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21.
The present study was carried out to investigate the effect of Curacron (profenofos), Sumicidin (fenvalerate) and Dimilin (difluobenzuron) on the in vitro rate of protein and RNA synthesis by rabbit liver and muscle tissues. The synthesis of protein and RNA were significantly stimulated in the liver and inhibited in the muscle by graded doses of these insecticides. Profenofos showed maximum effect on protein synthesis in both tissues at a dose of 0.2 microgram/mL, while the maximum effect on RNA synthesis occurred at 0.2 microgram/mL, while the maximum effect on RNA synthesis occurred at 0.2 microgram mL in the liver and at 2 micrograms/mL in the muscle. Fenvalerate caused maximum stimulation in both liver protein and RNA synthesis at a dose of 2 micrograms/mL, and maximum inhibition in the muscle at 10 and 0.2 micrograms/mL for protein and RNA synthesis respectively. The maximum effect of Dimilin on both tissues was reached at 5 micrograms/mL for protein synthesis and at 0.2 microgram/mL for RNA synthesis. The effect of Dimilin on RNA synthesis was more pronounced in both tissues than its effect on protein synthesis, but this trend was reversed in the case of profenofos and fenvalerate. Present data also showed antagonism between these insecticides on the rate of protein and RNA synthesis.  相似文献   
22.

The Stone (limestone) and Marble (trade name) Industry (SMI) is one of the most important and active industries in Palestine, as being economically and financially rewarding and greatly beneficial to the public and private sectors. This industry, which employs about 15,000–20,000 workers, contributes 20–25% to the total industrial revenues of Palestine, and 4.5% to the total gross national product. Despite its benefits, SMI has adverse effects on public health, the environment, biodiversity, water systems (both surface and underground), green cover, and ecosystems in general, as it is considered one of the most air- water-, soil-, and noise-polluting sources. To achieve the purpose of this research paper, available data and literature are analyzed, evaluated, and used, in order to provide a comprehensive understanding of the status of SMI, in light of sustainable development. This relates to various perspectives, including limestone geology, geopolitics, socioeconomics, culture, technology, legislation, as well as climate change, acid rain, and harmful effects of the SMI scale on public health and safety, environmental well-being, and challenges facing the industry. Two field studies, carried out in northern and southern West Bank, dealing with particulate matter (PM1, PM2.5, PM7, PM10, and TSP) and environmental pollution, were analyzed, and their results were compared with each other, as well as with the World Health Organization’s (WHO) guidelines. It is found that both West Bank’s areas are heavily polluted, resulting in considerable adverse impacts on public health, the environment, and green cover. Based on the findings of this paper, it is recommended that SMI should properly adhere to WHO guidelines and international standards to make the industry safer and more durable and sustainable, with fewer negative impacts on public health, the environment, and green cover.

  相似文献   
23.
Oxygen-18 (180) and deuterium isotopes were used to estimate the evaporation from the Aswan High Dam Lake and to investigate the inter-relation between the lake water and adjacent groundwater.According to stable isotopic analysis of samples taken in 1988 and 1989, the lake can be divided into two sections. In the first section extending between Abu Simbel and a point between EI-Alaki and Krosko, a remarkable vertical gradient of 180 and deuterium isotopic composition was observed. The second northern sector extending to the High Dam is characterised by a lower vertical isotopic gradient. In this sector in general, higher values of 18O and deuterium contents were found at the top and lower values at the bottom. Also a strong horizontal increase of the heavy isotope content was observed. Thus, in the northern section evaporation is of dominating influence on the isotopic composition of the lake water.With the help of an evaporation pan experiment it was possible to calibrate the evaporative isotope enrichment in the lake and to facilitate a preliminary estimate of evaporative losses of lake water. The evaporation from the lake was estimated to be about 19% of the input water flow rate.The groundwater around the lake was investigated and samples from production wells and piezometers were subjected to isotopic analysis. The results indicate that recent recharge to the groundwater aquifer is limited to wells near to the lake and up to a maximum distance of about 10 km. The contribution of recent Nile water to the groundwater in these wells was estimated to range between 23 and 70%. Beyond this distance, palaeowater was observed with highly depleted deuterium and 180 contents, which was also confirmed by 14c dating. The age of palaeo groundwater in this area can reach values of more than 26,000 years.Recommendations are given for efficient water management of the lake water.  相似文献   
24.
Environmental Science and Pollution Research - Separation of oil-water (OW) emulsions is investigated using a photocatalytic demulsification approach. Experiments were conducted using two types of...  相似文献   
25.
