WorldWideScience

Sample records for peri-urban aquatic plant

  1. Nitrogen sources, transport and processing in peri-urban floodplains

    OpenAIRE

    Gooddy, D.C.; Macdonald, D.M.J.; Lapworth, D.J.; Bennett, S.A.; Griffiths, K.J.

    2014-01-01

    Peri-urban floodplains are an important interface between developed land and the aquatic environment and may act as a source or sink for contaminants moving from urban areas towards surface water courses. With increasing pressure from urban development the functioning of floodplains is coming under greater scrutiny. A number of peri-urban sites have been found to be populated with legacy landfills which could potentially cause pollution of adjacent river bodies. Here, a peri-urban floodplain ...

  2. Aquatic plants

    DEFF Research Database (Denmark)

    Madsen, T. V.; Sand-Jensen, K.

    2006-01-01

    Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between terre...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water.......Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...

  3. Understanding the peri-urban economy

    DEFF Research Database (Denmark)

    Monsson, Christian Kjær

    2013-01-01

    Christian Kjær Monsson suggests that the peri-urban economy should be understood as a metaphor of a mosaic.......Christian Kjær Monsson suggests that the peri-urban economy should be understood as a metaphor of a mosaic....

  4. Nitrogen sources, transport and processing in peri-urban floodplains.

    Science.gov (United States)

    Gooddy, D C; Macdonald, D M J; Lapworth, D J; Bennett, S A; Griffiths, K J

    2014-10-01

    Peri-urban floodplains are an important interface between developed land and the aquatic environment and may act as a source or sink for contaminants moving from urban areas towards surface water courses. With increasing pressure from urban development the functioning of floodplains is coming under greater scrutiny. A number of peri-urban sites have been found to be populated with legacy landfills which could potentially cause pollution of adjacent river bodies. Here, a peri-urban floodplain adjoining the city of Oxford, UK, with the River Thames has been investigated over a period of three years through repeated sampling of groundwaters from existing and specially constructed piezometers. A nearby landfill has been found to have imprinted a strong signal on the groundwater with particularly high concentrations of ammonium and generally low concentrations of nitrate and dissolved oxygen. An intensive study of nitrogen dynamics through the use of N-species chemistry, nitrogen isotopes and dissolved nitrous oxide reveals that there is little or no denitrification in the majority of the main landfill plume, and neither is the ammonium significantly retarded by sorption to the aquifer sediments. A simple model has determined the flux of total nitrogen and ammonium from the landfill, through the floodplain and into the river. Over an 8 km reach of the river, which has a number of other legacy landfills, it is estimated that 27.5 tonnes of ammonium may be delivered to the river annually. Although this is a relatively small contribution to the total river nitrogen, it may represent up to 15% of the ammonium loading at the study site and over the length of the reach could increase in-stream concentrations by nearly 40%. Catchment management plans that encompass floodplains in the peri-urban environment need to take into account the likely risk to groundwater and surface water quality that these environments pose. Crown Copyright © 2014. Published by Elsevier B.V. All

  5. Nitrogen sources, transport and processing in peri-urban floodplains

    International Nuclear Information System (INIS)

    Gooddy, D.C.; Macdonald, D.M.J.; Lapworth, D.J.; Bennett, S.A.; Griffiths, K.J.

    2014-01-01

    Peri-urban floodplains are an important interface between developed land and the aquatic environment and may act as a source or sink for contaminants moving from urban areas towards surface water courses. With increasing pressure from urban development the functioning of floodplains is coming under greater scrutiny. A number of peri-urban sites have been found to be populated with legacy landfills which could potentially cause pollution of adjacent river bodies. Here, a peri-urban floodplain adjoining the city of Oxford, UK, with the River Thames has been investigated over a period of three years through repeated sampling of groundwaters from existing and specially constructed piezometers. A nearby landfill has been found to have imprinted a strong signal on the groundwater with particularly high concentrations of ammonium and generally low concentrations of nitrate and dissolved oxygen. An intensive study of nitrogen dynamics through the use of N-species chemistry, nitrogen isotopes and dissolved nitrous oxide reveals that there is little or no denitrification in the majority of the main landfill plume, and neither is the ammonium significantly retarded by sorption to the aquifer sediments. A simple model has determined the flux of total nitrogen and ammonium from the landfill, through the floodplain and into the river. Over an 8 km reach of the river, which has a number of other legacy landfills, it is estimated that 27.5 tonnes of ammonium may be delivered to the river annually. Although this is a relatively small contribution to the total river nitrogen, it may represent up to 15% of the ammonium loading at the study site and over the length of the reach could increase in-stream concentrations by nearly 40%. Catchment management plans that encompass floodplains in the peri-urban environment need to take into account the likely risk to groundwater and surface water quality that these environments pose. - Highlights: • Peri-urban floodplains have been found to

  6. Nitrogen sources, transport and processing in peri-urban floodplains

    Energy Technology Data Exchange (ETDEWEB)

    Gooddy, D.C., E-mail: dcg@bgs.ac.uk [British Geological Survey, Maclean Building, Wallingford, Oxfordshire OX10 8BB (United Kingdom); Macdonald, D.M.J.; Lapworth, D.J. [British Geological Survey, Maclean Building, Wallingford, Oxfordshire OX10 8BB (United Kingdom); Bennett, S.A. [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Griffiths, K.J. [British Geological Survey, Maclean Building, Wallingford, Oxfordshire OX10 8BB (United Kingdom)

    2014-10-01

    Peri-urban floodplains are an important interface between developed land and the aquatic environment and may act as a source or sink for contaminants moving from urban areas towards surface water courses. With increasing pressure from urban development the functioning of floodplains is coming under greater scrutiny. A number of peri-urban sites have been found to be populated with legacy landfills which could potentially cause pollution of adjacent river bodies. Here, a peri-urban floodplain adjoining the city of Oxford, UK, with the River Thames has been investigated over a period of three years through repeated sampling of groundwaters from existing and specially constructed piezometers. A nearby landfill has been found to have imprinted a strong signal on the groundwater with particularly high concentrations of ammonium and generally low concentrations of nitrate and dissolved oxygen. An intensive study of nitrogen dynamics through the use of N-species chemistry, nitrogen isotopes and dissolved nitrous oxide reveals that there is little or no denitrification in the majority of the main landfill plume, and neither is the ammonium significantly retarded by sorption to the aquifer sediments. A simple model has determined the flux of total nitrogen and ammonium from the landfill, through the floodplain and into the river. Over an 8 km reach of the river, which has a number of other legacy landfills, it is estimated that 27.5 tonnes of ammonium may be delivered to the river annually. Although this is a relatively small contribution to the total river nitrogen, it may represent up to 15% of the ammonium loading at the study site and over the length of the reach could increase in-stream concentrations by nearly 40%. Catchment management plans that encompass floodplains in the peri-urban environment need to take into account the likely risk to groundwater and surface water quality that these environments pose. - Highlights: • Peri-urban floodplains have been found to

  7. Effect of air pollution on peri-urban agriculture: a case study

    International Nuclear Information System (INIS)

    Agrawal, M.; Singh, B.; Rajput, M.; Marshall, F.; Bell, J.N.B.

    2003-01-01

    Peri-urban agriculture is vital for the urban populations of many developing countries. Increases in both industrialization and urbanization, and associated air pollution threaten urban food production and its quality. Six hour mean concentrations were monitored for SO 2 , NO 2 and O 3 and plant responses were measured in terms of physiological characteristics, pigment, biomass and yield. Parameter reductions in mung bean (Vigna radiata), palak (Beta vulgaris), wheat (Triticum aestivum) and mustard (Brassica compestris) grown within the urban fringes of Varanasi, India correlated directly with the gaseous pollutants levels. The magnitude of response involved all three gaseous pollutants at peri-urban sites; O 3 had more influence at a rural site. The study concluded that air pollution in Varanasi could negatively influence crop yield. - Urban air pollution has a negative impact on peri-urban agriculture

  8. Effect of air pollution on peri-urban agriculture: a case study

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, M.; Singh, B.; Rajput, M.; Marshall, F.; Bell, J.N.B

    2003-12-01

    Peri-urban agriculture is vital for the urban populations of many developing countries. Increases in both industrialization and urbanization, and associated air pollution threaten urban food production and its quality. Six hour mean concentrations were monitored for SO{sub 2}, NO{sub 2} and O{sub 3} and plant responses were measured in terms of physiological characteristics, pigment, biomass and yield. Parameter reductions in mung bean (Vigna radiata), palak (Beta vulgaris), wheat (Triticum aestivum) and mustard (Brassica compestris) grown within the urban fringes of Varanasi, India correlated directly with the gaseous pollutants levels. The magnitude of response involved all three gaseous pollutants at peri-urban sites; O{sub 3} had more influence at a rural site. The study concluded that air pollution in Varanasi could negatively influence crop yield. - Urban air pollution has a negative impact on peri-urban agriculture.

  9. Horse keeping in peri-urban areas

    OpenAIRE

    Elgåker, Hanna

    2011-01-01

    The number of horses in Sweden has increased from 70 000 to almost 300 000 in 30 years. Today these horses are to a large extent kept for the purpose of hobby and leisure and create a substantial land use but link a diverse and a large amount of activities in peri-urban areas in Sweden. The sector contributes with new economic, social and physical possibilities, but also with conflicts between various stakeholders and interests. The overall aim of this work was to contribute to increased unde...

  10. Assessment on Peri-Urban Dairy Production System and Evaluation ...

    African Journals Online (AJOL)

    Assessment on Peri-Urban Dairy Production System and Evaluation of Quality of Cows' Raw Milk: A Case of Shambu, Fincha and Kombolcha Towns of Horro Guduru Wollega Zone, Ethiopia. ... Science, Technology and Arts Research Journal ... Keywords: Bacterial load Ethiopia Horro Guduru Peri-Urban Dairying Raw milk ...

  11. The Dynamics of Peri-Urbanization

    DEFF Research Database (Denmark)

    Ravetz, Joe; Fertner, Christian; Nielsen, Thomas Alexander Sick

    2013-01-01

    Provides insight + surprising solutions for the dramatic field of peri-urbanisation in Europe Introduces innovative tools for planners, scientists and lay-persons allowing to analyze the impact of peri-urbanisation onto sustainable development Has unique maps showing EU-periurbanisation effects...... on a pan-European level Has a conclusive didactic approach + text structure (e.g. inserts, boxes ...) Presently, peri-urbanisation is one of the most pervasive processes of land use change in Europe with strong impacts on both the environment and quality of life. It is a matter of great urgency...... and illustrated by means of 7 case studies which are at the core of the book. This volume presents a novel, future oriented approach to the planning and management of peri-urban areas with a main focus on scenarios and sustainability impact analysis. The research is unique in that it focuses on the future...

  12. Aquatic Plant Control Research Program

    National Research Council Canada - National Science Library

    Cofrancesco, Alfred

    1998-01-01

    .... This search for natural plant enemies (insects and fungal pathogens) has led researchers to the native ranges of noxious aquatic plants, located throughout the continents of Africa, Asia, Europe, and Australia...

  13. Lesotho - Urban and Peri-Urban Water and Metolong Dam

    Data.gov (United States)

    Millennium Challenge Corporation — Early on, MCC and the evaluator decided to focus the Urban and Peri-Urban Water evaluation on Package 1 infrastructure, which benefited Maseru and Mazenod. MCC later...

  14. Aquatic Plant Control Research Program. Allelopathic Aquatic Plants for Aquatic Plant Management: A Feasibility Study

    Science.gov (United States)

    1989-10-01

    1978. " Ecotoxicology of aquatic plant communi- ties," Principles of Ecotoxicology , SCOPE Report 12, Chapter 11, pp 239-255. [Heavy metals, Pollutants...Phragmites communis and Equisetum limosum were cultivated . They found plant-plant influences depend on soil type. Typha latifolia, S. A2 lacustris, and

  15. Beaver herbivory on aquatic plants.

    Science.gov (United States)

    Parker, John D; Caudill, Christopher C; Hay, Mark E

    2007-04-01

    Herbivores have strong impacts on marine and terrestrial plant communities, but their impact is less well studied in benthic freshwater systems. For example, North American beavers (Castor canadensis) eat both woody and non-woody plants and focus almost exclusively on the latter in summer months, yet their impacts on non-woody plants are generally attributed to ecosystem engineering rather than herbivory. Here, we excluded beavers from areas of two beaver wetlands for over 2 years and demonstrated that beaver herbivory reduced aquatic plant biomass by 60%, plant litter by 75%, and dramatically shifted plant species composition. The perennial forb lizard's tail (Saururus cernuus) comprised less than 5% of plant biomass in areas open to beaver grazing but greater than 50% of plant biomass in beaver exclusions. This shift was likely due to direct herbivory, as beavers preferentially consumed lizard's tail over other plants in a field feeding assay. Beaver herbivory also reduced the abundance of the invasive aquatic plant Myriophyllum aquaticum by nearly 90%, consistent with recent evidence that native generalist herbivores provide biotic resistance against exotic plant invasions. Beaver herbivory also had indirect effects on plant interactions in this community. The palatable plant lizard's tail was 3 times more frequent and 10 times more abundant inside woolgrass (Scirpus cyperinus) tussocks than in spatially paired locations lacking tussocks. When the protective foliage of the woolgrass was removed without exclusion cages, beavers consumed nearly half of the lizard's tail leaves within 2 weeks. In contrast, leaf abundance increased by 73-93% in the treatments retaining woolgrass or protected by a cage. Thus, woolgrass tussocks were as effective as cages at excluding beaver foraging and provided lizard's tail plants an associational refuge from beaver herbivory. These results suggest that beaver herbivory has strong direct and indirect impacts on populations and

  16. Macrophytes: Ecology of aquatic plants

    NARCIS (Netherlands)

    Bornette, G.; Puijalon, S.

    2009-01-01

    Aquatic plants contribute to maintaining key functions and related biodiversity in freshwater ecosystems, and to provide the needs of human societies. The way the ecological niches of macrophytes are determined by abiotic filters and biotic ones is considered. A simple, broadly applicable model of

  17. Differentiated surface fungal communities at point of harvest on apple fruits from rural and peri-urban orchards.

    Science.gov (United States)

    Shen, Youming; Nie, Jiyun; Li, Zhixia; Li, Haifei; Wu, Yonglong; Dong, Yafeng; Zhang, Jianyi

    2018-02-01

    The diverse fungal communities that colonize fruit surfaces are closely associated with fruit development, preservation and quality control. However, the overall fungi adhering to the fruit surface and the inference of environmental factors are still unknown. Here, we characterized the fungal signatures on apple surfaces by sequencing internal transcribed spacer 1 (ITS1) region. We collected the surface fungal communities from apple fruits cultivated in rural and peri-urban orchards. A total of 111 fungal genera belonging to 4 phyla were identified, showing remarkable fungal diversity on the apple surface. Comparative analysis of rural samples harboured higher fungal diversity than those from peri-urban orchards. In addition, fungal composition varied significantly across apple samples. At the genus level, the protective genera Coniothyrium, Paraphaeosphaeria and Periconia were enriched in rural samples. The pathogenic genera Acremonium, Aspergillus, Penicillium and Tilletiposis were enriched in peri-urban samples. Our findings indicate that rural samples maintained more diverse fungal communities on apple surfaces, whereas peri-urban-planted apple carried potential pathogenic risks. This study sheds light on ways to improve fruit cultivation and disease prevention practices.

  18. Understanding the dynamic changes in India's peri-urban regions ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Peri-urban areas, which are beyond a city's administrative limits but adjacent to it, are ... where there are resource constraints, and where access to services such as water, ... The project is funded through the Opportunity Fund of the Think Tank ... IDRC congratulates first cohort of Women in Climate Change Science Fellows.

  19. Journal of Aquatic Plant Management. Volume 36

    National Research Council Canada - National Science Library

    1998-01-01

    The U.S. Army Corps of Engineers (CE) Aquatic Plant Control Research Program (APCRP) is the Nation's only federally authorized research program directed to develop technology for the management of non-indigenous aquatic plant species...

  20. Aquatic plant control research

    Energy Technology Data Exchange (ETDEWEB)

    Pryfogle, P.A.; Rinehart, B.N. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Ghio, E.G. [Pacific Gas & Electric Company, San Francisco, CA (United States). Hydro Generation Engineering

    1997-05-01

    The Northwest region of the United States contains extensive canal systems that transport water for hydropower generation. Nuisance plants, including algae, that grow in these systems reduce their hydraulic capacity through water displacement and increased surface friction. Most control methods are applied in an ad hoc fashion. The goal of this work is to develop cost-effective, environmentally sound, long-term management strategies to prevent and control nuisance algal growth. This paper reports on a multi-year study, performed in collaboration with the Pacific Gas & Electric Company, to investigate algal growth in their canal systems, and to evaluate various control methodologies. Three types of controls, including mechanical, biological and chemical treatment, were selected for testing and evaluation. As part of this study, water quality data were collected and algal communities were sampled from numerous stations throughout the distribution system at regular intervals. This study resulted in a more comprehensive understanding of conditions leading to the development of nuisance algal growth, a better informed selection of treatment plans, and improved evaluation of the effectiveness for the control strategies selected for testing.

  1. Woody Vegetation Composition and Structure in Peri-urban Chongming Island, China

    Science.gov (United States)

    Zhao, Min; Escobedo, Francisco J.; Wang, Ruijing; Zhou, Qiaolan; Lin, Wenpeng; Gao, Jun

    2013-05-01

    Chongming, the world's largest alluvial island, is located within the municipality of Shanghai, China. Recent projects have now linked peri-urban Chongming to Shanghai's urban core and as a result will soon undergo substantial changes from urbanization. We quantitatively analyzed the structure and composition of woody vegetation across subtropical, peri-urban Chongming as a basis for sustainable management of these rapidly urbanizing subtropical ecosystems elsewhere. We used 178 permanent, random plots to statistically and spatially analyze woody plant composition and tree structure across the 1,041 km2 of Chongming. A total of 2,251 woody plants were measured comprising 42 species in 37 genera. We statistically and geospatially analyzed field data according to land uses and modeled air pollution removal by trees. Average tree diameter at breast height, total height, and crown widths on transportation land uses were greater than other land uses. These same values were lowest on forest land use and greater tree cover was associated with areas of increased anthropogenic activity. Less than 20 % of the woody vegetation was exotic and a species richness index was significantly different between land uses due to legacy effects. Composition of agriculture and forest land uses were similar to residential and transportation. Tree cover across Chongming was also estimated to annually remove 1,400 tons of air pollutants. We propose that this integrated and quantitative method can be used in other subtropical, peri-urban areas in developing countries to establish baseline trends for future sustainability objectives and to monitor the effects of urbanization and climate change.

  2. The global potential of local peri-urban food production

    Science.gov (United States)

    Kriewald, Steffen; Garcia Cantu Ros, Anselmo; Sterzel, Till; Kropp, Jürgen P.

    2013-04-01

    One big challenge for the rest of the 21st century will be the massive urbanisation. It is expected that more than 7 out of 10 persons will live in a city by the year 2050. Crucial developments towards a sustainable future will therefore take place in cities. One important approach for a sustainable city development is to re-localize food production and to close urban nutrient cycles through better waste management. The re-location of food production avoids CO2 emissions from transportation of food to cities and can also generate income for inhabitants. Cities are by definition locations where fertility accumulates. As cities are often built along rivers, their soils are often fertile. Furthermore, labour force and the possibility of producing fertilizer from human fecal matter within the city promises sustainable nutrients cycles. Although urban and peri-urban agriculture can be found in many cities worldwide and already have a substantial contribution to food supply, it has not jet been comprehensibly structured by research. We combine several worldwide data sets to determine the supply of cities with regional food production, where regional is defined as a production that occurs very close to the consumption within the peri-urban area. Therefore, urban areas are not defined by administrative boundaries but by connected built-up urban areas, and peri-urban area by the surrounding area with the same size multiplied with a scaling parameter. Both together accumulate to an urban-bio-region (UBR). With regard to national food consumption, a linear program achieves the best possible yield on agricultural areas and allows the computation of the fraction of population, which can be nourished. Additionally, several climate scenarios and different dietary patterns were considered. To close the gap between single case studies and to provide a quantitative overview of the global potential of peri-urban food production we used high resolution land-use data Global Land Cover

  3. Best Practice Irrigation Management and Extension in Peri-Urban Landscapes--Experiences and Insights from the Hawkesbury-Nepean Catchment, Australia

    Science.gov (United States)

    Maheshwari, B. L.; Plunkett, M.

    2015-01-01

    Purpose: The aim of this article to examine key irrigation management issues and their implications for future research and extension developments. Design/Methodology/Approach: Peri-urban landscapes are important as they supply fresh fruit, vegetables, turf, ornamental plants and other farm products to the cities. In this study, the…

  4. Challenges of urbanization and peri-urban development in Europe

    DEFF Research Database (Denmark)

    Nielsen, Thomas Alexander Sick; Nilsson, Kjell Svenne Bernhard

    2010-01-01

    Urbanisation has arguably been the most significant process of land use change in Europe since Second World War. Over 70% of Europe's population now lives in urban areas, which in turn, have grown in area by almost 80% over the last fifty years (EEA 2006). Urban areas cover approximately five...... percent of the territory of the European Union (EU25), and are growing more than twice as fast as the European population. A general consequence of the urbanisation trend and increasing wealth and mobility is urban sprawl, as well as the emergence of peri-urban areas....

  5. Purification of Water by Aquatic Plants

    OpenAIRE

    Morimitsu, Katsuhito; Kawahigashi, Tatsuo

    2013-01-01

    [Abstract] Water quality purification of many water systems including those occurring in rivers depends to a great degree on water quality purification activities of aquatic plants and microbes. This paper presents a discussion of results, based on laboratory experiments, of purification by aquatic plants.

  6. Qualitative relation between heavy metal concentration in soil and agricultural products: a Chinese peri-urban case study

    Science.gov (United States)

    Kikuchi, Ryunosuke; Ferreira, Carla Sofia; Dinis Ferreira, Antonio

    2017-04-01

    A peri-urban area refers to a transition or interaction zone, where urban and rural activities are juxtaposed, and landscape features are subject to rapid modifications, mainly due to human activities. It is reported that peri-urban areas which might include valuable protected areas (e.g. forested hills, preserved woodlands, prime agricultural lands, etc.) can provide essential life support services for urban residents. A peri-urban area is not only a zone experiencing the immediate impacts of land demands from urban growth and pollution, but it is also a wider market-related zone of influence, recognized for the supply of agricultural and natural resource products. It is reported that China's environmental crisis is one of the most pressing challenges to emerge from the country's rapid industrialization; therefore a field study was carried out to investigate the qualitative relation of soil property with vegetable agricultural products in the Chinese peri-urban area located in Luoyang city (34°37'N and 112°27'E). Soil, water and plant (e.g. squash, Cucurbita maxima) samples were taken over the study site, and heavy metal concentrations were analyzed. All the soil samples showed Cd concentrations exceeded the permissible level established by Chinese guidelines for soil quality (0.3 mg/kg). The contents of Zn, Pb and Cu also surpassed the Chinese guideline levels (Zn = 250 mg/kg, Pb = 50 mg/kg and Cu = 100 mg/kg) in several soil samples. Although the sampled plants contained some degree of all the heavy metals, only the Al concentration was high in the Cucurbita maxima samples (317 mg/kg), which is a specie of cultivated squash. Considering the world market and the global trade of agricultural products, it can be said that the food risk associated with farm products containing Al is not local but global. It is concluded that an environmental contamination of the peri-urban areas may lead to the threat to food security.

  7. MANAGING PHYSICAL DEVELOPMENT IN PERI-URBAN AREAS OF KUMASI, GHANA: A CASE OF ABUAKWA

    Directory of Open Access Journals (Sweden)

    Paul Amoateng

    2013-01-01

    Full Text Available A remarkable trait of the 21 st century has been the high rate of urbanization which has characterized the growth and development of cities especially in developing countries. This situation has fuelled rapid physical development and expansion of peri-urban areas as urban dwellers relocate to cities’ peripheries. Focusing on Abuakwa a peri-urban area in Kumasi, the second largest city in Ghana, this paper assesses the nature and extent of physical development in peri-urban areas, and identifies the factors contributing to the rapid development of peri-urban areas. The paper further examines the effects of the increasing physical growth on the development of peri-urban Abuakwa. Using a case study approach, both primary and secondary sources of data were collected from decentralized government institutions of Kumasi Metropolitan Assembly (KMA and Atwima Nwabiagya District Assembly (ANDA, as well as indigenes and relocated urban dwellers in Abuakwa. The paper reveals that the outward drift has manifested itself in an increased scramble for land for residential and commercial purposes in the peri-urban area. The resultant effect has been the fast and spontaneous physical development in the urban periphery which has significantly altered the peri-urban morphology. The paper recommends the establishment of Customary Land Secretariat (CLS to co-ordinate allocation of land, and the application of settlement growth management approaches to ensure the creation of a functional city and liveable peri-urban areas.

  8. Balancing urban and peri-urban exchange: water geography of rural livelihoods in Mexico.

    Science.gov (United States)

    Díaz-Caravantes, Rolando E

    2012-01-01

    The peri-urban area is the region where there is a more dynamic interaction between the urban and rural. The peri-urban area supplies natural resources, such as land for urban expansion and agricultural products to feed the urban population. In arid and semi-arid lands, such as northern Mexico, these areas may also be the source of water for the city's domestic demand. In addition, scholars argue that peri-urban residents may have a more advantageous geographical position for selling their labour and agricultural products in cities and, by doing so, sustaining their livelihoods. A considerable number of studies have examined the peri-urban to urban natural resources transfer in terms of land annexation, housing construction, and infrastructure issues; however, the study of the effects of the reallocation of peri-urban water resources to serve urban needs is critical as well because the livelihoods of peri-urban residents, such as those based on agriculture and livestock, depend on water availability. In the case of Hermosillo there is a tremendous pressure on the water resources of peri-urban small farm communities or ejidos because of urban demand. Based on interviews and structured surveys with producers and water managers, this paper examines how peri-urban livelihoods have been reshaped by the reallocation of the city's natural resources in many cases caused some ejido members or ejidatarios to lose livelihoods.

  9. Patterns and multi-scale drivers of phytoplankton species richness in temperate peri-urban lakes

    Energy Technology Data Exchange (ETDEWEB)

    Catherine, Arnaud, E-mail: arnocat@mnhn.fr [UMR7245 MCAM MNHN-CNRS, Muséum National d' Histoire Naturelle, CC 39, 12 rue Buffon, F-75231 Paris, Cedex 05 (France); Selma, Maloufi, E-mail: maloufi@mnhn.fr [UMR7245 MCAM MNHN-CNRS, Muséum National d' Histoire Naturelle, CC 39, 12 rue Buffon, F-75231 Paris, Cedex 05 (France); Mouillot, David, E-mail: david.mouillot@univ-montp2.fr [UMR 9190 MARBEC UM2-CNRS-IRD-UM1-IFREMER, CC 93, Place Eugène Bataillon, Université de Montpellier 2, F-34095 Montpellier (France); Troussellier, Marc, E-mail: troussel@univ-montp2.fr [UMR 9190 MARBEC UM2-CNRS-IRD-UM1-IFREMER, CC 93, Place Eugène Bataillon, Université de Montpellier 2, F-34095 Montpellier (France); Bernard, Cécile, E-mail: cbernard@mnhn.fr [UMR7245 MCAM MNHN-CNRS, Muséum National d' Histoire Naturelle, CC 39, 12 rue Buffon, F-75231 Paris, Cedex 05 (France)

    2016-07-15

    Local species richness (SR) is a key characteristic affecting ecosystem functioning. Yet, the mechanisms regulating phytoplankton diversity in freshwater ecosystems are not fully understood, especially in peri-urban environments where anthropogenic pressures strongly impact the quality of aquatic ecosystems. To address this issue, we sampled the phytoplankton communities of 50 lakes in the Paris area (France) characterized by a large gradient of physico-chemical and catchment-scale characteristics. We used large phytoplankton datasets to describe phytoplankton diversity patterns and applied a machine-learning algorithm to test the degree to which species richness patterns are potentially controlled by environmental factors. Selected environmental factors were studied at two scales: the lake-scale (e.g. nutrients concentrations, water temperature, lake depth) and the catchment-scale (e.g. catchment, landscape and climate variables). Then, we used a variance partitioning approach to evaluate the interaction between lake-scale and catchment-scale variables in explaining local species richness. Finally, we analysed the residuals of predictive models to identify potential vectors of improvement of phytoplankton species richness predictive models. Lake-scale and catchment-scale drivers provided similar predictive accuracy of local species richness (R{sup 2} = 0.458 and 0.424, respectively). Both models suggested that seasonal temperature variations and nutrient supply strongly modulate local species richness. Integrating lake- and catchment-scale predictors in a single predictive model did not provide increased predictive accuracy; therefore suggesting that the catchment-scale model probably explains observed species richness variations through the impact of catchment-scale variables on in-lake water quality characteristics. Models based on catchment characteristics, which include simple and easy to obtain variables, provide a meaningful way of predicting phytoplankton

  10. Patterns and multi-scale drivers of phytoplankton species richness in temperate peri-urban lakes

    International Nuclear Information System (INIS)

    Catherine, Arnaud; Selma, Maloufi; Mouillot, David; Troussellier, Marc; Bernard, Cécile

    2016-01-01

    Local species richness (SR) is a key characteristic affecting ecosystem functioning. Yet, the mechanisms regulating phytoplankton diversity in freshwater ecosystems are not fully understood, especially in peri-urban environments where anthropogenic pressures strongly impact the quality of aquatic ecosystems. To address this issue, we sampled the phytoplankton communities of 50 lakes in the Paris area (France) characterized by a large gradient of physico-chemical and catchment-scale characteristics. We used large phytoplankton datasets to describe phytoplankton diversity patterns and applied a machine-learning algorithm to test the degree to which species richness patterns are potentially controlled by environmental factors. Selected environmental factors were studied at two scales: the lake-scale (e.g. nutrients concentrations, water temperature, lake depth) and the catchment-scale (e.g. catchment, landscape and climate variables). Then, we used a variance partitioning approach to evaluate the interaction between lake-scale and catchment-scale variables in explaining local species richness. Finally, we analysed the residuals of predictive models to identify potential vectors of improvement of phytoplankton species richness predictive models. Lake-scale and catchment-scale drivers provided similar predictive accuracy of local species richness (R"2 = 0.458 and 0.424, respectively). Both models suggested that seasonal temperature variations and nutrient supply strongly modulate local species richness. Integrating lake- and catchment-scale predictors in a single predictive model did not provide increased predictive accuracy; therefore suggesting that the catchment-scale model probably explains observed species richness variations through the impact of catchment-scale variables on in-lake water quality characteristics. Models based on catchment characteristics, which include simple and easy to obtain variables, provide a meaningful way of predicting phytoplankton

  11. Community perceptions of human excreta as fertilizer in peri-urban agriculture in Ghana.

    Science.gov (United States)

    Mariwah, Simon; Drangert, Jan-Olof

    2011-08-01

    Although human excreta contain the necessary nutrients for plant growth, local authorities in Ghana spend huge sums of money to dispose them as waste. Reusing excreta for agricultural purposes saves expenditure for chemical fertilizers, improves soil fertility, reduces poverty and ensures food security. People's attitudes and perceptions about excreta vary between cultures and even within specific cultures. This study aimed to explore attitudes and perceptions among a peri-urban agricultural community towards sanitized human excreta and its use. The study adopted an exploratory design and collected data from 154 randomly selected households using questionnaires and focus group discussions. It was found that there is a general negative attitude to fresh excreta and the handling of it. However, the residents accept that excreta can be used as fertilizer, but they are not willing to use it on their own crops or consume crops fertilized with excreta. The study recommends open discussions in the community for a successful implementation of ecological sanitation.

  12. Evaluating the Benefits of Peri-Urban Agriculture.

    Science.gov (United States)

    Brinkley, Catherine

    2012-08-01

    By uniting literature from farmland preservation, growth management, food systems, economics, bioengineering, and environmental studies, this article provides an overview and valuation of the services that farms provide for urban areas. This article first analyzes the mission statements of 130 nationally accredited land trusts to ascertain the criteria used in preserving farmland. Land trusts present uniform preference for parcels that provide ecosystem services, wildlife habitat, viewsheds, local heritage, and agricultural productivity. The list of benefits provided by land trusts was compared to a literature review drawing from farmland amenity, agritourism, farmland preservation, and ecosystems studies to reveal the range of market values for the various benefits of farmland. The market value of farmland services varies from -$37,541 to 124,000 per acre depending on the method of analysis and location of the farm. This research has strong implications for land-use planning, economic opportunities, and ecosystems infrastructure in peri-urban areas.

  13. Peri-urban Dry Season Vegetable Production in Ibadan, Nigeria

    Directory of Open Access Journals (Sweden)

    Kintomo, AA.

    1997-01-01

    Full Text Available Peri-urban dry season vegetable production in Ibadan is increasingly becoming important, due to its relatively recent importance as a means of producing food in the city. Information on : (1 management practices ; (2 cropping systems ; and (3 economies of production, was hardly available. A diagnostic study organised in the dry season of 1994/95 addresses these issues. Its results indicate that the major crops in the system are Corchorus, Amaranthus and Celosia and are grown in intercropping systems. Farmers in the systems were constrained by poor drainage systems, weeds, dearth of improved seeds and marketing, inefficient input delivery system, high cost of input, pests and diseases and unavailability of labour at critical times. However, net benefits amounts to approximately N235650/ha/season ($ 2772. Significant and sustainable increases in productivity of the system could be achieved with the use of integrated water, crop, soil and pest management systems together with efficient input delivery systems.

  14. Aquatic Plant Control Research Program

    National Research Council Canada - National Science Library

    Cofrancesco, Alfred

    1998-01-01

    ... (Mydophyllum spice turn) and hydrilla (Hyddlla verticfflata). These species, which account for more that two thirds of all noxious aquatic weed acreage in the United States, have similar characteristics...

  15. Land use planning for sustainable development of peri-urban zones

    Directory of Open Access Journals (Sweden)

    Živanović-Miljković Jelena

    2012-01-01

    Full Text Available Taking into consideration that growth of urban population has impacts on land use and that managing urban population change is one of the most important contemporary challenges, this paper deals with the sustainable development of peri-urban zones which represent important an environment where employment opportunities are developed and resources exploited (particularly agricultural resources and environment where important recreational and leisure activities could be pursued. Within the review of current concepts and planning practices, the concepts of multifunctional agriculture and multifunctional landscapes in peri-urban zones are pointed out, as well as EU Developing Periurban Projects. The paper particularly focuses on the current situation in Serbia, where there is no specific legal basis for the planning of peri-urban areas, although there are positive examples of strategies, regulations and planning documents which treat agriculture and greenery in peri-urban zones in a sustainable manner.

  16. Occurrence of chemical contaminants in peri-urban agricultural irrigation waters and assessment of their phytotoxicity and crop productivity.

