203 research outputs found
Exchange Rate Policy under Floating Regime in Bangladesh: An Assessment and Strategic Policy Options
Get PDFThis paper examines the exchange rate policy in Bangladesh for the period 2000-08. Regime classification of the paper suggests that Bangladesh maintained a de facto managed floating regime by intervening in the foreign exchange market on a regular basis. This is at odds with the Bangladesh Bank's claim of maintaining de jure floating regimesince end-May 2003. A high exchange rate pass-through is observed along with high market pressure during the period of expansionary monetary policy. Given the thin foreign exchange market and high pass-through effects, it appears difficult for Bangladesh to mainatin a freely floating regime. Although Bangladesh maintained average competitiveness, the currency remained somewhat overvalued. Based on the findings, some pragmatic policies in managing the exchange rate in Bnagladesh have been suggested.Exchange Rate, Floating Regime, Bangladesh
A novel low-cost approach to estimate the incidence of Japanese encephalitis in the catchment area of three hospitals in Bangladesh
No full textAcute meningoencephalitis syndrome surveillance was initiated in three medical college hospitals in Bangladesh in October 2007 to identify Japanese encephalitis (JE) cases. We estimated the population-based incidence of JE in the three hospitals' catchment areas by adjusting the hospital-based crude incidence of JE by the proportion of catchment area meningoencephalitis cases who were admitted to surveillance hospitals. Instead of a traditional house-to-house survey, which is expensive for a disease with low frequency, we attempted a novel approach to identify meningoencephalitis cases in the hospital catchment area through social networks among the community residents. The estimated JE incidence was 2.7/100,000 population in Rajshahi (95% confidence interval [CI] = 1.8–4.9), 1.4 in Khulna (95% CI = 0.9–4.1), and 0.6 in Chittagong (95% CI = 0.4–0.9). Bangladesh should consider a pilot project to introduce JE vaccine in high-incidence areas.Repon C. Paul, Mahmudur Rahman, Emily S. Gurley, M. Jahangir Hossain, Serguei Diorditsa, ASM Mainul Hasan, Sultana S. Banu, ASM Alamgir, Muhammad Aziz Rahman, Hardeep Sandhu, Marc Fischer and Stephen P. Lub
Monte Carlo and analytic simulations in nanoparticle-enhanced radiation therapy
No full textAutumn D Paro,1 Mainul Hossain,2 Thomas J Webster,1,3,4 Ming Su1,4 1Department of Chemical Engineering, Northeastern University, Boston, MA, USA; 2NanoScience Technology Center and School of Electrical Engineering and Computer Science, University of Central Florida, Orlando, Florida, USA; 3Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia; 4Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Science, Wenzhou Medical University, Zhejiang, People’s Republic of China Abstract: Analytical and Monte Carlo simulations have been used to predict dose enhancement factors in nanoparticle-enhanced X-ray radiation therapy. Both simulations predict an increase in dose enhancement in the presence of nanoparticles, but the two methods predict different levels of enhancement over the studied energy, nanoparticle materials, and concentration regime for several reasons. The Monte Carlo simulation calculates energy deposited by electrons and photons, while the analytical one only calculates energy deposited by source photons and photoelectrons; the Monte Carlo simulation accounts for electron–hole recombination, while the analytical one does not; and the Monte Carlo simulation randomly samples photon or electron path and accounts for particle interactions, while the analytical simulation assumes a linear trajectory. This study demonstrates that the Monte Carlo simulation will be a better choice to evaluate dose enhancement with nanoparticles in radiation therapy. Keywords: nanoparticle, dose enhancement, Monte Carlo simulation, analytical simulation, radiation therapy, tumor cell, X-ray 
X-ray Radiation Enabled Cancer Detection And Treatment With Nanoparticles
Get PDFDespite significant improvements in medical sciences over the last decade, cancer still continues to be a major cause of death in humans throughout the world. Parallel to the efforts of understanding the intricacies of cancer biology, researchers are continuously striving to develop effective cancer detection and treatment strategies. Use of nanotechnology in the modern era opens up a wide range of possibilities for diagnostics, therapies and preventive measures for cancer management. Although, existing strategies of cancer detection and treatment, using nanoparticles, have been proven successful in case of cancer imaging and targeted drug deliveries, they are often limited by poor sensitivity, lack of specificity, complex sample preparation efforts and inherent toxicities associated with the nanoparticles, especially in case of in-vivo applications. Moreover, the detection of cancer is not necessarily integrated with treatment. X-rays have long been used in radiation therapy to kill cancer cells and also for imaging tumors inside the body using nanoparticles as contrast agents. However, X-rays, in combination with nanoparticles, can also be used for cancer diagnosis by detecting cancer biomarkers and circulating tumor cells. Moreover, the use of nanoparticles can also enhance the efficacy of X-ray radiation therapy for cancer treatment. This dissertation describes a novel in vitro technique for cancer detection and treatment using X-ray radiation and nanoparticles. Surfaces of synthesized metallic nanoparticles have been modified with appropriate ligands to specifically target cancer cells and biomarkers in vitro. Characteristic X-ray fluorescence signals from the X-ray irradiated nanoparticles are then used for detecting the presence of cancer. The method enables simultaneous detection of multiple iv cancer biomarkers allowing accurate diagnosis and early detection of cancer. Circulating tumor cells, which are the primary indicators of cancer metastasis, have also been detected where the use of magnetic nanoparticles allows enrichment of rare cancer cells prior to detection. The approach is unique in that it integrates cancer detection and treatment under one platform, since, X-rays have been shown to effectively kill cancer cells through radiation induced DNA damage. Due to high penetrating power of X-rays, the method has potential applications for in vivo detection and treatment of deeply buried cancers in humans. The effect of nanoparticle toxicity on multiple cell types has been investigated using conventional cytotoxicity assays for both unmodified nanoparticles as well as