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251.
In rural Africa, wild foods provide diversity, vitamins and minerals in the diet. They are also important at times of food shortage. This paper discusses issues concerning wild food use in semiarid West Africa, and presents the results of a study of the use of wild plant foods in northeast Nigeria. Interviews with farmers and herders identified a total of 67 wild foods, coming from 53 species of plant. Knowledge of wild foods varied according to ethnic group and gender. Some wild foods caused side effects if eaten in excess. Land-use change due to agricultural expansion seems to be increasing the areas where wild foods are most commonly found. Wild foods are important as a supplement to daily diet, and at times of food scarcity. In addition, they provide an opportunity to generate income when they are collected and traded. The paper concludes that wild foods are an important coping strategy for rural communities. Further research is needed to determine whether local institutions and community-based natural resource management regimes are sufficient to conserve this resource. 相似文献
252.
Viscous, semi-rigid interfacial films that are formed at the interface of certain multi-component non-aqueous phase liquid (NAPLs) and water can significantly reduce the rates of mass transfer of solutes. Creosote-water systems were investigated for their ability to form interfacial films. The effects of these films on the creosote-water partition and on mass transfer of a representative solute, naphthalene, were investigated in a series of experiments. The area-independent mass transfer coefficient of naphthalene contained in creosote decreased by 30% over a 1-week period in systems containing creosote and water. Further aging for up to 21 days did not result in significant additional decreases in the mass transfer coefficient. The creosote-water partition coefficient, however, did not change with extended contact. The presence of viscous interfacial films in creosote-water systems was demonstrated in pendant drop tests. These interfacial films most likely caused the reduction in solute mass transfer coefficients by providing significant resistance to the diffusion of solutes through the interfacial film. Results from mass transfer experiments conducted under different system conditions suggested that hindered diffusion of naphthalene through the bulk creosote phase, changes in composition of creosote as a result of extended dissolution, or changes in creosote-water interfacial area did not contribute to the decrease in naphthalene mass transfer coefficient. 相似文献
253.
Biswas SK Tarafdar SA Islam A Khaliquzzaman M Tervahattu H Kupiainen K 《Journal of the Air & Waste Management Association (1995)》2003,53(11):1355-1362
Airborne particulate matter (APM) samples collected at a semiresidential area in Dhaka, Bangladesh, during the periods of 1994 and 1997-2000 have been studied to assess the impact of the use of unleaded gasoline in Bangladesh. According to scanning electron microscopy/ energy-dispersive X-ray microanalyzer studies, lead (Pb) was found as Pb sulfates and Pb halides in motor-vehicle exhaust particles, whose diameters were some hundreds of nanometers. No significant changes in the annual averages of APM mass and black carbon concentrations have been observed over the period. The yearly average Pb concentration reached a maximum value of 370 ng/m3 in the particulate matter with an aerodynamic diameter < 2.5 microm fraction in 1998. In 2000, the concentration decreased to approximately one-third (106 ng/m3) of the high earlier values after the introduction of unleaded gasoline in 1999. A significant lowering of the blood Pb level of the population over next few years is expected as a result of this great decrease in Pb concentration. 相似文献
254.
The effects of a novel phosphorothionate (RPR-V) synthesized at Indian Institute of Chemical Technology, Hyderabad, was studied using three sub-chronic doses of 0.033 (low), 0.066 (medium) and 0.099 (high) mg kg(-1) in male and female rats for a period of 90 days. This long term and repeated treatment of RPR-V revealed that the membrane bound target enzymes Aspartate aminotransferase and Alanine aminotransferase increased significantly in serum and kidney, whereas these enzymes significantly decreased in liver and lung tissues when measured after 45 and 90 days of treatment. This compound also caused significant inhibition of RBC Acetylcholinesterase, target enzyme of organophosphorus compounds revealing its effect on normal synaptic transmission. Two way Anova studies disclosed that the alterations were mostly dose and time dependent, sexual dimorphism was not observed when the activities of male rats were compared with female rats. Enzyme recoveries were recorded after 28 days of post treatment, high degree positive correlation was observed with regard to these enzymes between serum versus kidney, whereas in case of serum versus liver and lung tissues high degree negative correlation was recorded. These enzyme profiles elucidates that they increased in serum but they decreased significantly in liver and lung indicating necrosis of these tissues. However, in case of kidney the level of these enzymes increased significantly with parallel to serum, which is suggestive of an increase synthesis of these enzymes, may be an adaptive mechanism due to the stress of the toxicant. These biomarker enzymes can be detected rapidly and hence may be used for the prediction and diagnosis of pesticide insults. 相似文献
255.