    Science.gov (United States)

    Margenat, Anna; Matamoros, Víctor; Díez, Sergi; Cañameras, Núria; Comas, Jordi; Bayona, Josep M

    2017-12-01

    Water scarcity and water pollution have increased the pressure on water resources worldwide. This pressure is particularly important in highly populated areas where water demand exceeds the available natural resources. In this regard, water reuse has emerged as an excellent water source alternative for peri-urban agriculture. Nevertheless, it must cope with the occurrence of chemical contaminants, ranging from trace elements (TEs) to organic microcontaminants. In this study, chemical contaminants (i.e., 15 TEs, 34 contaminants of emerging concern (CECs)), bulk parameters, and nutrients from irrigation waters and crop productivity (Lycopersicon esculentum Mill. cv. Bodar and Lactuca sativa L. cv. Batavia) were seasonally surveyed in 4 farm plots in the peri-urban area of the city of Barcelona. A pristine site, where rain-groundwater is used for irrigation, was selected for background concentrations. The average concentration levels of TEs and CECs in the irrigation water impacted by treated wastewater (TWW) were 3 (35±75μgL -1 ) and 13 (553±1050ngL -1 ) times higher than at the pristine site respectively. Principal component analysis was used to classify the irrigation waters by chemical composition. To assess the impact of the occurrence of these contaminants on agriculture, a seed germination assay (Lactuca sativa L) and real field-scale study of crop productivity (i.e., lettuce and tomato) were used. Although irrigation waters from the peri-urban area exhibited a higher frequency of detection and concentration of the assessed chemical contaminants than those of the pristine site (P1), no significant differences were found in seed phytotoxicity or crop productivity. In fact, the crops impacted by TWW showed higher productivity than the other farm plots studied, which was associated with the higher nutrient availability for plants. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Insetos galhadores associados a duas espécies de plantas invasoras de áreas urbanas e peri-urbanas Galling insects associated with two species of ruderal plants in urban and peri urban areas

    Directory of Open Access Journals (Sweden)

    Genimar R. Julião

    2005-03-01

    que áreas verdes em espaços urbanos são de fundamental importância na manutenção da diversidade de insetos.Insects have been considered as important bioindicators of environmental changes and habitat quality. In spite of its sessile habit, easy localization, abundance and host specificity, insects that induce galls have not been utilized in studies of this nature. It was investigated the suitability of gall-inducing insects associated to two ruderal host plant species (Baccharis dracunculifolia and Vernonia polyanthes: Asteraceae as bioindicators of habitat quality. The following questions were addressed: (i is gall-inducing insect diversity influenced by different types of land use?; (ii are the responses of galling insect communities different between host plants?; (iii how does the biotic and physical features of the biotope influence the gall-inducing insect diversity? It was found 6,226 galls, belonging to six galling insect species on V. polyanthes and 11 galling species on B. dracunculifolia. No difference was found in galling species richness among land use types. Nevertheless, gall-forming insect abundance was statistically different among the biotopes studied. Insect galls were more numerous in biotopes with lower urbanization levels. Gall abundance showed a strong and positive relationship with the percentage of vegetal cover. Gall-forming insect communities on both host species showed differential responses to the different land use types. The results suggest that three factors may be involved with galling insect diversity in urban areas: (i habitat structure in the biotope; (ii resource abundance (host plant abundance and distribution; and (iii frequency and intensity of management in reserves, parks, city squares, wastelands found at a given urban area.

  18. Plants in aquatic ecosystems: current trends and future directions

    NARCIS (Netherlands)

    O’Hare, Matthew T.; Aguiar, Francisca C.; Asaeda, Takashi; Bakker, Elisabeth S.; Chambers, Patricia A.; Clayton, John S.; Elger, Arnaud; Ferreira, Teresa M.; Gross, Elisabeth M.; Gunn, Iain D.M.; Gurnell, Angela M.; Hellsten, Seppo; Hofstra, Deborah E.; Li, Wei; Mohr, Silvia; Puijalon, Sara; Szoszkiewicz, Krzysztof; Willby, Nigel J.; Wood, Kevin A.

    2018-01-01

    Aquatic plants fulfil a wide range of ecological roles, and make a substantial contribution to the structure, function and service provision of aquatic ecosystems. Given their well-documented importance in aquatic ecosystems, research into aquatic plants continues to blossom. The 14th International

  19. Multifunctional Peri-Urban Agriculture and Local Food Access in the Kathmandu Valley, Nepal: A Review

    Directory of Open Access Journals (Sweden)

    Shreema Rana

    2015-12-01

    Full Text Available Based on the threatening global challenge of increasing urban population with decreasing resources to feed them, the existing literature is reviewed in this paper to highlight; i the urban food supply chain, and ii food security as a benefit of Peri-Urban Agriculture. This is deployed to fit the context of the developing regions of the world where urbanization does not occur in an organized manner. It is known that food grown in peri-urban areas (defined as the fastest growing areas that surround cities but are neither urban nor rural in the conventional sense is easily available to urban inhabitants. Such peri-urban areas have the least adverse effects on the environment from a food transportation perspective and are more resilient in times of uncertain physical (disaster and socioeconomic (fuel and food price rise pressures. Today, much fertile peri-urban land is converted haphazardly without considering its environmental value and agricultural potential. Likewise, peri-urban agriculture is still in the process of being acknowledged by both locals and policy-makers despite being an accepted mode of achieving food security. Therefore, this paper seeks to orient the review literature and underline the gaps that prevail at the grass-roots level of local preferences and values and at the policy-maker level. Using extensive literature review as the methodology, this study draws recent ideas on the multi-functionality of peri-urban agriculture and the sustainable contribution it makes to both developed and developing countries around the world. The findings of the review highlight the significance of peri-urban areas in the Kathmandu Valley for a sustainable and a reliable food chain. It also shows the existing but unrecognized features of peri-urban agriculture both at local and policy-making levels. It discusses the point of interest and possible extension of the multifunctional peri-urban agriculture for local food access, inviting further

  20. Opportunity for peri-urban Perth groundwater trade

    Science.gov (United States)

    Gao, Lei; Connor, Jeff; Doble, Rebecca; Ali, Riasat; McFarlane, Don

    2013-07-01

    Groundwater trade is widely advocated for reallocating scarce groundwater resources between competing users, and managing over-allocated and declining aquifers. However, groundwater markets are still in their infancy, and the potential benefits and opportunities need investigation, particularly where there is a need to reduce the extraction from declining aquifers. This article evaluates economic impacts of reducing groundwater extraction for irrigation use in peri-urban Perth, Australia, where irrigation, a lake-based ecosystem, and public water supply are highly dependent on a declining groundwater resource. We present an assessment of market-based water trading approaches to reduce groundwater extraction with an economic model representing diversity in returns to groundwater use across a population of irrigators. The results indicate that potential economic costs of a proportional reduction in available groundwater for irrigation are 18-21% less if groundwater trade is possible. We also evaluate a water buyback from irrigation to provide public water supply as an alternative to new infrastructure. We find that buying back up to around 50% of current irrigation allocations could create new public water supply only at the cost of 0.32-0.39 million per GL, which is less than one fifth of the costs of new desalinisation or recycled water supply options (2-3 million per GL). We conclude that, with rapid development of computer and internet based trading platforms that allows fast, efficient and low cost multiple party trading, it is increasingly feasible to realise the economic potentials of market-based trade approaches for managing overexploited aquifers.

  1. Occurrence and bioaccumulation of chemical contaminants in lettuce grown in peri-urban horticulture.

    Science.gov (United States)

    Margenat, Anna; Matamoros, Víctor; Díez, Sergi; Cañameras, Núria; Comas, Jordi; Bayona, Josep M

    2018-05-14

    Peri-urban horticulture performs environmental and socio-economic functions and provides ecological services to nearby urban areas. Nevertheless, industrialization and water pollution have led to an increase in the exposure of peri-urban vegetables to contaminants such as trace elements (TEs) and organic microcontaminants (OMCs). In this study, the occurrence of chemical contaminants (i.e., 16 TEs, 33 OMCs) in soil and lettuce leaves from 4 farm fields in the peri-urban area of the city of Barcelona was assessed. A rural site, outside the peri-urban area of influence, was selected for comparison. The concentration of TEs and OMCs ranged from non-detectable to 803 mg/kg dw and from non-detectable to 397 μg/kg dw respectively in the peri-urban soil, and from 6 · 10 -5 to 4.91 mg/kg fw and from non-detectable to 193 μg/kg fw respectively in lettuce leaves. Although the concentration of Mo, Ni, Pb, and As in the soil of the peri-urban area exceeded the environmental quality guidelines, their occurrence in lettuce complied with human food standards (except for Pb). The many fungicides (carbendazim, dimetomorph, and methylparaben) and chemicals released by plastic pipelines (tris(1-chloro-2-propyl)phosphate, bisphenol F, and 2-mercaptobenzothiazole) used in agriculture were prevalent in the soil and the edible parts of the lettuce. The occurrence of these chemical pollutants in the peri-urban area did not affect the chlorophyll, lipid, or carbohydrate content of the lettuce leaves. PCA (Principal Component Analysis) showed that soil pollution, fungicide application, and irrigation water quality are the most relevant factors determining the presence of contaminants in crops. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Sustainable electricity generation for rural and peri-urban populations of sub-Saharan Africa: The 'flexy-energy' concept

    International Nuclear Information System (INIS)

    Azoumah, Y.; Yamegueu, D.; Ginies, P.; Coulibaly, Y.; Girard, P.

    2011-01-01

    Access to energy is known as a key issue for poverty reduction. Electrification rate of sub-Saharan countries is one of the lowest among the developing countries. However, this part of the world has natural energy resources that could help raising its access to energy, then its economic development. An original 'flexy-energy' concept of hybrid solar PV/diesel/biofuel power plant, without battery storage, is performed in this paper. This concept is developed in order to not only make access to energy possible for rural and peri-urban populations in Africa (by reducing the electricity generation cost) but also to make the electricity production sustainable in these areas. For landlocked countries like Burkina Faso, this concept could help them reducing their electricity bill (then their fuel consumption) and accelerate their rural and peri-urban electrification coverage. - Research highlights: → Design and load management Optimization are big concerns for hybrid systems. → Hybrid solar PV/Diesel is economically viable for remote areas and environmental friendly. → 'Flexy-energy' concept is a flexible hybrid solar PV/diesel/biomass suitable for remote areas. → 'Flexy-energy' concept is a flexible hybrid solar PV/diesel/biomass suitable for remote areas.

  3. Institutions in transitioning peri-urban communities: spatial differences in groundwater access

    Science.gov (United States)

    Gomes, Sharlene L.; Hermans, Leon M.

    2016-05-01

    Urbanization creates challenges for water management in an evolving socio-economic context. This is particularly relevant in transitioning peri-urban areas like Khulna, Bangladesh where competing demands have put pressure on local groundwater resources. Users are unable to sufficiently meet their needs through existing institutions. These institutions provide the rules for service provision and act as guidelines for actors to resolve their water related issues. However, the evolving peri-urban context can produce fragmented institutional arrangements. For example in Khulna, water supply is based on urban and rural boundaries that has created water access issues for peri-urban communities. This has motivated local actors to manage their groundwater needs in various ways. General institutional theories are well developed in literature, yet little is known about institutions in transitioning peri-urban areas. Institutions that fail to adapt to changing dynamics run the risk of becoming obsolete or counter-productive, hence the need for investigating institutional change mechanisms in this context. This paper examines peri-urban case studies from Khulna using the Institutional Analysis and Development framework to demonstrate how institutions have contributed to spatial differences in groundwater access with local actors investing in formal and informal institutional change as a means of accessing groundwater.

  4. Modelling the influence of peri-urban trees in the air quality of Madrid region (Spain)

    International Nuclear Information System (INIS)

    Alonso, Rocio; Vivanco, Marta G.; Gonzalez-Fernandez, Ignacio; Bermejo, Victoria; Palomino, Inmaculada; Garrido, Juan Luis; Elvira, Susana; Salvador, Pedro; Artinano, Begona

    2011-01-01

    Tropospheric ozone (O 3 ) is considered one of the most important air pollutants affecting human health. The role of peri-urban vegetation in modifying O 3 concentrations has been analyzed in the Madrid region (Spain) using the V200603par-rc1 version of the CHIMERE air quality model. The 3.7 version of the MM5 meteorological model was used to provide meteorological input data to the CHIMERE. The emissions were derived from the EMEP database for 2003. Land use data and the stomatal conductance model included in CHIMERE were modified according to the latest information available for the study area. Two cases were considered for the period April-September 2003: (1) actual land use and (2) a fictitious scenario where El Pardo peri-urban forest was converted to bare-soil. The results show that El Pardo forest constitutes a sink of O 3 since removing this green area increased O 3 levels over the modified area and over down-wind surrounding areas. - Highlights: → Role of peri-urban vegetation in modifying O 3 pollution in Madrid (Spain). → The CHIMERE air quality model was adapted to Mediterranean conditions. → Preserving the peri-urban forest lowers O 3 concentrations over the surrounding areas. → Evergreen broadleaf and deciduous forests removed more atmospheric O 3 than conifers. - Peri-urban forests contribute to ameliorate ozone air pollution.

  5. Prospects of approach and characterization of Mar del Plata peri-urban, Argentina

    Directory of Open Access Journals (Sweden)

    Rosana Ferraro

    2013-10-01

    Full Text Available In Latin America in general, and in Argentina in particular, city growth without prior planning results in the formation of highly complex peri-urban areas. The urban-rural analysis based on the traditional model of country-city dichotomy is not enough to explain the processes that occur in these cities. On the basis of prior studies conducted in the peri- urban of Mar del Plata, Argentina, this paper aims to : a characterize the peri-urban by studying its functions throughout history, b propose a rereading for its further analysis through the complex systems theoretical-methodological approach, and c describe the main areas that account for its special heterogeneity and complexity. From an integral viewpoint, and taking the physical, sociocultural, productive, urban- residential and digester subsystems into account, the analysis of the peri-urban allowed to define areas with differential characteristics. Such areas admit higher disintegration in more detailed scales, making it easy to understand their operation and their problems. In conclusion, the complex systems approach results appropriate to promote the development of management strategies in areas as heterogeneous as the peri-urban.

  6. Cumulative Causation of Rural Migration and Initial Peri-Urbanization in China.

    Science.gov (United States)

    Hao, Lingxin

    2012-01-01

    This paper posits that rural migration feeds the high demand for cheap labor in peri-urbanization, which is driven by globalization, flows of foreign capital, and entrepreneurial local governments. While the gravity model and push/pull perspective ignore the dynamics of migratory course, we use the cumulative causation of migration theory to conceptualize social expectations for outmigration and social resources from migrant networks in destinations. Four major findings are drawn from this demographic analysis based on micro data from China's 2000 Census. First, the expectation of outmigration significantly increases outmigration, and this effect is independent of push factors. Second, foreign direct investment (FDI) contributes to attracting rural labor migrants from other provinces to peri-urban areas as it does to cities. Third, social resources from migrant networks play an important role in attracting rural labor migrants to both city and noncity destinations. Fourth, the importance of wage differentials declines in gravitating rural labor migrants to peri-urban areas. These findings provide tentative evidence that rural labor migration is indispensable during initial peri-urbanization. Infused with flows of FDI and entrepreneurial local governments, rural migration has created a favorable initial condition for peri-urbanization.

  7. Photosynthetic pathways of some aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Hough, R A [Wayne State Univ., Detroit; Wetzel, R G

    1977-12-01

    Over 40 species of aquatic angiosperms, including submersed, floating and emergent types, have been examined for photosynthetic status as part of a search for possible aquatic C/sub 4/ species. The C/sub 4/ system is viewed as potentially of adaptive value in certain aquatic situations, although evidence for its occurrence there is not conclusive. Emphasis was on plants from North-temperate softwater and hardwater lakes to explore both possibilities of CO/sub 2/ limitation, i.e., low total inorganic carbon in softwater vs. low free CO/sub 2/ in hardwater lakes. On the basis of leaf cross-section anatomy, all plants examined, with one exception, clearly did not show evidence of C/sub 4/ ''Krantz anatomy.'' In the submersed plant Potamogeton praelongus Wulf, large starch-producing chloroplasts were concentrated in cells surrounding vascular bundles and in a narrow band of cells between vascular bundles. The in situ photosynthetic rate of this plant was twice that of a related species, but other evidence including PEP carboxylase content and photorespiratory response to high O/sub 2/ did not confirm the presence of the C/sub 4/ photosynthesis.

  8. Exploring soil water budget of a pristine oak wood in peri-urban Rome, central Italy

    Directory of Open Access Journals (Sweden)

    Valerio Moretti

    2014-06-01

    Full Text Available 72 544x376 Normal 0 14 false false false IT X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabella normale"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif";} Exploring soil water budget of a pristine oak wood in peri-urban Rome, central Italy. The water budget in bounded and fenced areas was assessed by analyzing pedo-climatic conditions and the soil moisture content. Water content in the soil was measured using a Theta Probe Soil Moisture sensor (ML2x by Delta-T-Devices with a direct read-out device that provides soil moisture estimates as percent volume. The correlation between the experimental values obtained by the gravimetricmethod and thevalues directly measured by Theta Probe was found significant. Soil moisture at 100 cm depth indicates soil water as permanently available for plants through the year except during exceptionally dry summer periods. Therefore, oaks experienced no water deficiency with normal rainfall rates, possibly suffering root asphyxia during rainy years. Results are collected in fenced areas, sheltered by the action of the local fauna.

  9. Heavy metal status of soil and vegetables grown on peri-urban area of Lahore district

    Directory of Open Access Journals (Sweden)

    Ajmal Khan, Shahid Javid, Atif Muhmood, Tahir Mjeed, Abid Niaz and Abdul Majeed

    2013-05-01

    Full Text Available Use of wastewater for growing vegetables has become a common practice around big cities. Wastewater contains organic material and inorganic elements essential for plant growth but also contain heavy metals which may be lethal for animals and humans if their concentration increases than permissible limit. To monitor this situation, a survey was conducted to ascertain the addition of heavy metals into agricultural fields through wastewater irrigation and their translocation in to the edible parts of the vegetables. For this purpose, during year 2009-10, 25 sewage water, 76 soil, 40 leaf and 30 vegetable samples (tomato, spinach, carrot and cauliflower were taken from peri-urban area of Lahore district. These samples were analyzed for Zn, Cu, Fe, Mn, Pb, Cd and Ni contents. The analysis showed that in wastewater concentration of Cu (100 %, Mn (72 %, Ni (32 % and Cd (44% were higher than the safe limits while Zn, Fe and Pb concentration was below permissible limits. In soil DTPA extractable concentration of Zn, Cu, Fe, Mn, Pb, Ni and Cd was in safe limit and ranged between 1.30-8.02, 1.06 -5.42, 8.60-35.03, 8.7-30.07, 2.11-30.86, 0.28-1.76 and 0.05-0.52 mg kg-1 respectively. In vegetable, 100 % leaf and fruit samples were contaminated and accumulation of heavy metals was higher than the WHO/FAO recommended permissible limits.

  10. Pesticide impact study in the peri-urban horticultural area of Gran La Plata, Argentina.

    Science.gov (United States)

    Mac Loughlin, Tomás M; Peluso, Leticia; Marino, Damián J G

    2017-11-15

    Vegetable production systems are characterized by intense pesticide use, yet the effects on the surrounding environment are largely unknown and need to be studied. Given this knowledge gap, the objective of this work is to determine the impact of horticulture on a representative watercourse by conducting an integrated study of the occurrence and concentration of pesticides in bottom sediments and their relation to lethal and sublethal effects on benthic fauna. Two sampling campaigns were conducted during seasons of low and high pesticide application in five sites along the Carnaval creek, located in the peri-urban area of La Plata City (Buenos Aires, Argentina). The samples were tested for 36 pesticide compounds by GC-MS and LC-MS, and whole-sediment laboratory toxicity tests were performed using the native amphipod Hyalella curvispina. The results showed a general but variable distribution in the concentrations detected along the stream. For each sampling campaign (first/second), the total pesticide loads, measured as the sum of herbicides, insecticides and fungicides, were 1080/2329, 3715/88, and 367/5ngg -1 dw, respectively. Lethal and sublethal effects were observed in both sampling campaigns. In order to correlate both sets of results, data were assessed by multivariate analysis, including principal component analysis. The observed toxicity was considered to be mainly due to insecticides; thus, horticultural practices have an impact on nearby watercourses and can potentially endanger the benthic fauna. This is the first study in Argentina to assess the impact of pesticides on aquatic environments close to horticultural production areas. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Characteristics of peri-urbanization of a secondary city: a challenge in recent urban development

    Science.gov (United States)

    Rahayu, P.; Mardiansjah, F. H.

    2018-03-01

    Urbanization process creates a tremendous spatial phenomenon since the last century. Especially for the country of the South, the phenomenon is still relevant to the situation today and the processes will still going until the foreseeable future. The metropolitan-based of urbanization process involves the development of peri-urban areas, which could be defined as transitional zones between city and rural areas characterized by integrated mixed-structures of agricultural and non-agricultural activities. This article reveals the characteristics of periurbanization process of an emerging secondary city in Java, which uses Surakarta, the second largest city in Central Java Province based on the population size, as the case. During the last ten years, there have been significant changes in peri-urban areas regarding urban population, land use, and urban activities that strengthening the contribution of the urban component into peri-urban system.

  12. Towards a peri-urban political ecology of water quality decline

    NARCIS (Netherlands)

    Karpouzoglou, Timothy; Marshall, Fiona; Mehta, Lyla

    2018-01-01

    Recent years have witnessed an expanding body of peri-urban and urban scholarship. However, recent scholarship has yet to adequately address the central role of politics and power shaping water quality decline. The article focuses on the trans-Hindon region which is part of Ghaziabad city, close to

  13. Adapting to Climate Change in Peri-Urban Southeast Asia | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    The rapid growth of peri-urban areas in Southeast Asia is characterized by a lack of basic services, unplanned built environments, and relatively weak governments. Residents of these areas are particularly vulnerable to extreme climate events, such as hurricanes, drought, flooding, and desertification. This research will ...

  14. Marketing channel choice and marketing timing of peri-urban vegetable growers in Vietnam

    NARCIS (Netherlands)

    Wiersinga, R.C.; Wijk, van M.S.; Luyen, C.H.; Hoi, P.V.

    2007-01-01

    Agriculture is an important sector in the peri-urban area of Hanoi. It supplies 62 to 80% of vegetable consumption, of which 28% comes from Dong Anh district, which borders Hanoi City. Growing vegetables is an important income source for the farmers in Dong Anh as it contributes about 30% to their

  15. Situational analysis of the microbial water quality in a peri-urban catchment in South Africa

    CSIR Research Space (South Africa)

    Venter, SN

    1997-01-01

    Full Text Available A situational analysis of a peri-urban catchment experiencing microbial water quality problems was carried out using data collected over two and a half years. The water and land use in the area was determined. The main sources of pollution were...

  16. Factors affecting dairy production in peri-urban areas of Kampala

    African Journals Online (AJOL)

    demand for dairy products by the increasing urban population and the need to provide ... was therefore recommended that if milk production in the peri-urban areas of Kampala is to .... approximately 80% of the total labour use in dairy farming.

  17. Wastewater re-use for peri-urban agriculture: a viable option for adaptive water management?

    NARCIS (Netherlands)

    Kurian, M.; Reddy, V.R.; Dietz, T.; Brdjanovic, D.

    2013-01-01

    Urbanization is known to spur land modification in the form of conversion of common land to human settlements. This factor, combined with climate variability, can alter the duration, frequency and intensity of storm drain overflows in urban areas and lead to public health risks. In peri-urban

  18. Nutrient flows in urban and peri-urban agroecosystems in three West African cities

    NARCIS (Netherlands)

    Abdulkadir, A.

    2012-01-01

    Key words: Sustainability, CATPCA, two-step cluster analysis, farm types, nutrient balances, West Africa, gross margin, NUTMON/MONQI.

    Urban and peri-urban agriculture (UPA) is defined as the cultivation of crops and keeping livestock within and around cities. In addition to providing the

  19. Wastewater re-use for peri-urban agriculture : a viable option for adaptive water management?

    NARCIS (Netherlands)

    Kurian, M.; Ratna, Reddy V.; Dietz, A.J.; Brdjanovic, D.

    2013-01-01

    Urbanization is known to spur land modification in the form of conversion of common land to human settlements. This factor, combined with climate variability, can alter the duration, frequency and intensity of storm drain overflows in urban areas and lead to public health risks. In peri-urban

  20. Nutrient flows and balances in urban and peri-urban agroecosystems of Kano, Nigeria

    NARCIS (Netherlands)

    Abdulkadir, A.; Leffelaar, P.A.; Agbenin, J.O.; Giller, K.E.

    2013-01-01

    Nutrient balances are useful indicators to assess the sustainability of farming systems. This study study investigates inflow and outflow of major nutrients in urban and periurban production systems in Kano, Nigeria. To this end, 16 households representing three different urban and peri-urban (UPA)

  1. Greenhouse gas and ammonia emissions and mitigation options from livestock production in peri-urban agriculture

    NARCIS (Netherlands)

    Wei, S.; Bai, Z.H.; Chadwick, D.; Hou, Y.; Qin, W.; Zhao, Z.Q.; Jiang, R.F.; Ma, L.

    2018-01-01

    Livestock production in peri-urban areas constitutes an important sub-sector of the agricultural production system in China, and contributes to environmental degradation and local air borne pollution contributing to smog. As a result, local policies are being implemented to safeguard the

  2. Terrestrially derived glomalin-related soil protein quality as a potential ecological indicator in a peri-urban watershed.

    Science.gov (United States)

    Sui, Xueyan; Wu, Zhipeng; Lin, Chen; Zhou, Shenglu

    2017-07-01

    Glomalin, which sequesters substantial amounts of carbon, plays a critical role in sustaining terrestrial biome functions and contributes to the fate of many pollutants from terrestrial to aquatic ecosystems. Despite having focused on the amount of glomalin produced, very few attempts have been made to understand how landscapes and environmental conditions influence glomalin composition and characteristics. This study focused on glomalin-related soil protein (GRSP) exported as storm runoff including eroded sediment and water that was collected before flowing to surface waters in a peri-urban watershed. GRSP characteristics were assessed by Bradford protein analysis, fluorescence spectroscopy combined with parallel factor analysis (PARAFAC), and the determination of aromaticity based on the specific ultraviolet absorption value (280 nm) and molecular weight. General linear models (GLMs) was established by integrating microbial activity, land cover, water temperature, precipitation, and other solution chemical properties to explain the variations in GRSP characteristics. Results showed that a higher GRSP concentration in agricultural reference sites was produced in the form of specific materials with low molecular weight and aromaticity, as well as high percentage of C1 and C5 components which indicate microbial-processed sources, relative to urbanized and forested sites. Compared with forested land, urbanized land clearly produced runoff GRSP with low molecular weight and aromaticity, as well as more degradation of humic-like materials (C3 component). The highest GLM explaining 89% of the variables, including significant variables (p watershed management and thus protecting aquatic ecosystems.

  3. Distribution of heavy metals in peri-urban agricultural areas soils

    International Nuclear Information System (INIS)

    Iram, S.; Ahmad, I.; Akhtar, S.

    2012-01-01

    In industry oriented peri-urban areas, the heavy metals accumulation in soils caused by industrialization has become a potential threat. The top soil sample from 48 agricultural fields were collected from a typical industry based peri-urban areas (Lahore, Faisalabad, Multan, Kasur, Islamabad, Wah Cantt.) of Punjab, Pakistan to study the accumulation and distribution of heavy metals (Pb, Cd, Cr, Cu, Ni and Zn) by atomic absorption spectrophotometer. The aim of the study was to investigate influence of an industrialized environment on the accumulation of heavy metals in peri-urban agricultural soils. The results of the study showed that the Pb content in the soil ranged from 17.24 to 126.4 mg/kg and the highest Pb content was observed in Islamabad soil samples, and the lowest in that of Multan area. The Cd content ranged from 1.1 to 4.0 mg/kg in Lahore while the highest Cr concentration level was 210.2 mg/kg and it was observed in Kasur and lowest 30.60 in that of Multan. The Cu content ranged from 31.2 to 127.9 mg/kg (Kasur-Lahore). The highest Ni concentration (82.0 mg/kg) was observed in Lahore from the urban area and the lowest level of 12.15 mg/kg was observed in Multan. The Zn content ranged from 42.5 to 267.7 mg/kg (Faisalabad-Wah Cantt). The study concluded that the concentration level of the heavy metals (Pb, Cd, Cu, Ni, Cr, Zn) in the studied peri-urban areas was higher as compared to heavy metal content of normal Dutch soil. High automobile traffic and industrial waste both are the most likely sources of the contamination of the peri urban areas of Pakistan. (author)

  4. Changing communication ecologies in rural, peri-urban and urban Kenya

    DEFF Research Database (Denmark)

    Nielsen, Poul Erik; Gustafsson, Jessica

    2017-01-01

    This article aims to discuss changing media ecologies in rural, peri-urban and urban Kenya. The article is based on a comprehensive baseline study of 800 households carried out in October 2014 in Uasin Gishu County, Kenya. The survey recorded media access and use and civic engagement as well...... as demographic data. The findings suggest that media ecologies in rural, peri-urban as well as urban Kenya have undergone dramatic changes. The much hyped and unprecedented spread of mobile telephony has taken place simultaneously with the introduction of or increased access to radio and television including...... satellite television. Different emerging communication ecologies can be identified often with radio providing a solid foundation and in different ways combined with television and mobile phones. Even though mobile ownership, for example, has increased in all segments and areas, gender inequalities...

  5. Longitudinal study of urbanisation processes in peri-urban areas of Greater Copenhagen

    DEFF Research Database (Denmark)

    Busck, Anne Gravsholt; Fertner, Christian; Kristensen, Lone Søderkvist

    Urbanisation processes increasingly influence the use of land and properties in rural areas. In peri-urban areas population composition changes as the areas offer attractive possibilities of other gainful activities than agriculture (OGA), and residential and recreational alternatives to both urban...... have become redundant because of structural changes in agriculture. As a consequence, the structural components of the areas (land cover and landscape elements) thus appear more resistant to changes than transition of the socio-economic system (declining number of full-time farmers and increasing...... property prices because of the attractiveness of land. This raises questions of the desired future of the peri-urban area of Greater Copenhagen, and about the effectiveness of the existing planning systems and its ability to protect agriculture land, which has been a main objective since the beginning...

  6. Cover changes and regeneration status of a peri-urban mangrove

    OpenAIRE

    Mohamed, M.O.S.; Neukermans, G.; Kairo, J.; Dahdouh-Guebas, F.; Koedam, N.

    2008-01-01

    Stability of an ecosystem is determined by its resilience, regenerative capacity and numerous weak trophic links, amongst other natural and human induced factors. The Tudor creek mangroves, a typical peri-urban mangrove, are exposed to both episodic natural and recurrent human disturbances, including decades? long exposure to raw domestic sewage, sporadic unregulated-harvesting and episodic siltation. This study evaluates the regeneration patterns within extended gaps and the understorey. An ...

  7. The Mother-Infant Relationship and Infant Attachment in a South African Peri-Urban Settlement

    Science.gov (United States)

    Tomlinson, Mark; Cooper, Peter; Murray, Lynne

    2005-01-01

    A sample of 147 mother-infant dyads was recruited from a peri-urban settlement outside Cape Town and seen at 2- and 18-months postpartum. At 18 months, 61.9% of the infants were rated as securely attached (B); 4.1% as avoidant (A); 8.2% as resistant (C); and 25.8% disorganized (D). Postpartum depression at 2 months, and indices of poor parenting…

  8. Composting of selected organic wastes from peri-urban areas of Harare, Zimbabwe

    CSIR Research Space (South Africa)

    Mhindu, RL

    2013-08-01

    Full Text Available of selected o e a se f pi d degradation, atmospheric pollution, soil health, soil bio- waste and rely on agriculture as a source of livelihood. Mhindu et al. International Journal Of Recycling of Organic Waste in Agriculture 2013, : http... is an important source of organic matter. Soil organic matter improves physico-chemical and biological properties and Composting as a waste management strategy has multiple benefits for peri-urban agriculture considering the scarcity of animal manures among small...

  9. Impact of different irrigation systems on water quality in peri-urban areas of Gujarat, India

    OpenAIRE

    Vangani, Ruchi; Saxena, Deepak; Gerber, Nikolaus; Mavalankar, Dileep; von Braun, Joachim

    2016-01-01

    The ever-growing population of India, along with the increasing competition for water for productive uses in different sectors - especially irrigated agriculture and related local water systems and drainage - poses a challenge in an effort to improve water quality and sanitation. In rural and peri-urban settings, where agriculture is one of the main sources of livelihood, the type of water use in irrigated agriculture has complex interactions with drinking water and sanitation. In particular,...

  10. Traditional medicine for the rich and knowledgeable: challenging assumptions about treatment-seeking behaviour in rural and peri-urban Nepal

    Science.gov (United States)

    Thorsen, Rikke Stamp; Pouliot, Mariève

    2016-01-01

    Traditional medicine is commonly assumed to be a crucial health care option for poor households in developing countries. However, little research has been done in Asia to quantify the reliance on traditional medicine and its determinants. This research contributes to filling in this knowledge gap using household survey data collected from 571 households in three rural and peri-urban sites in Nepal in 2012. Questions encompassed household socioeconomic characteristics, illness characteristics, and treatment-seeking behaviour. Treatment choice was investigated through bivariate analyses. Results show that traditional medicine, and especially self-treatment with medicinal plants, prevail as treatment options in both rural and peri-urban populations. Contrarily to what is commonly assumed, high income is an important determinant of use of traditional medicine. Likewise, knowledge of medicinal plants, age, education, gender and illness chronicity were also significant determinants. The importance of self-treatment with medicinal plants should inform the development of health policy tailored to people’s treatment-seeking behaviour. PMID:26130610

  11. Energy assessment of peri-urban horticulture and its uncertainty: Case study for Bogota, Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Bojaca, C.R. [Centro de Investigaciones y Asesorias Agroindustriales, Facultad de Ciencias Naturales, Universidad de Bogota Jorge Tadeo Lozano, P.O. Box: 140196, Chia (Colombia); Schrevens, E. [Department of Biosystems, Faculty of Applied Bioscience Engineering, Katholieke Universiteit Leuven, Geo-Institute, Celestijnenlaan 200 E, 3001 Heverlee (Belgium)

    2010-05-15

    Scarce information is available about the energy use pattern of horticultural commodities in general and more specifically for peri-urban horticulture. Peri-urban horticulture in the outskirts of Bogota is an important source of vegetables for Colombia's capital city. Based on detailed follow-ups and periodic field measurements an output-input energy balance was performed with the main objective to study the energy use efficiency of those systems. An uncertainty analysis on the input factors and on the energy equivalents was then applied. Over a measurement period of 18-month, the energy use for coriander, lettuce, radish and spinach was investigated, respectively 12.1, 18.8, 6.6 and 10.7 GJ ha{sup -1} were consumed in these cropping systems. Negative balances were observed for all species exception made for spinach where an output:input ratio of 1.16 was found. The two-way uncertainty analysis showed the highest uncertainty for N-based fertilization while no significant effect was observed for seeds in direct sowing crops. Sustainability of peri-urban horticulture around Bogota is compromised not only because of the city expansion but also due to its inefficient energy use. Technical improvements are required to ensure the environmental subsistence of this important sector for the metropolitan area of the city. (author)

  12. Global assessment of urban and peri-urban agriculture: irrigated and rainfed croplands

    Science.gov (United States)

    Thebo, A. L.; Drechsel, P.; Lambin, E. F.

