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Influence of entomopathogenic fungus, Metarhizium anisopliae, alone and in combination with diatomaceous earth and thiamethoxam on mortality, progeny production, mycosis, and sporulation of the stored grain insect pests Full text
2017
Ashraf, Misbah | Fārūq, Muḥammad | Shakeel, Muhammad | Din, Naima | Hussain, Shahbaz | Saeed, Nadia | Shakeel, Qaiser | Rajput, Nasir Ahmed
The stored grain insects cause great damage to grains under storage conditions. Synthetic insecticides and fumigants are considered as key measures to control these stored grain insect pests. However, the major issue with these chemicals is grain contamination with chemical residues and development of resistance by insect pests to these chemicals. Biological control is considered as a potential alternative to chemical control especially with the use of pathogens, alone or in combination with selective insecticides. The present study was conducted to evaluate the synergism of Metarhizium anisopliae with diatomaceous earth (DE) and thiamethoxam against four insect pests on the stored wheat grains. In the first bioassay, the M. anisopliae was applied at 1.4 × 10⁴ and 1.4 × 10⁶conidia/ml alone and in integration with two concentrations (250 and 500 ppm) of tested DE. The tested fungus when combined with DE and thiamethoxam possessed synergistic impact as compared to their individual efficacy. Adult mortality increased with respect to increased exposure interval and doses. In the second bioassay, M. anisopliae was applied at 1.4 × 10⁴ conidia/ml individually and in combination with three concentrations (0.50, 0.75, and 1.00 ppm) of thiamethoxam. Results concluded that M. anisopliae integrated with DE and thiamethoxam provides more effective control of stored grain insect pests.
Show more [+] Less [-]PM2.5 emissions from different types of heavy-duty truck: a case study and meta-analysis of the Beijing-Tianjin-Hebei region Full text
2017
Song, Liying | Song, Hongqing | Lin, Jingyi | Wang, Cheng | Yu, Mingxu | Huang, Xiaoxia | Guan, Yu | Wang, Xing | Du, Li
Beijing-Tianjin-Hebei (BTH) region in China is affected seriously by the hazy weather that has a large impact on human health. PM₂.₅ is one of the most important reasons for hazy weather. Understanding the PM₂.₅ emission characteristics from different types of heavy-duty trucks (HDTs) is valuable in policies and regulations to improve urban air quality and mitigate vehicle emission in China. The investigation and analysis on HDT population and PM₂.₅ emission in BTH region are carried out. The results show that the population and PM₂.₅ emission of HDTs in BTH has risen for the last four consecutive years, from 404 thousand and 1795 tons in 2012 to 551 thousand and 2303 tons in 2015. The PM₂.₅ emission from HDTs in Hebei is about 10 times more than that of Beijing and 9 times more than that of Tianjin. The proportion of natural gas HDTs is about 5%; however, its PM₂.₅ emission only accounts for 0.94% in 2015, which indicates the utilization of HDTs powered by natural gas facilitate PM₂.₅ mitigation more than diesel in BTH. The tractor and pickup trucks are the main source of PM₂.₅ emission from different types of HDT, while special and dump trucks are relatively clean. This study has provided insights for management method and policy-making of vehicle in terms of environmental demand.
Show more [+] Less [-]Polymorphisms in XRCC1, ERCC2, and ERCC3 DNA repair genes, CYP1A1 xenobiotic metabolism gene, and tobacco are associated with bladder cancer susceptibility in Tunisian population Full text
2017
Feki-Tounsi, Molka | Khlifi, Rim | Louati, Ibtihel | Fourati, Mohamed | Mhiri, Mohamed-Nabil | Hamza-Chaffai, Amel | Rebai, Ahmed
Other than the established environmental risk factors associated with bladder cancer (BC), little is known about the genetic variations determining the individual susceptibility of this complex disease. This study aimed to investigate the relationship of BC with environmental agents and polymorphisms in XRCC1, ERCC2, and ERCC3 DNA repair genes and CYP1A1, CYP2D6, NAT1, and NAT2 xenobiotic metabolism genes through a hospital-based case-control study in Tunisia. The selection of the single nucleotide polymorphisms (SNPs) (rs25487, rs 13181, rs415407, rs446421, rs1058172, rs4921880, and rs1208) was performed using the dbSNP database. DNA genotyping was determined by PCR-RFLP after DNA extraction from whole blood. The risks of BC associated with every polymorphism as well as the studied environmental factors were estimated by multivariate-adjusted logistic regression using R software. In addition, gene–gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR) methods. Results showed that tobacco smoking and chewing parameters were significantly associated with BC risk. Single-gene variant analysis showed significant associations of the TT genotype of CYP1A1 and the rare GG genotype of ERCC2 with bladder cancer susceptibility (OR = 1.34, 95% CI 1.22–1.40, P < 0.0001). According to GMDR analysis, our findings indicated a significant association between BC and gene–gene interaction among the CYP1A1, ERCC3, and XRCC1. The present results suggest a potential role of XRCC1, ERCC2, ERCC3, and CYP1A1 besides tobacco intake in susceptibility to BC.
