Spontaneous emission of electric and magnetic dipoles in the vicinity of thin and thick metal

Strong modification of spontaneous emission of Eu3+ ions placed in close vicinity to thin and thick gold and silver films was clearly demonstrated in a microscope setup separately for electric and magnetic dipole transitions. We have shown that the magnetic transition was very sensitive to the thickness of the gold substrate and behaved distinctly different from the electric transition. The observations were described theoretically based on the dyadic Green's function approach for layered media and explained through modified image models for the near and far-field emissions. We established that there exists a "near-field event horizon", which demarcates the distance from the metal at which the dipole emission is taken up exclusively in the near field.Comment: 11 pages, 7 figure

Microemulsion Route for the Synthesis of Nano-Structured Catalytic Materials

Owing to their unique properties, use of microemulsion‐based synthetic techniques for the generation of shape‐controlled nanocatalyst is an area of great current interest. Nanocatalysts of any specific shape, morphology, surface area, size, geometry, homogeneity and composition are widely being prepared using the soft techniques of microemulsion. Easy handling, inexpensive equipment and mild reaction conditions make microemulsion an attractive reaction medium. Herein, a nanosized precursor reactant can be incorporated, leading to the formulation of a highly monodispersed metal nanoagglomerate with controlled size, shape and composition. Several factors such as presence of electrolyte, molar ratio of water to surfactant, nature and concentration of surfactant and solvent, size of water droplets and concentration of reducing agents influence the size of the nanoparticles. The reverse micelle method can be used for the fabrication of several nanosized catalysts with a diverse variety of suitable materials including silica, alumina, metals (e.g. Au, Pd, Rh, Pt), metal oxides, etc. The morphology, size distribution and shape of the nanocatalysts make them useable for a wide range of applications, for example, fuel cells, electrocatalysis, photocatalysis, environmental protection, etc. The recovery of nanoparticles from the reaction mixture is a challenge for the researchers. This chapter discusses the preparation of nanoparticles using microemulsion techniques, widely being used for the synthesis of nanocatalysts from a wide range of materials

Impact of Climate Change on Crops’ Productivity across Selected Agro-ecological Zones in Pakistan

This study estimates the impact of major climate variables (temperature and rainfall) on crops’ productivity across four agro-ecological zones of Pakistan. The crops selected were rice, wheat, maize, cotton and sugarcane. The study used panel data from 1991 to 2010 and applied panel least square techniques. The results revealed that the effect of climatic variables on crops yield varied across agro climatic zone due to differences in their climate conditions. Temperature and rainfall were the important determinants affecting crops productivity across agro climatic zones of Pakistan. Wheat productivity has been impacted more in Northern Irrigated Plain-a by average temperature and in Northern Dry Mountains by rainfall than the other zones. Rice productivity has been impacted more in Dry Mountains by average temperature and in the Indus Delta by rainfall than other zones. Sugarcane productivity has been impacted more by average temperature and rainfall in Indus Delta than zone IV. Maize productivity has been impacted more by average temperature and rainfall in Northern Dry Mountains than other zones. Finally the study recommends proper mitigative and adaptative strategies to enhance the positive and lessen the adverse impact of climate change on crops productivity across agro climatic zones of Pakistan. JEL Classifications: Q15, Q54, Q57 Keywords: Climate Change, Agro-ecological Zones, Rainfall, Temperature, Productivit

Non-specific immunity of BCG vaccine: A perspective of BCG immunotherapy

AbstractBCG is a widely used vaccine worldwide for neonates including Pakistan. BCG has more than 90% coverage through the EPI program which was introduced in 1965 in Pakistan. BCG has limited efficacy against the transmissible form of pulmonary tuberculosis in high TB endemic countries. However, BCG vaccination continues in these countries because BCG confers protection against the disseminated form of TB in children. BCG has also shown some protection against leprosy and certain forms of cancers. One reason for such nonspecific protection may be that BCG activates APCs via PAMPS that interacts with TLRs (2, 4 & 8), which initiate the inflammatory cascade thereby recruiting inflammatory cells to the site of infection and providing maturation signals for neutrophils, macrophages and dendritic cells. Such activation may be crucial for restricting the infection at the initial site. Furthermore, activation of the pro-inflammatory cascade also results in expression of adhesion molecules, co-stimulatory molecules as well as MHC class II molecule. MHC class II molecules engage CD4+ cells via the TCR receptor while the adhesion and costimulatory molecules bind to their respective receptors on CD4+ T cells for additional high affinity binding for T cell activation. Although activation of the innate arm may not provide subsequent memory, activation of T cells may introduce a certain level of memory response and therefore, may form a rational basis for BCG immunotherapy. This review, therefore, focuses on the immune activation related to both the innate and adaptive arm of the immune response that has been reported and further explores the utility of BCG immunotherapy related to non TB conditions

