Redox activity of urban quasi-ultrafine particles from primary and secondary sources

To characterize the redox activity profiles of atmospheric aerosols from primary (traffic) and secondary photochemical sources, ambient quasi-ultrafine particles were collected near downtown Los Angeles in two different time periods – morning (6:00–9:00 PDT) and afternoon (11:00–14:00 PDT) in the summer of 2008. Detailed chemical analysis of the collected samples, including water-soluble elements, inorganic ions, organic species and water soluble organic carbon (WSOC) was conducted and redox activity of the samples was measured by two different assays: the dithiothreitol (DTT) and the macrophage reactive oxygen species (ROS) assays. Tracers of secondary photochemical reactions, such as sulfate and organic acids were higher (2.1 ± 0.6 times for sulfate, and up to 3 times for the organic acids) in the afternoon period. WSOC was also elevated by 2.5 ± 0.9 times in the afternoon period due to photo-oxidation of primary particles during atmospheric aging. Redox activity measured by the DTT assay was considerably higher for the samples collected during the afternoon; on the other hand, diurnal trends in the ROS-based activity were not consistent between the morning and afternoon periods. A linear regression between redox activity and various PM chemical constituents showed that the DTT assay was highly correlated with WSOC (R² = 0.80), while ROS activity was associated mostly with water soluble transition metals (Vanadium, Nickel and Cadmium; R² > 0.70). The DTT and ROS assays, which are based on the generation of different oxidizing species by chemical PM constituents, provide important information for elucidating the health risks related to PM exposure from different sources. Thus, both primary and secondary particles possess high redox activity; however, photochemical transformations of primary emissions with atmospheric aging enhance the toxicological potency of primary particles in terms of generating oxidative stress and leading to subsequent damage in cells.     

Choosing vehicle capacity to minimize risk for transporting flammable materials

Highway transportation of hazardous materials (hazmat) has been an active area of research with significant efforts in the risk assessment and route selection domains. Almost all these works assume fixed (constant) truck capacity, and hence capacity-based vehicle selection has not been studied. In this paper, we make a first attempt to investigate the impact of different truck capacities on transport risk from moving flammables, such as gasoline or explosives, on a given route. We make use of three scenarios, under risk-neutral and risk-averse assumptions, to develop conditions for preferring a specific vehicle size. A problem instance based in the US is solved to gain managerial insights.     

Survival of bio-inoculants on fungicides-treated seeds of wheat,pea and chickpea and subsequent effect on chickpea yield

Survival of Mesorhizobium ciceri (SP₄) and Azotobacter chroococcum (CBD-15 and M₄) was tested on chickpea (Cicer arietinum) seeds treated with fungicides bavistin [methyl N-(1H-benzimidazol-2yl) carbamate] and thiram (tetramethyl-thiuram disulfide), whereas survival of phosphate solubilizing bacteria (PSB), Pseudomonas striata (27) and Bacillus polymyxa (H₅) was examined on two cultivars (Arkel and BV) of pea (Pisum sativum) seeds treated with thiram. Viability of Azotobacter chroococcum (W₅) was also examined on wheat (Triticum aestivum) seeds treated with bavistin, captan (cis-N-trichloromethyl thio-4 cyclohexane-1, 2-dicarboximide) and thiram under laboratory conditions using standard dilution and the plate count technique. All the tested strains of diazotrophs and PSB showed decline in their viable population on prolonged contact with fungicides. However, PSB showed variation in their viable population even with the cultivar.

BV cultivar of pea seeds showed better recovery of viable P. striata (10.75 to 10.61 log no. of viable cells with in 0-24 hrs) in the presence of thiram, whereas the Arkel cultivar of pea resulted in better recovery of viable B. polymyxa. Azotobacter chroococcum (W₅), a potential strain for wheat, showed better survival in the presence of bavistin, compared to thiram and captan. Higher viable population of Mesorhizobium ciceri (SP₄) and Azotobacter chroococcum (M₄) was recovered from chickpea seeds treated with bavistin compared to thiram. However, thiram-treated seeds resulted in a greater number of extractable Azotobacter chroococcum (CBD-15). Under field conditions, adverse effect of thiram was reflected on the performance of Mesorhizobium ciceri (SP₄) and A. chroococcum (M₄) strains, resulting in reduced root and shoot biomass and grain yield, compared to bavistin treated and culture inoculated treatment. CBD-15 showed better performance in the presence of thiram compared to bavistin.     