Show more [+] Less [-]Life cycle environmental impacts of bioethanol production from sugarcane molasses in Iran Full text
2017
Farahani, SaeidShahvarooghi | Asoodar, MohammadAmin
In recent years, bioethanol from sugarcane molasses has been produced on an industrial scale in Iran. The aim of this study was to evaluate molasses-based bioethanol production from an environmental point of view. Data were collected from Debel Khazai agro-industry situated in southern region of Iran by using face-to-face interviews and annual statistics of 2010 to 2016 (6-year life cycle of sugarcane cultivation). Ten impact categories including abiotic depletion (AD), acidification (AC), eutrophication (EP), global warming potential (GWP), ozone layer depletion (OLD), human toxicity (HT), freshwater aquatic ecotoxicity (FE), marine aquatic ecotoxicity (ME), terrestrial ecotoxicity (TE), and photochemical oxidation (PO) were selected based on CML methodology. Inventory data for production of the inputs were taken from Ecoinvent, BUWAL 250, and IDMAT 2001 databases. The results revealed that in sugarcane cultivation process, electricity and trash burning were the most important contributors to all impact categories except OLD and TE. In industrial phase, natural gas had the highest contribution to the most impact categories. Greenhouse gas (GHG) emission for production of 1000 L molasses-based bioethanol was 1322.78 kg CO₂ eq. By comparing total GHG emissions from 1000 L bioethanol to gasoline, the net avoided GHG emissions came out at 503.17 kg CO₂ eq. According to results, it is clear that with increasing irrigation efficiency and improving performance of heating systems in industrial phase, environmental burdens would be significantly reduced.
Show more [+] Less [-]A bioluminescent arsenite biosensor designed for inline water analyzer Full text
2017
Prévéral, Sandra | Brutesco, Catherine | Descamps, Elodie C. T. | Escoffier, Camille | Pignol, David | Ginet, Nicolas | Garcia, Daniel
Whole-cell biosensors based on the reporter gene system can offer rapid detection of trace levels of organic or metallic compounds in water. They are well characterized in laboratory conditions, but their transfer into technological devices for the surveillance of water networks remains at a conceptual level. The development of a semi-autonomous inline water analyzer stumbles across the conservation of the bacterial biosensors over a period of time compatible with the autonomy requested by the end-user while maintaining a satisfactory sensitivity, specificity, and time response. We focused here on assessing the effect of lyophilization on two biosensors based on the reporter gene system and hosted in Escherichia coli. The reporter gene used here is the entire bacterial luciferase lux operon (luxCDABE) for an autonomous bioluminescence emission without the need to add any substrate. In the cell-survival biosensor that is used to determine the overall fitness of the bacteria when mixed with the water sample, lux expression is driven by a constitutive E. coli promoter PᵣₚₒD. In the arsenite biosensor, the arsenite-inducible promoter P ₐᵣₛ involved in arsenite resistance in E. coli controls lux expression. Evaluation of the shelf life of these lyophilized biosensors kept at 4 °C over a year evidenced that about 40 % of the lyophilized cells can be revived in such storage conditions. The performances of the lyophilized biosensor after 7 months in storage are maintained, with a detection limit of 0.2 μM arsenite for a response in about an hour with good reproducibility. These results pave the way to the use in tandem of both biosensors (one for general toxicity and one for arsenite contamination) as consumables of an autonomous analyzer in the field.
