic vibration-to-electrical power generator that can harvest energy from low-frequency external vibrations. The efficiency of vibration-based harvesters is proportional to excitation frequency, so the proposed generator is designed to convert low- frequency environmental vibrations to a higher frequency by employing the frequency upconversion (FupC) technique. It has been shown that the generator can effectively harvest energy from environmental vibrations of 70-150 Hz and generates 0.57-mV voltage with 0.25-nW power from a single cantilever by up converting the input vibration frequency of 95 Hz-2 kHz. The fabricated generator size is 8.5*7*2.5 mm^3,and a total of 20 serially connected cantilevers have been used to multiply the generated voltage and power. The generator demonstrated in this paper is designed for the proof of concept, and the power and voltage levels can further be increased by increasing the number of cantilevers or coil turns.

Two  appropriate post-tax petroleum exploration models were constructed and tested for three hypothetical field profiles (i.e low, medium and high volume fields) from a development economics perspective and the proposed tax regimes tested for both oil price and development cost ($/bbl). 40% government participation through the international oil company was considered in both cases. The resulted government takes for the first proposal are 76.89%, 83.07%, and 86.94% for low, medium and high volume fields respectively. Respective percentages for the second proposal are 76.20%, 80.03% and 85.43%. These values are above the average global take of 64% but within the range of 40% to 87% for most world oil producers. Analysis of the models indicates an increase in government take as the development costs ($/bbl) increases but a decrease when the oil price ($/bb) increases, which shows regressivity. However, the second regime shows more neutrality, efficiency and focused stability, though still maintaining high government take. This contributes to more attraction for investment from both government and investors perspective. Thus, the second fiscal proposal is recommended to the Nigerian government, considering its incentives.