Stock Market Performance and Foreign Direct Investment (FDI) during Covid-19 in Emerging Markets

This study analyses the performance of the Pakistan Stock Exchange (PSX) during the Covid-19 with Foreign Direct Investment (FDI). The stock markets are considered as the indicators of the economy. The Covid-19 pandemic outbreak from China in December 2019 and became a global virus within no time. The Covid has affected the economies negatively, although the level remained different in different economies. The financial sectors of the developed markets also got affected by the Covid pandemic as it has affected the global  economies. In this study, Foreign Direct Investment is taken as the control variable to analyze the performance of PSX during covid-19. The Covid-19 positive cases are taken as a proxy for the Covid-19 data set. The sample data on weekly basis for stock prices in the Year 2020. The results indicate the Covid-19 has negatively affected the PSX, while FDI has a positive impact on the PSX performance.  &nbsp

The impact of mucosal infections on acquisition and progression of tuberculosis

More than one-third of the world\u27s population, or over 2 billion people, are infected with Mycobacterium tuberculosis, the causative pathogen of tuberculosis in humans. Why only 10% of those infected develop active disease while the remainder harbor latent infection remains one of the greatest scientific and public health mysteries. Bacterial persistence is characterized by a dynamic state of immunological tolerance between pathogen and host. The critical role of CD4(+) T cells in defense against intracellular pathogens became evident during epidemiological studies of HIV-1 infection, which showed a clear inverse relationship between CD4(+) T-cell count in peripheral blood and increased risk of infection with M. tuberculosis, pneumocystis and Toxoplasma gondii. There is also growing evidence of a common mucosal immune system, whereby immune cells activated at one mucosal site may disseminate to remote effector sites. In this commentary, we review emerging evidence from human studies that the outcome of M. tuberculosis infection is influenced by concurrent mucosal infections, using Helicobacter pylori and geohelminths as examples. Understanding how the complexity of microbial exposures influences host immunity may have important implications for vaccine development and therapeutic interventions

Assessment Of Knowledge, Attitude And Practices Of Healthcare Professionals Towards Pharmacovigilance Activites In Lahore, Pakistan: A Mixed Methods Approach

Adverse Drug Reactions (ADRs) are associated with a high rate of morbidity and mortality worldwide. To overcome the ADR related problems, many countries around the world have established national pharmacovigilance (PV) systems. Most of the PV systems rely on Spontaneous ADR reporting (SADR) by healthcare professionals (HCPs) such as physicians, pharmacists, and nurses. This thesis aims to explore the knowledge, attitude and practices of HCPs, by using mixed methodology and an intervention study regarding ADR reporting in Pakistan and perceived barriers and facilitators to improve pharmacovigilance activities

Influence of Overconfidence on Investment Decision

The Purpose of this research is to investigate the behavioral biases of investment advisors – The effect of overconfidence. The methods implied were descriptive distribution, reliability test, factor analysis and regression analysis.Peoples tend to perceive their initial performance better than it actually is, after learning the outcome. The test of this study shows the peoples tend to overestimate their initial capacity to choose the better performing asset from two alternatives or estimate the return of asset, after learning the realization.The results of overconfidence imply that people are overconfident. The evidence setting to narrow limits, effect is strong. Regression results show that significant F(P=.000)vale shows that the overall models are the good fit and all the variable included in these models are significantly explaining the variation. Keywords: Behavioral Biases, Overconfidence, Investment Decision, Regression Analysis, Reliability Test, Descriptive Analysis