Show more [+] Less [-]Effects of oral administration of 2,4-dichlorophenoxyacetic acid (2,4-D) on reproductive parameters in male Wistar rats Full text
2017
Marouani, Neila | Tebourbi, Olfa | Cherif, Donia | Hallegue, Dorsaf | Yacoubi, Mohamed Tahar | Sakly, Mohsen | Benkhalifa, Moncef | Ben Rhouma, Khemais
The 2,4-dichlorophenoxyacetic acid (2,4-D) is used worldwide in agriculture as a selective herbicide. It has been shown to produce a wide range of adverse effects on the health of both animals and humans from embryotoxicity and teratogenicity to neurotoxicity. In the present study, we have examined the effect of 2,4-D on male reproductive function of rats. Male Wistar rats received daily by force-feeding 100 or 200 mg of 2,4-D/kg body weight for 30 consecutive days. Rats exposed to 100 and 200 mg of 2,4-D/kg showed a significant decrease in body weights only after 24 days of treatment and in relative weights of testis, seminal vesicles and prostate at killing day, when compared with controls. Moreover, a decrease in testosterone and an increase in FSH and LH serum levels were detected in treated rats. Besides, exposure to this herbicide induced pronounced testicular histological alterations with enlarged intracellular spaces, tissue loosening and dramatic loss of gametes in the lumen of the seminiferous tubules. In addition, a decreased motility and a number of epididymal spermatozoa with an increased sperm abnormality rate were found in treated rats in comparison with control. With the highest dose, histological observations of seminal vesicles indicated a considerable decrease of secretions in the lumen, a thinness of the muscle layer surrounding the epithelium with branched mucosal crypts and reduced luminal space. In prostate, the heights of the cells decreased while acinar lumen were enlarged and they lost the typical invaginations. Our results suggest that a subacute treatment of 2,4-D promotes reproductive system toxicity.
Show more [+] Less [-]The effect of the feeding pattern of complex industrial wastewater on activated sludge characteristics and the chemical and ecotoxicological effluent quality Full text
2017
Caluwé, Michel | Dobbeleers, Thomas | Daens, Dominique | Blust, Ronny | Geuens, Luc | Dries, Jan
Research has demonstrated that the feeding pattern of synthetic wastewater plays an important role in sludge characteristics during biological wastewater treatment. Although considerable research has been devoted to synthetic wastewater, less attention has been paid to industrial wastewater. In this research, three different feeding strategies were applied during the treatment of tank truck cleaning (TTC) water. This industry produces highly variable wastewaters that are often loaded with hazardous chemicals, which makes them challenging to treat with activated sludge (AS). In this study, it is shown that the feeding pattern has a significant influence on the settling characteristics. Pulse feeding resulted in AS with a sludge volume index (SVI) of 68 ± 15 mL gMLSS⁻¹. Slowly and continuously fed AS had to contend with unstable SVI values that fluctuated between 100 and 600 mL gMLSS⁻¹. These fluctuations were clearly caused by the feeding solution. The obtained settling characteristics are being supported by the microscopic analysis, which revealed a clear floc structure for the pulse fed AS. Ecotoxicological effluent assessment with bacteria, Crustacea and algae identified algae as the most sensitive organism for all effluents from all different reactors. Variable algae growth inhibitions were measured between the different reactors. The chemical and ecotoxicological effluent quality was comparable between the reactors.
Show more [+] Less [-]Vetiver plantlets in aerated system degrade phenol in illegally dumped industrial wastewater by phytochemical and rhizomicrobial degradation Full text
2017
Phenrat, Tanapon | Teeratitayangkul, Pimpawat | Prasertsung, Isarawut | Parichatprecha, Rattapoohm | Jitsangiam, Peerapong | Narong Chōmchalao, | Wichai, Siriwan
This research evaluated the feasibility of using vetiver plantlets (Vetiveria zizanioides (L.) Nash) on a floating platform with aeration to degrade phenol (500 mg/L) in illegally dumped industrial wastewater (IDIWW). The IDIWW sample was from the most infamous illegal dumping site at Nong Nae subdistrict, Phanom Sarakham district, Chachoengsao province, Thailand. Laboratory results suggested that phenol degradation by vetiver involves two phases: Phase I, phytopolymerization and phyto-oxidation assisted by root-produced peroxide (H₂O₂) and peroxidase (POD), followed by phase II, a combination of phase I with enhanced rhizomicrobial degradation. The first 360–400 h of phenol degradation were dominated by phytopolymerization and phyto-oxidation yielding particulate polyphenols (PPP) or particulate organic matter (POM) as by-products, while phenol decreased to around 145 mg/L. In Phase II, synergistically, rhizomicrobial growth was ∼100-folds greater on the roots of the vetiver plantlets than in the IDIWW and participated in the microbial degradation of phenol at this lower phenol concentration, increasing the phenol degradation rate by more than three folds. This combination of phytochemical and rhizomicrobiological processes eliminated phenol in IDIWW in less than 766 h (32 days), while without the vetiver plantlets, phenol degradation by aerated microbial degradation alone may require 235 days. To our knowledge, this is the first that systematically reveals the complete phenol degradation mechanism by vetiver plantlets in real aerated wastewater.