    2014-11-01

    The role of urban agriculture in global food security is a topic of increasing discussion. Existing research on urban and peri-urban agriculture consists largely of case studies that frequently use disparate definitions of urban and peri-urban agriculture depending on the local context and study objectives. This lack of consistency makes quantification of the extent of this practice at the global scale difficult. This study instead integrates global data on croplands and urban extents using spatial overlay analysis to estimate the global area of urban and peri-urban irrigated and rainfed croplands. The global area of urban irrigated croplands was estimated at about 24 Mha (11.0 percent of all irrigated croplands) with a cropping intensity of 1.48. The global area of urban rainfed croplands found was approximately 44 Mha (4.7 percent of all rainfed croplands) with a cropping intensity of 1.03. These values were derived from the MIRCA2000 Maximum Monthly Cropped Area Grids for irrigated and rainfed crops and therefore their sum does not necessarily represent the total urban cropland area when the maximum extent of irrigated and rainfed croplands occurs in different months. Further analysis of croplands within 20 km of urban extents show that 60 and 35 percent of, respectively, all irrigated and rainfed croplands fall within this distance range.

  13. Global assessment of urban and peri-urban agriculture: irrigated and rainfed croplands

    International Nuclear Information System (INIS)

    Thebo, A L; Drechsel, P; Lambin, E F

    2014-01-01

    The role of urban agriculture in global food security is a topic of increasing discussion. Existing research on urban and peri-urban agriculture consists largely of case studies that frequently use disparate definitions of urban and peri-urban agriculture depending on the local context and study objectives. This lack of consistency makes quantification of the extent of this practice at the global scale difficult. This study instead integrates global data on croplands and urban extents using spatial overlay analysis to estimate the global area of urban and peri-urban irrigated and rainfed croplands. The global area of urban irrigated croplands was estimated at about 24 Mha (11.0 percent of all irrigated croplands) with a cropping intensity of 1.48. The global area of urban rainfed croplands found was approximately 44 Mha (4.7 percent of all rainfed croplands) with a cropping intensity of 1.03. These values were derived from the MIRCA2000 Maximum Monthly Cropped Area Grids for irrigated and rainfed crops and therefore their sum does not necessarily represent the total urban cropland area when the maximum extent of irrigated and rainfed croplands occurs in different months. Further analysis of croplands within 20 km of urban extents show that 60 and 35 percent of, respectively, all irrigated and rainfed croplands fall within this distance range. (letter)

  14. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ying; Li, Tingqiang; Wu, Chengxian [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); He, Zhenli [University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States); Japenga, Jan; Deng, Meihua [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Xiaoe, E-mail: xeyang@zju.edu.cn [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China)

    2015-12-15

    Highlights: • Heavy metal source apportionment was conducted in peri-urban agricultural areas. • Precise and quantified results were obtained by using isotope ratio analysis. • The integration of IRA, GIS, PCA, and CA was proved to be more reliable. • Hg pollution was from the use of organic fertilizers in this area. - Abstract: Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74–100% and 0–24% of the total Hg input, while road dusts and solid wastes contributed for 0–80% and 19–100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions.

  15. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils

    International Nuclear Information System (INIS)

    Huang, Ying; Li, Tingqiang; Wu, Chengxian; He, Zhenli; Japenga, Jan; Deng, Meihua; Yang, Xiaoe

    2015-01-01

    Highlights: • Heavy metal source apportionment was conducted in peri-urban agricultural areas. • Precise and quantified results were obtained by using isotope ratio analysis. • The integration of IRA, GIS, PCA, and CA was proved to be more reliable. • Hg pollution was from the use of organic fertilizers in this area. - Abstract: Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74–100% and 0–24% of the total Hg input, while road dusts and solid wastes contributed for 0–80% and 19–100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions.

  16. The peri-urban interface and house infestation with Triatoma infestans in the Argentine Chaco: an underreported process?

    Directory of Open Access Journals (Sweden)

    Yael M Provecho

    2014-10-01

    Full Text Available Peri-urban infestations with triatomine bugs, their sources and their dynamics have rarely been investigated. Here, we corroborated the reported occurrence of Triatoma infestans in a peri-urban area and in neighbouring rural houses in Pampa del Indio, in the Argentine Chaco, and identified its putative sources using spatial analysis and demographic questionnaires. Peri-urban householders reported that 10% of their premises had triatomines, whereas T. infestans was collected by timed manual searches or community-based surveillance in only nine (3% houses. Trypanosoma cruzi-infected T. infestans and Triatoma sordida were collected indoors only in peri-urban houses and were infected with TcV and TcI, respectively. The triatomines fed on chickens, cats and humans. Peri-urban infestations were most frequent in a squatter settlement and particularly within the recently built mud houses of rural immigrants, with large-sized households, more dogs and cats and more crowding. Several of the observed infestations were most likely associated with passive bug transport from other sources and with active bug dispersal from neighbouring foci. Thus, the households in the squatter settlement were at a greater risk of bug invasion and colonisation. In sum, the incipient process of domestic colonisation and transmission, along with persistent rural-to-urban migratory flows and unplanned urbanisation, indicate the need for active vector surveillance and control actions at the peri-urban interface of the Gran Chaco.

  17. Wasted waste—Disappearing reuse at the peri-urban interface

    International Nuclear Information System (INIS)

    Hofmann, Pascale

    2013-01-01

    Highlights: • Urban waste reuse in farming practices is significant for poor people's livelihoods. • Peri-urban garbage farming contributes to urban food security. • Informal reuse practices are not acknowledged in urban waste management strategies. • Poor people face increasing obstacles to access and use urban waste. • The continuation of reuse practices requires an enabling institutional framework. -- Abstract: Safe and sustainable management of waste presents a major challenge in cities in the Global South. For decades farmers in the peri-urban interface (PUI) have used biodegradable components of urban waste as inputs into their farming practices. Evidence from Kano, Nigeria; Kumasi, Ghana; Hubli-Dharwad and Kolkata, India reveals in rare detail how urban waste reuse plays an important role in the livelihood strategies of lower-income families nd while waste farming also contributes significantly to urban food security. Health implications affecting farmers, farm-workers and community members often overshadow these benefits as highlighted through the case studies. Additionally, increasing competition over land and resources in the PUI paired with other factors triggered by processes of rapid development and urbanisation have rendered it more difficult for the peri-urban poor to access and use urban waste. The article further explores additional challenges of an institutional nature linked to the informality of reuse practices and prevalent sector approaches that are exacerbated by the institutional fragmentation present in the PUI. It is argued that an integrated city-wide policy that reduces the threats to peri-urban reuse practices while enhancing urban food security and integrated waste management is crucial. However, any effort to sustain these practices needs to incorporate adequate health and safety procedures. Thus, peri-urban farmers, farm workers and labourers constitute important stakeholders in urban planning and decision-making processes

  18. Geochemical Assessment of Groundwater in the Peri-urban Environment of Buenos Aires, Argentina

    Science.gov (United States)

    Gallardo, A.

    2014-12-01

    Groundwater pollution is a major concern in peri-urban environments. Thus, water quality is being investigated at several domestic wells in Brandsen, 70 km south of Buenos Aires, Argentina. To present, about 20 water sources were sampled in orchards and small farms of the area. There is limited data about the wells construction, although collected information suggests that groundwater is derived from the superficial sandy loams of the Pampean Aquifer. Samples were analysed for major inorganic elements using ion chromatography and ICP-MS. Titration was used to estimate alkalinity. Physical characteristics (EC, pH, temperature) were measured on site. Results show that groundwater pH ranges from 6.5 to 7.8, with a specific conductance of 180 to 255 mS/m. A peak of 360 mS/m in one horticultural parcel is associated to local NO3- concentrations up to 140 mg/L. This value exceeds the maximum recommendations set by the WHO (50 mg/L). Considering that fertilizer inputs in that property are negligible, the high levels of NO3- might be attributed to effluents from a neighbour septic tank. An increase in NO3- (>150mg/L) was also detected in two conventional farms. This increase correlates to elevated SO42- concentrations (>300 mg/L) suggesting thus, fertilizers percolation into the saturated zone. The leaching of these fluids might be exacerbated by irrigation during new planting, and accumulations of fertilizer-solids in the root zones from previous seasons. Chloride concentrations average ~90 mg/L and would not pose a threat to health at the moment. Its main origin would be related to connate waters in the loam matrix, although some anthropogenic inputs might occur in the previously described farms. In general, the rest of the analysed elements fall within acceptable levels for drinking purposes as well. Nevertheless, further work is still necessary to better define the fate of the potential harmful elements and assess seasonal variations in water quality.

  19. Public Lakes, Private Lakeshore: Modeling Protection of Native Aquatic Plants

    Science.gov (United States)

    Schroeder, Susan A.; Fulton, David C.

    2013-07-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221-279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey ( n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners' behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  20. Public lakes, private lakeshore: Modeling protection of native aquatic plants

    Science.gov (United States)

    Schroeder, Susan A.; Fulton, David C.

    2013-01-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221–279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey (n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners’ behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  1. VASCULAR PLANTS AS ENGINEERS OF OXYGEN IN AQUATIC SYSTEMS

    Science.gov (United States)

    The impact of organisms on oxygen is one of the most dramatic examples of ecosystem engineering on Earth. In aquatic systems, which have much lower oxygen concentrations than the atmosphere, vascular aquatic plants can affect oxygen concentrations significantly not only on long t...

  2. Cytochemical and ultrastructural aspects of aquatic carnivorous plant turions

    Czech Academy of Sciences Publication Activity Database

    Plachno, B.J.; Adamec, Lubomír; Kozieradzka-Kiszkurno, M.; Świątek, P.; Kamińska, I.

    2014-01-01

    Roč. 251, č. 6 (2014), s. 1449-1454 ISSN 0033-183X Institutional support: RVO:67985939 Keywords : aquatic carnivorous plants * winter buds * storage functions Subject RIV: EF - Botanics Impact factor: 2.651, year: 2014

  3. Master plan: Guntersville Reservoir Aquatic Plant Management. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    In 1989, Congress provided funding to start a five-year comprehensive project to manage aquatic plants in Guntersville Reservoir, to be jointly implemented by the US Army Corps of Engineers (Corps) and Tennessee Valley Authority (TVA). TVA serves as the overall project coordinator and is the lead agency for this project. Known as the Joint Agency Guntersville Project (JAGP), the project will test and demonstrate innovative management technologies, and incorporate the most effective technologies into a comprehensive aquatic plant management plan for Guntersville Reservoir. The JAGP is intended to serve as a National Demonstration Project for aquatic plant management. As part of this JAGP, the Master Plan for Aquatic Plant Management for the Guntersville Reservoir Project, Alabama-Tennessee is authorized by Corps Contract Number DACW62-90-C-0067.

  4. Determining and Mapping the Probability of Aquatic Plant Colonization

    National Research Council Canada - National Science Library

    Balard, Jerrell

    1999-01-01

    ... at the Waterways Experiment Station. It is principally intended to be a forum whereby information pertaining to and resulting from the Corps of Engineers' nationwide Aquatic Plant Control Research Program (APCRP...

  5. Aquatic Plant Control Research Program. Volume A-00-1

    National Research Council Canada - National Science Library

    Kirk, James

    2000-01-01

    ... at the Waterways Experiment Station. It is principally intended to be a forum whereby information pertaining to and resulting from the Corps of Engineers' nationwide Aquatic Plant Control Research Program (APCRP...

  6. Wastewater for agriculture: A reuse-oriented planning model and its application in peri-urban China.

    Science.gov (United States)

    Murray, Ashley; Ray, Isha

    2010-03-01

    The benefits of Integrated Water Resources Management (IWRM) are widely known but its recommendations remain thinly implemented. Designing wastewater treatment plants for reuse in irrigation is a particularly underutilized IWRM opportunity that could potentially increase agricultural yields, conserve surface water, offset chemical fertilizer demand, and reduce the costs of wastewater treatment by eliminating nutrient removal processes. This paper presents a novel planning model, consisting of a reuse-centric performance assessment and optimization model to help design wastewater treatment plants for reuse in agriculture. The performance assessment and optimization model are described, and their coupled application is demonstrated in the peri-urban district of Pixian, China. Based on the results of the performance assessment, two reuse scenarios are evaluated: wastewater to supplement business as usual (BAU) irrigation, and wastewater to replace BAU irrigation. The results indicate that wastewater supplementation could increase profits by $20 million (M) annually; alternatively, wastewater replacement could conserve 35Mm(3) of water in local rivers each year. Copyright 2009 Elsevier Ltd. All rights reserved.

  7. Modeling the element cycle of aquatic plants

    International Nuclear Information System (INIS)

    Asaeda, Takashi

    2007-01-01

    Aquatic plants play an important role in element cycles in wetlands and the efficiency of the process is extremely related to their proportional biomass allocation to above- and belowground organs. Therefore, the framework of most macrophyte productivity models is usually similar with a mass-balance approach consisting of gross production, respiration and mortality losses and the translocation between organs. These growth models are incorporated with decomposition models to evaluate the annual cycle of elements. Perennial emergent macrophytes with a relatively large biomass have a particularly important role in element cycles. Their phenological stages, such as the beginning of hibernation of belowground rhizome systems, emergence of new shoots in spring with resources stocked in the rhizomes, flowering, downward translocation of photosynthetic products later on and then the mortality of the aboveground system in late autumn, depend on the environmental conditions, basically the nutrients, water depth, climatic variations, etc. Although some species retain standing dead shoots for a long time, dead shoots easily fall into water, starting to decompose in the immediate aftermath. However, their decomposition rates in the water are relatively low, causing to accumulate large amounts of organic sediments on the bottom. Together with the deposition of allochthonous suspended matters in the stand, this process decreases the water depth, transforming wetlands gradually into land. The depth of penetration of roots into the sediments to uptake nutrients and water is extremely site specific, however, in water-logged areas, the maximum penetrable depth may be approximately estimated by considering the ability of oxygen transport into the rhizome system. The growth of perennial submerged plants is also estimated by a process similar to that of emergent macrophytes. However, compared with emergent macrophytes, the root system of submerged macrophytes is weaker, and the nutrient

  8. Role, ownership and presence of domestic animals in peri-urban households of Kisumu, Kenya.

    Science.gov (United States)

    Barnes, A N; Mumma, J; Cumming, O

    2018-02-01

    Low- and middle-income countries are experiencing rapid urban population growth, particularly in peri-urban informal settlements. In these urban areas, animal husbandry remains a valuable source of income and protein-rich foods but may also present a risk of zoonotic disease threat. To date, there have been studies that have assessed the prevalence and nature of animal ownership in these communities. This cross-sectional survey assessed the geographical, sociocultural and economic factors behind the presence, ownership and purpose of domestic animals in three informal peri-urban communities of Kisumu, Kenya. A majority (n = 587) of the study households exhibited domestic animal presence in the living space yet only 32% of households reported animal ownership (n = 252). The purposes of ownership included: for meat/eggs (55%); for income, sale or trade (43%); for milk production (31%); and as companions/pets (31%). Among households that owned animals, 76% reported that at least one animal slept in the house at night. In multivariate logistic regression, the following factors were significantly associated with household animal ownership: ownership of agricultural land (OR = 1.94, 95% CI = 1.12, 3.35), perceiving a strong community bond (OR = 2.28, 95% CI = 1.25, 4.16), and household membership in a community group (OR = 1.64, 95% CI = 1.04, 2.60). This research demonstrates the high prevalence of animal ownership in a low-income and high-density peri-urban neighbourhood of an African city, which may facilitate zoonotic disease transmission. Further research should assess if and to what extent animal ownership in such communities is associated with disease risk. © 2017 The Authors. Zoonoses and Public Health Published by Blackwell Verlag GmbH.

  9. Adapting to Climate Change: Lessons from Farmers and Peri-Urban Fringe Residents in South Australia

    Directory of Open Access Journals (Sweden)

    Guy M. Robinson

    2018-03-01

    Full Text Available This paper reports on results from two major research projects conducted in South Australia. The first investigates adaptation to climate change in two of the state’s major grain and sheep farming regions, using semi-structured interviews and focus groups. The second uses a postal questionnaire and an internet-based survey of residents in the peri-urban fringes of Adelaide, the state capital, to examine knowledge of and attitudes to climate change and resulting adaptations, especially in the context of increasing risk of wildfires. The research on adaptation to climate change in agriculture focused on formal institutions (e.g., government agencies and communities of practice (e.g., farm systems groups. Both groups noted that farmers autonomously adapt to various risks, including those induced by climate variability. The types and levels of adaptation varied among individuals partly because of barriers to adaptation, which included limited communication and engagement processes established between formal institutions and communities of practice. The paper discusses possibilities for more effective transfers of knowledge and information on climate change among formal institutions, communities of practice, trusted individual advisors and farmers. Research in the peri-urban fringe revealed that actions taken by individuals to mitigate and/or adapt to climate change were linked to the nature of environmental values held (or ecological worldview and place attachment. Individuals with a strong place attachment to the study area (the Adelaide Hills who possessed knowledge of and/or beliefs in climate change were most likely to take mitigating actions. This was also linked to previous experience of major risk from wildfires. The paper concludes by discussing prospects for developing co-management for reducing the impact of climate change across multiple groups in rural and peri-urban areas.

  10. Trends in Urbanization and Implications for Peri-Urban Livelihoods in Accra, Ghana

    Science.gov (United States)

    Adom, Cynthia

    Urbanization is a common occurrence in both developed and developing worlds. Similar to occurrences in other developing world cities, Accra's urbanization is marked by fast, unplanned and uneven growth into mostly peripheral lands (Grant and Yankson 2002; Yeboah 2001; Ghana Statistical Service (GSS) 2002). Such trends in urbanization in places where data on the urbanization process is seriously inadequate and infrequent, (Rakodi 1997a; Ohadika 1991; Fasona and Omojola 2004) pose a major challenge to urban planning and management (Henderson 2002), and affect the livelihood base of several peri-urban households. Properly monitoring the urbanization process in the developing world and understanding its effects on people's lives depends on the availability of useful and up-to- date data (Weber and Puissant 2003; Mundia and Aniya 2006) that could be obtained using new and robust analytical techniques (Yang 2003). In addition, in the urban environment, differences in rates of urbanization, income, employment status, and gender dynamics across neighborhoods suggest that the impacts of increasing urbanization on peri-urban livelihoods are likely to vary across peoples and places. Against this backdrop, this dissertation uses Accra as a case study to, first, measures the nature and extent of urban expansion using a non-conventional technique, and then analyzes neighborhood - and gender-differentiated impacts of increasing urbanization on household livelihoods in peri-urban Accra. Study findings reveal: 1) major conversion of vegetated land to urban lands uses and support the effectiveness of the Self-Organizing Map and Landsat data to map complex and hazy urban tropical environments; 2) that the impacts of urbanization on peri-urban livelihoods are structured along the lines of neighborhood-level urbanization; changes brought by a higher rate of urbanization are more beneficial than harmful to household livelihoods; 3) that positive livelihood outcomes in high

  11. Strategies for transdisciplinary research on peri-urban groundwater management in the Ganges delta

    Science.gov (United States)

    Hermans, Leon; Thissen, Wil; Gomes, Sharlene; Banerjee, Poulomi; Narain, Vishal; Salehin, Mashfiqus; Hasan, Rezaul; Barua, Anamika; Alam Khan, Shah; Bhattacharya, Samir; Kempers, Remi; Banerjee, Parthasarathi; Hossain, Zakir; Majumdar, Binoy; Hossain, Riad

    2016-04-01

    Transdisciplinary science transcends disciplinary boundaries. The reasons to engage in transdisciplinary science are many and include the desire to nurture a more direct relationship between science and society, as well as the desire to explain phenomena that cannot be explained by any of the existing disciplinary bodies of knowledge in isolation. Both reasons also reinforce each other, as reality often features a level of complexity that demands and inspires the combination of scientific knowledge from various disciplines. The challenge in transdisciplinary science, however, is not so much to cross disciplinary boundaries, but to ensure an effective connection between disciplines. This contribution reports on the strategy used in a transdisciplinary research project to address groundwater management in peri-urban areas in the Ganges delta. Groundwater management in peri-urban areas in rapidly urbanizing deltas is affected by diverse forces such as rapid population growth, increased economic activity and changing livelihood patterns, and other forces which result in a growing pressure on available groundwater resources. Understanding the intervention possibilities for a more sustainable groundwater management in these peri-urban areas requires an understanding of the dynamic interplay between various sub-systems, such as the physical groundwater system, the water using activities in households and livelihoods, and the institutional system of formal and informal rules that are used by various parties to access groundwater resources and to distribute the associated societal and economic costs and benefits. The ambition in the reported project is to contribute both new scientific knowledge, as well as build capacity with peri-urban stakeholders to improve the sustainability and equitability of local groundwater management. This is done by combining science and development activities, led by different organizations. The scientific component further consists of three

  12. Peri-urban futures: Scenarios and models for land use change in Europe

    DEFF Research Database (Denmark)

    on a pan-European level Has a conclusive didactic approach + text structure (e.g. inserts, boxes ...) Presently, peri-urbanisation is one of the most pervasive processes of land use change in Europe with strong impacts on both the environment and quality of life. It is a matter of great urgency...... to determine strategies and tools in support of sustainable development. The book synthesizes the results of PLUREL, a large European Commission funded research project (2007-2010). Tools and strategies of PLUREL address main challenges of managing land use in peri-urban areas. These results are presented...

  13. Aquatic plant surface as a niche for methanotrophs

    Directory of Open Access Journals (Sweden)

    Naoko eYoshida

    2014-02-01

    Full Text Available This study investigated the potential local CH4 sink in various plant parts as a boundary environment of CH4 emission and consumption. By comparing CH4 consumption activities in cultures inoculated with parts from 39 plant species, we observed significantly higher consumption of CH4 associated with aquatic plants than other emergent plant parts such as woody plant leaves, macrophytic marine algae, and sea grass. In situ activity of CH4 consumption by methanotrophs associated with different species of aquatic plants was in the range of 3.7 – 37 μmol⋅h-1⋅g-1 dry weight, which was ca 5.7-370 fold higher than epiphytic CH4 consumption in submerged parts of emergent plants. The qPCR-estimated copy numbers of the particulate methane monooxygenase-encoding gene pmoA were variable among the aquatic plants and ranged in the order of 105 to 107 copies⋅g-1 dry weight, which correlated with the observed CH4 consumption activities. Phylogenetic identification of methanotrophs on aquatic plants based on the pmoA sequence analysis revealed a predominance of diverse gammaproteobacterial type-I methanotrophs, including a phylotype of a possible plant-associated methanotroph with the closest identity (86-89% to Methylocaldum gracile.

  14. Ricinus communis L. (castor bean) as a potential candidate for revegetating industrial waste contaminated sites in peri-urban Greater Hyderabad: remarks on seed oil.

    Science.gov (United States)

    Boda, Ravi Kiran; Majeti, Narasimha Vara Prasad; Suthari, Sateesh

    2017-08-01

    Ricinus communis L. (castor bean or castor oil plant) was found growing on metal-contaminated sites (4) of peri-urban Greater Hyderabad comprises of erstwhile industrial areas viz Bollaram, Patancheru, Bharatnagar, and Kattedan industrial areas. During 2013-2017, about 60 research papers have appeared focusing the role of castor bean in phytoremediation of co-contaminated soils, co-generation of biomaterials, and environmental cleanup, as bioenergy crop and sustainable development. The present study is focused on its use as a multipurpose phytoremediation crop for phytostabilization and revegetation of waste disposed peri-urban contaminated soils. To determine the plant tolerance level, metal accumulation, chlorophyll, protein, proline, lipid peroxidation, oil content, and soil properties were characterized. It was noticed that the castor plant and soils have high concentration of metals such as cadmium (Cd), lead (Pb), iron (Fe), manganese (Mn), and zinc (Zn). The soils have high phosphorous (P), adequate nitrogen (N), and low concentration of potassium (K). Iron (Fe) concentrations ranged from1672±50.91 to 2166±155.78 mg kg -1 in the soil. The trend of metal accumulation Fe>Zn>Mn>Pb>Cd was found in different plant parts at polluted sites. The translocation of Cd and Pb showed values more than one in industrial areas viz Bollaram, Kattedan, and Bharatnagar indicating the plants resistance to metal toxicity. Chlorophyll and protein content reduced while proline and malondialdehyde increased due to its tolerance level under metal exposure. The content of ricinoleic acid was higher, and the fatty acids composition of polluted areas was almost similar to that of the control area. Thus, R. communis L. can be employed for reclamation of heavy metal contaminated soils.

  15. Decentralized peri-urban wastewater treatment technologies assessment integrating sustainability indicators.

    Science.gov (United States)

    Mena-Ulecia, Karel; Hernández, Heykel Hernández

    2015-01-01

    Selection of treatment technologies without considering the environmental, economic and social factors associated with each geographical context risks the occurrence of negative impacts that were not properly foreseen, working against the sustainable performance of the technology. The principal aim of this study was to evaluate 12 technologies for decentralized treatment of domestic wastewater applicable to peri-urban communities using sustainability approaches and, at the same time, continuing a discussion about how to address a more integrated assessment of overall sustainability. For this, a set of 13 indicators that embody the environmental, economic and social approach for the overall sustainability assessment were used by means of a target plot diagram as a tool for integrating indicators that represent a holistic analysis of the technologies. The obtained results put forward different degrees of sustainability, which led to the selection of: septic tank+land infiltration; up-flow anaerobic reactor+high rate trickling filter and septic tank+anaerobic filter as the most sustainable and attractive technologies to be applied in peri-urban communities, according to the employed indicators.

  16. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils.

    Science.gov (United States)

    Huang, Ying; Li, Tingqiang; Wu, Chengxian; He, Zhenli; Japenga, Jan; Deng, Meihua; Yang, Xiaoe

    2015-12-15

    Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74-100% and 0-24% of the total Hg input, while road dusts and solid wastes contributed for 0-80% and 19-100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Model Perkembangan Perumahan di Wilayah Peri Urban Kota Surabaya (Studi Kasus : Kabupaten Sidoarjo

    Directory of Open Access Journals (Sweden)

    I Dewa Made Frendika Septanaya

    2012-09-01

    Full Text Available Saat ini perkembangan wilayah peri urban di berbagai kawasan metropolitan menunjukkan adanya pertambahan luas permukiman dalam jumlah banyak (real estate atau yang biasa di kategorikan sebagai proses formatif yang bersifat invasif. Kecenderungan beberapa wilayah peri urban yang menunjukkan pesatnya pertumbuhan perumahan ternyata tidak sepenuhnya terjadi di Kabupaten Sidoarjo. Fenomena  penurunan pengadaan perumahan yang terjadi pada periode  2006 – 2010 menyebabkan ketidakseimbangan antara rendahnya pengadaan (supply rumah dengan kebutuhan (demand atas perumahan yang semakin meningkat. Hasil akhir penelitian ini  menunjukkan bahwa faktor geografis (spasial dalam pemodelan GWR yang menyebabkan penuruan jumlah pengadaan perumahan di masing-masing kecamatan berbeda-beda, namun secara holistik disebabkan oleh pengaruh harga lahan, keterbatasan ketersediaan lahan kosong untuk peruntukan perumahan dan jarak dari lumpur Lapindo Kecamatan Porong. Sedangkan faktor aspasial yang mempengaruhi adalah stabilitas kondisi ekonomi, besarnya biaya taktis (transaction cost dan biaya dampak pembangunan (development impact fees, kendala perizinan serta aturan atau regulasi untuk pembebasan lahan yang tidak mengikat.

  18. Emerging feed markets for ruminant production in urban and peri-urban areas of Northern Ghana.

    Science.gov (United States)

    Konlan, S P; Ayantunde, A A; Addah, W; Dei, H K; Karbo, N

    2018-01-01

    Feed shortage in urban and peri-urban areas has triggered the emergence of feed markets in Northern Ghana. These markets were surveyed at three locations (Tamale, Bolgatanga, and Wa markets) to determine types and prices of feedstuffs sold across seasons; early dry (November-January), late dry (February-April), early wet (May-July), and main wet (August-October). Semi-structured questionnaire was used for data collection. Three samples of each feed type in the markets were bought from three different sellers per market in each season. The samples were oven dried to constant weight and price/kg DM of each feed determined. The total respondents were 169. Out of this number, 41% were feed sellers, 46% buyers, and 13% retailers. The feedstuffs found were crop residues (groundnut haulm and cowpea haulm), agro-industrial by-products (bran of maize, rice, and sorghum), fresh grasses (Rotteboellia cochinchinensis), and local browses (Ficus sp. and Pterocarpus erinaceous). Prices of feeds differed (P  0.05) in all seasons but that of crop residues were higher (P < 05) in early to late dry season than the wet season. Majority (90%) of respondents opined that the feed market will expand due to increasing number of livestock population in the peri-urban areas.

  19. Peri-urban dairy production systems in developing countries: Characteristics, potential and opportunities for improvement

    International Nuclear Information System (INIS)

    Devendra, C.

    2002-01-01

    Full text: Peri-urban dairy production systems in developing countries are discussed with reference to type of systems, their characteristics, potential, and opportunities for improvement. Three types of dairy systems are identified and described: smallholder systems, smallholder co-perative dairy production systems, and intensive dairy production systems. The first two systems are by far the most important, and are associated with increasing intensification. Buffaloes are especially important in South Asia, but elsewhere dairy production mainly involves Holstein-Friesian cross-bred cattle. Dairy goats are important in some countries, but are generally neglected in development programmes. The expansion and intensification of peri-urban dairy production is fuelled by increased demand for milk with associated problems of milk handling and distribution, hygiene and environmental pollution. The major constraints to production are inter alia, choice of species, breeds and availability of animals; feed resources and improved feeding systems; improved breeding, reproduction, and animal health care; management of animal manure, and organised marketing, and market outlets. These constraints provide major opportunities and challenges for research and development to increase dairy production, efficient management of natural resources, and improved livelihoods of poor farmers. Specific areas for research are identified, as also the need of a holistic focus involving interdisciplinary research and integrated natural resource management, in a shared partnership between farmers and scientists that can demonstrate increased productivity and sustainable production systems. Suggestions for performance indicators for such systems are indicated. (author)

  20. Understanding sediment sources in a peri-urban Mediterranean catchment using geochemical tracers

    Science.gov (United States)

    Ferreira, Carla; Walsh, Rory; Kikuchi, Ryunosuke; Blake, Will

    2016-04-01

    One of the main physical environmental impacts of urbanization is an increase in suspended sediment concentrations and loads, particularly in the constructional phase. Impacts in peri-urban catchments characterized by a mosaic of urban and non-urban landscape elements with varying roles in acting as sources and sinks of overland flow and slope wash have received little attention, particularly in Mediterranean environments. The present study uses a sediment 'fingerprinting' approach to determine the main sediment sources in the peri-urban Ribeira dos Covões catchment (6.2km2) in Portugal and how they change during storm events following contrasting antecedent weather. The catchment, rural until 1972, underwent discontinuous urbanization in 1973-1993, followed by an urban consolidation phase. Currently, its land-use is a complex mosaic of woodland (56%), urban (40%) and agricultural (4%) land parcels. Distinct urban patterns include some well-defined urban residential centres, but also areas of discontinuous urban sprawl. Since 2010, a major road was built and an enterprise park has been under construction, covering 1% and 5% of the catchment, respectively. The catchment has a Mediterranean climate. The geology comprises sandstone (56%), limestone (41%) and alluvial deposits (3%). Soils are generally deep (>3.0m), but shallow (urbanized and partly urbanized catchments, and to supporting them in designing and implementing effective land-use mosaics and site-specific measures to mitigate erosion.

  1. The role of a peri-urban forest on air quality improvement in the Mexico City megalopolis

    International Nuclear Information System (INIS)

    Baumgardner, Darrel; Varela, Sebastian; Escobedo, Francisco J.; Chacalo, Alicia; Ochoa, Carlos

    2012-01-01

    Air quality improvement by a forested, peri-urban national park was quantified by combining the Urban Forest Effects (UFORE) and the Weather Research and Forecasting coupled with Chemistry (WRF-Chem) models. We estimated the ecosystem-level annual pollution removal function of the park’s trees, shrub and grasses using pollution concentration data for carbon monoxide (CO), ozone (O 3 ), and particulate matter less than 10 microns in diameter (PM 10 ), modeled meteorological and pollution variables, and measured forest structure data. Ecosystem-level O 3 and CO removal and formation were also analyzed for a representative month. Total annual air quality improvement of the park’s vegetation was approximately 0.02% for CO, 1% for O 3, and 2% for PM 10 , of the annual concentrations for these three pollutants. Results can be used to understand the air quality regulation ecosystem services of peri-urban forests and regional dynamics of air pollution emissions from major urban areas. - Highlights: ► Air quality regulation functions and ecosystem structure of a peri-urban forest in Mexico were quantified. ► Air pollution removal-formation dynamics were estimated using the UFORE and WRF-Chem models. ► Peri-urban forests positively contributed to air qualtiy improvement in Mexico City. ► Results can be used to quantify the ecosystem services of peri-urban forests. - Coupled models estimated air quality improvement and pollution removal-formation by peri-urban forest ecosystems in the Mexico City airshed.

  2. Aquatic plants as potential sources of antimicrobial compounds ...

    African Journals Online (AJOL)

    Resistance of pathogens to common veterinary antibiotics hampers mastitis treatment and motivates the discovery of new antimicrobials. In this study, extracts from two aquatic plants, Salvinia auriculata and Hydrocleys nymphoides, were assayed against bovine mastitis pathogens. Selected parts of plants were extracted ...

