Hydraulic and Electrokinetic Delivery of Remediants for In-situ Remediation

Nano-scale zero valent iron (nZVI) has shown promising mobility and in-situ reactivity with chlorinated volatile organic compounds when injected into saturated porous media. The current study evaluated nZVI mobility and subsequent reactivity with in-situ contaminants in a variably saturated porous media. The nZVI particles, synthesized onsite at subzero temperatures, demonstrated complete trichloroethene (TCE) degradation within the target area. Furthermore, a three dimensional finite difference model (CompSim) was utilized to investigate nZVI mobility in variably saturated zones. Model predicted well head data were in very good agreement with field observations. Simulation results showed that the injected slurry migrated radially outward from the injection well and that nZVI travel distance increases were not proportional to the increase in injected nZVI volume. This study suggested that the numerical simulator can be a practical tool for optimal design of nZVI field applications. The second study aimed at alleviating back diffusion from low permeability porous media observed at numerous field studies. Experiments were conducted in a two-dimensional sandbox with alternate vertical layers of coarse sand and silt flooded with TCE at aqueous solubility. Electrokinetics (EK) was used to enhance permanganate delivery through the silt layers. The suite of experiments demonstrated that EK was able to drive more permanganate at a faster rate throughout the silt layers in comparison to no-EK experiments. The combined EK and permanganate application resulted in 4.4 orders of magnitude reduction in TCE concentrations compared to a 3.5 orders of magnitude reduction without EK application. This experiment demonstrated that EK coupled with permanganate application can be used to remediate low permeability strata. The third study investigated a novel approach of EK assisted persulfate delivery followed by electrical resistance heating (ERH) for persulfate activation for low permeability soil remediation. The study showed that EK delivered persulfate throughout the silt. The application of ERH was successfully able to activate the persulfate within the porous matrix leading to complete in-situ tetrachlorothene (PCE) degradation. To the authors’ knowledge, this study was the first to combine EK and ERH for persulfate delivery and activation for low permeability soil remediation

Vulnerability to HIV infection among sex worker and non-sex worker female injecting drug users in Dhaka, Bangladesh: evidence from the baseline survey of a cohort study

BACKGROUND: Very little is known about female injecting drug users (IDU) in Bangladesh but anecdotal evidence suggests that they are hidden and very vulnerable to HIV through both their injection sharing and sexual risk behaviors. In order to better understand the risks and vulnerability to HIV of female IDU, a cohort study was initiated through which HIV prevalence and risk behaviors was determined. METHODS: All female IDU (those who had injected in the last six months and were 15 years or older) who could be identified from three cities in the Dhaka region were enrolled at the baseline of a cohort study. The study was designed to determine risk behaviors through interviews using a semi-structured questionnaire and measure prevalence of HIV, hepatitis C and syphilis semiannually. At the baseline of the cohort study 130 female IDU were recruited and female IDU selling sex in the last year (sex workers) versus those not selling sex (non-sex workers) were compared using descriptive statistics and logistic regression. RESULTS: Of the 130 female IDU enrolled 82 were sex workers and 48 were non-sex workers. None had HIV but more sex workers (60%) had lifetime syphilis than non-sex workers (37%). Fewer sex worker than non-sex worker IDU lived with families (54.9% and 81.3% respectively), but more reported lending needles/syringes (29.3% and 14.6% respectively) and sharing other injection paraphernalia (74.4% and 56.3% respectively) in the past six months. Although more sex workers used condoms during last sex than non-sex workers (74.4% and 43.3% respectively), more reported anal sex (15.9% and 2.1% respectively) and serial sex with multiple partners (70.7% and 0% respectively). Lifetime sexual violence and being jailed in the last year was more common in sex workers. CONCLUSION: Female IDU are vulnerable to HIV through their injection and sexual risk behaviors and sex worker IDU appear especially vulnerable. Services such as needle exchange programs should become more comprehensive to address the needs of female IDU

Antidiabetic Effects of Momordica Charantia (Karela) in Male Long Evans Rat

The hypoglycemic effect of Momordica charantia (Karela) has been reported from many laboratories. To our knowledge, the underlying biochemical mechanism of action of this important clinical effect has not been reported. During the course of investigation of this aspect of the herbal fruit, it was reported from our laboratory that ethanolic extract of Momordica charantia suppressed gluconeogenesis in normal and streptozotocin (STZ) induced diabetic rats by depressing the hepatic gluconeogenic enzymes fructose-1,6-bisphosphatase and glucose-6-phosphatase. The herbal extract had also enhanced the activity of glucose-6-phosphate dehydrogenase, the rate-limiting enzyme of hexose monophosphate shunt (a pathway for the oxidation of glucose)

Remittances and Asset Accumulation in Bangladesh: A Study using Generalized Propensity Score

Drawing on a sample of households in Bangladesh, we utilize the Generalized Propensity Score (GPS) method to investigate the impact of internal and international remittances on households’ net assets. The analysis suggests an inverted U-shaped relationship between the amount of internal remittances and the net assets of households. The effect of international remittances on net assets is similarly inverted U-shaped. The paper also indicates not only the source but also the size of remittances effects the utilization of remittances for asset accumulation

Impact of Rapid Urbanization on the Rates of Infection by Vibrio cholerae O1 and Enterotoxigenic Escherichia coli in Dhaka, Bangladesh

Bangladesh is a country where acute dehydrating diarrhea or cholera is common and is seen at least two times every year and additionally in natural disasters. In addition cholera cases have increased in the country, especially in urban settings such as in the capital city, Dhaka, where the number of hospitalized patients with more severe disease has tremendously increased. In the present observation, we have concentrated on determining the occurrence of diarrhoea caused by the two most common bacterial agents V. cholerae O1 and enterotoxigenic Escherichia coli (ETEC) in a densely populated, disease prone area Mirpur in Dhaka for two years from March 2008 to February 2010. Stool or rectal specimens from diarrheal patients coming to the ICDDR,B hospital from Mirpur were tested for the two bacterial pathogens. We found that V. cholerae O1 was the major bacterial pathogen and a cause of severe cholera disease in 23% of patients (2,647 of a total of 11,395 patients) from Mirpur. We surmise that cholera vaccines, as well as other public health tools that can target such high risk groups in the country, will be able to reduce the disease morbidity and the transmission of pathogens to improve the quality of life in urban settings

Financing micro-entrepreneurs for poverty alleviation: a performance analysis of microfinance services offered by BRAC, ASA, and Proshika from Bangladesh

Microfinance services have emerged as an effective tool for financing microentrepreneurs to alleviate poverty. Since the 1970s, development theorists have considered non-governmental microfinance institutions (MFIs) as the leading practitioners of sustainable development through financing micro-entrepreneurial activities. This study evaluates the impact of micro-finance services provided by MFIs on poverty alleviation. In this vein, we examine whether microfinance services contribute to poverty alleviation, and also identify bottlenecks in micro-finance programs and operations. The results indicate that the micro-loans have a statistically significant positive impact on the poverty alleviation index and consequently improve the living standard of borrowers by increasing their level of income