Show more [+] Less [-]A comparative study for the stabilisation of heavy metal contaminated sediment by limestone, MnO2 and natural zeolite Full text
2017
Yi, Yuanjie | Wen, Jia | Zeng, Guangming | Zhang, Taotao | Huang, Fenghu | Qin, Haiyan | Tian, Shiyu
Three amendments including limestone, MnO₂ and natural zeolite were assessed for their stabilisation effects on Zn, Cu, Pb and Cd in sediment of east Dongting Lake, mid-south China. The metals were first subject to pollution status and potential ecological risk assessment to identify the current and potential hazards to ecology. Speciation of the metals in the sediment treated with amendments was then carried out by BCR sequential extraction procedure in order to evaluate metal contents and their potential mobility. The total concentrations of Zn, Cu, Pb and Cd in the east Dongting Lake were all above the means of national stream sediment and soil guidelines. The sediments were currently unpolluted to moderately pollute with Zn, Cu and Pb and strongly polluted with Cd. Zinc, Cu and Pb posed low risks to the lake ecosystem, and Cd had the highest potential risk that caused the overall risk of the sediment to be high or very high. Limestone stabilised Cu and Zn effectively, yet mobilisation of Cd and Pb by such amendment was also observed. MnO₂ effectively reduced the extractable Cd and Pb. The effect of natural zeolite on metal stabilisation in the sediment was least notable. Limestone and MnO₂ showed higher metal stabilisation efficiencies than zeolite. However, a single amendment is unable to achieve the goal of stabilisation for all metals. A combination use of the advantageous amendments or a search of a stronger stabiliser should be the interest of our future study.
Show more [+] Less [-]Degradation of the cytostatic 5-Fluorouracil in water by Fenton and photo-assisted oxidation processes Full text
2017
Governo, Mariana | Santos, Mónica S. F. | Alves, Arminda | Madeira, Luís M.
Cytostatics are part of the forefront research topics due to their high prescription, high toxicity, and the lack of effective solutions to stop their entrance and spread in the environment. Among them, 5-Fluorouracil (5-Fu) has received particular attention because is one of the most prescribed active substances in chemotherapy worldwide. The degradation of 5-Fu by advanced oxidation processes (AOPs) is a poorly addressed topic, and this work brings valuable inputs concerning this matter. Herein, the efficacy of Fenton’s process in the degradation of 5-Fu is explored for the first time; the study of the main variables and its successful application to the treatment of real wastewaters is demonstrated. Moreover, hydrogen peroxide-based and photo-assisted techniques (direct photolysis, photodegradation with H₂O₂ and photo-Fenton) are also investigated for purposes of comparison. Under the best operation conditions obtained (T = 30 °C, [Fe²⁺]₀ = 0.5 mM; [H₂O₂]₀ = 240 mM and pH = 3 for [5-Fu]₀ = 0.38 mM), 5-Fu was completely eliminated after 2 h of Fenton’s reaction and about 50 % of mineralization was reached after 8 h. The best performance was obtained by the photo-Fenton process, with 5-Fu mineralization level as high as 67 %, using an iron dose within the legal limits required for direct water discharge. Toxicity (towards Vibrio fischeri) of the effluents that resulted from the application of the above-mentioned AOPs was also evaluated; it was found that the degradation products generated from the photo-assisted processes are less toxic than the parent compound, putting into evidence the relevance of such technologies for degradation of cytostatics like 5-Fu.
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