Modeling impacts of industrial park activity on air quality of surrounding area for identifying isolation distance: A case of Tan Tao Industrial Park, Ho Chi Minh City, Viet Nam

Industrial factories have been addressed as the main contributor to the amount of air pollution in many urban areas around the world. The emissions of air pollutants from factories, combined with exhausted gases from automobile and domestic cooking activities, have placed enormous adverse effects on human health. Recently, air quality models, which usually figure out for industrial emission with representative indicators such as CO, NO2, SO2, and TSP, have triggered an application to identify a suitable isolation distance that could lessen affection on public health. Concerning to develop an air emission inventory for Tan Tao Industrial Park (IP) for three sources of points, line and area sources by using top-down and bottom-up approaches, this study aim to: (i) apply a system model of TAPM – AERMOD model to study the air pollution dispersion from the IP to the surrounding area, and (ii) identify a hygiene isolation distance for sensitive objects around industrial park, especially zones of community, based on their separating demand from contamination. Results show that the point sources are the dominant air emission sources of Tan Tao IP. Total emissions of Tan Tao IP in 2019 estimated at 413.15 tons of TSP/year, 280.9 tons of NO2/year, 621.99 tons of SO2/year, and 2720.21 tons of CO/year. Modeling results show that 1-hour maximum concentration of TSP, NO2, SO2, and CO in the simulation area is 581µg/m3, 4.069µg/m3, 5.478µg/m3, 40.695µg/m3, respectively, exceeding the standards. Especially, the pollution levels of NO2 were 20 times higher than the limit value, similar trends for SO2 (15 times higher). The hygiene isolation distance was suggested a widely ranged from 2910 meters in the North-West and in the rest directions of Ho Chi Minh City. Some sensitive objects such as residential areas, hospitals and kindergartens recently are inside the affected zone should be reckoned to have suitable solutions that keep their health safe. The method for calculation of hygiene isolation distances from industrial activities has a significant guiding not only for environmental safety action but also for public health protection.

Study of odor simulation and proposed odor isolation distance for some main pollutants (H2S, NH3, CH3SH ) for livestock activities: Applied in Ho Chi Minh City

Ho Chi Minh City (HCMC) is the largest city in Vietnam, with the highest economic growth rate and the most populous density in the country. By the year 2019, HCMC currently has 8.99 million people with 24 districts. Ho Chi Minh city has robust industrial and service development; therefore, HCMC focuses on developing large-scale livestock facilities with a large number of pigs and limiting small livestock facilities. According to statistic data, HCMC has a total of 290.152 pigs in 2018. These livestock facilities are mainly built in Cu Chi, Hoc Mon, Binh Chanh, Can Gio, and Nha Be districts. These livestock facilities in HCMC have inefficient waste treatment systems located interleaved with residential areas. So that, environmental issues are also a big challenge for the city's government because of the great influence of odor on the surrounding environment causing by the wind direction. The main purposes of this study are (i) calculation of odor emissions from livestock facilities, (ii) simulation of the odor from livestock facilities , and (iii) development of the safe distance of odor for livestock facilities in HCMC. The study results show that, the concertrations from livestock facilitties with capacity from from 50 to 200 pigs and 200 to 500 pigs are lower than QCVN 06:2009/BTNMT. The minimum distance for the livestock facility with capacity from over 500 to 1,000 pigs and over 1,000 pigs to the residential area are 230m and 650m, respectively. The procedure for calculating the odor isolation distance developing in this study could apply for other livestock facilities in other provinces, cities.

Gene flow mitigation by ecological approaches.

With an increased area of cultivating genetically modified (GM) plants worldwide, the ecological risks of transgenic plants released into the environment have caused concern. One of the risks is the occurrence of gene flow between GM plants and non-GM plants, including their wild relatives. Gene flow data from oilseed rape (Brassica napus), cotton (Gossypium hirsutum), maize (Zea mays), soybean (Glycine max), rice (Oryza sativa), and wheat (Triticum aestivum) indicate that the frequency of pollen-mediated gene flow is negatively related with distance between donor and recipient plants, and the frequency is relatively high in closely related species. We discuss five main ecological approaches to mitigate gene flow from GM plants to non-GM plants, including distance isolation, border or trap crops, barrier crops, agricultural practices, and through biological means. The required isolation distance has been adopted in managing GM crops in some countries, and cultivating tall crops, or border or trap crops, can decrease the requisite isolation distance to mitigate gene flow. Combining several approaches is more effective than a single approach in mitigating gene flow, because the frequency of pollen-mediated gene flow depends on plant genotype, flowering time, wind speed and direction, and other factors. Thus, in the framework of biosafety assessment of GM plants, mitigating the occurrence of gene flow between GM and non-GM plants is a key step to decrease the ecological risk of post- commercial cultivation of GM plants.

