期刊文献+
共找到72篇文章
< 1 2 4 >
每页显示 20 50 100
Environment Development and Health Safety System in Rural Areas of Bangladesh (Noakhali and Lakshmipur Districts)
1
作者 Asif Kader 《Journal of Environmental Protection》 2024年第2期193-225,共33页
At present time, Bangladesh is developing its position in all sectors of world prosperity. Economic development of Bangladesh depends on working ability of whole population of this country, although Bangladesh is not ... At present time, Bangladesh is developing its position in all sectors of world prosperity. Economic development of Bangladesh depends on working ability of whole population of this country, although Bangladesh is not developed in health status of its whole population. A large percentage of people live in rural areas without any proper shelter. This study revealed the environmental development and health safety system in rural areas of Bangladesh, which is located in Noakhali and Lakshmipur districts of Bangladesh. Many sections were studied, which are the main structure of environmental development and health safety system of southeastern region of Bangladesh. The study found that there were three types of handicraft enterprises in the surveyed area such as handicraft input, like palm leaf, factories, Betel nut businesses, and Coconut businesses were headed and owned by the women and they were unaware of their health, environment and waste management or reduction of pollution. This study also reveals that microentrepreneurs did not ensure purified water supply and hygienic toilets within enterprises in the study area. The study also found that a significant portion of the microentrepreneurs are workers, and their family members were always fewer users of protective equipment during the COVID-19 pandemic. This study identified that most MEs faced transport or carrying facilities or big costing problems, including problems in available services for raw materials in the high category. In contrast, the high cost of transport facilities was very intensive in the study area. Moreover, it found that Microentrepreneurs (MEs) faced high product marketing costs for transport facilities, and a lack of proper pricing of the products in the study area. In addition, it explored that most of the microentrepreneurs did not receive sufficient credit support, and they faced negative attitudes and delayed responses from the credit services providers in the study area. It also found that the majority of the microentrepreneurs argued that capital support, loan, aid, technological assistance, infrastructural assistance, availability of skilled labor forces, availability of raw materials, and getting the government assistance and services were the major reasons for the highest growth of the enterprises in the study area. In addition, entire MEs had no knowledge and understanding of climate change in the study area. It is worth mentioning that MEs were not aware of climate change and its impacts on nature in the handicrafts sector and in their daily lives. A significant portion of the MEs took safety measures against risk and protected themselves and workers within the enterprises in the study area. MEs had various demands such as infrastructural development, economic assistance (/aid/loan/grants/financial), training and development, assistance for environment development, and machinery assistance for promoting their business. MEs argued that the implementation of their suggestion is the key to improve the current situation of the enterprises. The MEs suggested appointing expert workers, ensuring quality inputs, training workers and reserving products carefully. 展开更多
关键词 COVID-19 HANDICRAFT INGREDIENTS MICROENTERPRISE ENVIRONMENT Climate-Change Waste-Management
下载PDF
Government and Community Involvement in Environmental Protection and Flood Risk Management: Lessons from Keko Machungwa, Dar es Salaam, Tanzania
2
作者 Tumpale Sakijege Junun Sartohadi +2 位作者 Muh Aris Marfai Gabriel Kassenga Samson Kasala 《Journal of Environmental Protection》 2014年第9期760-771,共12页