  3. Phosphorus flows in a peri-urban region with intensive food production: A case study.

    Science.gov (United States)

    Bittman, S; Sheppard, S C; Poon, D; Hunt, D E

    2017-02-01

    Excess phosphorus (P) in peri-urban regions is an emerging issue, whereas there is global depletion of quality mined supplies of P. The flow of P across the landscape leading to regional surpluses and deficits is not well understood. We computed a regional P budget with internal P flows in a fairly discreet peri-urban region (Lower Fraser Valley, BC) with closely juxtaposed agricultural and non-agricultural urban ecosystems, in order to clarify the relationship between food production, food consumption and other activities involving use of P (e.g. keeping pets and horses and using soaps). We hypothesized changes that might notably improve P efficiency in peri-urban settings and wider regions. Livestock feed for the dairy and poultry sectors was the largest influx of P: the peri-urban land is too limited to grow feed grains and they are imported from outside the region. Fertilizer and import of food were the next largest influxes of P and a similar amount of P flows as food from the agricultural to urban ecosystems. Export of horticultural crops (berries and greenhouse crops) and poultry represented agricultural effluxes that partially offset the influxes. P efficiency was lower for horticultural production (21%) than animal production (32%), the latter benefited from importing feed crops, suggesting a regional advantage for animal products. There was 2.0, 3.8, 5.7 and 5.6 tonnes imported P per $ million farm cash receipts for horticulture, dairy, poultry meat and eggs. Eliminating fertilizer for corn and grass would reduce the ratio for the dairy industry. The net influx, dominated by fertilizer, animal feed and food was 8470 tonnes P per year or 3.2 kg P per person per year, and of this the addition to agricultural soils was 3650 tonnes P. The efflux in sewage effluent to the sea was 1150 tonnes P and exported sewage solids was 450 tonnes P. Municipal solid waste disposal was most difficult to quantify and was about 1800 tonnes P, 80% of which was partly reused

  4. Late Cretaceous Aquatic Plant World in Patagonia, Argentina

    Science.gov (United States)

    Cúneo, N. Rubén; Gandolfo, María A.; Zamaloa, María C.; Hermsen, Elizabeth

    2014-01-01

    In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla) and a monocot (Araceae). Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae). Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form) and the eudicot angiosperm Nelumbo (Nelumbonaceae) are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae), ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America. PMID:25148081

  5. Late cretaceous aquatic plant world in Patagonia, Argentina.

    Directory of Open Access Journals (Sweden)

    N Rubén Cúneo

    Full Text Available In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla and a monocot (Araceae. Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae. Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form and the eudicot angiosperm Nelumbo (Nelumbonaceae are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae, ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America.

  6. Culture Methodology for Experimental Investigations Involving Rooted Submersed Aquatic Plants.

    Science.gov (United States)

    1984-11-01

    stolons or runners are best planted as intact plants (Sculthorpe 1967). Many species can be propagated from seed in addition to the above methods...J. 1984. Growth response of Myriophyllwm spicatu and Hydrilla verticillata when exposed to continuous, low concentrations of fluridone . Tech. Rept. A...aquatic plants, water, and bottom sediments. Weed Sci. 20:482-486. Sastroutomo, S. S. 1980. Dormancy and germination in axillary turions of iijiilZla

  7. Mercury uptake and accumulation by four species of aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Kathleen [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)]. E-mail: skinnk@sage.edu; Wright, Nicole [NEIWPCC-NYSDEC, 625 Broadway, 4th Floor, Albany, NY 12233-3502 (United States)]. E-mail: ndwright@gw.dec.state.ny.us; Porter-Goff, Emily [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)

    2007-01-15

    The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox[reg] (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox[reg] results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively. - Four species of aquatic plants reduced mercury in water.

  8. Mercury uptake and accumulation by four species of aquatic plants

    International Nuclear Information System (INIS)

    Skinner, Kathleen; Wright, Nicole; Porter-Goff, Emily

    2007-01-01

    The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox[reg] (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox[reg] results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively. - Four species of aquatic plants reduced mercury in water

  9. EATING HABITS, DIETARY DIVERSITY AND APTITUDE FOR PRACTICING HORTICULTURE OF PERI-URBAN FAMILIES FROM CARDEL, VERACRUZ, MEXICO

    Directory of Open Access Journals (Sweden)

    Marco Antonio Toral Juárez

    2012-11-01

    Full Text Available The urban and peri-urban families represent 75% of the Mexican population. The poverty and form of feed seem to be associated with obesity, degenerative diseases and malnutrition. Therefore, the aim of this study was to evaluate the eating habits and dietary diversity of Cardel city, Veracruz, Mexico peri-urban families and know the aptitude of families to practice horticulture at home. Dietary diversity was determined using the scoring method of staple foods. Eating habits and aptitude to practice horticulture were obtained by a survey type Likert scale. The 35% of the families presented good eating habits, 19% regular and 46% of households showed poor dietary habits. Dietary diversity was 29.4 ± 8.7 in primary foods. The Likert general index was 2.9 and represented an average availability to practice peri-urban horticulture. Food diversity of families peri-urban is a function of family economic capacity, in contrast, food habits and socioeconomic status are not associated and finally there were identified multiple factors that positively influence the willingness of the mother of family to practice horticulture.

  10. Atmospheric pollutants in peri-urban forests of Quercus ilex: evidence of pollution abatement and threats for vegetation.

    Science.gov (United States)

    García-Gómez, Héctor; Aguillaume, Laura; Izquieta-Rojano, Sheila; Valiño, Fernando; Àvila, Anna; Elustondo, David; Santamaría, Jesús M; Alastuey, Andrés; Calvete-Sogo, Héctor; González-Fernández, Ignacio; Alonso, Rocío

    2016-04-01

    Peri-urban vegetation is generally accepted as a significant remover of atmospheric pollutants, but it could also be threatened by these compounds, with origin in both urban and non-urban areas. To characterize the seasonal and geographical variation of pollutant concentrations and to improve the empirical understanding of the influence of Mediterranean broadleaf evergreen forests on air quality, four forests of Quercus ilex (three peri-urban and one remote) were monitored in different areas in Spain. Concentrations of nitrogen dioxide (NO2), ammonia (NH3), nitric acid (HNO3) and ozone (O3) were measured during 2 years in open areas and inside the forests and aerosols (PM10) were monitored in open areas during 1 year. Ozone was the only air pollutant expected to have direct phytotoxic effects on vegetation according to current thresholds for the protection of vegetation. The concentrations of N compounds were not high enough to directly affect vegetation but could be contributing through atmospheric N deposition to the eutrophization of these ecosystems. Peri-urban forests of Q. ilex showed a significant below-canopy reduction of gaseous concentrations (particularly NH3, with a mean reduction of 29-38%), which indicated the feasibility of these forests to provide an ecosystem service of air quality improvement. Well-designed monitoring programs are needed to further investigate air quality improvement by peri-urban ecosystems while assessing the threat that air pollution can pose to vegetation.

  11. Removal of Ozone by Urban and Peri-Urban Forests: Evidence from Laboratory, Field, and Modeling Approaches

    Science.gov (United States)

    Carlo Calfapietra; Arianna Morani; Gregorio Sgrigna; Sara Di Giovanni; Valerio Muzzini; Emanuele Pallozzi; Gabriele Guidolotti; David Nowak; Silvano Fares

    2016-01-01

    A crucial issue in urban environments is the interaction between urban trees and atmospheric pollution, particularly ozone (O3). Ozone represents one of the most harmful pollutants in urban and peri-urban environments, especially in warm climates. Besides the large interest in reducing anthropogenic and biogenic precursors of O3...

  12. Diet of dingoes and other wild dogs in peri-urban areas of north-eastern Australia

    Science.gov (United States)

    Allen, Benjamin L.; Carmelito, Erin; Amos, Matt; Goullet, Mark S.; Allen, Lee R.; Speed, James; Gentle, Matt; Leung, Luke K.-P.

    2016-03-01

    Knowledge of the resource requirements of urban predators can improve our understanding of their ecology and assist town planners and wildlife management agencies in developing management approaches that alleviate human-wildlife conflicts. Here we examine food and dietary items identified in scats of dingoes in peri-urban areas of north-eastern Australia to better understand their resource requirements and the potential for dingoes to threaten locally fragmented populations of native fauna. Our primary aim was to determine what peri-urban dingoes eat, and whether or not this differs between regions. We identified over 40 different food items in dingo scats, almost all of which were mammals. Individual species commonly observed in dingo scats included agile wallabies, northern brown bandicoots and swamp wallabies. Birds were relatively common in some areas but not others, as were invertebrates. Dingoes were identified as a significant potential threat to fragmented populations of koalas. Dietary overlap was typically very high or near-identical between regions, indicating that peri-urban dingoes ate the same types or sizes of prey in different areas. Future studies should seek to quantify actual and perceived impacts of, and human attitudes towards, peri-urban dingoes, and to develop management strategies with a greater chance of reducing human-wildlife conflicts.

  13. HomeSpace:Maputo Dwelling Processes in ten Rapidly Expanding Peri-Urban Areas of an African City

    DEFF Research Database (Denmark)

    Eskemose Andersen, Jørgen; Sollien, Silje Erøy; Costa, Ana Bénard da

    2013-01-01

    This chapter deals with key concepts and preliminary findings of the ressearch programme "Home Space-Meanings and perceptions of the built envioment in Peri-urban Maputo, Mozambique." The Programme examines the nature of emerging forms of "urbanism as a way of Life" in a rapidly urbanizing African...

  14. Iodine-129 in aquatic organisms near nuclear fuels processing plants

    International Nuclear Information System (INIS)

    Watson, D.G.

    1975-04-01

    Concentrations of 129 I in two aquatic habitats near nuclear fuel processing plants were highest in algae and crustaceans. These two forms may be useful in future monitoring of 129 I. There is some indication of an increase in atom ratios and specific activity in aquatic organisms over that in water and sediments. Additional measurements should be made to verify this conclusion. Efforts should continue to measure the possible long term build-up of 129 I in aquatic environments receiving effluents from fuels reprocessing plants. Even at very low rates of release to the environment, the long physical half-life of 129 I creates the potential for build-up of this nuclide to significant levels. (U.S.)

  15. Enhancing ecosystem services for flood mitigation: a conservation strategy for peri-urban landscapes?

    Directory of Open Access Journals (Sweden)

    José Barbedo

    2014-06-01

    Full Text Available A key reason why some ecosystem services are undervalued is because they are not easily perceived both by beneficiaries and potential providers. Hydrological modeling allows us to assess, quantify, and visualize the causal link between a particular human intervention and the positive or negative impacts this has on flooding. This study uses such a model to test hypothetical changes in land use in the Brazilian coastal city of Paraty. We discuss how the adoption of higher density patterns of urban development can respond to the needs of a growing population, while safeguarding cultural landscapes of high environmental value against unsustainable urban sprawl and encroachment. Results of the modeling exercise show how water-flow regulation services can be improved, and to what extent restoring natural functions and properties of peri-urban floodplains may reduce urban flooding.

  16. Relations and areas of interaction between landowners in a peri-urban area

    DEFF Research Database (Denmark)

    Richardt, Ann-Sofie

    2016-01-01

    While land management can be a subject of conflict in places where the composition of landowners is socially and culturally diverse, it also holds the potential of bringing landowners together across social groups. This chapter uses the case of a peri-urban area near Copenhagen, Denmark, to examine...... the relations landowners have through their use and management of land within and across social groups. To elaborate the analysis and discussion of social groups, social coherence and fragmentation, this chapter introduces the concepts of homophily and self-categorisation. Interviews with 40 landowners from two...... parishes addressed four types of land-based relations: (1) exchange of help and services; (2) debate of farming/management; (3) shared interests and (4) friendship. While the pattern of relations overall supported the idea that people interact more with their own social group, the analysis also showed...

  17. Everyday mobility and infrastructure in the configuration of non peri-urban rural space

    Directory of Open Access Journals (Sweden)

    Eduardo Cerón Aparicio

    2018-01-01

    Full Text Available The purpose of this article is to determine how the non peri-urban rural space in the Mexico’s central region, which is a highly urbanized context, is organized. Changes taking place within the framework of globalization promote greater openness and flexibilization in the territory, resulting in an increased mobility, which takes a great diversity of forms and expands everyday interaction spaces. In order to study this phenomenon, this article examines the usual movements of rural population, which allow for the definition of ties between rural space and its rural-urban entourage. According to the origin-destination analysis of displacements, the balance of territorial changes is negative as for mobility practices, as well with regard to the interweaving of new interaction networks with their urban environment. Interaction places have remained in the traditional municipal space, even when favorable physical conditions exist for displacement.

  18. Social connectedness is associated with food security among peri-urban Peruvian Amazonian communities.

    Science.gov (United States)

    Lee, Gwenyth O; Surkan, Pamela J; Zelner, Jon; Paredes Olórtegui, Maribel; Peñataro Yori, Pablo; Ambikapathi, Ramya; Caulfield, Laura E; Gilman, Robert H; Kosek, Margaret N

    2018-04-01

    Food insecurity is a major global public health issue. Social capital has been identified as central to maintaining food security across a wide range of low- and middle-income country contexts, but few studies have examined this relationship through sociocentric network analysis. We investigated relationships between household- and community-level social connectedness, household food security, and household income; and tested the hypothesis that social connectedness modified the relationship between income and food security. A cross-sectional census with an embedded questionnaire to capture social relationships was conducted among eleven peri-urban communities. Community connectedness was related to study outcomes of food security and per-capita income through regression models. Of 1520 households identified, 1383 were interviewed (91.0%) and 1272 (83.9%) provided complete data. Households in the youngest communities had the most total contacts, and the highest proportion of contacts outside of the community. Household income was also associated with more outside-community contacts (0.05 more contacts per standard deviation increase in income, psecure households reported more contacts nearby (0.24 increase in household food insecurity access scale (HFIAS) for each additional contact, psecurity (-0.92 decrease in HFIAS for each one-unit increase in community mean degree, p=0.008). There was no evidence that social connectedness modified the relationship between income and food security such that lower-income households benefited more from community membership than higher-income households. Although households reported networks that spanned rural villages and urban centers, contacts within the community, with whom food was regularly shared, were most important to maintaining food security. Interventions that build within-community connectedness in peri-urban settings may increase food security.

  19. Life stories of depressed adult women in peri-urban Namibia

    Directory of Open Access Journals (Sweden)

    NN Shifiona

    2006-09-01

    Full Text Available The problems with women in peri-urban Namibie are faced with are multi-dimensional.Like women in other communities they face the pressure of having a number of responsibilities, namely working, being a wife and mother, taking care of their families and perhaps caring for aging parents. Sometimes the pressure can be too overwhelming to manage. As a result, many women become depressed. Studies on depression among black African women in Namibia could not be traced. It was therefore considered to find out how women suffering from depression from this part of the world tell their life stories. The purpose of the study was two-fold: Firstly, to explore and describe the life stories of depressed adult women in peri-urban Namibia, and secondly to use the information obtained to describe guidelines for psychiatric nurses working with these patients at psychiatric outpatient clinics as well as in the community. A qualitative phenomenological research design of an explorative, descriptive and contextual nature was used. The researcher approached the subjects and their experiences with an open mind. Ten depressed adult women between 21-55 years were involved in the research. The researcher strived to adhere to the principles of trustworthiness. To ensure this Guba’s model (in Krefting, 1991: 217 of trustworthiness was adopted. All the interviews were analysed following Tesch’s method (Creswell, 1994: 154-55. The services of an independent coder were obtained. The results indicated that impaired interpersonal interactions and stressful life events have a negative influence on the daily life of women leading to the development of depressive symptoms. Guidelines to support psychiatric nurses working with depressed women were drawn up.

  20. Life stories of depressed adult women in peri-urban Namibia.

    Science.gov (United States)

    Shifiona, N N; Poggenpoel, M; Myburgh, C P H

    2006-05-01

    The problems women in peri-urban Namibia are faced with are multi-dimensional. Like women in other communities they face the pressure of having a number of responsibilities, namely working, being a wife and mother, taking care of their families and perhaps caring for aging parents. Sometimes the pressure can be too overwhelming to manage. As a result, many women become depressed. Studies on depression among black African women in Namibia could not be traced. It was therefore considered to find out how women suffering from depression from this part of the world tell their life stories. The purpose of the study was two-fold: Firstly, to explore and describe the life stories of depressed adult women in peri-urban Namibia, and secondly to use the information obtained to describe guidelines for psychiatric nurses working with these patients at psychiatric outpatient clinics as well as in the community. A qualitative phenomenological research design of an explorative, descriptive and contextual nature was used. The researcher approached the subjects and their experiences with an open mind. Ten depressed adult women between 21-55 years were involved in the research. The researcher strived to adhere to the principles of trustworthiness. To ensure this Guba's model (in Krefting, 1991: 217) of trustworthiness was adopted. All the interviews were analysed following Tesch's method (Creswell, 1994: 154-55). The services of an independent coder were obtained. The results indicated that impaired interpersonal interactions and stressful life events have a negative influence on the daily life of women leading to the development of depressive symptoms. Guidelines to support psychiatric nurses working with depressed women were drawn up.

  1. Infection of Ixodes ricinus by Borrelia burgdorferi sensu lato in peri-urban forests of France.

    Directory of Open Access Journals (Sweden)

    Axelle Marchant

    Full Text Available Lyme borreliosis is the most common tick-borne disease in the northern hemisphere. In Europe, it is transmitted by Ixodes ticks that carry bacteria belonging to the Borrelia burgdorferi sensu lato complex. The objective of this work was to explore eco-epidemiological factors of Lyme borreliosis in peri-urban forests of France (Sénart, Notre-Dame and Rambouillet. We investigated whether the introduction of Tamias sibiricus in Sénart could alter the density of infected ticks. Moreover, the density and tick infection were investigated according to the tree species found in various patches of Sénart forest. For this purpose, ticks were sampled during 3 years. In the Sénart forest, the density of nymph and adult ticks showed no significant difference between 2008, 2009 and 2011. The nymph density varied significantly as a function of the month of collection. Regarding the nymphs, a higher rate of infection and infected density were found in 2009. Plots with chipmunks (C presented a lower density of both nymphs and adult ticks than plots without chipmunks (NC did. A higher rate of infection of nymphs with Borrelia was seen in C plots. The prevalence of the various species of Borrelia was also found to vary between C and NC plots with the year of the collect. The presence of chestnut trees positively influenced the density of both nymphs and adults. The infected nymph density showed a significant difference depending on the peri-urban forest studied, Sénart being higher than Rambouillet. The prevalence of Borrelia species also differed between the various forests studied. Concerning the putative role that Tamias sibiricus may play in the transmission of Borrelia, our results suggest that its presence is correlated with a higher rate of infection of questing ticks by Borrelia genospecies and if its population increases, it could play a significant role in the risk of transmission of Lyme borreliosis.

  2. Hydrothermal processing of biomass from invasive aquatic plants

    Science.gov (United States)

    W. James Catallo; Todd F. Shupe; Thomas L. Eberhardt

    2008-01-01

    The purpose of this study was to examine the hydrothermal (HT) treatment of three invasive aquatic plants (i.e., Lemna sp., Hydrilla sp., and Eichhornia sp.) with respect to the generation of semi-volatile hydrocarbon product mixtures and biomass volume reduction. Identical HT treatments yielded similar semi-...

  3. Evaluation of Plan Implementation: Peri-urban Development and the Shanghai Master Plan 1999-2020

    Directory of Open Access Journals (Sweden)

    Jinghuan He

    2015-01-01

    Full Text Available Since the 1980s China has experienced unprecedented urbanisation as a result of a series of reforms promoting rapid economic development. Shanghai, like the other big cities along China’s coastline, has witnessed extraordinary growth in its economy and population with industrial development and rural-to-urban migration generating extensive urban expansion. Shanghai’s GDP growth rate has been over 10 per cent for more than 15 years. Its population in 2013 was estimated at 23.47 million, which is double its size in 1979. The urban area enlarged by four times from 644 to 2,860 km2 between 1977 and 2010. Such demanding growth and dramatic changes present big challenges for urban planning practice in Shanghai. Plans have not kept up with development and the mismatch between the proposals in plans and the actual spatial development has gradually increased, reaching a critical level since 2000. The mismatch in the periurban areas is more notable than that in the existing urban area, but there has not been a systematic review of the relationship between plan and implementation. Indeed, there are few studies on the evaluation of plan implementation in China generally. Although many plans at numerous spatial levels are successively prepared and revised, only few of them have been evaluated in terms of their effectiveness and implementation.  This particularly demanding context for planning where spatial development becomes increasingly unpredictable and more difficult to influence presents an opportunity to investigate the role of plans under conditions of rapid urbanisation. The research project asks to what extent have spatial plans influenced the actual spatial development in the peri-urban areas of Shanghai? The research pays particular attention to the role of the Shanghai Master Plan 1999-2020 (Plan 1999. By answering the main research question this study seeks to contribute to a better understanding of present planning practice in Shanghai

  4. Urban and peri-urban agricultural production along railway tracks: a case study from the Mumbai Metropolitan Region

    Directory of Open Access Journals (Sweden)

    Prem Jose Vazhacharickal

    2013-12-01

    Full Text Available Urban and peri-urban agriculture (UPA contributes to food security, serves as an opportunity for income generation, and provides recreational services to urban citizens. With a population of 21 Million people, of which 60 % live in slums, UPA activities can play a crucial role in supporting people’s livelihoods in Mumbai Metropolitan Region (MMR. This study was conducted to characterize the railway gardens, determine their role in UPA production, and assess potential risks. It comprises a baseline survey among 38 railway gardeners across MMR characterized by different demographic, socio-economic, migratory, and labour characteristics. Soil, irrigation water, and plant samples were analyzed for nutrients, heavy metals, and microbial load. All the railway gardeners practiced agriculture as a primary source of income and cultivated seasonal vegetables such as lady’s finger (Abelmoschus esculentus L. Moench, spinach (Spinacia oleracea L., red amaranth (Amaranthus cruentus L., and white radish (Raphanus sativus var. longipinnatus which were irrigated with waste water. This irrigation water was loaded with 7–28 mg N l^(−1, 0.3–7 mg P l^(−1, and 8–32 mg K l^(−1, but also contained heavy metals such as lead (0.02–0.06 mg Pb l^(−1, cadmium (0.03–0.17 mg Cd l^(−1, mercury (0.001–0.005 mg Hg l^(−1, and pathogens such as Escherichia coli (1,100 most probable number per 100 ml. Levels of heavy metals exceeded the critical thresholds in surface soils (Cr, Ni, and Sr and produce (Pb, Cd, and Sr. The railway garden production systems can substantially foster employment and reduce economic deprivation of urban poor particularly slum dwellers and migrant people. However this production system may also cause possible health risks to producers and consumers.

  5. Socio-economic characterization of integrated cropping systems in urban and peri-urban agriculture of Faisalabad, Pakistan

    Directory of Open Access Journals (Sweden)

    Shoaib Ur Rehman

    2013-12-01

    Full Text Available Faisalabad city is surrounded by agricultural lands, where farmers are growing vegetables, grain crops, and fodder for auto-consumption and local marketing. To study the socioeconomic impact and resource use in these urban and peri-urban agricultural production (UPA systems, a baseline survey was conducted during 2009–2010. A total of 140 households were selected using a stratified sampling method and interviewed with a structured questionnaire. The results revealed that 96 % of the households rely on agriculture as their main occupation. Thirty percent of the households were owners of the land and the rest cultivated either rented or sharecropped land. Most of the families (70 % were headed by a member with primary education, and only 10 % of the household head had a secondary school certificate. Irrigationwater was obtained from waste water (37 %, canals (27 %, and mixed alternative sources (36 %. A total of 35 species were cultivated in the UPA systems of which were 65% vegetables, 15% grain and fodder crops, and 5% medicinal plants. Fifty-nine percent of the households cultivated wheat, mostly for auto-consumption. The 51 % of the respondents grew cauliflower (Brassica oleracea L. and gourds (Cucurbitaceae in the winter and summer seasons, respectively. Group marketing was uncommon and most of the farmers sold their produce at the farm gate (45 % and on local markets (43 %. Seeds and fertilizers were available from commission agents and dealers on a credit basis with the obligation to pay by harvested produce. A major problem reported by the UPA farmers of Faisalabad was the scarcity of high quality irrigation water, especially during the hot dry summer months, in addition to lacking adequate quantities of mineral fertilizers and other inputs during sowing time. Half of the respondents estimated their daily income to be less than 1.25 US$ and spent almost half of it on food. Monthly average household income and expenses were 334 and 237 US

  6. Aquatic Plant Management Program current status and seasonal workplan

    Energy Technology Data Exchange (ETDEWEB)

    Burns, E.R.; Bates, A.L.; Webb, D.H.

    1993-07-01

    The objective of the TVA Aquatic Plant Management Program is to support in an environmentally and economically responsible manner, the balanced multiple uses of the water resource of the Tennessee Valley. This is accomplished by following an integrated approach to prevent introduction and spread of noxious species, documenting occurrence and spread of existing species, and suppressing or eliminating problems in designated high use areas. It is not the TVA objective, nor is it biologically feasible and prudent to eliminate all aquatic vegetation. Aerial photography, helicopter reconnaissance, and field surveys are used to assess distributions and abundance of various aquatic macrophytes. Water level fluctuations are supplemented by herbicide applications to control undesirable vegetation. Investigations are conducted to evaluate water level fluctuation schemes, as well as biological, mechanical, and alternative chemical control techniques which offer potential for more environmentally compatible and cost-effective management operations.

  7. Remediation of feedlot effluents using aquatic plants

    OpenAIRE

    Rizzo, Pedro Federico; Arreghini, Silvana; Serafini, Roberto José María; Bres, Patricia Alina; Crespo, Diana Elvira; Fabrizio de Iorio, Alicia Rosa

    2012-01-01

    Feedlots have increased in several regions of Argentina, particularly in the Pampas. The absence of adequate treatments of the effluents produced in these establishments creates serious problems to the society. Phytoremediation can be defined as inexpensive and environmentally sustainable strategy used to remove pollutants by plants. The aim of this study was to evaluate the remediation potential of two ...

  8. A field guide to valuable underwater aquatic plants of the Great Lakes

    Science.gov (United States)

    Schloesser, Donald W.

    1986-01-01

    Underwater plants are a valuable part of the Great Lakes ecosystem, providing food and shelter for aquatic animals. Aquatic plants also help stabilize sediments, thereby reducing shoreline erosion. Annual fall die-offs of underwater plants provide food and shelter for overwintering small aquatic animals such as insects, snails, and freshwater shrimp.

  9. State of Washington Aquatic Plant Management Program

    Science.gov (United States)

    1979-10-01

    endothall (DMA salt); and herbivorous fish, insects , and pathogens. 4. Comments Received from Public Review of the Draft Environmental Impact Statement...SNYIAOWMNWAL MANWULATION UIONOGC SSUCTION DREDGE HAND RUMOVA HOTTON SHADING WATER LEVEL FLUCTUATIONS HERBIVOROUS FIS1H INSECTS , PAT1OGIENS, ETC. set...the control of acuatic plants. 52 4. PROBABLE IMPACTS OF THE PROPOSED ACTION ON~ THE ENVIRON4MENT 4.01 Impacts on Air Quality, Noise and Traffic. 4.01.1

  10. Nitrogen and protein contents in some aquatic plant species

    Directory of Open Access Journals (Sweden)

    Krystyna Bytniewska

    2015-01-01

    Full Text Available Nitrogen and protein contents in higher aquatic plants deriving from a natural habitat were determined. The following plants were examined: Spirodela polyrrhiza (L. Schleid., Elodea canadensis Rich., Riccia fluitans L. Total nitrogen and nitrogen of respective fractions were determined by the Kjeldahl method. Nitrogen compounds were fractionated according to Thimann et al. Protein was extracted after Fletcher and Osborne and fractionated after Osborne. It was found, that total protein content in the plants under examination constitutes 18 to 25%o of dry matter. Albumins and glutelins are the most abundant protein fractions.

  11. Influence of landscape mosaic on streamflow of a peri-urban catchment under Mediterranean climate

    Science.gov (United States)

    Ferreira, Carla; Walsh, Rory; Ferreira, António

    2017-04-01

    Peri-urban areas tend to be characterized by patchy landscape mosaics of different land-uses. Although the impact of land-use changes on catchment hydrology have been widely investigated, the impact of mixed land-use patterns on the streamflow of peri-urban areas is still poorly understood. This study aims to (i) explore and quantify streamflow delivery from sub-catchments characterized by distinct landscape mosaics; (ii) assess the impact of different urbanization styles on hydrograph properties; and (iii) explore the influence of urbanization type on flow connectivity and stream discharge. The study was carried out in Ribeira dos Covões, a small (6.2km2) peri-urban catchment in central Portugal. The climate is Mediterranean, with a mean annual rainfall of 892mm. Catchment geology comprises sandstone (56%), limestone (41%) and alluvial deposits (3%). Soils developed on sandstone are generally deep (>3m) Fluvisols and Podsols, whereas on limestone the Leptic Cambisols are typically shallow (blocks and of high population density (9900 inhabitants km-2). The study uses hydrological data recorded over three hydrological years, starting in November 2010, in a monitoring network comprising eight streamflow gauging stations (instrumented with water level recorders) and five rainfall gauges. The gauging stations provide information on the discharge response to rainstorms of the catchment outlet and upstream sub-catchments of different size, urban pattern (in terms of percentage urban land-use and impervious area, distance to the stream network, and storm water management), and lithology (either sandstone or limestone). Annual storm runoff coefficients were lowest (13.7%) in catchments dominated by forest (>80%) and greatest (17.3-17.6%) in the most urbanized sub-catchments (49-53% urban). Impervious area seems to control streamflow particularly during dry periods. Winter runoff (streamflow per unit area) was 2-4 times higher than summer runoff in highly urbanized areas

  12. Spatio-temporal variability of streamwater chemistry within a Peri-urban Mediterranean catchment

    Science.gov (United States)

    Ferreira, Carla S. S.; Walsh, Rory P. D.; Ferreira, António J. D.; Coelho, Celeste O. A.

    2015-04-01

    The complex landscape of peri-urban areas, characterized by a mosaic of land-uses and urban fabric, provides different sources of runoff and pollutants which affect stream ecosystems. This study investigates the impact of land-uses and their location within catchments on streamwater quality in a peri-urban Mediterranean catchment, including temporal variations driven by antecedent weather and rainstorm characteristics. The study is based in Ribeira dos Covões, a small (6 km2) catchment in the city of Coimbra, central Portugal. Land-use is dominated by woodland (56%) and urban cover (40%), with a small agriculture area (4%). Streamwater was monitored at the catchment outlet (ESAC) and three upstream locations: Espírito Santo and Porto Bordalo, with similar urban cover (42% and 49%) but different imperviousness (27% and 15%) and lithologies (sandstone versus limestone), and Quinta with lower urban extent (25%) but including a construction site covering 10% of the area. Samples collected throughout ten rainfall events between October 2011 and March 2013 were analysed for natural water chemistry and major pollutants (notably ammonium, nitrates, total phosphorus, COD and metals). In the paper, temporal variations in water quality are explored via hysteresis loop and correlation analysis. Hydrological regime exerted a major influence on water quality. Major nutrients declined within and after the dry summer than in winter events, because of limited dilution by the low stream baseflow. Through the wet season, increasing baseflow led to increased concentrations of major cations (Na, Mg and Ca) because of reduced dilution by solute-poor stormflow. Espírito Santo, the most urbanized sub-catchment, displayed higher concentrations of COD and NO3 (tended to peak with stormflow), but the latter was thought to result from agricultural fields located adjacent the tributary. At the catchment outlet (ESAC), the high Nk and NH4 concentrations exceeded water quality standards (2 mg

  13. Influence of urbanization pattern on stream flow of a peri-urban catchment under Mediterranean climate

    Science.gov (United States)

    Ferreira, Carla S. S.; Walsh, Rory P. D.; Ferreira, António J. D.; Steenhuis, Tammo S.; Coelho, Celeste A. O.

    2015-04-01

    The demand for better life quality and lower living costs created a great pressure on peri-urban areas, leading to significant land-use changes. The complexity of mixed land-use patterns, however, presents a challenge to understand the hydrological pathways and streamflow response involved in such changes. This study assesses the impact of a actively changing Portuguese peri-urban area on catchment hydrology. It focuses on quantifying streamflow delivery from contributing areas, of different land-use arrangement and the seasonal influence of the Mediterranean climate on stream discharge. The study focuses on Ribeira dos Covões a small (6 km2) peri-urban catchment on the outskirts of Coimbra, one of the main cities in central Portugal. Between 1958 and 2012 the urban area of the catchment expanded from 8% to 40%, mostly at the expense of agriculture (down from 48% to 4%), with woodland now accounting for the remaining 56% of the catchment area. The urban area comprises contrasting urban settings, associated with older discontinuous arrangement of buildings and urban structures and low population density (urban cores dominated by apartment blocks and high population density (9900 inhabitants/km). The hydrological response of the catchment has been monitored since 2007 by a flume installed at the outlet. In 2009, five rainfall gauges and eight additional water level recorders were installed upstream, to assess the hydrological response of different sub-catchments, characterized by distinct urban patterns and either limestone or sandstone lithologies. Annual runoff coefficients range between 14% and 22%. Changes in annual baseflow index (36-39% of annual rainfall) have been small with urbanization (from 34% to 40%) during the monitoring period itself. Annual runoff coefficients were lowest (14-7%) on catchments >80% woodland and highest (29% on sandstone; 18% on limestone) in the most urbanized (49-53% urban) sub-catchments. Percentage impermeable surface seems to

  14. Impact of power plants on aquatic systems: a social perspective

    International Nuclear Information System (INIS)

    Coutant, C.C.

    1975-01-01

    Topics discussed are: aquatic effects of thermal electric power stations; legal aspects of water pollution; EPA provisions for levels of thermal discharges to assure protection and propagation of a balanced, indigenous population of shellfish, fish, and wildlife in a body of water; cost benefit analysis of steam electric power effluents; cooling systems and siting of power plants; simulation modeling of population dynamics; and sociological aspects of water pollution

  15. Method for treating wastewater using microorganisms and vascular aquatic plants

    Science.gov (United States)

    Wolverton, B. C. (Inventor)

    1983-01-01

    A method for treating wastewater compresses subjecting the wastewater to an anaerobic setting step for at least 6 hours and passing the liquid effluent from the anaerobic settling step through a filter cell in an upflow manner. There the effluent is subjected first to the action of anaerobic and facultative microorganisms, and then to the action of aerobic microorganisms and the roots of at least one vascular aquatic plant.

  16. Differentiated surface fungal communities at point of harvest on apple fruits from rural and peri-urban orchards

    OpenAIRE

    Shen, Youming; Nie, Jiyun; Li, Zhixia; Li, Haifei; Wu, Yonglong; Dong, Yafeng; Zhang, Jianyi

    2018-01-01

    The diverse fungal communities that colonize fruit surfaces are closely associated with fruit development, preservation and quality control. However, the overall fungi adhering to the fruit surface and the inference of environmental factors are still unknown. Here, we characterized the fungal signatures on apple surfaces by sequencing internal transcribed spacer 1 (ITS1) region. We collected the surface fungal communities from apple fruits cultivated in rural and peri-urban orchards. A total ...

  17. LAND RIGHTS AND INTRA-HOUSEHOLD EMPLOYMENT AND RESOURCE USE IN THE PERI-URBAN AREA OF BANJUL, THE GAMBIA

    OpenAIRE

    Roth, Michael J.; Carr, Ben; Cochrane, Jeffrey A.

