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Comparison of the trapping effect and antioxidant enzymatic activities using three different light sources in cockchafers Texte intégral
2017
Gao, Yan | Li, Ganghua | Li, Kebin | Lei, Chaoliang | Huang, Qiuying
Light traps have been widely used for controlling underground pests. However, very little is known regarding the relationship between trapping effect and antioxidant enzymatic activities using light irradiation in underground pests. Thus, we determined the trapping effect of three light sources of the frequoscillation pest-killing lamp on two species of cockchafers, Serica orientalis Motschulsky (Coleoptera: Melolonthidae) and Anomala corpulenta Motschulsky (Coleoptera: Rutelidae), and evaluated the effect of the same three light sources on the activities of their antioxidant enzymes. The catches of S. orientalis were significantly higher compared to A. corpulenta using light source A in peanut fields in China. After irradiation by light source A, the malondialdehyde (MDA) contents and activities of superoxide dismutase (SOD) and glutathione S-transferases (GST) in S. orientalis were significantly and marginally significantly lower compared to A. corpulenta. Taken together, these results indicated a weaker antioxidant enzyme activity response to light stress and a larger quantity of trapping catches using light irradiation in cockchafers. Thus, we proposed a potential negative relationship between trapping effect and antioxidant enzymatic activities in response to light irradiation in cockchafers.
Afficher plus [+] Moins [-]Multibiomarker responses in aquatic insect Belostoma elegans (Hemiptera) to organic pollution in freshwater system Texte intégral
2017
Lavarías, S. | Ocon, C. | van Oosterom, V López | Laino, A. | Medesani, D. A. | Fassiano, A. | Garda, H. | Donadelli, J. | de Molina, M Ríos | Capítulo, A Rodrigues
The present study analyzes a battery of biomarkers in the water bug Belostoma elegans from a stream polluted with organic matter (OMS), and another one considered as reference site (RS) during spring-summer season (December to March). Biochemical parameters of glucidic, lipidic and oxidative metabolic pathways were analyzed in males and females of this insect. In general, no significant differences were observed in all biomarkers assayed between both sexes, except lactate concentration which was higher in males than in females (p < 0.0006) in the first three months. About carbohydrate metabolism parameters, only pyruvate-kinase showed significant differences between insects collected in both streams (p < 0.05) during December. However, the total lipid content, saturated fatty acid, and mainly triacylglycerol were higher in insects from RS compared to those from OMS (p < 0.002) in all sampled months. Levels of lipoperoxidation, protein oxidation, reduced glutathione and glutathione-S-transferase activity showed no differences between insects collected from both streams. Nevertheless, the significant increase observed in superoxide dismutase and catalase activities (p < 0.004) could be due to the elevated oxidative metabolism in insects from RS compared to those from OMS with lower dissolved oxygen. Regarding those responding parameters, males accounted for the differences between the two sites during the study period. In conclusion, our results support that lipidic energetic reserves and antioxidant enzyme activities in B. elegans could be used as biomarkers of environmental pollution by organic matter.
Afficher plus [+] Moins [-]Extraction and representation of common feature from uncertain facial expressions with cloud model Texte intégral
2017
Wang, Shuliang | Chi, Hehua | Yuan, Hanning | Geng, Jing
Human facial expressions are key ingredient to convert an individual’s innate emotion in communication. However, the variation of facial expressions affects the reliable identification of human emotions. In this paper, we present a cloud model to extract facial features for representing human emotion. First, the uncertainties in facial expression are analyzed in the context of cloud model. The feature extraction and representation algorithm is established under cloud generators. With forward cloud generator, facial expression images can be re-generated as many as we like for visually representing the extracted three features, and each feature shows different roles. The effectiveness of the computing model is tested on Japanese Female Facial Expression database. Three common features are extracted from seven facial expression images. Finally, the paper is concluded and remarked.
Afficher plus [+] Moins [-]Does trade matter for carbon emissions in OECD countries? Evidence from a new trade openness measure Texte intégral
2017
Gözgor, Giray
This paper analyzes the impacts of the per capita income, the per capita energy consumption, and the trade openness on the level of per capita carbon emissions in the panel dataset of 35 Organization for Economic Cooperation and Development (OECD) countries over the period 1960–2013. Along with the nominal trade openness, the paper uses a different trade openness measure, so called as the “trade potential index” (TPI). To the best of our knowledge, this is the first paper that uses the TPI in the empirical environmental Kuznets curve (EKC) hypothesis literature. The paper finds that the EKC hypothesis is valid and there is an “inverted-U” relationship between the income and the carbon emissions. In addition, the paper observes that there is a positive effect of the energy consumption on the carbon emissions. Furthermore, the results indicate that both trade openness measures are negatively associated with the carbon emissions in the OECD countries in the long run.