Since the 1960s, most cities in developing countries have faced a high rate of urbanization, which in turn has caused more harm to low-income earners, in urban areas. A majority of low-income earners most often face d... Since the 1960s, most cities in developing countries have faced a high rate of urbanization, which in turn has caused more harm to low-income earners, in urban areas. A majority of low-income earners most often face difficulties in accessing land in planned areas, as a result they are forced to build houses in unplanned settlements that are vulnerable to natural hazards. The situation is worse to the extent that people encroach the most vulnerable areas (hazard lands). As concentration of people increases, these unplanned areas become more unsafe to live in. This is partly due to the risks associated with natural hazards particularly flooding. Further, vulnerability of unplanned settlements in developing countries is aggravated by hosts of problems caused by many factors, including inadequate Government involvement in: environmental protection especially managing hazard lands and helping the community to minimize risks associated with hazards. This paper addresses this issue. It argues that community and Government initiatives are vital to any strategy for flood risk reduction and environmental protection in general. The study employed both the primary and the secondary data sources. Data collection tools and techniques involved in this study included: Checklist to various leaders, interview using questionnaires, focus group discussion, analysis of aerial photographs and non participant observation. A total of 70 households from within Keko Machungwa were interviewed. The study revealed that flooding is largely contributed by construction done by a large scale developer on a water course;and when affected community initiated a strategy to solve the problem they partially succeed due to inadequate support from the Government and other stakeholders. These findings could be useful to strengthen policy and legislation in environmental protection, management and flood control as well as in intervening land use conflicts between local community and developers. 展开更多
关键词 Environmental Protection COMMUNITY GOVERNMENT Flood RISKS Keko Machungwa
下载PDF
Evaluation and Impact of a Polluted Stream on the Integrated Management of a Drinking Water Resource: A Case Study of the Middle Vaal River, South Africa
3
作者 Shalene Janse van Rensburg Sandra Barnard 《Journal of Water Resource and Protection》 2019年第2期148-165,共18页
The Koekemoerspruit is a possible pollution source of the Middle Vaal River, an important drinking water source in South Africa. This case study aimed to establish the water quality of the Koekemoerspruit, to evaluate... The Koekemoerspruit is a possible pollution source of the Middle Vaal River, an important drinking water source in South Africa. This case study aimed to establish the water quality of the Koekemoerspruit, to evaluate the impact of the Koekemoerspruit on the Vaal River, and to use this information to identify shortcomings in the monitoring program. Monthly and weekly samples from both the Vaal River and the Koekemoerspruit were analyzed at an accredited testing laboratory based on ISO 17025 for 20 chemical methods. A dataset from 2002 to 2015 was statistically analyzed by means of Statistica software, the Mann-Kendall test and the Sens’s slope to determine descriptive statistics and significant trends respectively. The sites’ water quality was evaluated by comparison with both national drinking water standards and environmental target water quality objectives. Results indicated that the target water quality objectives for orthophosphate, nitrate and nitrite, and ammonia concentrations were considerably exceeded in the Koekemoerspruit. The drinking water quality of the Koekemoerspruit and the Middle Vaal was noncompliant with South African standards. Color, electrical conductivity, turbidity, sulfate, recoverable cyanide and arsenic at one site posed aesthetic, operational, acute and chronic health risks. Color, mean ammonia and total chlorophyll concentrations displayed significant trends of increase over time and increased drastically after 2012 at the site where water enters the Middle Vaal River. However, the Koekemoerspruit did not seem to have a significant impact on the overall water quality of the Middle Vaal River, except for total chlorophyll concentrations. Moreover, the review and recommendations for optimizing the water quality monitoring program proved that original monitoring objectives have been achieved. The reviewed monitoring program has consequently been adopted in the water safety plan to address the shortcomings that were identified during this case study. 展开更多
关键词 Target Water Quality EUTROPHICATION Domestic Wastewater Mining Pollution
下载PDF
Evaluation of the Productivity of Intercropping Plantain Cultivar (PITA 3) Fertilized with Two Types of Manure, under Coconut Tree Based (Cocos nucifera L.), on the Tertiary Sands of Côte d’Ivoire
4
作者 Pierre-Marie Janvier Coffi Joséphine Tamia Ama +3 位作者 Thierry Tacra Lekadou Siaka Traore Charly Fernand Agoh Didier Martial Saraka Yao 《Agricultural Sciences》 2023年第10期1405-1419,共15页