    1996-01-01

    As part of cooperative research program examining factor markets in peri-urban areas of The Gambia (Banjul and Serekunda) to see if they are constraining agricultural growth and employment, particularly in the horticultural subsector, the household production survey reported in this study assesses inter- and intrahousehold issues of market access and constraints to land-improving investment and productivity. Implemented in 1993, survey is highly disaggregated by plot, gender, enterprise, and ...

  18. Occurrence of chemical contaminants in peri-urban agricultural irrigation waters and assessment of their phytotoxicity and crop productivity

    OpenAIRE

    Margenat, Anna; Matamoros Mercadal, Víctor; Díez, Sergi; Cañameras Riba, Núria; Comas Angelet, Jordi; Bayona Termens, Josep Maria

    2017-01-01

    Water scarcity and water pollution have increased the pressure on water resources worldwide. This pressure is particularly important in highly populated areaswherewater demand exceeds the available natural resources. In this regard, water reuse has emerged as an excellent water source alternative for peri-urban agriculture. Nevertheless, itmust copewith the occurrence of chemical contaminants, ranging fromtrace elements (TEs) to organic microcontaminants. In this study, chemical contaminants ...

  19. Assessment of farmers’ knowledge on fertilizer usage for peri-urban vegetable production in the Sunyani Municipality, Ghana

    DEFF Research Database (Denmark)

    Obour, Peter Bilson; Dadzie, Frederick Asankom; Kristensen, Hanne Lakkenborg

    2015-01-01

    How to optimize fertilizer application (i.e. by choosing the best fertilizer types, dosage, time of application, and application methods) to sustain and increase crop production and quality in intensively cropped weathered soils in Ghana is understudied. The purpose of the study was to assess...... services, the media, and at the point of sales are recommended to improve sustainable use of fertilizers for peri-urban vegetable production....

  20. Hydrogen fluoride damage to vegetation from peri-urban brick kilns in Asia: A growing but unrecognised problem?

    International Nuclear Information System (INIS)

    Ahmad, Muhammad Nauman; Berg, Leon J.L. van den; Shah, Hamid Ullah; Masood, Tariq; Büker, Patrick; Emberson, Lisa; Ashmore, Mike

    2012-01-01

    The rapid urbanisation of many cities in south and south-east Asia has increased the demand for bricks, which are typically supplied from brick kilns in peri-urban areas. We report visible foliar damage to mango, apricot and plum trees in the vicinity of traditional Bull’s Trench brick kilns in Peshawar, Pakistan. Visible injury symptoms, hydrogen fluoride concentrations in air, and foliar fluoride concentrations were all greater in the vicinity of brick kilns than at more distant sites, indicating that fluoride emissions from brick kilns were the main cause of damage. Interviews with local farmers established the significant impact of this damage on their livelihoods. Since poorly regulated brick kilns are often found close to important peri-urban agricultural areas, we suggest that this may be a growing but unrecognised environmental problem in regions of Asia where emission control in brick kilns has not been improved. - Highlights: ► Demand for bricks is increasing in many parts of Asia. ► Fluoride emissions from brick kilns may pose a threat to peri-urban agriculture. ► We found extensive injury to fruit orchards close to brick kilns in Peshawar. ► Local farmers suffered large economic losses but did not identify brick kilns as a cause of this. ► The extent of crop damage from brick kilns with poor emission control in the region may not be fully recognised. - Hydrogen fluoride emissions from brick kilns may cause extensive but unrecognised damage to peri-urban crops in Asia.

  1. Management of waste by-products in medium-scale commercial poultry facilities in peri-urban Ibadan, Nigeria

    OpenAIRE

    AKINTAYO OLUREMI; QUAINOO JEMIMAH

    2016-01-01

    Due to increasing human population in and around the city, it is important to pay attention to issues related to the environment and human health, especially poultry waste management towards environmental sustainability in peri-urban areas. The three waste by-products of primary concern in poultry production are the litter, the manure and dead birds common to all operations. With the aid of a pre-tested and validated questionnaire, data were obtained from forty poultry farmers whose medium-sc...

  2. Prevalence and risk factor's analysis of bovine brucellosis in peri-urban areas under intensive system of production in Gujarat, India

    OpenAIRE

    M. D. Patel; P. R. Patel; M. G. Prajapati; A. N. Kanani; K. K. Tyagi; A. B. Fulsoundar

    2014-01-01

    Aim: A study on surveillance of bovine brucellosis in dairy herds of peri-urban areas under intensive system of production was carried out by milk-ELISA. Various risk factors were identified having significant association with occurrence of bovine brucellosis in dairy herds of peri-urban areas. Materials and Methods: Five randomly selected peri-uban areas of six cities of Gujarat were included in the present study. Five randomly selected dairy herds under intensive system of production fro...

  3. The role of wildlife in the transmission of parasitic zoonoses in peri-urban and urban areas

    Directory of Open Access Journals (Sweden)

    Ute Mackenstedt

    2015-04-01

    Full Text Available During the last 100 years in many countries of the world, there have been dramatic changes in natural/rural landscapes due to urbanization. Since many wildlife species are unable to adapt to these alterations in their environment, urbanization is commonly responsible for a decline of biodiversity in areas of urban development. In contrast, some wild animal species are attracted to peri-urban and urban habitats due to the availability of an abundant food supply and the presence of structures in which to shelter. Urban foxes and/or raccoons are common sights in many peri-urban and urban areas of Europe where they can reach far higher population densities than in their natural habitats. The same is true for foxes and dingoes in some urban areas of Australia. Unfortunately, some of these highly adaptable species are also hosts for a number of parasites of public health and veterinary importance. Due to the complexity of many parasitic life cycles involving several host species, the interactions between wild animals, domestic animals and humans are not fully understood. The role of potential hosts for transmission of a zoonotic disease in urban or peri-urban areas cannot be extrapolated from data obtained in rural areas. Since more than 75% of human diseases are of zoonotic origin, it is important to understand the dynamics between wildlife, domestic animal species and humans in urbanized areas, and to conduct more focused research on transmission of zoonotic parasites including arthropod vectors under such conditions.

  4. Underperformance of Planning for Peri-Urban Rural Sustainable Development: The Case of Mentougou District in Beijing

    Directory of Open Access Journals (Sweden)

    Jing Lin

    2016-08-01

    Full Text Available As the basic cell of social structures and spatial units, rural settlement is now experiencing profound changes through the rapid urbanization process underway in China, particularly in peri-urban areas which serve as the main platform and battlefield for urban–rural integration in China’s latest round of new urbanization. Therefore, how to achieve better planning for rural settlement in peri-urban areas is becoming a pressing and paramount research agenda. This paper attempts to explore the possible reasons for the underperformance of planning practice for rural settlement in peri-urban areas of China by taking the Mentougou district of Beijing as a case study. Following a quick and comprehensive review of planning in Mentougou district, a systematic and critical evaluation is then conducted accordingly. It shows that the plans generally play a positive role in development orientation and implementation. Yet, there is still a lot of room for improvement, particularly in the following aspects: (1 lack of initiative and innovation at the local level; (2 lack of long-term vision and consistent implementation; (3 lack of rationale-oriented approach; (4 lack of scientific and in-depth research; (5 lack of multi-stakeholder participation. As a way forward, this paper thus proposes a revised planning scheme for local practice, including classification of typologies and the customized planning design for each typology. At last, this paper calls for more in-depth scientific research on some key topics in the planning field, domestically and internationally.

  5. Determinants of Antenatal Healthcare Utilisation by Pregnant Women in Third Trimester in Peri-Urban Ghana

    Directory of Open Access Journals (Sweden)

    Jones Asafo Akowuah

    2018-01-01

    Full Text Available Access to quality healthcare still remains a major challenge in the efforts at reversing maternal morbidity and mortality. Despite the availability of established maternal health interventions, the health of the expectant mother and the unborn child remains poor due to low utilisation of interventions. The study examined the socioeconomic determinants of antenatal care utilisation in peri-urban Ghana using pregnant women who are in their third trimester. Two-stage sampling technique was used to sample 200 pregnant women who were in their third trimester from the District Health Information Management System software. Well-structured questionnaire was the instrument used to collect data from respondents. Descriptive statistics and inferential statistics including binary logit regression model were used to analyse the data with the help of SPSS and STATA software. The results showed varying utilisation levels of ANC. From the regression result, age, household size, and occupational status were identified as the important socioeconomic determinants of antenatal care utilisation among the respondents. The important system factors which influence antenatal care utilisation by the respondents are distance to ANC, quality of service, and service satisfaction. The study concludes that socioeconomic and health system factors are important determinants of antenatal care utilisation. Stepping up of interventions aimed at improving the socioeconomic status and addressing health system and proximity challenges could be helpful in improving antenatal care utilisation by pregnant women in Ghana.

  6. Lighting rural and peri-urban homes of the Gambia using solar photovoltaics (PV)

    Energy Technology Data Exchange (ETDEWEB)

    Sanneh, E.S.; Hu, A.H. [National Taipei Univ. of Technology, Taiwan (China). Inst. of Environmental Engineering Technology

    2009-07-01

    The main fuel supplies of Gambia are fuel woods, petroleum products, and liquefied petroleum gas (LPG). This study considered the use of solar photovoltaic (PV) as a principal source of power for rural and peri-urban communities in Gambia. The country currently has high rates of poverty and malnutrition, and it is expected that the provision of electricity to communities will encourage economic growth. Gambia is also heavily dependent on foreign imports of oil. To date, PV systems have been used for water pumping, refrigeration, and telecommunications projects. The study showed that better access to sustainable energy services is needed at the micro-level to stimulate businesses and income-generating activities, as well as at the macro level to foster economic growth. Financing methods for developing solar energy in Gambia include credit financing; PV market transformative initiatives; revolving loan funds; and government-granted renewable energy concessions for institutionally-owned and maintained systems. A pilot program has been established to investigate the acceptability of PV lighting systems for rural populations. 46 refs., 2 tabs., 7 figs.

  7. Intensive Circulation of Japanese Encephalitis Virus in Peri-urban Sentinel Pigs near Phnom Penh, Cambodia.

    Directory of Open Access Journals (Sweden)

    Julien Cappelle

    2016-12-01

    Full Text Available Despite the increased use of vaccination in several Asian countries, Japanese Encephalitis (JE remains the most important cause of viral encephalitis in Asia in humans with an estimated 68,000 cases annually. Considered a rural disease occurring mainly in paddy-field dominated landscapes where pigs are amplifying hosts, JE may nevertheless circulate in a wider range of environment given the diversity of its potential hosts and vectors. The main objective of this study was to assess the intensity of JE transmission to pigs in a peri-urban environment in the outskirt of Phnom Penh, Cambodia. We estimated the force of JE infection in two cohorts of 15 sentinel pigs by fitting a generalised linear model on seroprevalence monitoring data observed during two four-month periods in 2014. Our results provide evidence for intensive circulation of JE virus in a periurban area near Phnom Penh, the capital and most populated city of Cambodia. Understanding JE virus transmission in different environments is important for planning JE virus control in the long term and is also an interesting model to study the complexity of vector-borne diseases. Collecting quantitative data such as the force of infection will help calibrate epidemiological model that can be used to better understand complex vector-borne disease epidemiological cycles.

  8. 'Chasing for Water': Everyday Practices of Water Access in Peri-Urban Ashaiman, Ghana

    Directory of Open Access Journals (Sweden)

    Megan Peloso

    2014-02-01

    Full Text Available Despite recent reports suggesting that access to improved sources of drinking water is rising in Ghana, water access remains a daily concern for many of those living in the capital region. Throughout the Greater Accra Metropolitan Area (GAMA, the urban poor manage uncertainty and establish themselves in the city by leveraging a patchwork system of basic services that draws importantly from informal systems and supplies. This paper takes a case study approach, using evidence gathered from two-months of fieldwork in a peri-urban informal settlement on the fringe of Accra, to explore everyday practices involved in procuring water for daily needs that routinely lead residents outside of the official water supply system. Findings from this case study demonstrate that respondents make use of informal water services to supplement or 'patch up' gaps left by the sporadic water flow of the official service provider, currently Ghana Water Company Ltd. (GWCL. Basic water access is thus constructed through an assemblage of coping strategies and infrastructures. This analysis contributes to understandings of heterogeneity in water access by attending to the everyday practices by which informality is operationalised to meet the needs of the urban poor, in ways that may have previously been overshadowed. This research suggests, for example, that although water priced outside of the official service provider is generally higher per unit, greater security may be obtained from smaller repetitive transactions as well as having the flexibility to pursue multiple sources of water on a day-to-day basis.

  9. A planning-oriented sustainability assessment framework for peri-urban water management in developing countries.

    Science.gov (United States)

    Starkl, Markus; Brunner, Norbert; López, Eduardo; Martínez-Ruiz, José Luis

    2013-12-15

    DPSIR and the three-pillar model are well-established frameworks for sustainability assessment. This paper proposes a planning-oriented sustainability assessment framework (POSAF). It is informed by those frameworks but differs insofar as it puts more emphasis on a constructivist conception which recognises that sustainability needs to be defined anew for each planning problem. In finding such a consensus definition, POSAF uses participatory scenario analysis and participatory planning, technical feasibility study, participatory assessment, analysis of trade-offs and social networks in an unusual combination and for goals that differ from the original conceptions of these methods. POSAF was applied in a peri-urban area of Mexico City for the design of improved water service provision, integrating solid waste management. It supported consensus amongst users about the importance of environmental issues, informed planners about the values of stakeholders and users, detected local differences, and identified possible conflicts at an early stage of decision-making. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Sustainable sewerage servicing options for peri-urban areas with failing septic systems.

    Science.gov (United States)

    Sharma, A K; Tjandraatmadja, G; Grant, A L; Grant, T; Pamminger, F

    2010-01-01

    The provision of water and wastewater services to peri-urban areas faces very different challenges to providing services to cities. Sustainable solutions for such areas are increasingly being sought, in order to solve the environmental and health risks posed by failing septic systems. These solutions should have the capability to reduce potable water demand, provide fit for purpose reuse options, and minimise impacts on the local and global environment. A methodology for the selection of sustainable sewerage servicing systems and technologies is presented in this paper. This paper describes the outcomes of applying this methodology to a case study in rural community near Melbourne, Australia, and describes the economic and environmental implications of various sewerage servicing options. Applying this methodology has found that it is possible to deliver environmental improvements at a lower community cost, by choosing servicing configurations not historically used by urban water utilities. The selected solution is currently being implemented, with the aim being to generate further transferable learnings for the water industry.

  11. THE PATTERNS AND CHARACTERISTICS OF PERI-URBAN SETTLEMENT IN EAST UNGARAN DISTRICT, SEMARANG REGENCY

    Directory of Open Access Journals (Sweden)

    Febrina Sri Arta

    2015-10-01

    Full Text Available East Ungaran District is a peri-urban area arising from the urban-rural interaction between Semarang City and Semarang Regency. Interaction of these two regions is supported with the accessibility that is characterized by high commuting flows. The impact of this interaction is mix of urban and rural characteristics in East Ungaran District. This conditions will also affect land use in East Ungaran District, such as housing, economic facilities, and residential infrastructure. The increase of unplanned settlements has the potential to lead to inefficient land use, particularly in residential infrastructure. The purpose of this research is to examine patterns and characteristics of settlements in the East Ungaran District in 2015. This research uses descriptive quantitative with a spatial approach using remote sensing techniques. The results show that there are two types of settlement patterns in East Ungaran District, i.e, clustered pattern and random pattern. The characteristics of settlements are medium up to the good socio-economic condition (such as high income, good education, certificate ownership, permanent construction of housing, and good health and good condition in infrastructure (determined by road conditions, sources of clean water, waste disposal systems, and sanitary systems. © 2015 GJGP UNDIP. All rights reserved.

  12. Quantitative assessment of aquatic impacts of power plants

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, D.H.; Arnold, E.M.; Skalski, J.R.; Fickeisen, D.H.; Baker, K.S.

    1979-08-01

    Progress is reported in a continuing study of the design and analysis of aquatic environmental monitoring programs for assessing the impacts of nuclear power plants. Analysis of data from Calvert Cliffs, Pilgrim, and San Onofre nuclear power plants confirmed the generic applicability of the control-treatment pairing design suggested by McKenzie et al. (1977). Substantial progress was made on the simulation model evaluation task. A process notebook was compiled in which each model equation was translated into a standardized notation. Individual model testing and evaluating was started. The Aquatic Generalized Environmental Impact Simulator (AGEIS) was developed and will be tested using data from Lake Keowee, South Carolina. Further work is required to test the various models and perfect AGEIS for impact analyses at actual power plant sites. Efforts on the hydrologic modeling task resulted in a compendium of models commonly applied to nuclear power plants and the application of two well-received hydrodynamic models to data from the Surry Nuclear Power Plant in Virginia. Conclusions from the study of these models indicate that slight inaccuracies of boundary data have little influence on mass conservation and accurate bathymetry data are necessary for conservation of mass through the model calculations. The hydrologic modeling task provides valuable reference information for model users and monitoring program designers.

  13. Quantitative assessment of aquatic impacts of power plants

    International Nuclear Information System (INIS)

    McKenzie, D.H.; Arnold, E.M.; Skalski, J.R.; Fickeisen, D.H.; Baker, K.S.

    1979-08-01

    Progress is reported in a continuing study of the design and analysis of aquatic environmental monitoring programs for assessing the impacts of nuclear power plants. Analysis of data from Calvert Cliffs, Pilgrim, and San Onofre nuclear power plants confirmed the generic applicability of the control-treatment pairing design suggested by McKenzie et al. (1977). Substantial progress was made on the simulation model evaluation task. A process notebook was compiled in which each model equation was translated into a standardized notation. Individual model testing and evaluating was started. The Aquatic Generalized Environmental Impact Simulator (AGEIS) was developed and will be tested using data from Lake Keowee, South Carolina. Further work is required to test the various models and perfect AGEIS for impact analyses at actual power plant sites. Efforts on the hydrologic modeling task resulted in a compendium of models commonly applied to nuclear power plants and the application of two well-received hydrodynamic models to data from the Surry Nuclear Power Plant in Virginia. Conclusions from the study of these models indicate that slight inaccuracies of boundary data have little influence on mass conservation and accurate bathymetry data are necessary for conservation of mass through the model calculations. The hydrologic modeling task provides valuable reference information for model users and monitoring program designers

  14. Mercury uptake and accumulation by four species of aquatic plants.

    Science.gov (United States)

    Skinner, Kathleen; Wright, Nicole; Porter-Goff, Emily

    2007-01-01

    The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively.

  15. Aquatic adventitious roots of the wetland plant Meionectes brownii can photosynthesize

    DEFF Research Database (Denmark)

    Rich, Sarah Meghan; Ludwig, Martha; Pedersen, Ole

    2011-01-01

    • Many wetland plants produce aquatic adventitious roots from submerged stems. Aquatic roots can form chloroplasts, potentially producing endogenous carbon and oxygen. Here, aquatic root photosynthesis was evaluated in the wetland plant Meionectes brownii, which grows extensive stem-borne aquatic...... roots during submergence. • Underwater photosynthetic light and CO(2) response curves were determined for aquatic-adapted leaves, stems and aquatic roots of M. brownii. Oxygen microelectrode and (14)CO(2)-uptake experiments determined shoot inputs of O(2) and photosynthate into aquatic roots. • Aquatic...... adventitious roots contain a complete photosynthetic pathway. Underwater photosynthetic rates are similar to those of stems, with a maximum net photosynthetic rate (P(max)) of 0.38 µmol O(2) m(-2) s(-1); however, this is c. 30-fold lower than that of aquatic-adapted leaves. Under saturating light with 300 mmol...

  16. Spatiotemporal dynamics of suspended sediment within an actively urbanizing peri-urban catchment in Portugal

    Science.gov (United States)

    Walsh, Rory; Ferreira, Carla; Ferreira, Antonio

    2016-04-01

    Suspended sediment levels tend to be enhanced in urban catchments, but vary considerably with (amongst many other factors) the degree of active urban development or redevelopment within the catchment and 'urbanization style'. Relatively little, however, is known about the relationship between suspended solids and urbanization style in peri-urban Mediterranean environments. This paper focuses on spatiotemporal suspended sediment dynamics within a typical Portuguese peri-urban catchment, Ribeira dos Covoes, that is undergoing rapid urbanization. The catchment currently has a 40% urban cover, with 17% impervious surfaces, dispersed between woodland (56%) and agricultural areas (4%). The study uses suspended sediment concentration measurements made at the catchment outlet (ESAC) and in three upstream tributaries: (i) Espírito Santo, with a largest urban area (49%); (ii) Porto Bordalo, 39% urbanized; and (iii) Quinta, 22% urbanized, most of which (18%) being an enterprise park under construction. Water sampling was carried out manually during 10 storm hydrographs between October 2011 and March 2013. Suspended sediment concentrations (SSC) were derived by laboratory analysis of the filtered samples using the gravimetric method. In addition total dissolved solids concentrations (TDS) were estimated using conductivity readings. Greatest SSCs were recorded in the Quinta sub-catchment and at the catchment outlet at ESAC (113-4320 mg L-1 and 200-1656 mg L-1, respectively) than in the Espírito Santo and Porto Bordalo sub-catchments (183-852 mg L-1 and 47-598 mg L-1 respectively, despite their greater impervious cover. The greatest SSCs for Quinta result from it containing the construction site, but it showed lower TDS (56-4010 mg L-1), perhaps due to the coarse sandy nature of the construction site. Higher TDS concentrations, however, were displayed in Porto Bordalo (27-5400 mg L-1), possibly due to the loamy soil. Espírito Santo, comprising sandy-loam soils, displayed 27

  17. Phytofabrication of silver nanoparticles by using aquatic plant Hydrilla verticilata

    Directory of Open Access Journals (Sweden)

    MAHENDRA RAI

    2012-07-01

    Full Text Available Sable N, Gaikwad S, Bonde S, Gade A, Rai M. 2012. Phytofabrication of silver nanoparticles by using aquatic plant Hydrilla verticilata. Nusantara Bioscience 4: 45-49. In the context of current drive to developed new green technology in nanomaterials, synthesis of nanoparticles is of considerable importance. There has been considerable work done in the field of nanoscience and nanotechnology during the last decade due to the introduction of various protocols for the synthesis of nanoparticles by using plants and microorganisms. Here we firstly report the extracellular phytosynthesis of silver nanoparticles (Ag-NPs using aquatic plants Hydrilla verticilata. The characterization of the phytosynthesized Ag-NPs was done with the help of UV-Vis spectroscopy, FTIR, Nanoparticle Tracking Analysis (NTA, Zeta potential and SEM. The SEM micrograph revealed the synthesis of polydispersed spherical nanoparticles, with the average size of 65.55 nm. The phytofabricated Ag-NPs can be used in the field of medicine and agriculture, due to their antimicrobial potential.

  18. Ecogenotoxicity testing of aquatic environment by comet assay in plants

    Directory of Open Access Journals (Sweden)

    Anita Mukherjee

    2015-05-01

    Full Text Available One of the goals of environmental monitoring is the detection of potentially hazardous compounds in water. We have set up a standard method to apply the Comet assay in aquatic plants that could be of great interest to evaluate cytotoxicity, genotoxicity and oxidative stress on the same species regarded as most sensitive to environmental pollutants. The aim of the present study was to set up of standardized procedure to evaluate genotoxicity in aquatic plants- Ceratophyllum demersum one that is submerged free floating and the other is Lemna minor - a fresh water floating plant by Comet assay. Electrophoresis and unwinding times were adapted to obtain minimum DNA migration evaluated as tail intensity % or tail moment in the control group and, at the same time maximum sensitivity for DNA damage with known genotoxicants. We further investigated the cytotoxicity and oxidative stress induced in the same species. Based on the repeatability of results obtained we suggest that Ceratophyllum, Lemna can serve as model species and Comet assay could be adopted to monitor the eco-genotoxicity of water pollutants.

  19. Farms as a resilience factors to land degradation in peri-urban areas

    Directory of Open Access Journals (Sweden)

    Paolo Zappavigna

    2013-09-01

    Full Text Available The purpose of this study was the analysis of the effects induced by urban pressures on the socio-economic and territorial characteristics of the rural peri-urban areas in order to identify planning and intervention strategies aimed at enhancing the quality of agriculture and landscape. A survey was conducted in the surroundings of Parma on farms located in the vicinity of urban areas. The structural, productive and social characteristics of the family-farm units were analyzed. The survey updated an identical survey, carried out in 1986, in which it was examined a sample of 208 farms. The units surveyed were evaluated in two aspects: the “vitality”, which takes into account the structural characteristics (size, production, labour force, etc., and the “stability”, in which a crucial role is played by the age of the conductor and the presence of a successor. It was found that only 28% of the original farm sample is still alive, one third has disappeared, 30% was absorbed by existing farms, 8% has been abandoned. The factors most favourable to the survival resulted those referred to the vitality, especially the physical and economic size of the farm, the presence of cattle, the percentage of land in property, the presence of young labour. Among the factors that predispose to the abandonment, the urbanization processes were found to be determinants, in terms of expansion of both the built-up area and of that planned as urbanisable. The research has highlighted the importance of the vitality of the farms together with a context that has maintained its original rural features. These combined aspects can better define what we call the resiliency of the landfarms system i.e. the capability of positively reacting to the variable modifications of the internal and external conditions.

  20. Anuran road-kills neighboring a peri-urban reserve in the Atlantic Forest, Brazil.

    Science.gov (United States)

    Coelho, Igor Pfeifer; Teixeira, Fernanda Zimmermann; Colombo, Patrick; Coelho, Artur Vicente Pfeifer; Kindel, Andreas

    2012-12-15

    Mortality from road-kills may figure among the important causes of decline in amphibian populations and species extinctions worldwide. Evaluation of the magnitude, composition, and temporal and spatial distributions of amphibian road-kills is a key step for mitigation planning, especially in peri-urban reserves. Once a month for 16 months, we surveyed, on foot, a 4.4 km section of state road ERS-389 bordering the Itapeva reserve in the southern Atlantic Forest. We recorded 1433 anuran road-kills and estimated a mortality rate of 9002 road-kills/km/year. The species most often recorded were the largest ones: Leptodactylus latrans, Rhinella icterica, Leptodactylus gracilis and Hypsiboas faber; 54.5% of the carcasses could not be identified. Anuran mortality was concentrated in summer, and was associated with temperature, rainfall and photoperiod. Leptodactylus road-kills were strongly influenced by vehicle traffic, probably because of its high abundance during the entire study period. Road-kill hotspots differed for anurans as a group and for single species, and we found an association among spatial patterns of mortality and types of land cover, distance from the nearest waterbody, roadside ditches, and artificial light. Traffic should be banned temporarily during periods of high mortality, which can be forecasted based on meteorological data. A comprehensive mitigation approach should take into account hotspots of all anuran records, and also of target species for selecting locations for amphibian passages and fencing. Roadside ditches, artificial waterbodies, and conventional street lights should be reduced as much as possible, since they may represent ecological traps for anuran populations. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. An Assessment of Peri-Urban Groundwater Quality from Shallow Dug Wells, Mzuzu, Malawi

    Science.gov (United States)

    Holm, R.; Felsot, A.

    2012-12-01

    Throughout Malawi, governmental, non-governmental, religious and civic organizations are targeting the human need for water. Diarrheal diseases, often associated with unsafe drinking water, are a leading cause of mortality in children under five in Malawi with over 6,000 deaths per year (World Health Organization, 2010). From January to March 2012, a field study was undertaken in Malawi to study water quality and develop a public health risk communication strategy. The region studied, Area 1B, represents a comparatively new peri-urban area on the edge of Mzuzu city. Area 1B is serviced by a piped municipal water supply, but many shallow dug wells are also used for household water. Groundwater samples were collected from 30 shallow dug well sites and analyzed for nitrate, total coliform, Escherichia coli, total hardness, total alkalinity and pH. In addition to water quality analyses, a structured household questionnaire was administered to address water use, sanitation, health, consumption patterns, and socioeconomics. Results showed that more than half of the groundwater samples would be considered of unacceptable quality based on World Health Organization (WHO) standards for E. coli contamination. Low levels of nitrate were found in groundwater, but only one well exceeded WHO standards. The structured questionnaire revealed that some residents were still consuming groundwater despite the access to safer municipal water. In general, the widespread E. coli contamination was not statistically correlated with well depth, latrine proximity, or surface features. Similarly, nitrate concentrations were not significantly correlated with proximity to latrines. On the other hand, nitrate was correlated with well depth, which is expected given the high potential for leaching of anionic highly water soluble compounds. E. coli was significantly correlated with nitrate concentration. Projects targeting the need for clean water need to recognize that households with access to a

  2. Multitemporal mapping of peri-urban carbon stocks and soil sealing from satellite data.

    Science.gov (United States)

    Villa, Paolo; Malucelli, Francesco; Scalenghe, Riccardo

    2018-01-15

    Peri-urbanisation is the expansion of compact urban areas towards low-density settlements. This phenomenon directly challenges the agricultural landscape multifunctionality, including its carbon (C) storage capacity. Using satellite data, we mapped peri-urban C stocks in soil and built-up surfaces over three areas from 1993 to 2014 in the Emilia-Romagna region, Italy: a thinly populated area around Piacenza, an intermediate-density area covering the Reggio Emilia-Modena conurbation and a densely anthropized area developing along the coast of Rimini. Satellite-derived maps enabled the quantitative analysis of spatial and temporal features of urban growth and soil sealing, expressed as the ratio between C in built-up land and organic C in soils (Cc/Co). The three areas show substantial differences in C stock balance and soil sealing evolution. In Piacenza (Cc/Co=0.07 in 1993), although questioned by late industrial expansion and connected residential sprawl (Cc/Co growth by 38%), most of the new urbanisation spared the best rural soils. The Reggio Emilia-Modena conurbation, driven by the polycentricism of the area and the heterogeneity of economic sectors (Cc/Co rising from 0.08 to 0.14 from 1993 to 2014), balances sprawl and densification. Rimini, severely sealed since the 1960s (Cc/Co=0.23 in 1993), densifies its existing settlements and develops an industrial expansion of the hinterland, with Cc/Co growth accelerating from +15% before 2003 to +36% for the last decade. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Spatio-temporal dynamics of surface water quality in a Portuguese peri-urban catchment

    Science.gov (United States)

    Ferreira, Carla; Walsh, Rory; Coelho, Celeste; Ferreira, António

    2016-04-01

    Urban development poses great pressure on water resources, but the impact of different land-uses on streamwater quality in partly urbanized catchments is not well understood. Focussing on a Portuguese peri-urban catchment, this paper explores the impact of a mosaic of different urban and non-urban land-uses on streamwater quality, and the influence of a seasonal Mediterranean climate on pollutant dynamics. The catchment has a 40% urban cover, dispersed amongst patches of woodland (56%) and agricultural fields (4%). Apart from the catchment outlet, streamwater quality was assessed at three sub-catchment sites: (i) Porto Bordalo, encompassing a 39% urban area with a new major road; (ii) Espírito Santo, draining a sub-catchment with 49% urban cover, mostly comprising detached houses surrounded by gardens; and (iii) Quinta, with a 25% urban cover. The Porto Bordalo sub-catchment is underlain by limestone, whereas the Espírito Santo and Quinta sub-catchments overlie sandstone. Water quality variables (notably nutrients, heavy metals and COD) were assessed for samples collected at different stages in the storm hydrograph responses to ten rainfall events occurring between October 2011 and March 2013. Urban areas had great impacts on COD, with highest median concentrations in Espírito Santo (18.0 mg L-1) and lowest in Quinta (9.5 mgL-1). In Espírito Santo, the management of gardens triggered greatest median concentrations of N-NO3 (1.46 mgL-1, purban patterns and storm drainage system, should help enable urban planners to minimize adverse impacts of urbanization on water quality.

  4. Aquatic plants are open flexible structures - a reply to Sukhodolov

    DEFF Research Database (Denmark)

    Sand-Jensen, K.

    2005-01-01

    1. Aquatic plant stands are flexible, mesh-like open structures that undergo modification in shape and experience a cascade of declining flow velocities and micro-scale Reynolds numbers with increasing distance into the stands. It is not possible to define or measure the frontal area of this open...... other problems. Relating drag coefficients to macro-scale Reynolds numbers would result in exactly the same form of relationship as to water velocity because macro-scale Reynolds numbers changed in direct proportion to water velocity in the experiments, while kinematic viscosity and characteristic...

  5. Aquatic Plant/microbial Filters for Treating Septic Tank Effluent

    Science.gov (United States)

    Wolverton, B. C.

    1988-01-01

    The use of natural biological processes for treating many types of wastewater have been developed by NASA at the John C. Stennis Space Center, NSTL, Mississippi, during the past 15 years. The simplest form of this technology involves the use of aquatic plant/marsh filters for treatment of septic tank effluent. Septic tank effluent from single home units can be treated to advanced secondary levels and beyond by using a 37.2 sq m (400 sq ft) surface area washed gravel filter. This filter is generally 0.3 m (1 ft) deep with a surface cover of approximately 0.15 m (6 in.) of gravel. The plants in this filter are usually aesthetic or ornamental such as calla lily (Zantedeschia aethiopica), canna lily (Canna flaccida), elephant ear (Colocasia esculenta), and water iris (Iris pseudacorus).

  6. The AVuPUR project (Assessing the Vulnerability of Peri-Urban Rivers) : experimental and modelling strategy

    Science.gov (United States)

    Braud, I.; Chancibault, K.; Debionne, S.; Lieme Kouyi, G.; Sarrazin, B.; Jacqueminet, C.