Afficher plus [+] Moins [-]Effects of anthropogenic activities on the heavy metal levels in the clams and sediments in a tropical river Texte intégral
2017
Wong, Koe Wei | Yap, Chee Kong | Nulit, Rosimah | Hamzah, Mohd Suhaimi | Chen, Soo Kien | Cheng, Wan Hee | Karamī, ʻAlī | Al-Shami, Salman Abdo
The present study aimed to assess the effects of anthropogenic activities on the heavy metal levels in the Langat River by transplantation of Corbicula javanica. In addition, potential ecological risk indexes (PERI) of heavy metals in the surface sediments of the river were also investigated. The correlation analysis revealed that eight metals (As, Co, Cr, Fe, Mn, Ni, Pb and Zn) in total soft tissue (TST) while five metals (As, Cd, Cr, Fe and Mn) in shell have positively and significantly correlation with respective metal concentration in sediment, indicating the clams is a good biomonitor of the metal levels. Based on clustering patterns, the discharge of dam impoundment, agricultural activities and urban domestic waste were identified as three major contributors of the metals in Pangsun, Semenyih and Dusun Tua, and Kajang, respectively. Various geochemical indexes for a single metal pollutant (geoaccumulation index (I gₑₒ), enrichment factors (EF), contamination factor (C f) and ecological risk (Er)) all agreed that Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn are not likely to cause adverse effect to the river ecosystem, but As and Pb could pose a potential ecological risk to the river ecosystem. All indexes (degree of contamination (C d), combined pollution index (CPI) and PERI) showed that overall metal concentrations in the tropical river are still within safe limit. River metal pollution was investigated. Anthropogenic activities were contributors of the metal pollution. Geochemical indexes showed that metals are within the safe limit.
Afficher plus [+] Moins [-]Environmental risk assessment of pesticides: state of the art and prospective improvement from science Texte intégral
2017
Boivin, Arnaud | Poulsen, Véronique
Pesticide risk assessment in the European regulatory framework is mandatory performed for active substances (pesticides) and the plant protection products they are constituents of. The aim is to guarantee that safe use can be achieved for the intended use of the product. This paper provides a feedback on the regulatory environmental risk assessment performed for pesticide registration at the EU and member state levels. The different steps of pesticide registration are addressed considering both exposure and hazard. In this paper, we focus on the environmental fate and behaviour in surface water together with the aquatic ecotoxicity of the substances to illustrate pesticide regulatory risk assessment performed for aquatic organisms. Current methodologies are presented along with highlights on potential improvements. For instance, as regards exposure aspects, moving from field based to landscape risk assessments is promising. Regarding ecotoxicology, ecological models may be valuable tools when applied to chemical risk assessment. In addition, interest and further developments to better take into account mitigation measures in risk assessment and management are also presented.
Afficher plus [+] Moins [-]Research on nutrient pollution load in Lake Taihu, China Texte intégral
2017
Wang, Jianjian | Zhao, Qiaohua | Pang, Yong | Hu, Kaiming
The eutrophication of Lake Taihu is the joint result of internal and external pollution. Research on the sources and flux loads of total nitrogen (TN) and total phosphorus (TP) has great significance for the control and management of the eutrophication issues facing Lake Taihu. We used hydrologic and water quality surveys of the surrounding rivers, precipitation investigations, and an experimental simulation of suspended sediment to analyze the sources of TN and TP to Lake Taihu and to estimate the flux loads of TN and TP. Our results indicate that (1) surrounding rivers, atmospheric deposition, and sediment suspension were the three main sources of TN and TP, with annual flux loads of 29.6 thousand t and 2.8 thousand t, respectively; (2) for the flux load of TN, influxes from surrounding rivers accounted for 61.1%, while atmospheric deposition contributed 23.5%, with both of these sources varying seasonally. Total nitrogen released from sediments contributed 15.4% of the TN load of Lake Taihu; (3) for TP flux load, surrounding rivers accounted for 42.8% and also showed seasonal variation. Atmospheric deposition and sediment release accounted for 17.9 and 39.3% with no significant seasonal variation. This article quantitatively analyzed the sources and loads of TN and TP and provided a basis for pollution control in Lake Taihu.