Population genetic analysis of Fagus orientalis Lipsky from the territory of the Crimea and the Caucasus

The genetic structure of 20 populations of Fagus orientalis Lipsky (oriental beech) from the territory of the Crimea and the Caucasus was studied on the basis of microsatellite polymorphism (SSR – simple sequence repeats). The isolation distance test performed in the GenePop program showed a high correlation of genetic differences and the logarithm of geographic distance in geographic coordinates at the 0.91 level. Interpopulation genetic differentiation of Fagus orientalis (Fst) ranged from 0.01 to 0.67. On the basis of the obtained genetic data and analysis of the literature on fossil materials, we present a preliminary reconstruction of the possible pathways for spread and the formation of the modern area of the species in the Crimea and on the Caucasian Isthmus within the Caucasian ecoregion. The earliest separation occurred in the populations of the mountainous Crimea and the Stavropol Upland, which retained the unique features of the genotype of the ancestral form in conditions of island isolation. Apparently, beeches from relict mid-mountain populations in refugia of mesophilic vegetation are close to the ancestral form: Colchis (Avadhara, Abkhazia) in the west and Kakheti (Lagodekhi, Georgia) in the east. The observed similarity at the upper border of the beech belt in different regions of the Caucasian Isthmus indicates a parallelism in the development and formation of high-mountain populations of the species.

Effective isolation distance for prevention of cassava virus infections in Uganda

Cassava brown streak disease (CBSD) and cassava mosaic disease (CMD) are the major viral diseases of cassava in Uganda. Although isolation distance of “50 m” has been recommended by MAAIF in Uganda for prevention of virus infections in crops, the minimum isolation distance has not been verified for effectiveness in cassava. This study assessed the effective isolation distance for management of viral diseases in cassava. Virus-clean cassava cultivars (NASE 03, NASE 14 and NAROCASS 1) from farmers’ fields were used as field sourced (FS) planting materials. Tissue culture (TC) material of the same cultivars were sourced from the National Crops Resources Research Institute and Makerere University Agricultural Research Institute tissue culture laboratories. Both FS and TC materials were tested at isolation distances of 50, 100, 150 and 250 m for virus prevention. The experiment was laid out in a randomised complete block design and was run for 12 months after planting (MAP). Mean CBSD/CMD prevalence significantly varied (P<0.05) among isolation distances in both FS and TC plants, and the 250 m isolation distance was the most effective in reducing disease prevalence. Across cultivars and planting material category at 12 MAP, the 50 m isolation distance had the highest foliar incidence for CBSD (29.2%) and CMD (16.1%); while severity for CBSD was 1.4 and 1.2 for CMD. At 250 m, all FS and TC plants had CBSD/CMD severity of 1.0 and 0% incidence. These results show that 250 m isolation distance can provide an option to disseminate popular, but CBSD/CMD susceptible cassava cultivars thereby manage CBSD/CMD.

A new isolation device for shortening gene flow distance in small-scale transgenic maize breeding

The transmission of pollen is the main cause of maize gene flow. Under the compulsory labeling system for genetically modified (GM) products in China, isolation measures are crucial. At present, there is no effective isolation device for preventing and controlling the short-range flow of GM maize pollen. The purposes of the present experiments were to overcome the deficiencies of existing technology and to demonstrate a new isolation device for decreasing the gene flow distance of GM maize. The isolation device we invented was shown to be more robust than traditional isolation methods, and it can be disassembled and repeatedly reused. The most important point was that the frequency of gene flow could be greatly reduced using this device. When the distance from the isolation device was more than 1 m, the gene flow rate could be decreased to less than 1%, and when the distance from the isolation device was more than 10 m, the gene flow rate could be reduced to less than 0.1%. When the isolation device was adopted to isolate GM maize in conjunction with bagging the tassels of GM maize at the pollination stage, the gene flow could be controlled to less than 0.1% when the distance from the isolation device was more than 1 m. This device was, however, only applicable for small plots and can shorten the isolation distance of GM maize planting and improve the purity of seeds, all while meeting the needs of close isolation breeding. The use of this device represents a feasible method for risk prevention and control of GM crops.

