Background A bacterial biosensor refers to genetically engineered bacteria that produce an assessable signal in the presence of a physical or chemical agent in the environment. Methods We have designed and evaluated a bacterial biosensor expressing a luciferase reporter gene controlled by pbr and cadA promoters in Cupriavidus metallidurans (previously termed Ralstonia metallidurans) containing the CH34 and pI258 plasmids of Staphylococcus aureus, respectively, and that can be used for the detection of heavy metals. In the present study, we have produced and evaluated biosensor plasmids designated pGL3-luc/pbr biosensor and pGL3-luc/cad biosensor, that were based on the expression of luc+ and under the control of the cad promoter and the cadC gene of S. aureus plasmid pI258 and pbr promoter and pbrR gene from plasmid pMOL30 of Cupriavidus metallidurans. Results We found that the pGL3-luc/pbr biosensor may be used to measure lead concentrations between 1–100 μM in the presence of other metals, including zinc, cadmium, tin and nickel. The latter metals did not result in any significant signal. The pGL3-luc/cad biosensor could detect lead concentrations between 10 nM to 10 μM. Conclusions This biosensor was found to be specific for measuring lead ions in both environmental and biological samples.

Environmental pollution is one of the main causes of disease, death, and disability worldwide. International Labor Organization (ILO) estimates mortality caused by occupational cancer worldwide to be two times higher than occupational accidents. Approximately, 10 important risk factors account for 85% of all occupational cancers. Factors for occupational cancer includes Asbestos, chemicals such as aniline, chromates, dinitrotoluene, arsenic and its inorganic compounds, beryllium and its compounds, cadmium and nickel compounds, wood dust, crystalline silica, brown coal phosphors, furnace emissions, pollution caused by diesel equipment, Nano-Materials, biological agents, ionizing radiation and non-ionizing radiation, thermal shock, shift work, stress and work while sitting. Also some other environmental factors can cause cancer which concludes air, water and soil pollutions, smoking, sunlight, radon gas, electromagnetic fields, agriculture, behavior and lifestyle (such as alcohol and tobacco consumption, diet, sleep patterns, personal habits and social and cultural environment behaviors). More than 75% of mortality due to cancer can be avoided via controlling occupational and environmental risk factors. Most of cancers are not hereditary and caused by occupational and environmental biological agents, and are potentially preventable. So, it is recommended that more researches should be performed in this field in order to detect more scientific and effective methods to detect number and type of cancers due to occupational and environmental factors.

Cancer is the second common cause of death worldwide and a significant ratio of all cancers is related to occupational and living environments. On the other side, cancer prevalence could be controlled and prevented via policies to improve occupational and living environments. However, a main challenge in prevention of occupational cancer is the lack of knowledge about the exposure rate and number of exposed persons. CAREX database, which is established by the program of Europe against cancer, provides information for the number of exposed persons based on country, carcinogen, and type of industry. CAREX is established in early years of 1990 decade by Finland Institute of Health (FIOH) in cooperation with IARC and European experts, as a tool for estimation of the burden due to occupational cancer in Europe, and shortly thereafter is expanded for use in almost 15 countries in European Union by 55 industrial groups. Several other countries have used CAREX for their countries and have provided some main progressions for the performance model. CAREX project in Canada was modeled in 2007, in an effort to develop a Canadian specific and advanced tool for assessing exposure to carcinogenic agents based on EU CAREX. In this model, not only occupational exposure, but also environmental exposure has been considered. Estimation of exposure with CAREX helps to inform primary prevention activities and to improve global occupational cancer, and its strength points are systematic nature, good coverage and ease of use, and can be used in other countries of the world.

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Rank-based sampling methods have a wide range of applications in environmental and ecological studies as well as medical research and they have been shown to perform better than simple random sampling (SRS) for estimating several parameters in finite populations. In this paper, we obtain nonparametric confidence intervals for quantiles based on randomized nomination sampling (RNS) from continuous distributions. The proposed RNS confidence intervals provide higher coverage probabilities and their expected length, especially for lower and upper quantiles, can be substantially shorter than their counterparts under SRS design. We observe that a design parameter associated with the RNS design allows one to construct confidence intervals with the exact desired coverage probabilities for a wide range of population quantiles without the use of randomized procedures. Theoretical results are augmented with numerical evaluations and a case study based on a livestock data set. Recommendations for choosing the RNS design parameters are made to achieve shorter RNS confidence intervals than SRS design and these perform well even when ranking is imperfect.

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Environmental pollution is one of the main causes of disease, death, and disability worldwide. International Labor Organization (ILO) estimates mortality caused by occupational cancer worldwide to be two times higher than occupational accidents. Approximately, 10 important risk factors account for 85% of all occupational cancers. Factors for occupational cancer includes Asbestos, chemicals such as aniline, chromates, dinitrotoluene, arsenic and its inorganic compounds, beryllium and its compounds, cadmium and nickel compounds, wood dust, crystalline silica, brown coal phosphors, furnace emissions, pollution caused by diesel equipment, Nano-Materials, biological agents, ionizing radiation and non-ionizing radiation, thermal shock, shift work, stress and work while sitting. Also some other environmental factors can cause cancer which concludes air, water and soil pollutions, smoking, sunlight, radon gas, electromagnetic fields, agriculture, behavior and lifestyle (such as alcohol and tobacco consumption, diet, sleep patterns, personal habits and social and cultural environment behaviors). More than 75% of mortality due to cancer can be avoided via controlling occupational and environmental risk factors. Most of cancers are not hereditary and caused by occupational and environmental biological agents, and are potentially preventable. So, it is recommended that more researches should be performed in this field in order to detect more scientific and effective methods to detect number and type of cancers due to occupational and environmental factors.

The objective of the current research is to propose new polymer composites with optimal acoustic properties. To do so, the ethylene‐vinyl acetate foam is employed as the based polymer and the nano silica, nano clay and graphene nanoplatelets are used as extra ingredients. The appropriate amounts of the blowing agent and nano materials are determined using the Taguchi design technique. Using the L9(34) Taguchi array, different foams are manufactured and their specifications are determined experimentally. Most importantly, the sound absorption and transmission loss of the foams are measured and utilized to specify their noise reduction coefficient (NRC) as well as their average transmission loss (ATL). To maximize the NRC and ATL, optimal formulations are derived based on the Taguchi method. Then the optimal foams are manufactured to characterize their acoustic properties. Experimentations show that both NRC and ATL are respectively improved by 9.76% and 7.98% compared to the best NRC and ATL record of the samples of the Taguchi table. Some new samples with at most one nano material are also produced to study the synergistic effects of the nano materials. Measurements of the acoustic properties of these foams revealed that the combination of the nano materials offers superior acoustic properties.