    2009-04-01

    Due to the development of urbanisation and the associated pollutions, peri-urban rivers face an increasing pressure on the receiving waters and an enhancement of floods. In order to limit the risks and define adapted management scenarios, it is important to identify the key factors over which action is possible. In particular, due to the Water Framework Directive, discharge of polluted water into rivers must be limited and actions must be undertaken in order to restore the ecological quality of water. In this context, integrated modelling tools, taking into account anthropogenic effects on the water cycle are interesting as they provide ways to test and evaluate the efficiency of different management scenarios. However improvements are still required to derive tools allowing a continuous and long term modelling of the hydrological cycle in peri-urban areas. The models must take into account the surface heterogeneity (mixture of rural and urbanised areas), and also the natural and artificial water pathways, which influence the water quality. These questions are the focus of the AVuPUR (Assessing the Vulnerability of Peri-Urban Rivers) project. Its aims are 1) to provide a better description of the heterogeneity of peri-urban catchments and of the associated water pathways using field survey, GIS and remote sensing analysis of high resolution images; 2) to provide long term detailed simulation models of the hydrological cycle in peri-urban catchments to increase our understanding of the processes involved; 3) to improve existing hydrological models with a better handling of the urbanised areas in order to derive tools usable by stakeholders; 4) to run long term simulations of the hydrological cycle using past and future land-use and climate scenarios and quantify the impact on the hydrological regime. The project focuses on two experimental catchments: the Yzeron catchment (147 km2), a peri-urban catchment located in the west of Lyon (south-east of France) and the Ch

  7. Dairy farms typology and management of animal genetic resources in the peri-urban zone of Bamako (Mali

    Directory of Open Access Journals (Sweden)

    Abdoulaye Toure

    2015-05-01

    Full Text Available Facing growth in demand, dairy production in peri-urban areas of developing countries is changing rapidly. To characterise this development around Bamako (Mali, this study establishes a typology of dairy production systems with a special focus on animal genetic resources. The survey included 52 dairy cattle farms from six peri-urban sites. It was conducted in 2011 through two visits, in the dry and harvest seasons. The median cattle number per farm was 17 (range 5–118 and 42% of farmers owned cropland (8.3± 7.3 ha, minimum 1 ha, maximum 25 ha. Feeding strategy was a crucial variable in farm characterisation, accounting for about 85% of total expenses. The use of artificial insemination and a regular veterinary follow-up were other important parameters. According to breeders’ answers, thirty genetic profiles were identified, from local purebreds to different levels of crossbreds. Purebred animals raised were Fulani Zebu (45.8 %, Maure Zebu (9.2 %, Holstein (3.0 %, Azawak Zebu (1.3 %, Mere Zebu (0.5% and Kuri taurine (0.1 %. Holstein crossbred represented 30.5% of the total number of animals (19.0% Fulani-Holstein, 11.2% Maure-Holstein and 0.3% Kuri-Holstein. Montbéliarde, Normande and Limousin crossbreds were also found (6.6 %, 0.7% and 0.3 %, respectively. A multivariate analysis helped disaggregate the diversity of management practices. The high diversity of situations shows the need for consideration of typological characteristics for an appropriate intervention. Although strongly anchored on local breeds, the peri-urban dairy systems included a diversity of exotic cattle, showing an uncoordinated quest of breeders for innovation. Without a public intervention, this dynamic will result in an irremediable erosion of indigenous animal genetic resources.

  8. An integrated approach to assess the dynamics of a peri-urban watershed influenced by wastewater irrigation

    Science.gov (United States)

    Mahesh, Jampani; Amerasinghe, Priyanie; Pavelic, Paul

    2015-04-01

    In many urban and peri-urban areas of India, wastewater is under-recognized as a major water resource. Wastewater irrigated agriculture provides direct benefits for the livelihoods and food security of many smallholder farmers. A rapidly urbanizing peri-urban micro-watershed (270 ha) in Hyderabad was assessed over a 10-year period from 2000 to 2010 for changes in land use and associated farming practices, farmer perceptions, socio-economic evaluation, land-use suitability for agriculture and challenges in potential irrigated area development towards wastewater use. This integrated approach showed that the change in the total irrigated area was marginal over the decade, whereas the built-up area within the watershed boundaries doubled and there was a distinct shift in cropping patterns from paddy rice to paragrass and leafy vegetables. Local irrigation supplies were sourced mainly from canal supplies, which accounted for three-quarters of the water used and was largely derived from wastewater. The remainder was groundwater from shallow hard-rock aquifers. Farmer perception was that the high nutrient content of the wastewater was of value, although they were also interested to pay modest amounts for additional pre-treatment. The shift in land use towards paragrass and leafy vegetables was attributed to increased profitability due to the high urban demand. The unutilised scrubland within the watershed has the potential for irrigation development, but the major constraints appear to be unavailability of labour and high land values rather than water availability. The study provides evidence to support the view that the opportunistic use of wastewater and irrigation practices, in general, will continue even under highly evolving peri-urban conditions, to meet the livelihood needs of the poor driven by market demands, as urban sprawl expands into cultivable rural hinterlands. Policy support is needed for enhanced recognition of wastewater for agriculture, with flow

  9. Source identification of heavy metals in peri-urban agricultural soils of southeast China: An integrated approach.

    Science.gov (United States)

    Hu, Wenyou; Wang, Huifeng; Dong, Lurui; Huang, Biao; Borggaard, Ole K; Bruun Hansen, Hans Christian; He, Yue; Holm, Peter E

    2018-06-01

    Intensive human activities, in particular agricultural and industrial production have led to heavy metal accumulation in the peri-urban agricultural soils of China threatening soil environmental quality and agricultural product security. A combination of spatial analysis (SA), Pb isotope ratio analysis (IRA), input fluxes analysis (IFA), and positive matrix factorization (PMF) model was successfully used to assess the status and sources of heavy metals in typical peri-urban agricultural soils from a rapidly developing region of China. Mean concentrations of Cd, As, Hg, Pb, Cu, Zn and Cr in surface soils (0-20 cm) were 0.31, 11.2, 0.08, 35.6, 44.8, 119.0 and 97.0 mg kg -1 , respectively, exceeding the local background levels except for Hg. Spatial distribution of heavy metals revealed that agricultural activities have significant influence on heavy metal accumulation in the surface soils. Isotope ratio analysis suggested that fertilization along with atmospheric deposition were the major sources of heavy metal accumulation in the soils. Based on the PMF model, the relative contribution rates of the heavy metals due to fertilizer application, atmospheric deposition, industrial emission, and soil parent materials were 30.8%, 33.0%, 25.4% and 10.8%, respectively, demonstrating that anthropogenic activities had significantly higher contribution than natural sources. This study provides a reliable and robust approach for heavy metals source apportionment in this particular peri-urban area with a clear potential for future application in other regions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Urban and peri-urban family-based pig-keeping in Cambodia: Characteristics, management and perceived benefits and constraints.

    Directory of Open Access Journals (Sweden)

    Gunilla Ström

    Full Text Available Keeping pigs in urban and peri-urban areas may not only provide many benefits for the urban households, but may also be challenging and a potential health hazard. The aim of this cross-sectional study was to describe household characteristics and to evaluate perceived benefits and constraints among pig-keepers in the urban and peri-urban areas of Phnom Penh, Cambodia. The study included 204 households and a structured questionnaire was used to interview the household member responsible for taking care of the pigs. Descriptive analyses showed that most households kept between 5 and 15 pigs and that all households kept their pigs in confinement. About 97% of the households owned the pigs themselves and the pigs were generally managed by female household members (43%. Pigs were mainly kept for commercial purposes and more than 60% of the households stated that income from pig-keeping was the main or one of the main sources of revenue for the household. More than 82% reported that they had experienced disease outbreaks among their pigs during the past three years and disease outbreaks were more commonly reported in households with lower socio-economic position (P = 0.025. Disease outbreaks were considered one of the main constraints, along with expensive feed and low payment prices for the slaughter pigs, but few households considered sanitary or other public health issues problematic. Thus, pig-keeping makes an important contribution to the livelihoods of urban and peri-urban households, but many households face external constraints on their production, such as diseases and low revenues, which may have a negative impact on their livelihoods.

  11. Social constructions of environmental services in a rapidly densifying peri-urban area under dual governance in Durban, South Africa

    Directory of Open Access Journals (Sweden)

    Catherine Sutherland

    2016-12-01

    Full Text Available Background: Biodiversity plays a critical role in improving the quality of life and resilience of poor urban communities in Durban. Objectives: However, the rapid densification that is taking place in the ‘rural periphery’ of the city is impacting significantly on the integrity of ecosystems, which provide valuable ecosystem services. It is also changing the relations between people and the environment. Mzinyathi and eSkebheni, in the north-west of Durban, are peri-urban areas located on Ingonyama Trust land and hence they are governed by both the traditional authority and the eThekwini Municipality. The settlement pattern is changing rapidly here as middle and upper income residents move into the area, changing the way of life from being rural and ‘traditional’ to urban and ‘modern’. Method: This paper focused on the nexus of rapid urban growth, dual governance systems, biodiversity loss and cultural change in these two areas. It adopted a qualitative methodology and social constructivist approach. Data on the value of environmental services in the area was collected through interviewing the traditional authority, provincial and municipal planners and environmentalists, and household members. Results: The paper revealed that environmental services are constructed in multiple ways within a particular socio-historical and political context, that they have value to peri-urban communities, and that their function and use is changing as a result of the ‘modernisation’ of the area. The impact of the dual governance system and traditional land allocation process on environmental services is significant. This has implications for long term sustainability, for the quality of life of peri-urban residents and for planning and urban governance.

  12. Discussion on Sustainable Water Technologies for Peri-Urban Areas of Mexico City: Balancing Urbanization and Environmental Conservation

    Directory of Open Access Journals (Sweden)

    Laura Essl

    2012-09-01

    Full Text Available Often centralized water supply, sanitation and solid waste services struggle to keep up with the rapid expansion of urban areas. The peri-urban areas are at the forefront of this expansion and it is here where decentralized technologies are increasingly being implemented. The introduction of decentralized technologies allows for the development of new opportunities that enable the recovery and reuse of resources in the form of water, nutrients and energy. This resource-oriented management of water, nutrients and energy requires a sustainable system aimed at low resource use and high recovery and reuse rates. Instead of investigating each sector separately, as has been traditionally done, this article proposes and discusses a concept that seeks to combine the in- and outflows of the different sectors, reusing water and other liberated resources where possible. This paper shows and demonstrates examples of different types of sustainable technologies that can be implemented in the peri-urban areas of Mexico City [rainwater harvesting, EcoSan and biofiltros (small constructed wetlands, and (vermi-composting]. An innovative participatory planning method, combining scenario development with a participatory planning workshop with key stakeholders, was applied and resulted in three concept scenarios. Specific technologies were then selected for each concept scenario that the technical feasibility and applicability was assessed. Following this, the resulting resource flows (nutrients, water and energy were determined and analyzed. The results show that decentralized technologies not only have the potential to deliver adequate water supply, sanitation and solid waste services in peri-urban areas and lessen environmental pollution, but also can recover significant amounts of resources thereby saving costs and providing valuable inputs in, for instance, the agricultural sector. Social acceptance of the technologies and institutional cooperation, however, is

  13. Discussion on Sustainable Water Technologies for Peri-Urban Areas of Mexico City: Balancing Urbanization and Environmental Conservation

    Directory of Open Access Journals (Sweden)

    Tiemen A. Nanninga

    2012-09-01

    Full Text Available Often centralized water supply, sanitation and solid waste services struggle to keep up with the rapid expansion of urban areas. The peri-urban areas are at the forefront of this expansion and it is here where decentralized technologies are increasingly being implemented. The introduction of decentralized technologies allows for the development of new opportunities that enable the recovery and reuse of resources in the form of water, nutrients and energy. This resource-oriented management of water, nutrients and energy requires a sustainable system aimed at low resource use and high recovery and reuse rates. Instead of investigating each sector separately, as has been traditionally done, this article proposes and discusses a concept that seeks to combine the in- and outflows of the different sectors, reusing water and other liberated resources where possible. This paper shows and demonstrates examples of different types of sustainable technologies that can be implemented in the peri-urban areas of Mexico City [rainwater harvesting, EcoSan and biofiltros (small constructed wetlands, and (vermi-composting]. An innovative participatory planning method, combining scenario development with a participatory planning workshop with key stakeholders, was applied and resulted in three concept scenarios. Specific technologies were then selected for each concept scenario that the technical feasibility and applicability was assessed. Following this, the resulting resource flows (nutrients, water and energy were determined and analyzed. The results show that decentralized technologies not only have the potential to deliver adequate water supply, sanitation and solid waste services in peri-urban areas and lessen environmental pollution, but also can recover significant amounts of resources thereby saving costs and providing valuable inputs in, for instance, the agricultural sector. Social acceptance of the technologies and institutional cooperation

  14. Social and cultural features of cholera and shigellosis in peri-urban and rural communities of Zanzibar

    Directory of Open Access Journals (Sweden)

    Hutubessy Raymond

    2010-11-01

    Full Text Available Abstract Background Responding to the high burden of cholera in developing countries, the WHO now considers vaccination as a supplement to the provision of safe drinking water and improved sanitation in the strategy for cholera control in endemic settings. Cultural concepts of illness affect many aspects of public health. In the first step of a two-step strategy to examine determinants of cholera vaccine acceptance, this study identified social and cultural features of diarrhoeal illness for cholera control in endemic communities. Methods A cultural epidemiological study with locally adapted vignette-based interviews was conducted in two cholera-endemic communities of Zanzibar. A random sample of unaffected peri-urban (n = 179 and rural (n = 177 adults was interviewed to study community ideas of cholera and shigellosis, considering categories of distress, perceived causes, and help-seeking behaviour. Results Cholera was recognised by 88%. Symptoms of dehydration were most prominent in reports at the peri-urban site. Interference with work leading to strain on household finances was frequently emphasised. Dirty environment was the most prominent perceived cause, followed by unsafe drinking water and germ-carrying flies. Causes unrelated to the biomedical basis of cholera were reported more often by rural respondents. Rural women had more difficulty (20% to identify a cause than men (7.1%, p = 0.016. Peri-urban self treatment emphasised rehydration; the rural community preferred herbal treatment and antibiotics. Shigellosis was recognised by 70%. Fewer regarded it as very serious compared with cholera (76% vs. 97%, p Conclusions This study clarified local views of cholera and shigellosis relevant for diarrhoeal disease control in Zanzibar. The finding that rural women were less likely than men to specify causes of cholera suggests more attention to them is required. Better health education is needed for cholera in rural areas and for shigellosis

  15. Urban and peri-urban precipitation and air temperature trends in mega cities of the world using multiple trend analysis methods

    Science.gov (United States)

    Ajaaj, Aws A.; Mishra, Ashok K.; Khan, Abdul A.

    2018-04-01

    Urbanization plays an important role in altering local to regional climate. In this study, the trends in precipitation and the air temperature were investigated for urban and peri-urban areas of 18 mega cities selected from six continents (representing a wide range of climatic patterns). Multiple statistical tests were used to examine long-term trends in annual and seasonal precipitation and air temperature for the selected cities. The urban and peri-urban areas were classified based on the percentage of land imperviousness. Through this study, it was evident that removal of the lag-k serial correlation caused a reduction of approximately 20 to 30% in significant trend observability for temperature and precipitation data. This observation suggests that appropriate trend analysis methodology for climate studies is necessary. Additionally, about 70% of the urban areas showed higher positive air temperature trends, compared with peri-urban areas. There were not clear trend signatures (i.e., mix of increase or decrease) when comparing urban vs peri-urban precipitation in each selected city. Overall, cities located in dry areas, for example, in Africa, southern parts of North America, and Eastern Asia, showed a decrease in annual and seasonal precipitation, while wetter conditions were favorable for cities located in wet regions such as, southeastern South America, eastern North America, and northern Europe. A positive relationship was observed between decadal trends of annual/seasonal air temperature and precipitation for all urban and peri-urban areas, with a higher rate being observed for urban areas.

  16. Integrated model of biopurification system for home sewage. A proposal for peri-urban communities from south center of Chile

    International Nuclear Information System (INIS)

    Parra Pierart, Izaul; Chiang Rojas, Gustavo

    2013-01-01

    The rapid growth of world population and its impacts has led to search new sources of water supply. Wastewater constitutes an additional source to satisfy the demand of this resource. Diverse researchers have designed alternatives for improve its processing and promote its utilization. This study examines some alternatives of bio-purification and proposes a conceptual design of a hybrid system that combines the use of a bio filter with artificial wetlands. The model designed contributes to improve water resources management and has educational, landscape and environmental benefits for peri-urban communities. Besides constitutes an alternative to promote more efficiently natural resources management at the local level.

  17. Sustainability, resilience and governance of an urban food system: a case study of peri-urban Wuhan

    OpenAIRE

    Dolley, Jonathan

    2017-01-01

    While it is clear that urban food systems need to be made resilient so that broader sustainability\\ud goals can be maintained over time, it has been a matter of debate as to how resilience should be\\ud conceptualised when applied to social-ecological systems. Through a case study of peri-urban\\ud Wuhan, this research develops and applies a resilience based conceptual framework for periurban\\ud food systems analysis in order to explore the potential for an enhanced understanding of\\ud resilien...

  18. Use of portable X-ray fluorescence spectrometry for environmental quality assessment of peri-urban agriculture.

    Science.gov (United States)

    Weindorf, David C; Zhu, Yuanda; Chakraborty, Somsubhra; Bakr, Noura; Huang, Biao

    2012-01-01

    Urban expansion into traditional agricultural lands has augmented the potential for heavy metal contamination of soils. This study examined the utility of field portable X-ray fluorescence (PXRF) spectrometry for evaluating the environmental quality of sugarcane fields near two industrial complexes in Louisiana, USA. Results indicated that PXRF provided quality results of heavy metal levels comparable to traditional laboratory analysis. When coupled with global positioning system technology, the use of PXRF allows for on-site interpolation of heavy metal levels in a matter of minutes. Field portable XRF was shown to be an effective tool for rapid assessment of heavy metals in soils of peri-urban agricultural areas.

  19. Biogeochemical features of aquatic plants in the Selenga River delta

    Science.gov (United States)

    Shinkareva, Galina; Lychagin, Mikhail

    2014-05-01

    The Selenga River system provides more than a half of the Lake Baikal total inflow. The river collects a significant amount of pollutants (e.g. heavy metals) from the whole basin. These substances are partially deposited within the Selenga delta, and partially are transported further to the lake. A generous amount of aquatic plants grow in the delta area according to its favorable conditions. This vegetation works as a specific biofilter. It accumulates suspended particles and sorbs some heavy metals from the water. The study aimed to reveal the species of macrophytes which could be mostly important for biomonitoring according to their chemical composition. The field campaign took place in the Selenga River delta in July-August of 2011 (high water period) and in June of 2012 (low water period). 14 species of aquatic plants were collected: water starwort Callitriche hermaphroditica, small yellow pond lily Nuphar pumila, pondweeds Potamogeton crispus, P. pectinatus, P. friesii, broadleaf cattail Typha latifolia, hornwort or coontail Ceratophyllum demersum, arrowhead Sagittaria natans, flowering rush (or grass rush) Butomus umbellatus, reed Phragmites australis, parrot's feather Myriophyllum spicatum, the common mare's tail Hippuris vulgaris, Batrachium trichophyllum, canadian waterweed Elodea canadensis. The samples were dried, grinded up and digested in a mixture of HNO3 and H2O2. The chemical composition of the plant material was defined using ICP-MS and ICP-AES methods. Concentrations of Fe, Mn, Cr, Ni, Cu, B, Zn, V, Co, As, Mo, Pb, and U were considered. The study revealed that Potamogeton pectinatus and Myriophyllum spicatum concentrate elements during both high and low water periods. Conversely the Butomus umbellatus and Phragmites australis contain small amount of heavy metals. The reed as true grasses usually accumulates fewer amounts of elements than other macrophytes. To compare biogeochemical specialization of different species we suggest to use

  20. Improving the productivity of smallholder dairy cattle in peri-urban Morogoro, United Republic of Tanzania

    International Nuclear Information System (INIS)

    Nkya, R.; Aboud, A.A.; Kessy, B.M.

    1999-01-01

    The work reported was conduced in two Phases. In Phase I, a sample survey was conducted in the peri-urban areas of Morogoro, Tanzania, to gather information on smallholder farming activities. Fifty-two smallholder farmers provided information on the existing livestock production systems and related family activities, including constraints to dairy production in the area. During Phase II, 24 smallholder farmers keeping a total of 65 cows participated in a field trial aimed at investigating the suitability of a farm formulated concentrate (FC) as a dry season supplement. Phase I survey results showed that 49% of smallholder farmers practised zero grazing (ZG), while 34.5% of farmers practised partial grazing (PG). Zero grazed cows received an estimated 28.2 ± 7.6 kg cut grass per cow/d, while PG cows received 8.1 ± 1.1 kg cut grass per cow/d, in addition to 6-9 h grazing. The average herd size per farm unit was 4.8 and 5.3 cows for W and PG farms, respectively. 27.3% of farms maintained mature bulls. All cows received around 2.4 ± 1.3 kg/cow/d of a supplement, based mainly on maize bran, during milking in two equal amounts. In addition to natural pastures, feed resources included crop by-products, green fodder, crop residues, minerals and other non-conventional feeds such as brewer's waste. Thus, it appeared that farmers rarely supplemented their animals with good protein concentrates and as a result animals often experienced protein deficiency during the dry season. Supplementation with 0.8 kg of FC comprising of maize bran (70%), cottonseed cake (28%) and minerals (2%), per litre of milk produced, during the dry season in Phase II, improved milk yield (34%), and maintained body condition (2.8-3.1). In relation to reproductive performance post-partum anoestrus period was reduced from 86.3 ± 6.6 to 71.2 ± 5.3 days and calving to conception from 102.4 ± 5.1 to 80.4 ± 4.7 days. Feeding 0.8 kg FC per litre of milk was cost effective if there was an increase in

  1. Galling insects associated with two species of ruderal plants in urban and peri urban areas

    OpenAIRE

    Julião, Genimar R.; Fernandes, G. Wilson; Negreiros, Daniel; Bedê, Lúcio; Araújo, Raquel C.

    2005-01-01

    Os insetos têm sido considerados importantes indicadores de mudanças ambientais e da qualidade de habitats. Apesar de seu hábito séssil, fácil visualização, abundância, e especificidade de hospedeiro, insetos indutores de galhas não têm sido utilizados em estudos desta natureza. Neste estudo foi investigado o uso potencial de insetos galhadores associados a duas espécies de plantas hospedeiras ruderais (Baccharis dracunculifolia e Vernonia polyanthes: Asteraceae) como bioindicadores da qualid...

  2. Aquatic Plant Control Research Program. Use of the White Amur for Aquatic Plant Management.

    Science.gov (United States)

    1984-08-01

    the body cavities. Curvature of the spine can Black Bass Act (16 U.S.C. 856-856). This result from imbalanced diets in some areas. law, which supports... Malaysian Aquwculture Joural frequently publish papers on the white Proceeding. of te Indo-PaW Fisheries Council amur (Table Al). Publications which...prepared diets . Data on plant consumption are found in The following popular articles present Woynarovich (1968), Vietmeyer (1976) and positive and

  3. Propagation and Establishment of Native Plants for Vegetative Restoration of Aquatic Ecosystems

    Science.gov (United States)

    2013-06-01

    ERDC/EL TR-13-9 ii Abstract Aquatic plants are a vital, but often missing, component of shallow, freshwater systems. Manmade systems, such as... water quality problems; development of noxious algal blooms; and, often, susceptibility to invasion by harmful, non-native, aquatic weeds. If...emergent aquatic plants that we have successfully used in founder colony establishment in US water bodies. ............................................. 7

  4. Insect herbivory on native and exotic aquatic plants: phosphorus and nitrogen drive insect growth and nutrient release

    OpenAIRE

    Grutters, B.M.C.; Gross, E.M.; Bakker, E.S.

    2016-01-01

    Eutrophication and globalisation facilitate the dominance of exotic plants in aquatic ecosystems worldwide. Aquatic omnivores can provide biotic resistance to plant invasions, but little is known about whether obligate aquatic herbivores can do the same. Herbivores such as insects can decimate aquatic vegetation, but may not be able to consume exotic plants due to their more or less specialised nature of feeding. We experimentally tested the larval feeding of an aquatic insect, the moth Parap...

  5. Transmission of antibiotic-resistant Escherichia coli between cattle, humans and the environment in peri-urban livestock keeping communities in Morogoro, Tanzania

    DEFF Research Database (Denmark)

    Lupindu, Athumani M; Dalsgaard, Anders; Msoffe, Peter L. M.

    2015-01-01

    Urban and peri-urban livestock farming is expanding world-widely because of increased urbanization and demands for food of animal origin. Such farming practices pose a public health risk as livestock are reservoirs of several zoonotic pathogens. In an attempt to determine the fecal transmission...... infrastructures (Odd Ratio=11.2, 95% CI=1.1-119.3) were associated with E. coli showing identical PFGE types within and between clusters. There is a need to improve animal husbandry and manure management practices to reduce risks of transmission of enteropathogens between livestock and humans in urban and peri-urban...... between livestock and people, 100 household clusters keeping cattle in close proximity of humans were selected in urban and peri-urban areas of Morogoro in Tanzania. One hundred eighteen ampicillin and tetracycline resistant Escherichia coli (40 from human stool, 50 from cattle feces, 21 from soil...

  6. An updated checklist of aquatic plants of Myanmar and Thailand

    Directory of Open Access Journals (Sweden)

    Yu Ito

    2014-01-01

    Full Text Available The flora of Tropical Asia is among the richest in the world, yet the actual diversity is estimated to be much higher than previously reported. Myanmar and Thailand are adjacent countries that together occupy more than the half the area of continental Tropical Asia. This geographic area is diverse ecologically, ranging from cool-temperate to tropical climates, and includes from coast, rainforests and high mountain elevations. An updated checklist of aquatic plants, which includes 78 species in 44 genera from 24 families, are presented based on floristic works. This number includes seven species, that have never been listed in the previous floras and checklists. The species (excluding non-indigenous taxa were categorized by five geographic groups with the exception of to reflect the rich diversity of the countries' floras.

  7. Effect of aquatic plants on 95Zr concentration in slightly polluted water

    International Nuclear Information System (INIS)

    Shi Jianjun; Yang Ziyin; Chen Hui

    2004-01-01

    Effect of three aquatic plants (Ceratophyllum demersum, Azolla caroliniana and Eichhornia crassipes) on 95 Zr concentration in slightly polluted water was studied by using isotope tracer techniques. The results showed that the aquatic plants had strong ability of 95 Zr concentration in water. The concentration factor (CF) were from 56.78 to 112.94, so three aquatic plants were suggested be bio-indicators for 95 Zr polluted water. The specific activity of 95 Zr in water decreased with time when the aquatic plants were put in slightly 95 Zr polluted water. The descent of specific activity of 95 Zr in water was very quick during the beginning period (0-3d). The time for the specific activity reduced to 50% was only 3 days, indicating that theres aquatic plants could be used to purge slightly 95 Zr polluted water. The effect of Eichhornia crassipes on purging 95 Zr in water was the best among the three aquatic plants. The specific activity of 95 Zr in bottom clay only decreased 5% after putting aquatic plants in water, indicating that desorption of 95 Zr from bottom clay was not easy. As the bottom clay had strong ability of adsorption and fixation to 95 Zr, the effect of aquatic plant on purging 95 Zr adsorbed by bottom clay was not visible

  8. Ecological and human health risks from metal(loid)s in peri-urban soil in Nanjing, China.

    Science.gov (United States)

    Ding, Zhuhong; Hu, Xin

    2014-06-01

    In order to investigate the ecological and human health risks of metal(loid)s (Cu, Pb, Zn, Ni, Cd, Mn, Cr, and As) in peri-urban soils, 43 surface soil samples were collected from the peri-urban area around Nanjing, a megacity in China. The average contents were 1.19, 67.8, 37.6, 105, 167, 44.6, 722, and 50.8 mg kg(-1) for Cd, Cr, Ni, Pb, Zn, Cu, Mn, and As, respectively. A significant positive correlation was found between Cu, Pb, Zn, Cd, Mn, and As (p urban soil samples. Potential ecological risk indices show that the metal(loid)s in the soil could result in higher ecological risks. Cd is the main contributor to the risk, followed by As. The levels of Cu, Pb, Zn, Cd, Mn, and As in stomach and intestinal phases show a positive linear correlation with their total contents. Mn, Zn, Ni, Cd, and Pb in stomach phase showed higher bioaccessibility, while in intestinal phase, Cu, Cr, and As had the higher bioaccessibility. The carcinogenic risk in children and adults posed by As, Pb, and Cr via ingestion was deemed acceptable. The non-carcinogenic risks posed by these metal(loid)s via ingestion to children are higher than to adults and mainly result from As.

  9. The Philani Mentor Mothers Intervention: Neighbourhood wide impact on child growth in Cape Town's peri-urban settlements.

    Science.gov (United States)

    Tomlinson, Mark; Hartley, Mary; le Roux, Ingrid; Rotheram-Borus, Mary Jane

    2016-01-01

    The purpose of this research was to determine whether or not routine home visiting (by the Philani Maternal Child Health and Nutrition Project) influences the prevalence of stunted, wasted and underweight children in Cape Town peri-urban settlements. The study was a cross-sectional cohort in which weight and height measurements were collected for all children from 24 matched neighbourhoods; three years earlier 12 of these neighbourhoods were randomized to receive the home visiting intervention and 12 did not. The research took place at all households located within the 24 neighbourhoods in Khayelitsha and Mfuleni peri-urban settlements. Participants included 8715 children aged 0-6 years old (4694 intervention; 4021 control). A total of 41.3% of children were stunted, 3.1% were underweight and 1.4% were wasted. Children in the intervention group were significantly less likely to be underweight or severely underweight for age than children in the control group. While the rates of stunting were also significantly lower in intervention areas, the effect was not clinically significant, and no significant differences were found between the study arms on the prevalence of wasting. The Philani model is effective in the prevention and rehabilitation of underweight children. Philani could strengthen their intervention by focussing specifically on screening for child stunting in addition to underweight children. The results also suggests that efforts to address the long-term adverse effects of undernutrition require structural and economic transformation, in addition to socio-medical intervention.

  10. Negotiating the labyrinth of modernity's promise a paradigm analysis of energy poverty in peri-urban Kumasi, Ghana

    Science.gov (United States)

    Odarno, Lily Ameley

    Energy poverty in developing countries has been conventionally attributed to a lack of access to sufficient, sustainable and modern forms of energy (ESMAP 2001; Modi et al. 2006). Per this definition, Sub--Saharan Africa is the most energy poor region in the world today. In line with this, efforts at addressing energy poverty in the region have concentrated on the expansion of access to modern energy sources, particularly electricity. In spite of the implementation of diverse energy development interventions, access to modern energy services remains limited. That energy poverty remains one of the most pressing challenges in Sub--Saharan Africa today in spite of the many decades of energy development necessitates a candid and thorough re--evaluation of the questions that have been traditionally asked about this issue and the solutions that have been offered in response to it. Based on theoretical analyses and empirical studies in peri--urban Kumasi, Ghana, this study attempts to offer some of the much needed re--evaluations. Using Kuhn's paradigm approach as a conceptual tool, this dissertation identifies peri--urban energy poverty as a paradigm--scale conflict in the modern arrangement of energy--development relations. By emphasizing the importance of context and political economy in understanding energy poverty, the study proposes strategies for an alternative paradigm in which energy--development relations are fundamentally redefined; one which enlists appropriate knowledge, technologies, and institutions in addressing the needs of the energy poor in ways which promote environmental values, social equity and sustainable livelihoods.

  11. Phthalate esters (PAEs): Emerging organic contaminants in agricultural soils in peri-urban areas around Guangzhou, China

    International Nuclear Information System (INIS)

    Zeng Feng; Cui Kunyan; Xie Zhiyong; Wu Lina; Liu Min; Sun Guoquan; Lin Yujun; Luo Danling; Zeng, Zunxiang

    2008-01-01

    This study reports the first data on the concentrations and distribution of phthalate esters (PAEs) in the agricultural soils from the peri-urban areas of Guangzhou city. Σ 16 PAEs concentrations ranged from 0.195 to 33.6 μg g -1 -dry weight (dw). Elevated levels of PAEs were recorded in the vegetable fields located next to the urban districts, and a decreasing trend exists following the distance away from the urban center. Diisobutyl phthalate (DiBP), Di-n-butyl phthalate (DnBP), and Di(2-ethylhexyl) phthalate (DEHP) dominated the PAEs in the agricultural soils. Significant relationship (correlation coefficient R 2 = 0.85, p < 0.01, n = 40) was present between the accumulation of PAEs and total organic carbons in agricultural soils. In addition, both pH and texture of soils are found to be important factors affecting the level of PAEs. This study shows that the agricultural soils in the peri-urban area of Guangzhou city were moderately polluted by PAEs. - PAEs are determined in agricultural soils at high concentration levels, which imply a potential risk for the food chain

  12. A new framework for modeling urban land expansion in peri-urban area by combining multi-source datasets and data assimilation

    Science.gov (United States)

    Zhang, Z.; Xiao, R.; Li, X.

    2015-12-01

    Peri-urban area is a new type region under the impacts of both rural Industrialization and the radiation of metropolitan during rapid urbanization. Due to its complex natural and social characteristics and unique development patterns, many problems such as environmental pollution and land use waste emerged, which became an urgent issue to be addressed. Study area in this paper covers three typical peri-urban districts (Pudong, Fengxian and Jinshan), which around the Shanghai inner city. By coupling cellular automata and multi-agent system model as the basic tools, this research focus on modelling the urban land expansion and driving mechanism in peri-urban area. The big data is aslo combined with the Bayesian maximum entropy method (BME) for spatiotemporal prediction of multi-source data, which expand the dataset of urban expansion models. Data assimilation method is used to optimize the parameters of the coupling model and minimize the uncertainty of observations, improving the precision of future simulation in peri-urban area. By setting quantitative parameters, the coupling model can effectively improve the simulation of the process of urban land expansion under different policies and management schemes, in order to provide scientificimplications for new urbanization strategy. In this research, we precise the urban land expansion simulation and prediction for peri-urban area, expand the scopes and selections of data acquisition measurements and methods, develop the new applications of the data assimilation method in geographical science, provide a new idea for understanding the inherent rules of urban land expansion, and give theoretical and practical support for the peri-urban area in urban planning and decision making.

  13. Remote Sensing and Modeling for Improving Operational Aquatic Plant Management

    Science.gov (United States)

    Bubenheim, Dave

    2016-01-01

    The California Sacramento-San Joaquin River Delta is the hub for California’s water supply, conveying water from Northern to Southern California agriculture and communities while supporting important ecosystem services, agriculture, and communities in the Delta. Changes in climate, long-term drought, water quality changes, and expansion of invasive aquatic plants threatens ecosystems, impedes ecosystem restoration, and is economically, environmentally, and sociologically detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California and local governments to develop science-based, adaptive-management strategies for the Sacramento-San Joaquin Delta. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and waterway managers make science-informed decisions regarding management and outcomes. The team provides a comprehensive understanding of agricultural and urban land use in the Delta and the major water sheds (San Joaquin/Sacramento) supplying the Delta and interaction with drought and climate impacts on the environment, water quality, and weed growth. The team recommends conservation and modified land-use practices and aids local Delta stakeholders in developing management strategies. New remote sensing tools have been developed to enhance ability to assess conditions, inform decision support tools, and monitor management practices. Science gaps in understanding how native and invasive plants respond to altered environmental conditions are being filled and provide critical biological response parameters for Delta-SWAT simulation modeling. Operational agencies such as the California Department of Boating and Waterways provide testing and act as initial adopter of decision support tools. Methods developed by the project can become routine land and water management tools in complex river delta systems.

