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1.
Air pollution is a major contributor to several respiratory problems, it affects the whole population in general but children are more susceptible. Exposure to automobile exhaust is associated with increased respiratory symptoms and may impair lung function in children. In view of this, the study was conducted among the children of Delhi, the capital city of India, where ambient air quality was much above the National Ambient Air Quality Standards. The study was conducted in children aged 9–17 years. Pulmonary function test was carried out following the guideline of American Thoracic Society using a portable, electronic spirometer. Air quality data was collected from Central and State Pollution Control Boards. In addition, the level of particulate matter in indoor air was measured by portable laser photometer. Lung function was reduced in 43.5% schoolchildren of the urban area compared with 25.7% of control group. The urban children had increased prevalence of restrictive, obstructive, as well as combined type of lung functions deficits. Besides higher prevalence, the magnitude of lung function deficits was also much more in them. After controlling potential confounders like season, socioeconomic conditions and ETS, PM10 level in ambient air was found to be associated with restrictive (OR?=?1.35, 95% CI 1.07–1.58), obstructive (OR?=?1.45, 95% CI 1.16–1.82), and combined type of lung function deficits (OR?=?1.74, 95% CI 1.37–2.71) in children. Spearman's rank correlation test reaffirmed the association. The study confirms that the level of air pollution is affecting the children.  相似文献   
2.
The peanut plant (Arachis hypogaea L.), when infected by a microbial pathogen, is capable of producing stilbene-derived compounds that are considered antifungal phytoalexins. In addition, the potential health benefits of other stilbenoids from peanuts, including resveratrol and pterostilbene, have been acknowledged by several investigators. Despite considerable progress in peanut research, relatively little is known about the biological activity of the stilbenoid phytoalexins. This study investigated the activities of some of these compounds in a broad spectrum of biological assays. Since peanut stilbenoids appear to play roles in plant defense mechanisms, they were evaluated for their effects on economically important plant pathogenic fungi of the genera Colletotrichum, Botrytis, Fusarium, and Phomopsis. We further investigated these peanut phytoalexins, together with some related natural and synthetic stilbenoids (a total of 24 compounds) in a panel of bioassays to determine their anti-inflammatory, cytotoxic, and antioxidant activities in mammalian cells. Several of these compounds were also evaluated as mammalian opioid receptor competitive antagonists. Assays for adult mosquito and larvae toxicity were also performed. The results of these studies reveal that peanut stilbenoids, as well as related natural and synthetic stilbene derivatives, display a diverse range of biological activities.  相似文献   
3.
Investigations on the effect of competition on stand structure of spring oilseed rape
On the basis of a field experiment with spring oilseed rape, frequency distributions of plant dry matter and plant height were investigated. Samples were taken at four developmental stages: rosette, begin of flowering, end of flowering, ripeness (harvest). To understand the effect of competition in a plant population on frequency distribution, distance of rows (16 cm, 32 cm) and number of plants (60, 90 and 120 plants/m2) were varied. Differences in frequency distribution were estimated by skewness and kurtosis.
The results show that with age of the plant population the skewness of the plant character dry matter decreases from a high positive value till ripeness to a low positive value; kurtosis also decreases during development and tends to a value of 0 at ripeness. The effect of competition as produced by number of plants for area is mirrored by a positive skewness increasing with increasing number of plants per area. The value for kurtosis also increases with the stronger competition as consequence of plant density. Row distance did not show specific effects of frequency distribution. Plant height did, generally speaking, not react to competition.  相似文献   
4.
Australian Oryza are an understudied and underexploited genetic resource for rice improvement. Four species are indigenous: Oryza rufipogon, Oryza meridionalis, Oryza australiensis are widespread across northern Australia, whereas Oryza officinalis is known from two localities only. Molecular analysis of these wild populations is required to better define the distinctness of the taxa and the extent of any gene flow between them and rice. Limited collections of these wild populations are held in seed and DNA banks. These species have potential for domestication in some cases but also have many traits of potential value in the improvement of domesticated rice. Stress tolerance (biotic and abiotic) and grain quality characteristics in these populations may be useful.  相似文献   
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6.
