Effect of commercial pesticides on plant growth-promoting activities of Burkholderia sp. strain L2 isolated from rhizosphere of Lycopersicon esculentum cultivated in agricultural soil

The in vitro study was carried out to examine the toxicity of four commercially used pesticides (phorate, mancozeb, chlorpyrifos, and endosulfan) at the recommended dose (1X) and higher field doses (1.5X, 2X, 2.5X, and 3X) on plant growth-promoting activities of Burkholderia sp. strain L2, isolated from pesticide-treated rhizosphere of Lycopersicon esculentum. At the recommended dose, level of toxicity of all the pesticides to phosphate solubilization activity and indole-3-acetic acid (IAA) production was less detrimental as compared to exceeding doses. At maximum dose rate of each pesticide, the percentage decrease in phosphate solubilization and IAA production over control was found in order of chlorpyrifos < mancozeb < endosulfan < phorate. Present study proves that Burkholderia sp. strain L2 could be used as a potential microbial inoculant in the agricultural soil having persistent pesticide residues.     

Physiologically based pharmacokinetic modeling of perfluoroalkyl substances in the human body

Currently, there are limited data on the levels of perfluoroalkyl substances other than perfluorooctane sulfonic acid and perfluorooctanoic acid in the human body. Most of this information has been extracted from biological monitoring of plasma while the occurrence of perfluoroalkyl substances in other human tissues is rarely studied. The objective of the present study was to develop a physiologically based pharmacokinetic model to assess the concentration of perfluoroalkyl substances in human tissues, based on an existing model previously validated for perfluorooctane sulfonic acid and perfluorooctanoic acid. Experimental data on concentrations of perfluoroalkyl substances in human tissues from individuals in Tarragona County (Catalonia, Spain) were used to estimate the values of some distribution and elimination parameters needed for the simulation. No significant correlations were found between these parameters and the chain lengths. The model was finally validated for five perfluoroalkyl substances.     

Informal Institutional Responses to Government Interventions: Lessons from Madhupur National Park,Bangladesh

Madhupur National Park is renowned for severe resource ownership conflicts between ethnic communities and government authorities in Bangladesh. In this study, we applied the Institutional Analysis and Development framework to identify: (i) past and present informal institutional structures within the ethnic Garo community for land resource management; (ii) the origin of the land ownership dispute; (iii) interaction mechanisms between formal and informal institutions; and (iv) change in land management authority and informal governance structures. We identify that the informal institutions of the traditional community have undergone radical change due to government interventions with implications for the regulation of land use, informal institutional functions, and joint-decision-making. Importantly, the government’s persistent denial of the role of existing informal institutions is widening the gap between government and community actors, and driving land ownership conflicts in a cyclic way with associated natural resource degradation.     

Building low-carbon and disaster-resilient communities: integrating climate mitigation and adaptation into the assessment of self-help housing design

Housing is not only one of the major sources of carbon dioxide (CO₂) emissions, but it has been increasingly vulnerable to climate-induced disasters, particularly those sheltering the urban poor. Both mitigation and adaptation measures are therefore required for the design and construction of low-income housing to encourage low carbon development and improve resilience to disasters. As self-help housing—the common type of housing for the urban poor in developing countries—is usually built by ordinary people with participatory approach, it is crucial to develop a low-carbon and disaster-resilient assessment tool for assisting them in making informed decisions during planning process. The objective of this article is to propose a new approach for developing a low-carbon and disaster-resilient assessment tool for self-help housing (LoDAT-SH) by combining opinions from experts and community residents to assign weights, identify indicators, and establish benchmarks with the aim to develop a simple, relevant, and practical tool for non-expert users like self-help residents. The application of the proposed methodology to a case study of a developing country, Thailand, shows the ability of LoDAT-SH, which contains 45 indicators in the four categories of low carbon development, disaster resilience, community participation, and financial consideration, in enabling self-help residents to assess the performance of their housing design, identify potential measures to create a low-carbon and disaster-resilient housing, and prioritize such actions. To support the creation of a low-carbon and disaster-resilient housing as the mitigation and adaptation strategy for urban development at the global level, the study suggests that the methodology of LoDAT-SH should be replicated to develop a more comprehensive assessment tool applicable for the use in self-help housing design in other developing countries, which will house about 900 million of the urban poor by 2020.     

Dissipation and effect of chlorophenoxy herbicide on plant pigments and carbohydrates of sunflower (Helianthus annuus L.)

The dissipation pattern of the chlorophenoxy herbicides (2,4‐D and 2,4,5‐T) residues in sunflower plants (Helianthus annuus L.) has been studied along with its effect on the changes of plant pigments (chlorophyll‐a,b, total chlorophyll, carotene and anthocyanin), sugar and starch in different parts of the plant. The residues of 2,4‐D and 2,4,5‐T remained for larger period of time (10 days) at higher concentrations than the lower concentration. The concentrations of chlorophylls and carotene were found to be reduced with the application of both 2,4‐D and 2,4,5‐T. But the chlorophyll concentrations were slowly normalized accompanied with the reduction of the herbicide residues. For anthocyanin, there was no significant effect. In case of carbohydrate, the sugar concentration was found to be raised by all doses in leaf and stem. The change in starch content in different plant parts did not follow an uniform pattern at different doses of herbicides.     

A rapid method for determination of Aroclor 1260 in cattle adipose tissue

Abstract

A simple analytical procedure for the determination of Aroclor 1260 in cattle adipose tissue is described. The polychlorinated biphenyls residues are extracted from the tissue using a soxhlet extractor and the extracts are cleaned up using a florisil SEP‐PAK cartridge. The residues are detected using a gas chromatograph equipped with an electron capture detector. The effect of extraction time of the Aroclor 1260 residues from the tissue has been investigated and a period of four hours is found to give satisfactory percent recoveries. Greater than 85 percent recoveries were obtained from adipose tissue spiked with Aroclor 1260. The method can be used to detect Aroclor 1260 residue levels as low as 0.10 parts per million.

The method was used to analyze thirty‐one cattle adipose tissue samples out of which twenty‐six samples were taken from cattle suspected of exposure to a pasture containing electrical transformers and capacitors containing Aroclor 1260. Five control samples were collected from cattle with no known exposure. All twenty‐six samples were found to contain non‐detectable Aroclor 1260 residues.