  14. Uranium removal from water by five aquatic plants

    International Nuclear Information System (INIS)

    Hu Nan; Ding Dexin; Li Guangyue; Wang Yongdong; Li Le; Zheng Jifang

    2012-01-01

    Hydroponic solution culture experiments were conducted on the growth of Eichhornia crassipes, Lemna minor L, Azolla imbircata, Potamogeton crispus, and Alligator alternanthera Herb in water with 0.15, 1.50 and 15.00 mg . L -1 concentrations of uranium, and on the uranium removal from the water by the aquatic plants. For the 21 days of hydroponic solution culture experiments, Azolla imbircata exhibited the strongest resistance to uranium and its growth inhibition rates induced by the water with 0.15, 1.50 and 15.00 mg · L -1 concentrations of uranium were 4.56%, 2.48%, 6.79%, respectively, and the uranium removal rates from the water by the plant amounted to 94%, 97% and 92%, respectively. Further experiments revealed that the most uranium removal could be achieved when 7.5 g Azolla imbircata was grown in 1 L of water, and the time required for the plant to reduce the uranium concentration in water with 1.25, 2.50, 5.00 and 10.00 mg · L -l concentrations of uranium below that stipulated in the national emission standards of China were 17, 19, 23 and 25 days, respectively. The results have laid foundation for further studies of phytoremediation of uranium contaminated water. (authors)

  15. The impact of human activities in soils and sediments on urban and peri-urban areas

    Science.gov (United States)

    Horváth, Adrienn; Szita, Renáta; Bidló, András; Gribovszki, Zoltán

    2017-04-01

    In this current research we would like to detect the amount of the differences between the natural, the suburb and the urban areas. The aim of the investigation was to determine the impact of human activities on urban and peri-urban soils of Sopron. 72 urban soil samples were collected on 6 sub-catchments for analysing the background pollution of Rák Creek in Sopron. After the analysis of chemical and physical properties of urban soil samples, two element fractions - the total (HNO3+H2O2-extractable) and the available NH4-acetate+EDTA-extractable - were used for element determination. Toxic elements were measured by ICP-OES in the urban soils and the sediments as well. in case of sediment samples from thalweg and dead region. That were collected from the bank of the Rák creek at 6 sampling points to calculate enrichment factors to assess the possible harmful effects of toxic metals. The field and laboratory data were processed using a GIS softver DigiTerraMap. Six elements were selected for analyses Co, Cd, Ni, Cu, Zn, Pb, which are prominent in urban soils. Statistical analysis was carried out with Microsoft Office Excel 2003, STATISTICA 11 and R Studio. C2 program was used for the distribution of toxic elements. Based on results e.g. pH, etc., there were definite differences between natural HAZ, BAN, semi-natural HAJNAL and urbanized FASOR, GYORI, TESCO areas and significant differences in toxic element distribution as well. The toxic elements of sediment showed the following tendency: Pb > Zn > Cu > Ni = Co. The Co and the Ni values were lower than the natural background limits. The Cutotal exceeded the first interventional pollution limit > 75 mg.kg-1 and the available Zn and Pb were higher than the suggested interventional pollution limits Znavailable >40 mg.kg-1; Pbavailable >25 mg.kg-1 at GYORI sub-catchment. The EF values were generally higher in dead region than in thalweg except of GYORI point. Lead had the highest EF values between the five metals

  16. Broad-Scale Comparison of Photosynthesis in Terrestrial and Aquatic Plant Communities

    DEFF Research Database (Denmark)

    Sand-Jensen, Kaj; Krause-Jensen, D.

    1997-01-01

    Comparisons of photosynthesis in terrestrial and aquatic habitats have been impaired by differences in methods and time-scales of measurements. We compiled information on gross photosynthesis at high irradiance and photosynthetic efficiency at low irradiance from 109 published terrestrial studies...... communities probably due to more efficient light utilization and gas exchange in the terrestrial habitats. By contrast only small differences were found within different aquatic plant communities or within different terrestrial plant communities....... of forests, grasslands and crops and 319 aquatic studies of phytoplankton, macrophyte and attached microalgal communities to test if specific differences existed between the communities. Maximum gross photosynthesis and photosynthetic efficiency were systematically higher in terrestrial than in aquatic...

  17. Heavy metal content of selected African leafy vegetables planted in ...

    African Journals Online (AJOL)

    Heavy metal content of selected African leafy vegetables planted in urban and peri-urban Nairobi, Kenya. ... African Journal of Environmental Science and Technology ... Government clean-up activities and monitoring of waste disposal is ...

  18. Remote sensing of aquatic plants. [New York, Florida, Texas, Louisiana, Mississippi, South Carolina

    Science.gov (United States)

    Long, K. S.; Link, L. E., Jr.

    1977-01-01

    Various sensors were tested in terms of their ability to detect and discriminate among noxious aquatic macrophytes. A survey of researchers currently studying the problem and a brief summary of their work is included. Results indicated that the sensor types best suited to assessment of the aquatic environment are color, color infrared, and black-and-white infrared film, which furnish consistently high contrasts between aquatic plants and their surroundings.

  19. Learner Perceptions of the Introduction of Computer-Assisted Learning in Mathematics at a Peri-Urban School in South Africa

    Science.gov (United States)

    Hartley, M. Shaheed; Treagust, David F.

    2014-01-01

    This study responded to a national call to improve the outcomes in mathematics in the Grade 12 matriculation examination in South Africa by reporting learners' perceptions of the introduction of computer-assisted learning in their mathematics classrooms. Three Grade 12 mathematics classes in a peri-urban school in South Africa were visited over a…

  20. REPAiR: REsource Management in Peri-urban AReas: Going Beyond Urban Metabolism : D6.1 Governance and Decision-Making Processes in Pilot Cases

    NARCIS (Netherlands)

    Arlati, Alessandro; Berruti, Gilda; Dabrowski, M.M.; Fraser, Thomas; Heukens, Erwin; Knieling, Jörg; Mezei, C; Obersteg, Andreas; Oppe, Orsolya; Palestino, Maria Federica; Varju, Viktor

    2017-01-01

    REPAiR will develop, test, and implement strategies for improved urban
    metabolisms in six peri-urban living labs (›PULLs‹) in the case study areas of
    Amsterdam, Ghent, Hamburg, Łódź, Naples, and Pécs. In the frame of REPAiR a
    geodesign decision support environment (GDSE) will be

  1. Determinants of late antenatal care presentation in rural and peri-urban communities in South Africa: A cross-sectional study.

    Science.gov (United States)

    Ebonwu, Joy; Mumbauer, Alexandra; Uys, Margot; Wainberg, Milton L; Medina-Marino, Andrew

    2018-01-01

    To investigate and compare determinates for delayed first presentation to antenatal care (ANC) services. A cross-sectional study was conducted amongst pregnant women attending their first ANC visit in rural Capricorn District and peri-urban Tlokwe sub-district communities in South Africa. Data collection included questionnaires and medical record abstraction. Bivariate and multivariate analyses assessed factors associated with late ANC presentation. We recruited 807 pregnant women. Of these, 51% of rural women and 28% of peri-urban women presented late for first ANC. Rural women were more likely to present late for first ANC (AOR = 2.65; 95% CI 1.98-3.55) and report barriers to accessing ANC services (PANC presentation in rural communities was associated with being married (AOR = 2.36; 95% CI 1.33-4.19), employed (AOR = 1.90; 95% CI 1.03-3.50), ANC after presenting early (AOR 0.51; 95% CI 0.30-0.89) and being pregnant for the first time (AOR = 0.56; 95% CI 0.34-0.94). Both rural and peri-urban women had high rates of late presentation for first ANC. However, women in the rural communities were more likely to present late. Unplanned pregnancy was an independent risk factor in both rural and peri-urban communities. Interventions around family planning, especially for adolescent girls and young women, are needed to improve early presentation for ANC.

  2. Increasing nutrient use efficiency through improved feeding and manure manegement in urban and peri-urban livestock units of a West African city: A scenario analysis

    NARCIS (Netherlands)

    Diogo, V.; Schlecht, E.; Buerkert, A.; Rufino, M.C.; Wijk, van M.T.

    2013-01-01

    In many African cities urban and peri-urban agriculture (UPA) plays a major role in creating jobs and contributing to food security. However, many small-scale UPA systems are characterised by excessive nutrient inputs to the livestock unit and poor handling of manure. To assess the impact of

  3. Exploring the diversity of urban and peri-urban agricultural systems in Sudano-Sahelian West Africa: An attempt towards a regional typology

    NARCIS (Netherlands)

    Dossa, L.C.; Abdulkadir, A.; Amadou, H.; Sangare, S.; Schlecht, E.

    2011-01-01

    Developing appropriate and innovative technologies and policies to respond to the challenges that urban and peri-urban agriculture (UPA) faces in West Africa requires a better understanding of the existing production systems. Although there is an increasing recognition of the importance of UPA in

  4. Exploring the Use of ICTs in Learning and Disseminating Livestock Husbandry Knowledge to Urban and Peri-Urban Communities in Tanzania

    Science.gov (United States)

    Angello, Consolata

    2015-01-01

    This paper discusses the importance of various Information and Communication Technologies (ICTs) in learning and disseminating relevant information on livestock husbandry in Tanzania. The paper is part of a study that investigated the extent of use of ICTs by urban and peri-urban livestock keepers and how access and dissemination of livestock…

  5. Sedimentary records of sewage pollution using faecal markers in contrasting peri-urban shallow lakes

    Energy Technology Data Exchange (ETDEWEB)

    Vane, C.H., E-mail: chv@bgs.ac.uk [British Geological Survey, Keyworth, Nottingham, NG12 5GG (United Kingdom); Kim, A.W. [British Geological Survey, Keyworth, Nottingham, NG12 5GG (United Kingdom); McGowan, S. [School of Geography, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Leng, M.J.; Heaton, T.H.E.; Kendrick, C.P. [NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham, NG12 5GG (United Kingdom); Coombs, P. [British Geological Survey, Keyworth, Nottingham, NG12 5GG (United Kingdom); Yang, H. [Environmental Change Research Centre, University College London, WC1 6BT (United Kingdom); Swann, G.E.A. [NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham, NG12 5GG (United Kingdom)

    2010-12-15

    slurry input to Coneries Pond. The greater concentration of {beta}-sitosterol in sediments from Church and Clifton Ponds as compared to Coneries is attributed in part to their greater diversity and extent of aquatic plants and avian faeces.

  6. Ash characteristics and plant nutrients in some aquatic biomasses

    Science.gov (United States)

    Masto, Reginald; Pandit, Ankita; George, Joshy; Mukhopadhyay, Sangeeta; Selvi, Vetrivel; Ram, Lal

    2016-04-01

    Aquatic biomasses are explored as potential fuel source for direct combustion because of their faster growth and no land requirement. The energy density and the ash characteristics of the aquatic biomasses are to be evaluated for their suitability for energy extraction. In the study, four aquatic plant samples namely Eichornia crassipes, Hydrilla verticilleta, Lemna minor, Spirogyra spp were collected from a pond in Digwadih Campus of Central Institute of Mining and Fuel Research, Dhanbad. The biomasses were air dried, powdered and ashed at different temperatures. Volatile C was relatively lower in Spirogyra and Hydrilla (53 %) than Eichornia (62.6 %) or Lemna (59.7 %), whereas fixed C was higher for Eichornia and Lemna (about 10 %) and lower for Hydrilla (1 %). Ultimate analysis showed that the carbon content was in the order Eichornia > Lemna > Spirogyra > Hydrilla. The IR spectra of each raw biomass is compared to their respective ashes obtained at different temperatures (500-900°C). With increase in ashing temperature from 500-900°C there is gradual breakdown of the cellulosic structure hence, peaks around 2900-2800cm-1 caused by aliphatic C-H vibration tends to disappear slowly in ash. More number of peaks appears at lower wavenumbers in ashes of all the biomass samples indicating towards increased percentage of inorganic ion species. Considerable enrichment of SiO2 is validated with prominent peaks at 1100-900 cm-1 in all the ashes. Lemna and Spirogyra has a similar ash composition (Si > Al > Ca > K), whereas, Ca was higher in Hydrilla (Si > Ca > K > Al). Eichornia (Si > K > Ca > Al) has higher K and Ca than Al. SiO2 and Al2O3 were higher in Spirogyra, while SiO2 and CaO in Eichornia and Hydrilla. K first increased from 500-700/800⁰C, and then decreased from 800-900⁰C. Cl is lost slowly in ash from 500-700/800⁰C and then by a drastic reduction from 800-900⁰C. S is enhanced in ash at all temperatures although the change is quite small. Most of the Cl

  7. Limited Evidence for Infection of Urban and Peri-urban Nonhuman Primates with Zika and Chikungunya Viruses in Brazil.

    Science.gov (United States)

    Moreira-Soto, Andres; Carneiro, Ianei de Oliveira; Fischer, Carlo; Feldmann, Marie; Kümmerer, Beate M; Silva, Nama Santos; Santos, Uilton Góes; Souza, Breno Frederico de Carvalho Dominguez; Liborio, Fernanda de Azevedo; Valença-Montenegro, Mônica Mafra; Laroque, Plautino de Oliveira; da Fontoura, Fernanda Rosa; Oliveira, Alberto Vinicius Dantas; Drosten, Christian; de Lamballerie, Xavier; Franke, Carlos Roberto; Drexler, Jan Felix

    2018-01-01

    Chikungunya virus (CHIKV) and Zika virus (ZIKV) emerged in the Americas in 2013. Limited antigenic variability of CHIKV and ZIKV may restrict urban transmission cycles due to population protective immunity. In Africa, sylvatic transmission cycles involving nonhuman primates (NHP) are known for CHIKV and ZIKV, causing cyclic reemergence in humans. To evaluate whether sylvatic cycles can be expected in Latin America, we tested 207 NHP collected between 2012 and 2017 in urban and peri-urban settings in Brazil for infection with ZIKV and CHIKV. No animal tested positive for viral RNA in genus-specific and species-specific reverse transcription-PCR (RT-PCR) assays. In contrast, six animals (2.9%) from the families Atelidae, Callitrichidae, and Cebidae showed ZIKV-specific antibodies and 11 (5.3%) showed CHIKV-specific antibodies in plaque reduction neutralization tests (PRNT). Reactivity was monotypic against either ZIKV or CHIKV in all cases, opposing unspecific virucidal activity of sera. PRNT endpoint titers were low at 1:40 in all NHP, and positive specimens did not correspond to the likely dispersal route and time of introduction of both arboviruses. All antibody-positive samples were therefore tested against the NHP-associated yellow fever virus (YFV) and Mayaro virus (MAYV) and against the human-associated dengue virus (DENV) by PRNT. Two ZIKV-positive samples were simultaneously DENV positive and two CHIKV-positive samples were simultaneously MAYV positive, at titers of 1:40 to 1:160. This suggested cross-reactive antibodies against heterologous alphaviruses and flaviviruses in 24% of ZIKV-positive/CHIKV-positive sera. In sum, low seroprevalence, invariably low antibody titers, and the distribution of positive specimens call into question the capability of ZIKV and CHIKV to infect New World NHP and establish sylvatic transmission cycles. IMPORTANCE Since 2013, Zika virus (ZIKV) and chikungunya virus (CHIKV) have infected millions of people in the Americas via

  8. Peri-urban areas and food-energy-water nexus sustainability and resilience strategies in the age of climate change

    CERN Document Server

    Magoni, Marcello; Menoni, Scira

    2017-01-01

    This book explores the nexus among food, energy and water in peri-urban areas, demonstrating how relevant this nexus is for environmental sustainability. In particular it examines the effective management of the nexus in the face of the risks and trade-offs of mitigation policies, and as a mean to create resilience to climate change. The book delineates strategies and actions necessary to develop and protect our natural resources and improve the functionality of the nexus, such as: integrated management of the major resources that characterize the metabolism of a city, stronger coordination among stakeholders who often weight differently the services that are relevant to their individual concerns, integration of efforts towards environmental protection, adaptation to and prevention of climate change and disaster risks mitigation.

  9. Utilisation of oral health services, oral health needs and oral health status in a peri-urban informal settlement.

    Science.gov (United States)

    Westaway, M S; Viljoen, E; Rudolph, M J

    1999-04-01

    Interviews were conducted with 294 black residents (155 females and 138 males) of a peri-urban informal settlement in Gauteng to ascertain utilisation of oral health services, oral health needs and oral health status. Only 37 per cent of the sample had consulted a dentist or medical practitioner, usually for extractions. Teenagers and employed persons were significantly less likely to utilise dentists than the older age groups and unemployed persons. Forty per cent were currently experiencing oral health problems such as a sore mouth, tooth decay and bleeding/painful gums. Two hundred and twelve (73 per cent) interviewees wanted dental treatment or advice. Residents who rated their oral health status as fair or poor appeared to have the greatest need for oral health services. The use of interviews appears to be a cost-effective method of determining oral morbidity.

  10. Limited Evidence for Infection of Urban and Peri-urban Nonhuman Primates with Zika and Chikungunya Viruses in Brazil

    Science.gov (United States)

    2018-01-01

    ABSTRACT Chikungunya virus (CHIKV) and Zika virus (ZIKV) emerged in the Americas in 2013. Limited antigenic variability of CHIKV and ZIKV may restrict urban transmission cycles due to population protective immunity. In Africa, sylvatic transmission cycles involving nonhuman primates (NHP) are known for CHIKV and ZIKV, causing cyclic reemergence in humans. To evaluate whether sylvatic cycles can be expected in Latin America, we tested 207 NHP collected between 2012 and 2017 in urban and peri-urban settings in Brazil for infection with ZIKV and CHIKV. No animal tested positive for viral RNA in genus-specific and species-specific reverse transcription-PCR (RT-PCR) assays. In contrast, six animals (2.9%) from the families Atelidae, Callitrichidae, and Cebidae showed ZIKV-specific antibodies and 11 (5.3%) showed CHIKV-specific antibodies in plaque reduction neutralization tests (PRNT). Reactivity was monotypic against either ZIKV or CHIKV in all cases, opposing unspecific virucidal activity of sera. PRNT endpoint titers were low at 1:40 in all NHP, and positive specimens did not correspond to the likely dispersal route and time of introduction of both arboviruses. All antibody-positive samples were therefore tested against the NHP-associated yellow fever virus (YFV) and Mayaro virus (MAYV) and against the human-associated dengue virus (DENV) by PRNT. Two ZIKV-positive samples were simultaneously DENV positive and two CHIKV-positive samples were simultaneously MAYV positive, at titers of 1:40 to 1:160. This suggested cross-reactive antibodies against heterologous alphaviruses and flaviviruses in 24% of ZIKV-positive/CHIKV-positive sera. In sum, low seroprevalence, invariably low antibody titers, and the distribution of positive specimens call into question the capability of ZIKV and CHIKV to infect New World NHP and establish sylvatic transmission cycles. IMPORTANCE Since 2013, Zika virus (ZIKV) and chikungunya virus (CHIKV) have infected millions of people in the

  11. Development of a Methodology for the Derivation of Aquatic Plant Water Quality Criteria

    Science.gov (United States)

    Aquatic plants form the base of most aquatic food chains, comprise biodiversity-building habitats and are functionally important in carbon assimilation and oxygen evolution. The USEPA, as stated in the Clean Water Act, establishes criterion values for various pollutants found in ...

  12. Using Remote Sensing Mapping and Growth Response to Environmental Variability to Aide Aquatic Invasive Plant Management

    Science.gov (United States)

    Bubenheim, David L.; Schlick, Greg; Genovese, Vanessa; Wilson, Kenneth D.

    2018-01-01

    Management of aquatic weeds in complex watersheds and river systems present many challenges to assessment, planning and implementation of management practices for floating and submerged aquatic invasive plants. The Delta Region Areawide Aquatic Weed Project (DRAAWP), a USDA sponsored area-wide project, is working to enhance planning, decision-making and operational efficiency in the California Sacramento-San Joaquin Delta. Satellite and airborne remote sensing are used map (area coverage and biomass density), direct operations, and assess management impacts on plant communities. Archived satellite records enable review of results following previous climate and management events and aide in developing long-term strategies. Examples of remote sensing aiding effectiveness of aquatic weed management will be discussed as well as areas for potential technological improvement. Modeling at local and watershed scales using the SWAT modeling tool provides insight into land-use effects on water quality (described by Zhang in same Symposium). Controlled environment growth studies have been conducted to quantify the growth response of invasive aquatic plants to water quality and other environmental factors. Environmental variability occurs across a range of time scales from long-term climate and seasonal trends to short-term water flow mediated variations. Response time for invasive species response are examined at time scales of weeks, day, and hours using a combination of study duration and growth assessment techniques to assess water quality, temperature (air and water), nitrogen, phosphorus, and light effects. These provide response parameters for plant growth models in response to the variation and interact with management and economic models associated with aquatic weed management. Plant growth models are to be informed by remote sensing and applied spatially across the Delta to balance location and type of aquatic plant, growth response to altered environments and

  13. Association of Roadway Proximity with Indoor Air Pollution in a Peri-Urban Community in Lima, Peru

    Directory of Open Access Journals (Sweden)

    Lindsay J. Underhill

    2015-10-01

    Full Text Available The influence of traffic-related air pollution on indoor residential exposure is not well characterized in homes with high natural ventilation in low-income countries. Additionally, domestic allergen exposure is unknown in such populations. We conducted a pilot study of 25 homes in peri-urban Lima, Peru to estimate the effects of roadway proximity and season on residential concentrations. Indoor and outdoor concentrations of particulate matter (PM2.5, nitrogen dioxide (NO2, and black carbon (BC were measured OPEN ACCESS Int. J. Environ. Res. Public Health 2015, 12 13467 during two seasons, and allergens were measured in bedroom dust. Allergen levels were highest for dust mite and mouse allergens, with concentrations above clinically relevant thresholds in over a quarter and half of all homes, respectively. Mean indoor and outdoor pollutant concentrations were similar (PM2.5: 20.0 vs. 16.9 μg/m3, BC: 7.6 vs. 8.1 μg/m3, NO2: 7.3 vs. 7.5 ppb, and tended to be higher in the summer compared to the winter. Road proximity was significantly correlated with overall concentrations of outdoor PM2.5 (rs = −0.42, p = 0.01 and NO2 (rs = −0.36, p = 0.03, and outdoor BC concentrations in the winter (rs = −0.51, p = 0.03. Our results suggest that outdoor-sourced pollutants significantly influence indoor air quality in peri-urban Peruvian communities, and homes closer to roadways are particularly vulnerable.

  14. Epidemiology of tobacco use and dependence in adults in a poor peri-urban community in Lima, Peru

    Directory of Open Access Journals (Sweden)

    Weygandt Paul

    2012-03-01

    Full Text Available Abstract Background Tobacco smoking is an important public health concern worldwide leading to both chronic disease and early death. In Latin America, smoking prevalence is estimated at approximately 30% and prior studies suggest that the prevalence in Peru is 22% to 38%. We sought to determine the prevalence of daily smoking in a poor peri-urban community in Lima, Peru. Methods We conducted a cross-sectional survey in a random sample of adults ≥40 years of age living in Pampas de San Juan de Miraflores, Lima, Peru. We asked participants to respond to a survey that included questions on sociodemographics, tobacco use and dependence. Results We enrolled 316 participants. Average monthly household income was ≤ 400 USD and nearly all homes had running water, sewage, and electricity. Most individuals had not completed high school. Smoking prevalence was 16% overall, yet daily smoking prevalence was 1.9%. Former daily smokers comprised 3.8% of current nonsmokers and 9.1% current occasional smokers. Average scores for the Fagerstrom Test for Nicotine Dependence for daily smokers and occasional smokers were 1.5 and 0, respectively. Conclusions Daily use of tobacco is uncommon among adults in peri-urban communities of Lima, Peru, unlike their counterparts in Lima and other Latin American capital cities. Tobacco dependence is also low. Hence, efforts aimed at primary prevention are of utmost importance in these communities. This study provides an accurate baseline using an internationally recognized assessment tool (Global Adult Tobacco Survey, allowing for accurate assessment of tobacco control interventions over time.

  15. Enhancing faecal sludge management in peri-urban areas of Lusaka through faecal sludge valorisation: challenges and opportunities

    Science.gov (United States)

    Tembo, J. M.; Nyirenda, E.; Nyambe, I.

    2017-03-01

    Lusaka, the capital city of Zambia, has two million inhabitants with 70% residing in peri-urban areas. Ninety (90) % of this population employ pit latrines for excretion generating approximately 22,680 tons of faecal sludge per annum. This sludge is inadequately managed hence of the generated amount, over 60% remains within the residential environment thereby compromising both the environment and public health. To foster a solution to this problem, a study was commissioned to assess faecal sludge valorisation potential and how it would impact on Faecal Sludge Management. The study evaluated policy, institutional and regulatory frameworks, sanitation practices including latrine construction and usage aspects and also characterised the faecal sludge for selected parameters relevant to valorisation. Four peri-urban areas were adopted as study sites. Policy issues together with existing institutional and regulatory frameworks were assessed through literature review. Sanitation practices were evaluated through physical observations, focus group discussions, interviews and questionnaire administration. Faecal sludge characterisation was through sampling and analysis. It was observed that there are policy gaps in fostering faecal sludge valorisation. Sanitation practices and latrines construction also do not favour valorisation. The quality of the raw sludge has potential for valorisation though again, some parameters like solid waste content require drastic changes in sanitation practices in order not to compromise the reuse potential of the sludge. It was concluded that if faecal sludge management is to be enhanced through valorisation, there is need to have policies promoting pit latrine faecal sludge reuse and strengthened regulatory and institutional frameworks in this respect.

  16. Coliform Contamination of Peri-urban Grown Vegetables and Potential Public Health Risks: Evidence from Kumasi, Ghana.

    Science.gov (United States)

    Abass, Kabila; Ganle, John Kuumuori; Adaborna, Eric

    2016-04-01

    Peri-urban vegetable farming in Ghana is an important livelihood activity for an increasing number of people. However, increasing quality and public health concerns have been raised, partly because freshwater availability for irrigation purposes is a major constraint. This paper investigated on-farm vegetable contamination and potential health risks using samples of lettuce, spring onions and cabbage randomly selected from 18 vegetable farms in peri-urban Kumasi, Ghana. Vegetable samples were tested for total coliform, fecal coliform, Escherichia coli and Salmonella spp. bacteria contamination using the Most Probable Number method. Results show high contamination levels of total and fecal coliforms, and Escherichia coli bacteria in all 18 vegetable samples. The mean total coliform/100 ml concentration for spring onions, lettuce and cabbage were 9.15 × 10(9), 4.7 × 10(7) and 8.3 × 10(7) respectively. The mean fecal coliform concentration for spring onions, lettuce and cabbage were also 1.5 × 10(8), 4.15 × 10(7) and 2.15 × 10(7) respectively, while the mean Escherichia coli bacteria contamination for spring onions, lettuce and cabbage were 1.4 × 10(8), 2.2 × 10(7) and 3.2 × 10(7) respectively. The level of total coliform, fecal coliform and Escherichia coli bacteria contamination in all the vegetable samples however declined as the distance between the main water source (Wiwi River) and farms increases. Nonetheless, all contamination levels were well above acceptable standards, and could therefore pose serious public health risks to consumers. Increased education and supervision of farmers, as well as public health and food hygiene education of consumers, are critical to reducing on-farm vegetable contamination and the health risks associated with consumption of such vegetables.

  17. Evaluating the potential of multi-purpose nature based solutions in peri-urban landscapes - a preliminary assessment

    Science.gov (United States)

    Geris, Josie; Wilkinson, Mark; Stutter, Marc; Guenther, Daniel; Soulsby, Chris

    2016-04-01

    Many communities across the world face the increasing challenge of balancing water quantity and quality protection and improvement with accommodating new growth and urban development. Urbanisation is typically associated with detrimental changes in water quality, sediment delivery, and effects on water storage and flow pathways (e.g. increases in flooding). Current mitigation solutions are typically based on isolated design strategies used at specific small scale sites and for storm water only. More holistic catchment scale approaches are urgently required to effectively manage the amount of water flows and protect the raw water quality in peri-urban landscapes. This project aims to provide a better understanding of the connectivity between natural and managed flow pathways, storage, and biogeochemical processes in the peri-urban landscape to eventually aid a more integrated water quantity and quality control design. For an actively urbanising catchment in NE Scotland we seek to understand the spatio-temporal character of the natural flow pathways and associated water quality, and how these may be used to support the design of nature based solutions during urbanisation. We present preliminary findings from a dense and multiscale monitoring network that includes hydrometric, tracer (stable water isotopes) and water quality (turbidity (sediment), nitrate, phosphate) data during a range of contrasting hydroclimatological conditions and at different stages of the development of urban infrastructure. These demonstrate a highly variable nature, both temporally and spatially, with water quality dynamics out of sync with storm responses and depending on management practices. This highlights potential difficulties for managing water quantity and quality simultaneously at the catchment scale, and suggests that a treatment train approach may be required. Well-designed nature based solutions that tackle both water quantity and quality issues will require adaptability and a

  18. Research on accumulating the harmful elements in geothermal water with aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Bingbing; Guo, Licong; Peng, Yongqing [Institute of Energy Sources (China); The Institute of Biology (China))

    1988-11-10

    As a result of component analyses for geothermal water, environmental pollution potentialities with use of geothermal water were generally recognized with high mineral material and high content of F{sup -}in North China. Although injection methods are effective to eliminate the environment pollution of geothermal fluid, the technique and cost of injection are not practical at present yet for the technical level and financial capacity of China and other developing countries. Through the comparison of physical, chemical and biological methods, the biological method possesses low cost and great disposed quantity. After making the test for accumulating harmful elements in geothermal water with aquatic plants to find suitable one, nine kinds of aquatic plants, which can accumulate elements of Cl{sup -}, Na{sup +} and F{sup -}, were selected for further tests. As a test result, the aquatic plants which could comprehensively accumulate Na{sup +}, Cl{sup -} and F{sup -} were Ceratophyllum demersum, Mymphoides pettatum and Spirodela polyrrhiza, the aquatic plant which could comprehensively accumulate Na{sup +} and Cl{sup -} was Alternanthera philoxenoids, and the aquatic plant which could accumulate F{sup -} was Lemna minor. These aquatic plants were considered as the optimized plants for purifying geothermal water. 4 refs., 5 tabs.

  19. UPTAKE AND PHYTOTRANSFORMATION OF ORGANOPHOSPHORUS PESTICIDES BY AXENICALLY CULTIVATED AQUATIC PLANTS

    Science.gov (United States)

    The uptake and phytotransformation of organophosphorus (OP) pesticides (malathion, demeton-S-methyl, and crufomate) was investigated in vitro using the axenically aquatic cultivated plants parrot feather (Myriophyllum aquaticum), duckweed (Spirodela oligorrhiza L.), and elodea (E...

  20. Potential Use of Native and Naturalized Insect Herbivores and Fungal Pathogens of Aquatic and Wetland Plants

    National Research Council Canada - National Science Library

    Freedman, Jan E; Grodowitz, Michael J; Swindle, Robin; Nachtrieb, Julie G

    2007-01-01

    ...) scientists to identify naturalized and/or native herbivores of aquatic plants in an effort to develop alternative management strategies through an understanding of the agents' biology and ecology...

  1. Aquatic plant Azolla as the universal feedstock for biofuel production.

    Science.gov (United States)

    Miranda, Ana F; Biswas, Bijoy; Ramkumar, Narasimhan; Singh, Rawel; Kumar, Jitendra; James, Anton; Roddick, Felicity; Lal, Banwari; Subudhi, Sanjukta; Bhaskar, Thallada; Mouradov, Aidyn

    2016-01-01

    The quest for sustainable production of renewable and cheap biofuels has triggered an intensive search for domestication of the next generation of bioenergy crops. Aquatic plants which can rapidly colonize wetlands are attracting attention because of their ability to grow in wastewaters and produce large amounts of biomass. Representatives of Azolla species are some of the fastest growing plants, producing substantial biomass when growing in contaminated water and natural ecosystems. Together with their evolutional symbiont, the cyanobacterium Anabaena azollae, Azolla biomass has a unique chemical composition accumulating in each leaf including three major types of bioenergy molecules: cellulose/hemicellulose, starch and lipids, resembling combinations of terrestrial bioenergy crops and microalgae. The growth of Azolla filiculoides in synthetic wastewater led up to 25, 69, 24 and 40 % reduction of NH 4 -N, NO 3 -N, PO 4 -P and selenium, respectively, after 5 days of treatment. This led to a 2.6-fold reduction in toxicity of the treated wastewater to shrimps, common inhabitants of wetlands. Two Azolla species, Azolla filiculoides and Azolla pinnata, were used as feedstock for the production of a range of functional hydrocarbons through hydrothermal liquefaction, bio-hydrogen and bio-ethanol. Given the high annual productivity of Azolla, hydrothermal liquefaction can lead to the theoretical production of 20.2 t/ha-year of bio-oil and 48 t/ha-year of bio-char. The ethanol production from Azolla filiculoides, 11.7 × 10 3  L/ha-year, is close to that from corn stover (13.3 × 10 3  L/ha-year), but higher than from miscanthus (2.3 × 10 3  L/ha-year) and woody plants, such as willow (0.3 × 10 3  L/ha-year) and poplar (1.3 × 10 3  L/ha-year). With a high C/N ratio, fermentation of Azolla biomass generates 2.2 mol/mol glucose/xylose of hydrogen, making this species a competitive feedstock for hydrogen production compared with other bioenergy crops

  2. Insect herbivory on native and exotic aquatic plants: phosphorus and nitrogen drive insect growth and nutrient release

    NARCIS (Netherlands)

    Grutters, B.M.C.; Gross, E.M.; Bakker, E.S.

    2016-01-01

    Eutrophication and globalisation facilitate the dominance of exotic plants in aquatic ecosystems worldwide. Aquatic omnivores can provide biotic resistance to plant invasions, but little is known about whether obligate aquatic herbivores can do the same. Herbivores such as insects can decimate

  3. Influences of aquatic plants on the fate of the pyrethroid insecticide lambda-cyhalothrin in aquatic environments.

    Science.gov (United States)

    Hand, L H; Kuet, S F; Lane, M C; Maund, S J; Warinton, J S; Hill, I R

    2001-08-01

    Aquatic exposure assessments for pesticides are generally based on laboratory studies performed in water alone or water sediment systems. Although aquatic macrophytes, which include a variety of bryophytes, macroalgae, and angiosperms, can be a significant component of many aquatic ecosystems, their impact on pesticide fate is generally not included in exposure assessments. To investigate the influence of aquatic plants on the fate and behavior of the pyrethroid insecticide lambda (lambda)-cyhalothrin, two laboratory experiments (to assess adsorption and degradation) and an indoor microcosm study (to assess fate under semirealistic conditions) were conducted. In the laboratory studies, adsorption to macrophytes was extensive and essentially irreversible, and degradation occurred rapidly by cleavage of the ester bond. In the indoor microcosm, which contained water, sediment, and macrophytes from a pond, degradation was also rapid, with DT50 and DT90 values of less than 3 and 19 h, respectively, for dissipation from the water column and of less than 3 and 56 h, respectively, for the whole system. For adsorptive and readily degraded pesticides like lambda-cyhalothrin, we conclude that macrophytes have considerable influence on fate and behavior in surface waters.