Pressure on land tenure is having a negative impact on the coconut sector, reducing farmers’ incomes. Intercropping cultivars plantain under coconut based has been considered as a solution to this problem. The aim of... Pressure on land tenure is having a negative impact on the coconut sector, reducing farmers’ incomes. Intercropping cultivars plantain under coconut based has been considered as a solution to this problem. The aim of this work is to diversify the sources of income for coconut growers. The plantain variety PITA 3, popularised by the CNRA, was grown in coconut inter-rows (PB113<sup>+</sup>), with two types of manure (chemical, organic). Six (06) treatments D1, D2, D3, D4, D5 and D6 were studied. In the tenth month after planting, treatment D3, which included banana plants fertilised with 9 kg of manure/plant, got the best agromorphological performance: height (264.08 cm), neck circumference (57.68 cm) and 12 leaves. In terms of production parameters, D3 banana plants had a shorter production cycle (347 days) and the highest diet mass (9.3 kg). However, the plants that received no fertiliser (D6) showed stunted growth and were unable to produce brunch. The fertilization of plantain with 10 t/ha of laying hen droppings permitted good development and production of plantains on tertiary sands. 展开更多
关键词 INTERCROPPING COCONUT Plantain PITA 3 MANURE Tertiary Sands
下载PDF
Landfill Site Suitability Assessment Using Geographic Information System (GIS) and Analytic Hierarchy Process (AHP) in Butuan City, Philippines
5
作者 Francis Jhun T.Macalam Kaleb P.Arreza +1 位作者 Angelica T.Magpantay Kristine Y.Rabaño 《Journal of Environmental & Earth Sciences》 2023年第1期95-107,共13页
Landfilling is one of the most effective and responsible ways to dispose of municipal solid waste(MSW).Identifying landfill sites,however,is a challenging and complex undertaking because it depends on social,environme... Landfilling is one of the most effective and responsible ways to dispose of municipal solid waste(MSW).Identifying landfill sites,however,is a challenging and complex undertaking because it depends on social,environmental,technical,economic,and legal issues.This study aims to map the optimal sites that were environmentally suitable for locating a landfill site in Butuan City,Philippines.With reference to the policy requirements from DENR Section I,Landfill Site Identification Criteria and Screening Guidelines of National Solid Waste Management Commission,the integration of a Geographic Information System(GIS)model builder and Analytical Hierarchy Process(AHP)has been used in this study to address the aforementioned challenges related to the landfill site suitability analysis.Based on the generated sanitary landfill suitability map,results showed that Barangay Tungao(1131.42967 ha)and Florida(518.48 ha)were able to meet and consider the three(3)main components,namely economic,environmental,and physical criteria,and are highly suit­able as landfill site locations in Butuan City.It is recommended that there will conduct a geotechnical evaluation,involv­ing rigorous geological and hydrogeological assessment employing a combination of site investigation and laboratory techniques.In addition,additional specific social,ecological,climatic,and economic factors need to be considered(i.e.including impact on humans,flora,fauna,soil,water,air,climate,and landscape). 展开更多
关键词 Geographic information system Sanitary landfill Analytic hierarchy process Butuan City Site suitability
下载PDF
Characterization of red mud derived from a combined Bayer Process and Calcining method for alumina refining 被引量:5
6
作者 Chuxia LIN Yonggui LIU 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期40-40,共1页
关键词 红泥 铝土矿 化学性质 酸性压制 氧化铝 精炼工艺
下载PDF
High-temperature granulites and supercontinents 被引量:4
7
作者 J.L.R.Touret M.Santosh J.M.Huizenga 《Geoscience Frontiers》 SCIE CAS CSCD 2016年第1期101-113,共13页
The formation of continents involves a combination of magmatic and metamorphic processes. These processes become indistinguishable at the crust-mantle interface, where the pressure-temperature(P-T)conditions of(ul... The formation of continents involves a combination of magmatic and metamorphic processes. These processes become indistinguishable at the crust-mantle interface, where the pressure-temperature(P-T)conditions of(ultra) high-temperature granulites and magmatic rocks are similar. Continents grow laterally, by magmatic activity above oceanic subduction zones(high-pressure metamorphic setting), and vertically by accumulation of mantle-derived magmas at the base of the crust(high-temperature metamorphic setting). Both events are