Produced water is water trapped in underground formations that is brought to the surface along with oil or gas production. Oilfield impacted soil is the most common environmental problem associated with oil production. The produced water associated with oil-production contaminates the soil and causes the outright death of plants, and the subsequent erosion of topsoil. Also, impacted soil serves to contaminate surface waters and shallow aquifers. This paper is intended to provide an approach for full characterization of contaminated soil by produced water, by means of analysis of both the produced water and the impacted soil using several recommended analytical techniques and then identify and assay the main constituents that cause contamination of the soil. Gialo-59 oilfield (29N, 21E), Libya, has been chosen as the case study of this work. The field has a long history of petroleum production since 1959, where about 300,000 bbl of produced water be discharged into open pit. Test samples of contaminated soil were collected from one of the disposal pits. Samples of produced water were collected from different points throughout the oil production process, and the analyses were carried out at the labs of Libyan Petroleum Institute, Tripoli, Libya. The results are compared with the local environmental limiting constituents in order to prepare for a plan of soil remediation. The results showed that the main constituents (pollutants) that impact the soil are salts and hydrocarbon compounds. Accordingly; an action of soil remediation has been proposed to remove the salts and degradation of hydrocarbons.  相似文献   
26.
A new African species of hystricognathous rodent, Gaudeamus lavocati sp. nov., is described herein from the early Oligocene deposits of Zallah locality (Sirt basin, Central Libya). The dental morphology of this species is very close to that of some earliest South American caviomorphs. It allows a reinterpretation of molar crest homologies among earliest caviomorphs, pentalophodonty being confirmed as the plesiomorphic molar condition in Caviomorpha. This morphological resemblance argues for close affinities between Gaudeamus and earliest South American hystricognaths. Cladistic analysis supports Gaudeamus lavocati sp. nov. as the first known African representative of Caviomorpha, implying that its ancestors were part of the African phiomyid group that crossed the South Atlantic by a direct immigration route. Alternatively, the series of derived dental features of Gaudeamus could also be interpreted as evolutionary synchronous convergences of an African hystricognath lineage towards the specialized pattern of some caviomorphs. However, the high level of similarities concerning teeth morphology and enamel microstructure and the similar age of fossiliferous strata on both continents make this interpretation less probable. The phylogenetic position of this taxon is of considerable importance because it represents an enigmatic component of the phiomorph–caviomorph radiation in Africa and appears as a new clue toward the understanding of caviomorph origins.  相似文献   
27.
Environment, Development and Sustainability - Groundwater in semiarid regions is of extreme importance due to limited water resources and increasing population demand. Hence, a better knowledge of...  相似文献   
28.
Quality assessment of various bottled waters marketed in Saudi Arabia   总被引:1,自引:0,他引:1  
This study focuses on the chemical analysis of the available brands of domestic bottled water in Riyadh City, Saudi Arabia. The distribution of the chemical constituents (major, minor, and trace elements) is determined and compared with the chemical content labeled on the bottles and with drinking water standards of Saudi Arabian, World Health Organization, and U.S. Environmental Protection Agency. The obtained results indicated that except for fluoride and bromate, the concentrations of dissolved salts, soluble cations and anions, nitrate, and trace elements of most bottled waters on sale were within the permissible limits set by standards used. On the other hand, the comparison between determined and reported label values recorded a substantial variation in some parameter values. Results indicated that more than 18 % of the sampled bottled waters exceeded the allowable limits for drinking water. Generated Piper diagrams revealed that the majority of investigated waters were sodium chloride–sulfate type; however, the hydrochemical modeling indicated that all water samples were undersaturated for anhydrite, gypsum, and halite.  相似文献   
29.
Strongyloidiasis presents a major health hazard when reusing wastewater. Albendazol with a concentration of 4 mg/l, a contact time of 45 min, pH 1.2 and pH 10.2, killed the larva. The larva was also killed with a 0.03% concentration of iodine and a detention time of 30 min or a 0.04% concentration of iodine and a contact time of 10 min. The required detention time to inactivate larva in water was found to be 17 days. The minimum revealed residual chlorine to kill the larvae was 4 mg/l with 120 min of detention time, and a minimum contact time was found to be 80 min with a residual of 23 mg/l. Many methods are available to inactivate the Strongyloides stercoralis, which could be acids, alkaline chemicals, larvicidal chemicals, super chlorination, or just detention time. The best method must be determined according to the prevailing specific environmental site and the feasibility of the selected method(s).  相似文献   
30.
The purpose of this study was to determine if the advantages and disadvantages of a new automotive seating concept, known as the micro-adjuster control system, could be reliably evaluated using both a physiological assessment technique (i.e., electromyography [EMG]) and a subjective questionnaire. The results indicate that psychophysical measures of discomfort and the root mean squared (RMS) activity of the EMG are statistically related, r (8) = ?.788, p = .020. More specifically, subjective perceptions of comfort were found to improve with decreasing levels of muscle activity. This implies that seat comfort can be evaluated on the basis of physiological as well as subjective responses to prolonged driving. This finding should drastically improve automobile seat design efforts.  相似文献   
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