nanoparticles modified with a variety of surface coatings. Appropriate surface modifications have significantly reduced inherent toxicity of nanoparticles, providing possibilities for future clinical applications. To investigate cellular damages caused by X-ray radiation, an on-chip biodosimeter has been fabricated based on three dimensional microtissues which allows direct monitoring of responses to X-ray exposure for multiple mammalian cell types. Damage to tumor cells caused by X-rays is known to be significantly higher in presence of nanoparticles which act as radiosensitizers and enhance localized radiation doses. An analytical approach is used to investigate the various parameters that affect the radiosensitizing properties of the nanoparticles. The results can be used to increase the efficacy of nanoparticle aided X-ray radiation therapy for cancer treatment by appropriate choice of X-ray beam energy, nanoparticle size, material composition and location of nanoparticle with respect to the tumor cell nucleus
The productivity effects of decentralized reforms - an analysis of the Chinese industrial reforms
Get PDFThe empirical literature on the effects of ownership has not distinguished between the effects of ownership and the effects of control. It has also generally ignored the dynamic effects of various ownership and control rights. Using a rich set of panel data about changes in China's state-owned enterprises, the author examines the static and dynamic effects of decentralizing ownership and control rights. He finds that productivity and growth rates improved significantly when reform improved the incentives for managers and employees to learn and to work hard - for example by decentralizing the rights to control wages, make production decisions, and appoint new managers. Increasing profit-retention rates and adopting performance contracts - conventionally viewed as the most important reforms for China's state enterprises - did not improve productivity much. Overall, decentralization accounted for a least 42 percent of productivity growth in Chinese state enterprises in the 1980s. Much of that gain came from improvements in the growth rate of productivity rather than in improved levels of productivity.Labor Policies,Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform,Public Health Promotion,Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform,Health Monitoring&Evaluation,Municipal Financial Management
The"IPO-Plus": a new approach to privatization
Get PDFEvery approach to privatization entails tradeoffs. The chief advantage of case-by-case privatization -including sales for cash or initial public offerings (IPOs)- is efficiency. Case-by-case privatization generates revenues, gives shareholders control over managers, and provides access to capital and skills. But it is slow and does not promote widespread public participation. Voucher-based mass privatization programs, by contrast, are designed to promote equity in the distribution of wealth, through widespread participation. But they do not ensure efficiency because they may not generate revenues, bring in new capital or skills, or give shareholders control over managers. To promote equity and efficiency, the authors propose a new form of privatization -IPO-Plus- that incorporates key features of both case-by-case privatization and mass privatization. IPO-Plus promotes equity through widespread (but not mass) participation in privatization. It promotes efficiency by making privatization transparent, by fostering capital market development, and by creating independent financial institutions that would press companies to improve their financial performance. It relies not on vouchers but on the sale of low-priced public shares. It allows deferred payment for company shares as an incentive to purchase them as well as downwardly flexible share prices. Because the quality of the enterprises chosen for privatization is essential to the success of the IPO-Plus program, it is important that few enterprises targeted for IPO-Plus be published before the program is launched. This will motivate potential investors to join the program by setting up management companies, establishing public investment funds, and buying shares in them. IPO-Plus is more likely than mass privatization to create real owners. Investors in IPO-Plus are given a subsidy, but only in proportion to what they themselves choose to pay. The individual determines (up to a ceiling) how much to invest in the program. IPO-Plus is particularly appropriate where the objective is to encourage outside ownership rather than significant employee ownership. It encourages the emergence of market intermediaries and ensures the concentration of enterprise shares in investment funds. Outside ownership and concentration of share voting rights provide the basis for enterprise restructuring and economic growth.Payment Systems&Infrastructure,International Terrorism&Counterterrorism,Economic Theory&Research,Banks&Banking Reform,Municipal Financial Management,Banks&Banking Reform,Municipal Financial Management,Payment Systems&Infrastructure,Economic Theory&Research,International Terrorism&Counterterrorism
Nanoparticle Location and Material-Dependent Dose Enhancement in X-ray Radiation Therapy
No full textNanoparticles of high atomic number (Z) materials can act as radiosensitizers to enhance radiation dose delivered to tumors. An analytical approach is used to calculate dose enhancements to tumor endothelial cells and their nuclei for a series of nanoparticles (bismuth, gold and platinum) located at different locations relative to nuclei by considering contributions from both photoelectrons and Auger electrons. The ratio of the dose delivered to cells with and without the nanoparticles is known as the dose enhancement factor (DEF). DEFs depend on material composition, size, and location of nanoparticles with respect to the cell and the nucleus. Energy of irradiating X-ray beam affects X-ray absorption by nanoparticles and plays an important role in dose enhancements. For diagnostic X-ray sources, bismuth nanoparticles provide higher dose enhancements than gold and platinum nanoparticles for a given nanoparticle size, concentration and location. The highest DEFs are achieved for nanoparticles located closest to the nucleus, where energy depositions from short-range Auger electrons are maximum. With nanoparticles ranging in diameter between 2 and 400 nm, the dose enhancement increases with decrease in particle size. The results are useful in finding optimized conditions for nanoparticle-enhanced X-ray radiation therapy of cancer. © 2012 American Chemical Society
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