separated from each other in time; the vertical accretion postdating lateral growth by several tens of millions of years. Fluid inclusion data indicate that during the high-temperature metamorphic episode the granulite lower crust is invaded by large amounts of low H2O-activity fluids including high-density CO2 and concentrated saline solutions(brines). These fluids are expelled from the lower crust to higher crustal levels at the end of the high-grade metamorphic event. The final amalgamation of supercontinents corresponds to episodes of ultra-high temperature metamorphism involving large-scale accumulation of these low-water activity fluids in the lower crust.This accumulation causes tectonic instability, which together with the heat input from the subcontinental lithospheric mantle, leads to the disruption of supercontinents. Thus, the fragmentation of a supercontinent is already programmed at the time of its amalgamation. 展开更多
关键词 CONTINENTS SUPERCONTINENTS Magmatism and metamorphism Fluids TECTONICS
下载PDF
Saving Dupinga Watershed in Gabaldon, Nueva Ecija Philippines: Insights from Community Based Forest Management Model 被引量:2
8
作者 Arneil G. Gabriel Eric G. Claudio Feliciano A. Bolisay 《Open Journal of Ecology》 2017年第2期140-157,共18页
The world is losing its forest. The study described the multi-sectoral initiatives done to protect the Dupinga watershed. By using Community Based Forest Management (CBFM) as theoretical framework and analytic descrip... The world is losing its forest. The study described the multi-sectoral initiatives done to protect the Dupinga watershed. By using Community Based Forest Management (CBFM) as theoretical framework and analytic descriptive method of research, issues and concerns related to watershed protection are discussed. The study argued that the multi-sectoral collaboration of the Local Government Unit of Gabaldon, the Department of Environment and Natural Resources (DENR), Peoples Organizations, Non Government Organizations (NGO) and Community Organization is a CBFM in progress. Alternative source of income and community tourism may strengthen and sustain the multi-stake-holders collaboration existing in the area while capacity building program for community participation and forest management may provide insights for a sustainable watershed protection and management. 展开更多
关键词 SUSTAINABLE Development Case Study COMMUNITY Based FOREST Management Dupinga WATERSHED in the Philippines
下载PDF
Slab rollback and microcontinent subduction in the evolution of the Zambales Ophiolite Complex(Philippines):A review 被引量:2
9
作者 Graciano P.Yumul Jr. Carla B.Dimalanta +11 位作者 Ricky C.Salapare Karlo L.Queano Decibel V.Faustino-Eslava Edanjarlo J.Marquez Noelynna T.Ramos Betchaida D.Payot Juan Miguel R.Guotana Jillian Aira S.Gabo-Ratio Leo T.Armada Jenielyn T.Padrones Keisuke Ishida Shigeyuki Suzuki 《Geoscience Frontiers》 SCIE CAS CSCD 2020年第1期23-36,共14页
New radiolarian ages show that the island arc-related Acoje block of the Zambales Ophiolite Complex is possibly of Late Jurassic to Early Cretaceous age.Radiometric dating of its plutonic and volcanichypabyssal rocks ... New radiolarian ages show that the island arc-related Acoje block of the Zambales Ophiolite Complex is possibly of Late Jurassic to Early Cretaceous age.Radiometric dating of its plutonic and volcanichypabyssal rocks yielded middle Eocene ages.On the other hand,the paleontological dating of the sedimentary carapace of the transitional mid-ocean ridge-island arc affiliated Coto block of the ophiolite complex,together with isotopic age datings of its dikes and mafic cumulate rocks,also yielded Eocene ages.This offers the possibility that the Zambales Ophiolite Complex could have:(1)evolved from a Mesozoic arc(Acoje block)that split to form a Cenozoic back-arc basin(Coto block),(2)through faulting,structurally juxtaposed a Mesozoic oceanic crust with a younger Cenozoic lithospheric fragment or(3)through the interplay of slab rollback,slab break-off and,at a later time,collision with a microcontinent fragment,caused the formation of an island arc-related ophiolite block(Acoje)that migrated trench-ward resulting into the generation of a back-arc basin(Coto block)with a limited subduction signature.This Meso-Cenozoic ophiolite complex is compared with the other oceanic lithosphere fragments along the western seaboard of the Philippines in the context of their evolution in terms of their recognized environments of generation. 展开更多
关键词 OPHIOLITE Slab rollback RADIOLARIANS SUBDUCTION Zambales Philippines
下载PDF
The effect of ozone and drought on the photosynthetic performance of canola 被引量:3
10