Meeting the Tolerance: How Successful is Coexistence in Commodity Corn Handling Systems?

HighlightsMeeting the 0.9% tolerance level was challenging under most conditions.Non-GM loads in the simulation were able to meet a 1.5% or 3% tolerance level under specific conditions.Field isolation distance plays a large role in a non-GM load meeting the posted tolerance levelAbstract. The open-air growth environment used in maize production makes it nearly impossible to ensure 100% purity of specified genetic traits. One measure of successful coexistence is a low level of unintended material in seed, grain, and feed or food products, termed “adventitious presence” (AP). To allow the coexistence of genetically modified (GM) and non-genetically modified (non-GM) maize, tolerance levels regulate how much AP of genetically modified corn is allowed in each unit of maize. This research sought to model four factors contributing to levels of adventitious presence: seed purity, field isolation distance, combine cleanout, and grain elevator receipt and handling practices. Monte Carlo simulation was used to test nine scenarios to determine the feasibility of successfully meeting three tolerance levels for adventitious presence (0.9%, 1.5%, and 3.0%). After 50,000 iterations for each model, sensitivity analysis was performed to identify factors that play an important role in whether the load meets the posted tolerance level or not. Results suggest that non-GM maize loads would not meet a tolerance level of 0.9% in most cases. Non-GM maize loads were found to meet tolerance levels of 1.5% and 3.0% in certain cases. The most significant factors affecting the probability of the unit of maize meeting the posted tolerance level were field isolation distance, elevator handling practices, and seed purity. Keywords: Adventitious presence, Coexistence, Identity preservation, Monte Carlo simulation, Transgenic grain.

Isolation distance between municipal solid waste landfills and drinking water wells for bacteria attenuation and safe drinking

Groundwater pollution and human health risks caused by leachate leakage have become a worldwide environmental problem, and the harm and influence of bacteria in leachate have received increased attention. Setting the isolation distance between landfill sites and groundwater isolation targets is particularly important. Firstly, the intensity model of pollutant leakage source and solute transport model were established for the isolation of pathogenic Escherichia coli. Then, the migration, removal and reduction of bacteria in the aerated zone and ground were simulated. Finally, the isolation distance was calculated based on the acceptable water quality limits, and the influence of hydrogeological arameters was analyzed based on the parameter uncertainty. The results of this study suggest that the isolation distances vary widely ranging from 106 m–5.46 km in sand aquifers, 292 m–13.5 km in gravel aquifers and 2.4–58.7 km in coarse gravel aquifers. The gradient change of groundwater from 0.001 to 0.05 resulted in the isolation distance at the highest gradient position being 2–30 times greater than that at the lowest gradient position. There was a difference in the influence of the thickness of the vadose zone. For example, under the same conditions, with the increase of the thickness of the aeration zone, the isolation distance will be reduced by 1.5–5 times, or under the same thickness of the aeration zone, the isolation distance will be significantly shortened. Accordingly, this needs to be determined based on specific safety isolation requirements. In conclusion, this research has important guiding significance for the environmental safety assessment technology of municipal solid waste landfill.

Asynchronous Learning Networks: A Sloan Foundation Perspective

This paper is based on a chapter in THE LEARNING REVOLUTION, the challenge of Information Technology in Academia (Diana G.Oblinger and Sean C. Rush, eds.), to be published this year by Anker Publishing Co., Boston, Mass.Over the years small numbers of motivated individuals have studied by themselves, away from university centers, to acquire knowledge in post-secondary subjects. Correspondence study began over a century ago and since then, other forms of "distance education" have become established. In spite of all this progress, off-campus learners have worked mainly in isolation, with only occasional contact with instructors and peers.Today’s low-cost communications and computer technologies, however, enable learning in Asynchronous Learning Networks (ALNs), in the process simultaneously overcoming barriers of isolation, distance and those imposed by rigid time constraints. The paper describes some projects at institutions of higher education funded by the Sloan Foundation, identifies some early results and possible evolution of ALN’s to large scale implementations.