Afficher plus [+] Moins [-]Risk assessment of maize damage by wireworms (Coleoptera: Elateridae) as the first step in implementing IPM and in reducing the environmental impact of soil insecticides Texte intégral
2017
Furlan, L. | Contiero, B. | Chiarini, F. | Colauzzi, M. | Sartori, E. | Benvegnù, I. | Fracasso, F. | Giandon, P.
A survey of maize fields was conducted in northeast Italy from 1986 to 2014, resulting in a dataset of 1296 records including information on wireworm damage to maize, plant-attacking species, agronomic characteristics, landscape and climate. Three wireworm species, Agriotes brevis Candeze, A. sordidus Illiger and A. ustulatus Schäller, were identified as the dominant pest species in maize fields. Over the 29-year period surveyed, no yield reduction was observed when wireworm plant damage was below 15 % of the stand. A preliminary univariate analysis of risk assessment was applied to identify the main factors influencing the occurrence of damage. A multifactorial model was then applied by using the significant factors identified. This model allowed the research to highlight the strongest factors and to analyse how the main factors together influenced damage risk. The strongest factors were: A. brevis as prevalent damaging species, soil organic matter content >5 %, rotation including meadows and/or double crops, A. sordidus as prevalent damaging species, and surrounding landscape mainly meadows, uncultivated grass and double crops. The multifactorial model also showed how the simultaneous occurrence of two or more of the aforementioned risk factors can conspicuously increase the risk of wireworm damage to maize crops, while the probability of damage to a field with no-risk factors is always low (<1 %). These results make it possible to draw risk maps to identify low-risk and high-risk areas, a first step in implementing bespoke IPM procedures in an attempt to reduce the impact of soil insecticides significantly.
Afficher plus [+] Moins [-]Evaluation of migration of heavy metals and performance of product during co-pyrolysis process of municipal sewage sludge and walnut shell Texte intégral
2017
Liu, Yucheng | Liu, Qian | Chen, Mingyan | Ma, Lili | Yang, Bing | Chen, Ju | Lv, Zhongxiang | Liang, Qingling | Yang, Ping
A feasible and efficient type of biological sludge-activated carbon (BSAC) was produced by co-pyrolysis of municipal sewage sludge (MSS) and walnut shell (4:1, w/w) at 500 °C. It was found that BSAC was typical mesoporous material with favorable pore structure and abundant surface functional groups, whose performance was improved compared with conventional sludge-activated carbon (CSAC), combined with walnut shell-activated carbon (WSAC). The migration and transformation behavior of heavy metals (Zn, Cu, Ni, Cd, and Cr) in raw material after co-pyrolysis process were investigated. The results indicated that co-pyrolysis could promote mobile fraction (acid soluble/exchangeable and reducible fractions) of heavy metals to stable fraction (oxidizable and residual fractions). The leaching concentrations Cu, Ni, Cd, Cr, and Zn were lower than restrictive standards in China, and the environmental risk assessment results showed that after co-pyrolysis, the risk levels of Cu, Ni, and Cd were decreased to low risk, especially Cr in product was confirmed to no risk.
Afficher plus [+] Moins [-]Ultrastructure alterations induced by gamma irradiation in spermiogenesis of the ground beetle, Blaps sulcata: reference to environmental radiation protection Texte intégral
2017
Kheirallah, Dalia | El-Samad, Lamia | Fahmi, Naglaa | Osman, Wafaa
Ultrastructure alterations in spermiogenesis of the ground beetle, Blaps sulcata (Coleoptera: Tenebrionidae) were studied in normal adult males and in two male groups irradiated by gamma rays of 3 and 16 μSv/h dose rate. Ultrastructure examination of irradiated sperms revealed many alterations both in the head and in the flagellum regions of mature sperm. Alterations of the head region included nuclei with uncondensed chromatin materials and irregular nuclear envelope. Abnormal flagella contained malformed mitochondrial derivatives and damaged axonemes in addition to the absence of accessory bodies. Bi- and multi-flagellate sperms (with two, three, and four axonemes) were the most common alterations. Sperm cells with residual bodies were also obtained. Agglutinated sperms and sperms with enlarged and/or vacuolated cytoplasm were common. Sperm abnormalities were more pronounced in males irradiated by 16 μSv/h dose rate than those irradiated by 3 μSv/h. Spermiogenesis alterations induced by irradiation of B. sulcata may be used as a monitoring model for predicting the effects of environmental radioactivity.
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