作者 Bheki G Maliba Prabhu M Inbaraj Jacques M Berner 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2018年第5期1137-1144,共8页
Canola plants were fumigated in open-top chambers with ozone(O3)(120 ppb)under well-watered(WW)and water-stressed(WS)conditions for 4 weeks.Non-fumigated plants were also studied to facilitate comparison betwe... Canola plants were fumigated in open-top chambers with ozone(O3)(120 ppb)under well-watered(WW)and water-stressed(WS)conditions for 4 weeks.Non-fumigated plants were also studied to facilitate comparison between treatments for the same week and over time.Therefore,the treatments were:WW,WW-O3,WS and WS-O3.The fast chlorophyll a fluorescence transients OJIP for the four treatments emitted upon illumination of dark-adapted leaves were measured after week 1,2,3,4 and analysed by the JIP-test to evaluate the resulting changes in photosynthetic performance.Ozone fumigation led to a decline of total performance index(PI(total))in well-watered plants.The effect of O3 was minor under drought conditions,as revealed by a decrease of PI(total) by 3%.The PI(total) decreased as the treatment was prolonged,due to leaf ageing for all cases and the decline was more pronounced under WW-O3.Taking the average of all weeks,WW had the highest PI(total)and the lowest WW-O3(decrease by 27%),while in WS and WS-O3,it was lower than WW(14 and 17%,respectively).We found that the absorption(ABS)/reaction centre(RC)increases,while the maximum quantum yield of primary photochemistry(φ(Po))undergoes slight changes,and trapping(TR0)/RC closely followed the increase in ABS/RC.This indicates that O3and drought caused an increase in the functional antenna size.The maximum quantum yield of primary photochemistry showed slight differences for all treatments and over time,suggesting that this parameter is less sensitive to drought and O3 stress.Therefore,the more sensitive components of the photosynthetic electron transport chain appeared to be the probability that an electron from the intersystem electron carriers is transferred to reduce end electron acceptors at the PSI acceptor side(δ(Ro))and the RC density on a chlorophyll basis(RC/ABS). 展开更多
关键词 canola Chl a fluorescence JIP-test open-top chamber ozone
下载PDF
Slaughterhouse Wastewater Characterization and Treatment: An Economic and Public Health Necessity of the Meat Processing Industry in Ontario, Canada 被引量:1
11
作者 Ciro Bustillo-Lecompte Mehrab Mehrvar Edgar Quiñones-Bolaños 《Journal of Geoscience and Environment Protection》 2016年第4期175-186,共12页
The characteristics of the slaughterhouse effluents and current wastewater treatment practices in the province of Ontario, Canada are analyzed. Meat processing plants are found to produce large amounts of wastewater d... The characteristics of the slaughterhouse effluents and current wastewater treatment practices in the province of Ontario, Canada are analyzed. Meat processing plants are found to produce large amounts of wastewater due to the slaughtering process and cleaning of their facilities. Furthermore, the composition of the wastewater varies according to the type and number of animals slaughtered and the water requirements of the process. However, the slaughterhouse wastewater usually contains high levels of organics and nutrients. Several slaughterhouses in Ontario discharge their wastewater into the municipal sewer system after primary pretreatment at the meat processing plant. Therefore, due to the high-strength characteristics of the slaughterhouse effluents, an extensive treatment for a safe discharge into the environment is required. Thus, the combination of biological processes and advanced oxidation technologies for slaughterhouse wastewater treatment is evaluated in this study. Results show that the application of combined biological and advanced oxidation processes is recommended for on-site slaughterhouse wastewater treatment. 展开更多
关键词 Slaughterhouse Wastewater Anaerobic Digestion Activated Sludge Advanced Oxidation Processes
下载PDF
An Agent-Based Assessment of Land Use and Ecosystem Changes in Traditional Agricultural Landscape of Portugal 被引量:2
12
作者 Lilibeth A.Acosta Mark D.A.Rounsevell +3 位作者 Martha Bakker Ann Van Doorn Montserrat Gomez-Delgado Marc Delgado 《Intelligent Information Management》 2014年第2期55-80,共26页