Water quality improvement after shifting of idol immersion site: A case study of Upper Lake,Bhopal, India

Most of freshwater bodies all over the world are becoming polluted, thus decreasing the portability of the water. In India religious practices have deep relationship with water bodies. They also patronized religious practices and constructed numerous relatively small water bodies along with temples throughout the country. Today, with the rapid pace of urban development, most of these water bodies have become sinks for waste discharge, resulting in deterioration of their water quality. Upper Lake of Bhopal, constructed in the eleventh century, is typical example of urban water bodies and a major source of potable water for the people of Bhopal. Till the middle of the last century, the water of Upper Lake did not require any treatment before supply for drinking purposes. Idol worship is common in India. Idols are usually made up of wood, bamboo, straw, jute ropes, clay, and plaster of Paris and are painted with bright synthetic colors, which often contain heavy metals. Other materials, such as straw, jute ropes, flowers, leaves and germinated grains cause short-term deterioration of water quality on their decay, while heavy metals in the paints pose health hazards in the long-run. Religious issues are extremely sensitive and hence it was felt necessary to use the regard that the citizens had for the lake to build a consensus in support of change. The Bhoj Wetland Project was implemented with the aid of Japanese Bank of International Cooperation (JBIC) to take action for preserving the Upper Lake of Bhopal (called Bhoj Wetlands). Our study is highlighted to water quality parameters like turbidity, total hardness, DO (Dissolved oxygen), BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand) and heavy metals in the year 1999 and 2005 i.e. before implementation of project and completion of project.     

Locating air quality monitoring station using wind impact area diagram

In this study a new methodology is suggested to approximate the impact area downwind of an air pollution source, where air quality monitoring can be carried out to capture the maximum pollutant concentration. Hourly wind speed for a given month is grouped in to different wind speed ranges and the distance of pollutant travel is approximated from the average wind speed of that wind speed range. Since change in wind direction causes the impact distance to rotate, its rotation is approximated by the SD of wind direction change. Using this approach, area or region down wind of a source is determined and plotted. The pattern of monthly change of wind is better represented by the new type of diagram as compared to the wind rose diagram.     

Methane emissions from a coastal lagoon: Vembanad Lake,West Coast,India

An attempt has been made to estimate methane fluxes from a tropical coastal wetland the Vembanad Lake, a lagoon along the West Coast of India. It has been found that Vembanad Lake contributes significant amount of methane to the atmosphere. Average emissions varied spatially within the lake. Methane emissions were 193.2 +/- 24.5 mg m(-2) h(-1) at Kumaragam (fresh water) as compared to 9.3 +/- 9.6 mgm(-2) h(-1) at Pullot (brackish water) site. Seasonal variation was significant between pre- and post-monsoons. Soil temperature, time of the day, salinity sediment organic carbon, all control the rate of methane emissions from the Vembanad Lake.     

Human chromosomes in prenatal diagnosis: A one step high resolution technique

A simple high resolution technique for human chromosomes is described for fibroblasts obtained from amniotic fluid cell cultures. The application and clinical significance of this technique in prenatal diagnosis is discussed.     

Prenatal diagnosis of conjoined twins

A case of conjoined twins with open spina bifida prenatally diagnosed at the twenty-third week of gestation is presented. The early detection of this rare and unusual malformation was initiated by the observation of markedly elevated maternal serum alphafetoprotein values. Ultrasound evidence of a misshaped cephalic pole and the appearance of one fetal body on real-time ultrasound was strongly suggestive. Elective midtrimester termination confirmed the prenatal diagnosis and was followed by a benign postpartum course.     

Fenvalerate-induced macromolecular changes in the catfish,Clarias batrachus

The effects of sublethal concentration of fenvalerate on DNA, RNA, RNA/DNA ratio and protein contents were estimated in gill and kidney tissues of an air breathing fish, Clarias batrachus. Fenvalerate reduced the DNA content in gill, whereas it did not produce any significant effect on DNA in kidney. This tissue-specific change in DNA content may be due to differential effects of fenvalerate or its metabolite(s) on synthesis and/degradation of DNA in gill and kidney cells of the fish. RNA and protein contents declined substantially in both the tissues in response to fenvalerate treatment. However, RNA/DNA ratio remains unchanged. It indicates that decrease in protein content in response to fenvalerate treatment might have been brought about by reduce rate of translation of messenger (mRNA) without a decrease in concentration of ribosomes.