Marine sponges of the Genus Plakortis are typically unfouled; they can have a distinctive pleasant smell and an oily surface. A significant quantity of fragrant
oil was obtained from a Jamaican Plakortis sp. by cryo-trap. The oil was determined to be exclusively 2-decanone. The antifouling character of the oil was evaluated
by its effects on surface attachment of a gram negative bacterial model using confocal fluorescence microscopy as well as
its effects on the attachment of Dreissena polymorpha (zebra mussel). The ketone dramatically inhibited attachment of the bacteria and zebra mussels. The results suggest that
the oil impacts establishment of related epifauna on the Plakortis sponge in nature. Although the aliphatic ketone alone is not a potential commercial alternative for antifouling coatings,
incorporating the functionality into coating design should be considered in future studies. 相似文献
256.
Chlorpyrifos is a common organophosphorus insecticide used for crop protection. Chlorpyrifos use has induced heath issues and water pollution. Such issues may be solved by phytoremediation, which is the use of plants for the cleanup of pollutants. Here, we tested Plantago major L. to clean water and soils under laboratory conditions. Results show that the concentration of chlorpyrifos residues after 5 days exposure reached 36.86 μg/g in roots and 13.93 μg/g in upper plant tissues. Gas chromatography–mass spectrometry (GC–MS) analysis of chlorpyrifos metabolites suggests the formation of 3, 5, 6-trichloro-2-pyridinol (TCP) and diethyl 3,5,6-trichloropyridin-2-yl phosphate (chlorpyrifos-oxon). Chlorpyrifos-oxon was detected in the roots and the leaves after 2 h of testing. After 24 h of testing, the degradation product chlorpyrifos-oxon increased in the roots and the leaves then decreased gradually until the end of testing. TCP levels increased gradually to 192 h then decreased until the end of testing. 相似文献
257.
Eiman Al-Abdulghani Amr El-Sammak Mohammed Sarawi 《Journal of Coastal Conservation》2013,17(3):445-462
Kuwait Bay is an imperative characteristic of the State of Kuwait. It has a number of major activities existing around it, including, business, industrial and recreational ones. The phase of construction and development of projects, and their resulting pollution have led to major change in the features of the area. The purpose of this research is to serve as a managing tool for decision-making through the environmental assessment of Kuwait Bay. Due to the multiplicities and diversities of the man-made activities and the natural environmental setting of the bay, the impacts are out looked on a holistic approach rather than on a single approach. The methodology of assessment including, sampling and analysis of water and sediment, statistical analysis, as well as application of the Rapid Impact Assessment Matrix (RAIM) in order to analysis the impacts in an integrated approach. The southern areas of the bay are the main sources of pollution that distributed northward to cover the central region of the bay. Sulaibikhat Bay (South-West sector of the bay) is the most vulnerable area due to its exposure to anthropogenic activities such as reclamations, sewage inflow and other activities. The area near Shuwaikh Port is suffering due to reclamation processes. The northern and north-west sectors suffer from coastal erosion as well as from pollutants arriving via Shatt Al Arab. 相似文献
258.
Elucidation of phosphorous sorption by calcareous soils using principal component analysis 总被引:2,自引:0,他引:2
Kholoud Mashal Yahya S. Al-Degs Mohammed Al-Qinna Mohammed Salahat 《Chemistry and Ecology》2014,30(2):133-146
This study was conducted to understand the mechanisms governing P-sorption and desorption by calcareous soils (up to 48% CaCO 3). Batch experiments with KCl as background were carried out by adding varying amount of P up to 100 mgP.L?1. The desorption percentage (%DES) results show that little P was released from the adsorbed phase. Principal component analysis was applied to evaluate the combined influence of soil components on P sorption. The complex P sorption process can be related to specific soil components by the following equation: P? sorption=?2.20 (CaCO 3% )?0.04 (Fe? oxide)+0.04 (pHe)+11.02 (sand % )+3.35 (silt)?10.73 (clay)?1.24 (EC)?0.22 (OM)?0.81 (CEC)?1.93 (P? Olsen) (R2=0.9941, SSE=380). Sand% and clay% are the most significant variables for modelling P sorption data. The derived equation could be applied to predict P sorption in other soils that have similar compositions to those investigated herein. The degree of P saturation (DPS) threshold level for all soils was less than 3% except in the soil with the lowest iron oxide. All of the studied soils have exceeded the environmentally unacceptable P concentration except the soil with the lowest iron oxide content. 相似文献
259.
Problem
Limited literature suggests that gasoline prices have substantial effects on reducing fatal crashes. However, the literature focuses only on fatal crashes and does not examine the effects on all traffic crashes.Methods
Mississippi traffic crash data from April 2004–December 2008 from the Mississippi Highway Patrol and regular-grade unleaded gasoline price data from the Energy Information Administration of the U.S. Department of Energy were used to investigate the effects of gasoline prices on traffic safety by age, gender, and race.Results
Gasoline prices have both short-term and intermediate-term effects on reducing total traffic crashes and crashes of females, whites, and blacks. The intermediate-term effects are generally stronger than the short-term effects. Gasoline prices also have short-term effects on reducing crashes of younger drivers and intermediate-term effects on older drivers and male drivers.Impact on Industry
Higher gasoline taxes reduce traffic crashes and may result in additional societal benefits. 相似文献260.