This paper presents an assessment of land use changes and their impacts on the ecosystem in the Montado, a traditional agricultural landscape of Portugal in response to global environmental change. The assessment uses... This paper presents an assessment of land use changes and their impacts on the ecosystem in the Montado, a traditional agricultural landscape of Portugal in response to global environmental change. The assessment uses an agent-based model (ABM) of the adaptive decisions of farmers to simulate the influence on future land use patterns of socio-economic attributes such as social relationships and farmer reliance on subsidies and biophysical constraints. The application and development of the ABM are supported empirically using three categories of input data: 1) farmer types based on a cluster analysis of socio-economic attributes;2) agricultural suitability based on regression analysis of historical land use maps and biophysical attributes;and 3) future trends in the economic and climatic environments based on the A1fi scenario of the Intergovernmental Panel on Climate Change. Model sensitivity and uncertainty analyses are carried out prior to the scenario analysis in order to verify the absence of systematic errors in the model structure. The results of the scenario analysis show that the area of Montado declines significantly by 2050, but it remains the dominant land use in the case study area, indicating some resilience to change. An important policy challenge arising from this assessment is how to encourage next generation of innovative farmers to conserve this traditional landscape for social and ecological values. 展开更多
关键词 ABANDONMENT Agent-Based Model Cluster Analysis Ecosystem and Biodiversity Land Use Change Logistic Regression PORTUGAL Scenario Analysis Traditional Agricultural Landscape
下载PDF
The treatment of wastewaters with high phosphorous and high ammonia loadings using modified bauxite refinery residues
13
作者 Malcolm W. Clark Frank Gnanam +1 位作者 David M. McConchie Lee Fergusson 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期141-141,共1页
关键词 污水 营养 去除方法 废水处理 氨水
下载PDF
Cross-and counter-current treatment systems for the removal of equilibrium constrained metals on unconventional sorbants [Bauxsol (TM)]
14
作者 Malcolm W. Clark Jim Jonas +2 位作者 David M. McConchie Jim Rouse Christa Whitmore 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期127-127,共1页
关键词 微量金属 去除方法 清洁生产 地下水 水文化学
下载PDF
Soil chemical properties under modern and traditional farming systems at Khagrachari,Chittagong Hill Tracts,Bangladesh
15
作者 Shampa Biswas Mark E.Swanson +1 位作者 Jalal Uddin Md.Shoaib S.M.S.Sirajul 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第4期451-456,523,共7页
Land degradation in Chittagong hill tracts has been taking place due to shrinkage of forest cover, policy weakness, population explosion, and inappropriate hill farming system. Modem farming system in the Chittagong h... Land degradation in Chittagong hill tracts has been taking place due to shrinkage of forest cover, policy weakness, population explosion, and inappropriate hill farming system. Modem farming system in the Chittagong hill tracts like Sloping Agricultural Land Technology (SALT) is practiced to provide a new strategy for developing lands for economic productivity and bio-diversity conservation through establishment of ecological community rather than traditional shifting cultivation which is no longer sustainable according to the carrying capacity of ecosystem of Chittagong hill tracts. This study is to find out changing trends of soil chemical properties of sites under modem and traditional farming systems at Khagrachari district of Chittagong hill tracts. The result of the research shows that Sloping Agricultural Land Technology has significantly higher capacity of production due to the presence of the highest percentage of organic carbon, organic matter, compared with shifting cultivated site. The study recommends that shifting cultivation may be changed into a relatively stable semi-permanent farming system through developing participatory integrated farming systems to establish stable production environment in the Chittagong Hill Tracts. 展开更多
关键词 sloping agricultural land Technology sustainable hill farming system modem and traditional farming system chemical properties
下载PDF
Trend Analysis in Ecological Status and Macrophytic Characterization of Watercourses: Case of the Semois-Chiers Basin, Belgium Wallonia
16
作者 Sossey-Alaoui Khadija Rosillon Francis Tychon Bernard 《Journal of Water Resource and Protection》 2015年第13期988-1000,共13页