Tropical Animal Health and Production - The current experiment was performed to find the potential effect of inorganic and organic forms of zinc (Zn) on growth, intestinal histomorphology, immune...  相似文献   
7.
Investigations on the effect of competition with regard to the stand development of spring oilseed rape as dependent on environmental conditions
Field experiments were conducted to investigate the frequency distribution in spring oilseed rape as dependent on environmental growing conditions and plant density. As measures for frequency distribution skewness and kurtosis were estimated. The plant character determined was single plant dry matter. To understand the changes in the stand structure, samples were taken at the following developmental stages: rosette, begin of flowering, end of flowering and ripeness (harvest). Plant densities ranged from 60 plants/m2, 90 plants/m2 till 120 plants/m2
The results show that under unfavourable growing conditions, generally speaking, the values of (positive) skewness and kurtosis increase with the development of the plants; under favourable growing conditions, however, the values of skewness and kurtosis decrease from rosette till harvest.
Under unfavourable growing conditions as well as favourable ones, the values of skewness and kurtosis increase with strengthening of plant competition as consequence of increasing plant density. However, the trend during development and the height of the values as well as the quantitative relationships are strongly controlled by the general growing conditions. Frequency distribution, therefore, is not only a result of plant competition but also of differences in resources due to the general conditions of the location.  相似文献   
8.
The effects of short and long-term Hg exposure on the ionic regulation of the Red Sea harry,Aphanius dispar were studied.  相似文献   
9.
Elevated phosphate concentrations at Safaga and Quseir, Red Sea, Egyptian coast, wererelated to some ecological and nutritional aspects of the macro-alga Cystoseira myrica during1985. The results obtained were compared with those recorded for a non-polluted control site atGhardaqa. Chemical analysis of surface seawater samples revealed that the concentrations of dissolvedphosphate at Safaga and Quseir were 3 and 20 times as much as that at Ghardaqa, respectively.The standing crop of C. myrica showed two peaks in spring and autumn. Maximum biomass yield(491 g m-2) and number of individuals (127 m-2) of C. myrica were recorded in the spring at theGhardaqa site. Quseir C. myrica samples contained significantly higher protein-N, total-N andtotal-P values but lower carbohydrate values than the Safaga and Ghardaqa samples (LSD at 1%level). Tissue N:P molar ratios for C. myrica, Laurencia papillosa and Ulva lactuca collected fromGhardaqa ranged from 68-98, compared to 30-59 for the same species collected at thephosphorus polluted sites at Safaga and Quseir. The carbon levels and the C:N ratios of C. myricaexhibited no significant variations in the three studied sites. However, the C:P ratios of Ghardaqaplants were significantly higher than those of Safaga and Quseir.  相似文献   
10.
Higher rates of the two organophosphorus Insecticides (dimethoate and dursban) induced severe drop in the dry weight gain of Nostoc muscorum and Anabaena oryzae. The fungicide karathane seemed to be inhibitory to the growth of Anabaena whereas all levels of the fungicide, except the two higher stimulated the growth of Nostoc. Trifluralin at all levels inhibited the growth of both organisms. However the magnitude of inhibition was always more pronounced in Anabaena. The lowest concentrations of dursban and dimethoate favored chlorophyll a synthesis in the cells of both cyanobacteria. Contrary to chlorophyll, total carotenoid accumulation was significantly suppressed. Moderate and higher doses of karathane and trifluralin increased chlorophyll a biosynthesis in Nostoc and to lesser extent in Anabaena, a phenomenon that was accompanied by significant increase in total carotenoid content. Glucose uptake by both organisms from media was accelerated following adminestration of all pesticides, an effect that was intensified with further increase in concentrations. Dimethoate and dursban favored the total carbohydrate accumulation in the cells of both organisms, whereas karathane and trifluralin accentuated the process, more prominently in Nostoc.  相似文献   
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