排序方式: 共有62条查询结果,搜索用时 218 毫秒
51.
Zaher Drira Malika Bel Hassen Habib Ayadi Lotfi Aleya 《Environmental science and pollution research international》2014,21(4):2918-2934
The spatial and temporal variations in copepod communities were investigated during four oceanographic cruises conducted between July 2005 and March 2007 aboard the R/V Hannibal. A close relationship was observed between the temperature, salinity, hydrographic properties and water masses characterising the Gulf of Gabes. Indeed, water thermal stratification began in May–June, and a thermocline was established at a 20-m depth, but ranged from 25 m in July to more than 30 m in September. The zooplankton community is dominated by copepods representing 69 % to 83 % of total zooplankton. Spatial and temporal variation of copepods in relation to environmental factors shows their close relationship with the hydrodynamic features of the water column. Thermal stratification in the column, established in summer, supports copepod development. In fact, copepod abundance increases gradually with rising water temperature and salinity, starting from the beginning of thermal stratification (May–June 2006) and lasting until its completion (July 2005 and September 2006). When the water column is well mixed (March 2007), copepod abundance decreased. Our finding shows that temperature and salinity seem to be the most important physical factors and thus strongly influence the taxonomic diversity and distribution of the copepod population. They are characterised by the dominance of Oithona nana, representing 75–86 % of total cyclopoid abundance. The most abundant species during the stratification period were O. nana, Acartia clausi and Stephos marsalensis in July 2005 and September 2006. However, during the mixing period, Euterpina acutifrons was more abundant, representing 21 % of the total. Unlike the copepod community, which is more abundant during the period of high stratification, phytoplankton proliferates during semi-mixed conditions. 相似文献
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Khani Masoud Mousavi Seyyed Ebrahim Pahlavanzadeh Hassan Ale Ebrahim Habib Mozaffari Abbas 《Environmental science and pollution research international》2019,26(10):9686-9696
Environmental Science and Pollution Research - In the present study, a detailed investigation was carried out on MoO3 alumina-supported catalysts behavior in selective catalytic reduction of SO2 to... 相似文献
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Amira Rekik Sami Maalej Habib Ayadi Lotfi Aleya 《Environmental science and pollution research international》2013,20(6):3718-3734
'In connection with the Taparura Project, we studied the distribution of phytoplankton and zooplankton communities in relation to environmental variables at 18 stations sampled during four coastal cruises conducted between October 2009 and July 2010 on the north coast of Sfax (Tunisia, western Mediterranean Sea). The inshore location was largely dominated by diatoms (66 %) represented essentially by members of the genera Navicula, Grammatophora, and Licmophora. Dinophyceae were numerically the second largest group and showed an enhanced species richness. Cyanobacteriae developed in association with an important proliferation of colonial Trichodesmium erythraeum, contributing 39.4 % of total phytoplankton abundances. The results suggest that phytoplankters are generally adapted to specific environmental conditions. Copepods were the most abundant zooplankton group (82 %) of total zooplankton. A total of 21 copepod species were identified in all stations, with an overwhelming abundance of Oithona similis in autumn and summer, Euterpina acutifrons in winter, and Oncaea conifera in spring. The phosphogypsum restoration had been acutely necessary allowing dominant zooplankton species to exploit a wide range of food resources including phytoplankton and thus improving water quality. 相似文献
54.
Natural events and human activities cause changes in landscape structure. Landscape metrics are used as a useful tool to study landscape trends and ecological processes related to the landscape structure. These metrics are commonly calculated on wall-to-wall raster data from remote sensing. A recent trend is to use sample data to estimate landscape metrics. In this study, point sampling was used to estimate a vector-based and distance dependent contagion metric. The metric is an extension of the established contagion. The statistical properties, for both unconditional and conditional contagions, were assessed by a point (point pairs) sampling experiment in maps from the National Inventory of landscapes in Sweden. Random and systematic sampling designs were tested for nine point distances and five sample sizes and for two classification systems. The systematic design showed slightly smaller root mean square error (RMSE) and bias than the random design. Both true and estimated values were calculated using computer programs in FORTRAN, which was specifically written for the purpose of the study. For a given sample size, RMSE and bias increased with increasing point distance. The estimator of unconditional contagion had acceptable RMSE and bias for moderate sample sizes, but in the conditional case the bias (and thus the RMSE) was unacceptably large. The main reason for this is that small classes (by area) affect both the true value of the contagion and are often missing in the sample. The method proposed can be adopted in gradient-based model of landscape structure where no distinct border is assumed between polygons. The method can also be applied in field-based inventories. 相似文献
55.
Short-term in vitro and in vivo genotoxicity testing systems for some water bodies of Northern India
The genotoxicity of certain water bodies was evaluated employing the DNA repair defective mutants of Escherichia coli, induction of prophage lamda in the lysogen and the plasmid nicking assay. All the test DNA repair defective mutants invariably exhibited more sensitivity than their isogenic wild-type strains but distinctive patterns against the three water samples viz. industrial waste water and the groundwater samples obtained from industrial estate of Aligarh as well as river water of Yamuna at Agra. A significant level of phage induction was also recorded in the test system exhibiting maximum induction in case of industrial waste water followed by that in river and groundwater samples, respectively. The single- and double-strand breaks were also observed in the plasmid DNA treated with industrial waste water and the river water samples. These findings are suggestive of the DNA damage induced by the test samples with the probable role of SOS repair in E. coli. 相似文献
56.
Nouira Meriem Sammouda Habib 《Environmental science and pollution research international》2022,29(18):26263-26284
Environmental Science and Pollution Research - Building-integrated photovoltaic systems’ electrical efficiency decreases when their operating temperature increases. To overcome this drawback,... 相似文献
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Khan Rahat Islam Hossain Mohammad Touhidul Apon Md Adnan Sarker Islam Abu Reza Md Towfiqul Habib Md Ahosan Phoungthong Khamphe Idris Abubakr M. Techato Kuaanan 《Environmental science and pollution research international》2022,29(38):57357-57375
Environmental Science and Pollution Research - This study of a downstream segment (Brahmaputra, Bangladesh) of one of the longest transboundary (China-India-Bangladesh) Himalayan rivers reveals... 相似文献
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Environment, Development and Sustainability - Flash floods are among the most serious natural hazards. They are associated with exceptional rain events, characterized by short durations, very high... 相似文献
59.
Qayyum Muhammad Abdul Sultan Muhammad Habib Farooq Zahid Muddassir Khawaja Farooq Tahir Irfan Ahmad 《Environmental science and pollution research international》2022,29(55):83191-83210
Environmental Science and Pollution Research - Esophageal cancer is a very deadly disease ranking 8th most common cancer in terms of incidence and the 6th highest in terms of mortality both in the... 相似文献
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