In order to analyze the distribution and evolution of the aquatic vegetation and ecological status of the Semois-Chiers basin (Semois sub-basin and Chiers sub-basin), macrophyte surveys were conducted at 48 sites in 2... In order to analyze the distribution and evolution of the aquatic vegetation and ecological status of the Semois-Chiers basin (Semois sub-basin and Chiers sub-basin), macrophyte surveys were conducted at 48 sites in 2007 and 2013. Environmental parameters were also measured in order to characterize the waterbodies in terms of physico-chemical properties and anthropogenic pressure. The two-way clustering and indicator value (INDVAL) methods were used to assess groups of sites according to their macrophytic composition and species communities. The results showed a clear difference between streams in the Lorraine area (calcareous watercourses) and in the Ardennes (siliceous). Within each natural region, those with natural vegetation of high ecological status were separated from those dominated by resistant species. The Macrophytical Biological Index for Rivers (IBMR) was calculated for the sites visited in 2010 and 2013 and the results show a trend towards an increase of IBMR values of polluted sites. For the latter, the Wilcoxon test was performed to assess the significance of the difference in quality between 2010 and 2013. This showed a statistically significant difference (p-value = 0.035). Our results showed similarities with previous data, as well as some differences. The differences observed might indicate a gradual change in the composition of the vegetation in the study area, which was caused by changes in environmental conditions. They could also reflect a lack of information about the ecology of certain groups of plants, mainly bryophytes and macroalgae that were not considered in previous studies. Despite the measures implemented under the EU’s Water Framework Directive (WFD), the current vegetation of the Semois river differs little from that observed in 1996. The headwaters of a Semois river, described in previous studies as polytrophic and devoid of vegetation, show a slight improvement, with the appearance of macrophytic species. In some parts of the Chiers sub-basin, however, resistant species observed in 1999 persist. 展开更多
关键词 MACROPHYTES Semois-Chiers BASIN WFD IBMR ECOLOGICAL Quality
下载PDF
Heavy Metals, Metalloids, Their Toxic Effect and Living Systems
17
作者 Ferdous Seraj Tania Rahman 《American Journal of Plant Sciences》 2018年第13期2626-2643,共18页
Pollution of the biosphere by heavy metals is a global hazard that has accelerated since the beginning of the industrial revolution. Toxic heavy metals are harmful to living organisms even at low concentrations wherea... Pollution of the biosphere by heavy metals is a global hazard that has accelerated since the beginning of the industrial revolution. Toxic heavy metals are harmful to living organisms even at low concentrations whereas heavy metals that are essential trace elements are required by plants at low concentrations but can become toxic at high concentrations. Heavy metals released from different sources accumulate in soil and, where bioavailability is high enough;can adversely affect soil biological functioning and other properties, leading to the loss of soil and ecosystem fertility and health. It is important that heavy metal contaminated sites are remediated as heavy metals do not decompose into less harmful substances like organic contaminants, and thus are retained in the soil. In this review, we survey and analysis our current knowledge and understanding of the abundance of heavy metals in soil, their phytoavailability, their toxicity, their uptake and transport, role of rhizobia and other microbes and overall rhizosphere processes. 展开更多
关键词 Heavy METAL ARSENIC Zinc Nickel Contaminated Land METAL BIOAVAILABILITY METAL Toxicity RHIZOBIA RHIZOSPHERE
下载PDF
Available Approaches of Remediation and Stabilisation of Metal Contamination in Soil: A Review
18
作者 Tania Rahman Md. Ferdous Seraj 《American Journal of Plant Sciences》 2018年第10期2033-2052,共20页
Anthropogenic activities, such as mining of natural resources, manufac-turing industries, modern agricultural practices and energy production have resulted in the release of heavy metals with resultant harmful im-pact... Anthropogenic activities, such as mining of natural resources, manufac-turing industries, modern agricultural practices and energy production have resulted in the release of heavy metals with resultant harmful im-pacts in some natural environments. Toxic heavy metals are harmful to living organisms even at low concentrations. Therefore, heavy metal contaminated sites should be remediated as heavy metals do not decompose into less harmful substances and are retained in the soil. Conventional methods are used for remediation of heavy metal contaminated soils such as heavy metal extraction, immobilization and removal of soils to landfill produce large quantities of toxic products including insoluble hydroxides and are rarely cost effective. The advent of bioremediation technologies like biosparging, bioventing and bioaugmentation has provided an alternative to conventional methods for remediating heavy metal contaminated soils. A subset of bacteria found in the rhizosphere has been found to increase the tolerance of plants to heavy metals in soil. These bacteria commonly known as plant growth promoting rhizobacteria or Plant Growth Promoting Rhizobacteria (PGPR) are showing promise as a bioremediation technique for the stabilisation and remediation of heavy metal contami-nated sites. PGPR can improve plant growth via a variety of mechanism including fixing atmospheric N to improve N status and making plants more tolerant of heavy metals. Scattered literature is harnessed to review the principles, advantages and disadvantages of the available technologies for remediating heavy metal contaminated soils and is presented. 展开更多
关键词 In SITU BIOREMEDIATION Ex SITU BIOREMEDIATION PHYTOREMEDIATION RHIZOREMEDIATION Plant Growth Promoting RHIZOBACTERIA (PGPR)
下载PDF
Importance of a Well-distributed Frequency of Measurements in the Senescence Monitoring of Winter Wheat and Yield Estimates
19
作者 Louis Kouadio Bakary Djaby Moussa El Jarroudi Bernard Tychon 《Journal of Agricultural Science and Technology(B)》 2012年第12期1203-1213,共11页
Theoretical frequencies of green area index (GAI) measurements were assessed in order to bring out the optimum frequencies for the monitoring of the senescence of winter wheat as well as the relationships between me... Theoretical frequencies of green area index (GAI) measurements were assessed in order to bring out the optimum frequencies for the monitoring of the senescence of winter wheat as well as the relationships between metrics which could be derived and the final grain yield. Several profiles of GAI decreasing curves were elaborated based on field measurements. Two functions, usually employed in green leaf area decreasing curves fitting (i.e., modified Gompertz and logistic functions) were then used to characterize the senescence phase and to calculate their metrics. These analyses showed that the two curve fitting functions satisfactorily described the senescence phase on frequencies of four to six GAI measurements, well distributed throughout a period of 30-35 days. The regression-based modeling showed that those involving metrics from logistic function (i.e., maximum value of GAI, green area duration and senescent rate) were more suitable than that of the modified Gompertz function for wheat yield estimates. Such results could be useful for studies at larger scales (involving remote sensing airplane or satellite data) and focused on the senescence in terms of optimum number of measurements and frequencies for developing models for yield estimates. 展开更多
关键词 Green area index SENESCENCE logistic function YIELD wheat.
下载PDF
Antifungal Enantiomeric Styrylpyrones from Sanrafaelia ruffonammari and Ophrypetalum odoratum
20
作者 Hamisi M.Malebo Charles Kihampa +4 位作者 Clarence A.Mgina Fortunatus Sung’hwa Reiner Waibel Stephan A.Jonker Mayunga H.H.Nkunya 《Natural Products and Bioprospecting》 CAS 2014年第2期129-133,共5页
Phytochemical investigation of Sanrafaelia ruffonammari Verd and Ophrypetalum odoratum Diels that belongs to the rare genera confined to East African coastal forests led to the isolation of enantiomeric styrylpyrone d... Phytochemical investigation of Sanrafaelia ruffonammari Verd and Ophrypetalum odoratum Diels that belongs to the rare genera confined to East African coastal forests led to the isolation of enantiomeric styrylpyrone dimer,(±)-5-methoxy-7-phenyl-[4-methoxy-2-pyronyl]-1-(E)-styryl-2-oxabicyclo-[4.2.0]-octa-4-en-3-one(1)alongside(?)-6-styryl-7,8-epoxy-4-methoxypyran-2-one(2)and the enantiomeric(?)-(3)and(-)-6-styryl-7,8-dihydroxy-4-methoxypyran-2-ones(4).Their structures were established by means of spectroscopic methods.In this paper we reveal for the first time the occurrence of styrylpyrones in East African biodiversity.(?)-6-Styryl-7,8-epoxy-4-methoxypyran-2-one(2)and the dihydroxystyrylpyrone enantiomer(3)showed in vitro antifungal activity against Candida albicans at a concentration of 24.4 and 26.2 lM with zones of inhibition of 17 and 9 mm,respectively.Compound 2 exhibited strong activity in the brine shrimp test with LC50=1.7 lg/mL.Their high cytotoxic and antifungal activities render them candidates for further scientific attention for drug development programs against cancer and microbial infections. 展开更多
关键词 Sanrafaelia ruffonammari Verd Ophrypetalum odoratum Diels Styrylpyrones ANTIFUNGAL
下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部