  4. The aquatic habit and host plants of Paracles klagesi (Rothschild (Lepidoptera, Erebidae, Arctiinae in Brazil

    Directory of Open Access Journals (Sweden)

    Aurélio R. Meneses

    2013-09-01

    Full Text Available The aquatic habit and host plants of Paracles klagesi (Rothschild (Lepidoptera, Erebidae, Arctiinae in Brazil. The aquatic caterpillar Paracles klagesi (Rothschild, 1910 was collected from the headwaters of a stream in an ecotone between Cerrado and Babaçu forest in northeastern Brazil. The single caterpillar found was observed feeding on the macrophyte Tonina fluviatilis Aubl. (Eriocaulaceae and other aquatic plants of the family Nymphaeaceae present in the area, but also accepted as food Elodea canadensis Michx. (Hydrocharitaceae and Cabomba sp. (Cabombaceae under laboratory conditions.

  5. Improving Aquatic Plant Management in the California Sacramento-San Joaquin Delta

    Science.gov (United States)

    Bubenheim, David L.; Potter, Chris

    2018-01-01

    Management of aquatic weeds in complex watersheds and river systems present many challenges to assessment, planning and implementation of management practices for floating and submerged aquatic invasive plants. The Delta Region Areawide Aquatic Weed Project (DRAAWP), a USDA sponsored area-wide project, is working to enhance planning, decision-making and operational efficiency in the California Sacramento-San Joaquin Delta. Satellite and airborne remote sensing are used map (area coverage and biomass), direct operations, and assess management impacts on plant communities. Archived satellite records going are used to review results from previous climate and management events and aide in developing long-term strategies. Modeling at local and watershed scales provides insight into land-use effects on water quality. Plant growth models informed by remote sensing are being applied spatially across the Delta to balance location and type of aquatic plant, growth response to altered environments, phenology, environmental regulations, and economics in selection of management practices. Initial utilization of remote sensing tools developed for mapping of aquatic invasive weeds improved operational efficiency by focusing limited chemical use to strategic areas with high plant-control impact and incorporating mechanical harvesting when chemical use is restricted. These assessment methods provide a comprehensive and quantitative view of aquatic invasive plants communities in the California Delta, both spatial and temporal, informed by ecological understanding with the objective of improving management and assessment effectiveness.

  6. Recognition of pyrrolizidine alkaloid esters in the invasive aquatic plant Gymnocoronis spilanthoides (Asteraceae)

    Science.gov (United States)

    Introduction – The freshwater aquatic plant Gymnocoronis spilanthoides (Senegal tea plant, jazmín del bañado, Falscher Wasserfreund) is an invasive plant in many countries. Behavioural observations of pyrrolizidine alkaloid-pharmacophagous butterflies suggested the presence of pyrrolizidine alkaloid...

  7. Acute and chronic toxicity testing of bisphenol A with aquatic invertebrates and plants.

    Science.gov (United States)

    Mihaich, Ellen M; Friederich, Urs; Caspers, Norbert; Hall, A Tilghman; Klecka, Gary M; Dimond, Stephen S; Staples, Charles A; Ortego, Lisa S; Hentges, Steven G

    2009-07-01

    Bisphenol A (BPA, 4,4'-isopropylidine diphenol) is a commercially important chemical used primarily as an intermediate in the production of polycarbonate plastic and epoxy resins. Extensive effect data are currently available, including long-term studies with BPA on fish, amphibians, crustaceans, and mollusks. The aim of this study was to perform additional tests with a number of aquatic invertebrates and an aquatic plant. These studies include acute tests with the midge (Chironomus tentans) and the snail (Marisa cornuarietis), and chronic studies with rotifers (Brachionus calyciflorus), amphipods (Hyalella azteca), and plants (Lemna gibba). The effect data on different aquatic invertebrate and plant species presented in this paper correspond well with the effect and no-effect concentrations (NOECs) available from invertebrate studies in the published literature and are within the range found for other aquatic species tested with BPA.

  8. Prevalence and risk factor's analysis of bovine brucellosis in peri-urban areas under intensive system of production in Gujarat, India

    Directory of Open Access Journals (Sweden)

    M. D. Patel

    2014-07-01

    Full Text Available Aim: A study on surveillance of bovine brucellosis in dairy herds of peri-urban areas under intensive system of production was carried out by milk-ELISA. Various risk factors were identified having significant association with occurrence of bovine brucellosis in dairy herds of peri-urban areas. Materials and Methods: Five randomly selected peri-uban areas of six cities of Gujarat were included in the present study. Five randomly selected dairy herds under intensive system of production from each selected peri-urban area were included for further investigation. In total, 199 bulk and 582 individual milk samples were screened by milk-ELISA. Forty three different risk factors were identified and grouped into four major categories as general characteristics of farms, introduction of infection to farms, management systems of farms and exposure of disease. Further, their distribution and association with prevalence of bovine brucellosis was studied. Results: The overall herd and animal prevalence in peri-urban areas was 33.70 and 11.90%, respectively. Out of 11 risk factors on general characteristics of dairy farms, only five (herd size, type of animals, type of breed, age of owner and knowledge gained by owners showed significant (p<0.05 association with occurrence of bovine brucellosis. None of risk factors on introduction of infection to farms (n=6 and management systems of farms (n=11 was found significantly associated with occurrence of brucellosis. Among risk factors on exposure of disease (n=15, history of abortion, retention of placenta, still birth and metritis/endometritis showed significant (p<0.05 association with prevalence of bovine brucellosis. Conclusion: It was concluded that prevalence of bovine brucellosis in dairy herds under intensive system of production in peri-urban areas of Gujarat was comparatively higher than reported overall prevalence of brucellosis. Risk factors like larger herd in close confinement without adequate sheds

  9. Modeling of radiocesium transport kinetics in system water-aquatic plants

    International Nuclear Information System (INIS)

    Svadlenkova, M.

    1988-01-01

    Compartment models were used to describe the kinetics of the transport of radionuclides in the system water-biomass of aquatic plants. Briefly described are linear models and models with time variable parameters. The model was tested using data from a locality in the environs of the Bohunice nuclear power plant. Cladophora glomerata algae were the monitored plants, 137 Cs the monitored radionuclide. The models may be used when aquatic plants serve as bioindicators of the radioactive contamination of surface waters, for monitoring the transport of radionuclides in food chains. (M.D.). 10 refs

  10. Internal and External Dispersal of Plants by Animals: An Aquatic Perspective on Alien Interference

    Directory of Open Access Journals (Sweden)

    Casper H. A. van Leeuwen

    2018-02-01

    Full Text Available Many alien plants use animal vectors for dispersal of their diaspores (zoochory. If alien plants interact with native disperser animals, this can interfere with animal-mediated dispersal of native diaspores. Interference by alien species is known for frugivorous animals dispersing fruits of terrestrial plants by ingestion, transport and egestion (endozoochory. However, less attention has been paid to possible interference of alien plants with dispersal of diaspores via external attachment (ectozoochory, epizoochory or exozoochory, interference in aquatic ecosystems, or positive effects of alien plants on dispersal of native plants. This literature study addresses the following hypotheses: (1 alien plants may interfere with both internal and external animal-mediated dispersal of native diaspores; (2 interference also occurs in aquatic ecosystems; (3 interference of alien plants can have both negative and positive effects on native plants. The studied literature revealed that alien species can comprise large proportions of both internally and externally transported diaspores. Because animals have limited space for ingested and adhering diaspores, alien species affect both internal and external transport of native diaspores. Alien plant species also form large proportions of all dispersed diaspores in aquatic systems and interfere with dispersal of native aquatic plants. Alien interference can be either negative (e.g., through competition with native plants or positive (e.g., increased abundance of native dispersers, changed disperser behavior or attracting additional disperser species. I propose many future research directions, because understanding whether alien plant species disrupt or facilitate animal-mediated dispersal of native plants is crucial for targeted conservation of invaded (aquatic plant communities.

  11. [Development characteristics of aquatic plants in a constructed wetland for treating urban drinking water source at its initial operation stage].

    Science.gov (United States)

    Zheng, Jun; Ma, Xin-Tang; Zhou, Lan; Zhou, Qing-Yuan; Wang, Zhong-Qiong; Wang, Wei-Dong; Yin, Cheng-Qing

    2011-08-01

    The development characteristics and improvement measures of aquatic plants were studied in Shijiuyang Constructed Wetland (SCW) at its initial operation stage. SCW was a large-scale wetland aiming to help relieve the source water pollution in Jiaxing City. A checklist of vascular plants in SCW was built, and species composition, life forms, biomass and association distributions were examined. Our objectives were to examine the diversity and community structure of aquatic plants in SCW at its initial operation stage, and to find out the possible hydrophyte improvement measures. The survey results showed that there were 49 vascular plant species belonging to 41 genera, 25 families in SCW, which greatly exceeded the artificially transplanted 13 species. The life forms of present aquatic plants in SCW were dominated by hygrophilous plants (20 species) and emerged plants (17 species), which accounted for 75.5% of the total number of aquatic plants. The aquatic plants transplanted artificially were dominated by emerged plants (accounted for 69.2%), while those naturally developed were predominated by hygrophilous plants (accounted for 47.2%). The horizontal distribution of aquatic plant community in SCW was mixed in the form of mosaics, which made up typical association complex. Except association Aeschynomene indica L., the dominant species of other associations were all those transplanted artificially. The naturally grown species scattered throughout the SCW and only occupied a small percentage. A marked difference was detected on the species and species richness of aquatic plants in different regions of SCW. Biomass of aquatic plant associations in SCW was 167.7 t. SCW has shown a trend of succession heading for quick increase of plant diversity at the primary operation stage. This trend provides a good material base for the future stable community of aquatic plants in SCW. According to the current status of aquatic plants, some suggestions were put forward on the

  12. Treatment with aquatic plants by a Bagdi tribal healer of Rajbari District, Bangladesh

    Directory of Open Access Journals (Sweden)

    Mohsina Mukti

    2013-01-01

    Full Text Available Context: Tribal healers mainly use land plants in their medicinal formulations; use of aquatic plants has been scarcely reported. Aims: The aim of the present study was to conduct an ethnomedicinal survey working with a Bagdi tribal healer of Rajbari District, Bangladesh. Settings and Design: The survey was carried out working with a Bagdi healer, who lived alone in the wetlands of Rajbari District and used primarily aquatic plants for treatment. Materials and Methods: Interview of the healer was carried out with the help of a semi-structured questionnaire and the guided field-walk method. Results: The Bagdi healer was observed to use seven different aquatic plant species coming from five plant families for treatment of ailments such as hemorrhoids, tonsillitis, heart disorders, burning sensations and pain in hands or legs, blurred vision, debility, sexual weakness in males, chronic dysentery, infertility in women, constipation, chronic leucorrhea, blackness and foul odor of menstrual blood, hair loss, graying of hair and to keep the head cool. One plant was used to treat what the healer mentioned as "evil eye", this refers to their belief in black-magic. Conclusions: This is the first reported instance of a Bagdi healer who primarily uses aquatic plants for treatment. Ethnomedicinal uses of a number of the plants used by the Bagdi healer have been reported for other places in India and Pakistan. Taken together, the various uses of the different plant species opens up scientific possibilities of new drug discoveries from the plants.

  13. Effect of different water temperatures on growth of aquatic plants Salvinia natans and Ceratophyllum demersum

    Directory of Open Access Journals (Sweden)

    Khadija Kadhem Hreeb

    2016-12-01

    Full Text Available Objective: To evaluate the effect of some different water temperatures on growth of aquatic plants (Salvinia natans and Ceratophyllum demersum. Methods: The aquatic plants were brought from Shatt Al-Arab River in 2016. Equal weights of aquatic plants were aquacultured in aquaria, and were exposed to three different temperatures ( 12, 22 and 32 °C. Results: The results showed that the two plants did not show significant differences with respect to their effects on pH and electrical conductivity values. Time and temperature did not affect the values of pH and electrical conductivity. The values of dissolved oxygen was significantly influenced with variation of time and temperature, while the two plants did not have significant differences on dissolved oxygen values, nitrate ion concentration and was not significantly influenced with variation of plant species or temperature or time. Plant species and temperature significantly affected phosphate ion concentration, while the time did not significantly influence the concentration of phosphate ion. Chlorophyll a content and biomass were significantly influenced with the variation of plant species, and temperature . Conclusions: Aquatic plants has a species specific respond to temperatures change in their environment. Water plant, Ceratophyllum demersum is more tolerant to temperatures change than Salvinia natans.

  14. Organophosphate Pesticide Residues in Okra and Brinjal Grown in Peri-Urban Environment of Big Cities of Punjab

    International Nuclear Information System (INIS)

    Randhawa, M.A.; Zaman, M.; Anjum, F.M.; Asghar, A.

    2015-01-01

    Peri urban farming system is main supplier of vegetables to urban population and organophosphate pesticides exposure due to consumption of okra and brinjal to urban population has been estimated in this study. Okra and brinjal samples (90 samples for each vegetable) were collected from peri-urban farming area of Faisalabad, Multan and Gujranwala and were analysed by GC-ECD for quantification of chlorpyrifos, profenophos and triazophos residues. Data were statistically analyzed to calculate, mean and standard deviation. Quantification of pesticides residues revealed that 85 (47.22 percentage) samples were contaminated and 15 (8.33 percentage of total samples and 17.64 percentage of contaminated) samples showed residues value higher than MRL'S. Out of 85 contaminated samples 27 (31.76 percentage) samples were contaminated with chlorpyrifos, 30 (35.29 percentage) samples with profenofos and 29 (34.11) were contaminated with triazophos. The mean concentration of chlorpyrifos in okra was 0.192 mg Kg-1 and brinjal 0.197 mg Kg-1. The mean concentration for profenofos in okra was 0.02 mg Kg-1 and brinjal 0.035 mg Kg-1. Similarly mean concentration for triazophos in okra was 0.009 mg Kg-1 and brinjal 0.01 mg Kg-1. Overall, 6.67 percentage samples of okra and 6.66 percentage samples of brinjal contaminated with chlorpyrifos exceeded EU MRL of 0.05 mg kg-1. Okra samples were found contaminated at frequency of 4.44 percentage and brinjal samples at frequency of 5.56 percentage with higher profenofos residues level than MRL of 0.05 mg kg-1. Approximately, 6.67 percentage samples of okra and 5.6 percentage samples of brinjal had profenofos residue level above MRL of 0.01 mg kg-1. This study may be helpful for building database regarding regional exposure of urban population and facilitate in estimation of possible risk to their health in our daily life. (author)

  15. An epidemiological study of pleuropulmonary paragonimiasis among pupils in the peri-urban zone of Kumba town, Meme Division, Cameroon

    Directory of Open Access Journals (Sweden)

    Kefie-Arrey Charles

    2003-12-01

    Full Text Available Abstract Background Paragonimiasis have previously been reported in two zones of the Southwest Province of Cameroon including the Kupe mountain and Mundani foci. The aim of this study was to investigate the presence and epidemiology of paragonimiasis in the peri-urban zone of Kumba, Meme Division, located about 50 km away from the Kupe mountain focus. Methods Pupils of several government primary schools in 5 villages around Kumba underwent both parasitologic and clinical investigations in search of signs and symptoms of paragonimiasis. Mycobacterium tuberculosis was also searched for in the differential diagnosis.Freshwater crabs from neighbouring streams in the five villages were dissected in search of paragonimus metacercariae. Results Out of a total of 1482 pupils examined in all five villages, 309 individuals (147 males and 162 females were recruited for this study based on the presence of one or more signs or symptoms of paragonimiasis. Eggs of Paragonimus africanus were found in stools and/or sputum of pupils from all five villages, giving an overall paragonimus prevalence of 2.56%. There was no significant difference in the disease prevalence between the villages (X2 = 8.36, P = 0.08. The prevalence of Paragonimus africanus eggs amongst pupils with symptoms of paragonimiasis was 12.3% (38 of 309. Males were infected more than females (17.0% versus 8.0%, but the difference was not significant (X2 = 5.76, P = 0.16. All the 38 paragonimus egg positive subjects presented with cough, 23 (60.53% complained of chest pain while 16 (42.11% had haemoptysis. Stool examinations also detected some intestinal parasites including Ascaris lumbricoides (29.45%, Trichuris trichiura (6.47%, Necator americanus (2.27%, Strongyloides stercoralis (1.62%, Enterobius vermicularis (0.65%, and Entamoeba histolytica (4.53%. No case of M. tuberculosis was noted. Out of a total of 85 dissected crabs (Sudanonautes africanus, 6.02 % were infected with paragonimus

  16. Modelling the effects of land use changes on the streamflow of a peri-urban catchment in central Portugal

    Science.gov (United States)

    Hävermark, Saga; Santos Ferreira, Carla Sofia; Kalantari, Zahra; Di Baldassarre, Giuliano

    2016-04-01

    Many river basis around the world are rapidly changing together with societal development. Such developments may involve changes in land use, which in turn affect the surrounding environment in various ways. Since the start of industrialisation, the urban areas have extended worldwide. Urbanization can influence hydrological processes by decreasing evapotranspiration, infiltration and groundwater recharge as well as increasing runoff and overland flow. It is therefore of uttermost importance to understand the relationship between land use and hydrology. Although several studies have been investigating the impacts of urbanization on streamflow over the last decades, less is known on how urbanization affects hydrological processes in peri-urban areas, characterized by a complex mosaic of different land uses. This study aimed to model the impact of land use changes, specifically urbanization and commercial forest plantation, on the hydrological responses of the small Ribeira dos Covões peri-urban catchment (6,2 km2) located in central Portugal. The catchment has undergone rapid land use changes between 1958 and 2012 associated with the conversion of agricultural fields (cover area decreased from 48% to 4%) into woodland and urban areas, which increased from 44% to 56% and from 8% to 40%, respectively. For the study, the fully-distributed, physically-based modelling system MIKE SHE was used. The model was designed to examine both how past land use changes might have affected the streamflow and to investigate the impacts on hydrology of possible future scenarios, including a 50 %, 60 % and 70 % urban cover. To this end, a variety of data including daily rainfall since 1958 and forward, daily potential evapotranspiration from 2009 to 2013, monthly temperature averages from 1971 to 2013, land use for the years 1958, 1973, 1979, 1990, 1995, 2002, 2007 and 2012, streamflow from the hydrological years 2008 to 2013, catchment topography and soil types were used. The model

  17. A Geographical Information System Based Approach for Integrated Strategies of Tick Surveillance and Control in the Peri-Urban Natural Reserve of Monte Pellegrino (Palermo, Southern Italy)

    OpenAIRE

    Alessandra Torina; Valeria Blanda; Marcellocalogero Blanda; Michelangelo Auteri; Francesco La Russa; Salvatore Scimeca; Rosalia D’Agostino; Rosaria Disclafani; Sara Villari; Vittoria Currò; Santo Caracappa

    2018-01-01

    Ticks (Acari: Ixodidae) are bloodsucking arthropods involved in pathogen transmission in animals and humans. Tick activity depends on various ecological factors such as vegetation, hosts, and temperature. The aim of this study was to analyse the spatial/temporal distribution of ticks in six sites within a peri-urban area of Palermo (Natural Reserve of Monte Pellegrino) and correlate it with field data using Geographical Information System (GIS) data. A total of 3092 ticks were gathered via dr...

  18. Effects of urban sprawl on arthropod communities in peri-urban farmed landscape in Shenbei New District, Shenyang, Liaoning Province, China.

    Science.gov (United States)

    Bian, Zhen-Xing; Wang, Shuai; Wang, Qiu-Bing; Yu, Miao; Qian, Feng-Kui

    2018-01-08

    Peri-urban farmland provides a diversity of ecological services. However, it is experiencing increasing pressures from urban sprawl. While the effects of land use associated with farming on arthropod assemblages has received increasing attention, most of this research has been conducted by comparing conventional and organic cropping systems. The present study identifies the effects of urban sprawl and the role of non-cropped habitat in defining arthropod diversity in peri-urban farmed landscapes. Multi-scale arthropod data from 30 sampling plots were used with linear-mixed models to elucidate the effects of distance from urban areas (0-13 km; 13-25 km and >25 km, zones I, II, and III, respectively) on arthropods. Results showed that urban sprawl, disturbed farm landscapes, and disturbance in non-cropped habitats had negative effects on arthropods, the latter requiring arthropods to re-establish annually from surrounding landscapes via dispersal. While arthropod species richness showed no obvious changes, arthropod abundance was lowest in zone II. Generally, patch density (PD), Shannon diversity index (SHDI), and aggregate index (AI) of non-cropped habitat were major drivers of changes in arthropod populations. This study contributes to identifying the effects of urban sprawl on arthropod diversity and documenting the multiple functions of farm landscapes in peri-urban regions.

  19. Condom use at first and latest sexual events among young people: evidence from a rural and peri-urban setting in Uganda.

    Science.gov (United States)

    Tumwesigye, N M; Ingham, R; Holmes, D

    2013-06-01

    Condom use remains low among young people despite high prevalence of HIV, STIs, and unplanned pregnancy in Uganda. This paper presents patterns of condom use at first and latest sexual events and associated factors. The data were obtained from 445 sexually active unmarried people aged 15-24 from one peri-urban and another rural district. Stratified multi-stage cluster sampling technique was applied. Logistic regression was used to identify factors associated with condom use at each of the two sexual events, while multinomial logistic regression was used to establish factors correlated with condom use at both first and last sex. Factors associated with condom use at each event were residence in the peri-urban district and higher education attainment. Factors correlated with condom use at both first and last sex were residence in peri-urban district (pcondom use at first sex are different from those that affect condom use at latest sexual event. Prevention programmes against STIs, HIV and unplanned pregnancies among young people focus more on rural areas and those with minimal or no education.

  20. Aquatic grazers reduce the establishment and growth of riparian plants along an environmental gradient

    NARCIS (Netherlands)

    Veen, G.F.; Sarneel, J.M.; Ravensbergen, Lone; Huig, N.; van Paassen, José; Rip, W.; Bakker, E.S.

    2013-01-01

    Summary The establishment of riparian plants is determined by abiotic conditions and grazing, although it is usually presumed that the former are most important. We tested the impact of aquatic grazers on the survival and growth of establishing riparian plants and whether the impact of grazing

  1. Aquatic fate of aerially applied hexazinone and terbuthylazine in a New Zealand planted forest

    Science.gov (United States)

    Brenda R. Baillie; Daniel G. Neary; Stefan Gous; Carol A. Rolando

    2015-01-01

    Herbicides are used to control competing vegetation during tree establishment, and are often critical to the productivity and economic viability of a planted forest crop. Despite increasing public concern over herbicide use in planted forests and potential impact on the environment, there is limited information on the aquatic fate of many of these herbicides when...

  2. Combining tree-ring metal concentrations and lead, carbon and oxygen isotopes to reconstruct peri-urban atmospheric pollution

    Directory of Open Access Journals (Sweden)

    Annick Doucet

    2012-08-01

    Full Text Available In this study, we analysed the tree-ring metal concentrations and isotope ratios of five stands located in three contrasted settings to infer the diffuse air pollution history of the northern part of the Windsor–Québec City Corridor in eastern Canada. Tree-ring series show that the Cd and Zn accumulation rates were higher between 1960 and 1986 and that the long-term acidification of the soil (Ca/Al series was likely induced by NOx and SOx deposition (δ15N and δ13C trends as proxy. The Pb concentrations and 206Pb/207Pb ratios indicate that the dominant source of lead from 1880 to the 1920s was the combustion of north-eastern American coal, which was succeeded by the combustion of leaded gasoline from the 1920s to the end of the 1980s. Our modelling approach allows separating the climatic and anthropogenic effects on the tree-ring δ13C and δ18O responses. Diffuse air pollution caused an enrichment in 13C in all stands and a decrease of the δ18O values only in three of the stands. This study indicates that dendrogeochemistry can show contrasted responses to environmental changes and that the combination of several independent indicators constitutes a powerful tool to reconstruct the air pollution history in the complex context of peri-urban regions.

  3. Investigations into factors affecting the reproductive efficiency of dairy cattle in peri-urban areas of Sudan

    International Nuclear Information System (INIS)

    Idris, O.F.; Barri, M.E.; Ahmed, M.; El-Khedir, O.; Elbasheir, H.A.; Elsadig, A.A.; Abdel Mageed, T.O.

    1999-01-01

    A survey of the productivity, feeding and fertility of 63 cows from 6 farms and a second survey of 49 cows from 5 farms, including in both surveys one with pure bred Holstein Friesians and the rest with cross breeds, showed that those calving in thinner body condition had significantly poorer subsequent fertility. This implied that nutrition in late pregnancy may be an important determining factor in fertility in dairy cows in the peri-urban areas of Khartoum. Cows calving during the dry season were more at risk. No clear advantages or disadvantages were identified for pure-bred cows. Laboratory analysis of feeds, some assessment of intakes and some blood metabolite measurements suggested that neither dietary protein nor phosphate were constraints. The number of days to first progesterone rise on all farms was not extended and many cows conceived in less than 83 days after calving. Many others did not conceive at all but the number showing no evidence of oestrous cycles was small. Failure to conceive seemed to have been a greater problem than failure to cycle. With 27% of blood samples showing evidence of chronic inflammation through high globulin values, investigations into possible disease causes of poor fertility are needed. (author)

  4. Investigations into factors affecting the reproductive efficiency of dairy cattle in peri-urban areas of Sudan

    Energy Technology Data Exchange (ETDEWEB)

    Idris, O F; Barri, M E; Ahmed, M; El-Khedir, O; Elbasheir, H A; Elsadig, A A; Abdel Mageed, T O [Veterinary Research Administration, Khartoum (Sudan)

    1999-07-01

    A survey of the productivity, feeding and fertility of 63 cows from 6 farms and a second survey of 49 cows from 5 farms, including in both surveys one with pure bred Holstein Friesians and the rest with cross breeds, showed that those calving in thinner body condition had significantly poorer subsequent fertility. This implied that nutrition in late pregnancy may be an important determining factor in fertility in dairy cows in the peri-urban areas of Khartoum. Cows calving during the dry season were more at risk. No clear advantages or disadvantages were identified for pure-bred cows. Laboratory analysis of feeds, some assessment of intakes and some blood metabolite measurements suggested that neither dietary protein nor phosphate were constraints. The number of days to first progesterone rise on all farms was not extended and many cows conceived in less than 83 days after calving. Many others did not conceive at all but the number showing no evidence of oestrous cycles was small. Failure to conceive seemed to have been a greater problem than failure to cycle. With 27% of blood samples showing evidence of chronic inflammation through high globulin values, investigations into possible disease causes of poor fertility are needed. (author) 6 refs, 6 tabs

  5. Greenhouse Gas Implications of Peri-Urban Land Use Change in a Developed City under Four Future Climate Scenarios

    Directory of Open Access Journals (Sweden)

    Alison Rothwell

    2016-12-01

    Full Text Available Present decisions about urbanization of peri-urban (PU areas may contribute to the capacity of cities to mitigate future climate change. Comprehensive mitigative responses to PU development should require integration of urban form and food production to realise potential trade-offs. Despite this, few studies examine greenhouse gas (GHG implications of future urban development combined with impacts on PU food production. In this paper, four future scenarios, at 2050 and 2100 time horizons, were developed to evaluate the potential GHG emissions implications of feeding and housing a growing urban population in Sydney, Australia. The scenarios were thematically downscaled from the four relative concentration pathways. Central to the scenarios were differences in population, technology, energy, housing form, transportation, temperature, food production and land use change (LUC. A life cycle assessment approach was used within the scenarios to evaluate differences in GHG impacts. Differences in GHG emissions between scenarios at the 2100 time horizon, per area of PU land transformed, approximated 0.7 Mt CO2-e per year. Per additional resident this equated to 0.7 to 6.1 t CO2-e per year. Indirect LUC has the potential to be significant. Interventions such as carbon capture and storage technology, renewables and urban form markedly reduced emissions. However, incorporating cross-sectoral energy saving measures within urban planning at the regional scale requires a paradigmatic shift.

  6. Assessment of lead pollution in topsoils of a southern Italy area: Analysis of urban and peri-urban environment.

    Science.gov (United States)

    Guagliardi, Ilaria; Cicchella, Domenico; De Rosa, Rosanna; Buttafuoco, Gabriele

    2015-07-01

    Exposure to lead (Pb) may affect adversely human health. Mapping soil Pb contents is essential to obtain a quantitative estimate of potential risk of Pb contamination. The main aim of this paper was to determine the soil Pb concentrations in the urban and peri-urban area of Cosenza-Rende to map their spatial distribution and assess the probability that soil Pb concentration exceeds a critical threshold that might cause concern for human health. Samples were collected at 149 locations from residual and non-residual topsoil in gardens, parks, flower-beds, and agricultural fields. Fine earth fraction of soil samples was analyzed by X-ray Fluorescence spectrometry. Stochastic images generated by the sequential Gaussian simulation were jointly combined to calculate the probability of exceeding the critical threshold that could be used to delineate the potentially risky areas. Results showed areas in which Pb concentration values were higher to the Italian regulatory values. These polluted areas were quite large and likely, they could create a significant health risk for human beings and vegetation in the near future. The results demonstrated that the proposed approach can be used to study soil contamination to produce geochemical maps, and identify hot-spot areas for soil Pb concentration. Copyright © 2015. Published by Elsevier B.V.

  7. Mothers' knowledge about EPI and its relation with age-appropriate vaccination of infants in peri-urban Karachi.

    Science.gov (United States)

    Siddiqi, Nazish; Siddiqi, Azfar-e-alam; Nisar, Nighat; Khan, Altaf

    2010-11-01

    To evaluate the relation between the knowledge of mothers about EPI vaccinations and their infant's coverage. Effect of other socio-demographic variables on mothers' knowledge and child's coverage was also assessed. A cross-sectional survey was conducted, utilizing World Health Organization's thirty-cluster sampling strategy. All households with at least one infant were considered eligible. After obtaining verbal consent, the mother was interviewed to assess her knowledge and attitudes towards EPI vaccination. Infant's coverage status was verified by checking EPI card or verbal inquiry. A knowledge score was developed by summing all correct answers. A total of 210 mothers (7 per cluster) were identified and interviewed. The number and proportion of mothers correctly identifying the seven EPI diseases were as follows; Tuberculosis 57 (27.1%), Diphtheria 53 (25.2%), Pertussis 71 (33.8%), Tetanus 70 (33.3%), Measles 85 (40.5%), Polio 91 (43.3%) and Hepatitis B 65 (31.0%). Only ninety four (44.8%) children were appropriately vaccinated for their age. In the multivariate model, mothers' knowledge was not significantly associated with appropriate vaccination of their children (p = 0.22), however, mothers' education was found to be significant (p Mothers' knowledge about EPI vaccination in peri-urban Karachi was quite low and not associated with their children's EPI coverage. Mothers' educational status, however, was significantly associated with Child's coverage. This finding depicts a better health seeking behaviour of a more educated mother.

  8. Control of parasitic infections among school children in the peri-urban area of Botucatu, São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Regina Coeli Cunha Dórea

    1996-10-01

    Full Text Available Tide prevalence of intestinal parasitosis ivas investigated in a primaiy school located in Rubiâo Júnior, a peri-urban district of Botucatu, São Paulo slate, Brazil, in order to assess the effect of treatment and practical measures of prophylaxis in the control of parasitic infections among 7-to- 18-year-old school children of a low socio-economic status. The first series of parasitological examinations included 219 school children, ef which 123 (56.1 % were found to be infected with one or more parasite species. Eighty- four children canying pathogenic parasites were submitted to various anti-parasitic treatment schedules. We re-evaluated 15 (89 % students after 4 to 6 months post- chemotherapy. The results indicate that the combination of treatment with prophylactic measures has been successful in the control of parasitic infections, since reinfection rates were generally low ( 73-1 % in children infected with most parasite species. The reasons for the apparent failure in the control of infections caused by Hymenolepis nana and Strongyloides stercoralis are discussed.

  9. Local adaptive capacity as an alternative approach in dealing with hydrometeorological risk at Depok Peri-Urban City

    Science.gov (United States)

    Fitrinitia, I. S.; Junadi, P.; Sutanto, E.; Nugroho, D. A.; Zubair, A.; Suyanti, E.

    2018-03-01

    Located in a tropical area, cities in Indonesia are vulnerable to hydrometeorological risks such as flood and landslide and thus become prone to the climate change effects. Moreover, peri-urban cities had double burden as the consequences of main city spill over and also lack of urban facilities in overcoming the disaster. In another perspective, the city has many alternative resources to recover, so its create urban resiliency. Depok city becomes a case study of this research regarding with its development following the impact of Jakarta growth. This research purposes to capture how the local city dwellers could anticipate and adaptive with flood and landslide with their own mitigation version. Through mix method and spatial analysis using GIS techniques, it derives the two comparison approach, the normative and alternative that had been done by the city dwellers. It uses a spatial analysis to have a big picture of Depok and its environmental changing. It also divided into 4 local group of communities as a representative of city dwellers regarding the characteristic of a settlement with their level of risk. The result found type or characteristic of settlement which influenced the local adaptive capacity, from the establishment of infrastructure, health fulfillment and social livelihood with different kind of methods.

  10. Improvement of zebu cattle productivity in the Sahel region: Feed supplementation on smallholder farms in peri-urban Dakar

    International Nuclear Information System (INIS)

    Sawadogo, G.J.; Belemsaga, D.M.A.; Yameogo, N.; Manirarora, J.N.; Toukour, M.

    1999-01-01

    Two studies were conducted in the peri-urban area of Dakar to collect baseline information on feeding, milk production, reproduction, body weight and body condition (Phase I), and to examine the influence of supplementation with local by-products on productive and reproductive parameters of indigenous cattle in traditional smallholder farms (Phase II). Baseline data collected from smallholder farms between 1994 and 1996 indicated delayed first calving, long calving intervals, decreasing body condition score (BCS) and body weight and low milk yields as major problems associated with cattle productivity in the region. Fertility was related to forage availability; animals showed high fertility after the rainy season and low fertility during the dry season. Supplementation during the critical period of the dry season using agro-industrial by-products (brewer's grains, molasses, groundnut cake, oyster shell and salt) had beneficial effects on productivity. Supplementation reduced loss in body weight and body condition, maintained milk yield and growth rate of the calves during the dry season and reduced length of 'days open' and the calving interval. (author)

  11. A Pilot Study on Integrating Videography and Environmental Microbial Sampling to Model Fecal Bacterial Exposures in Peri-Urban Tanzania.

    Directory of Open Access Journals (Sweden)

    Timothy R Julian

    Full Text Available Diarrheal diseases are a leading cause of under-five mortality and morbidity in sub-Saharan Africa. Quantitative exposure modeling provides opportunities to investigate the relative importance of fecal-oral transmission routes (e.g. hands, water, food responsible for diarrheal disease. Modeling, however, requires accurate descriptions of individuals' interactions with the environment (i.e., activity data. Such activity data are largely lacking for people in low-income settings. In the present study, we collected activity data and microbiological sampling data to develop a quantitative microbial exposure model for two female caretakers in peri-urban Tanzania. Activity data were combined with microbiological data of contacted surfaces and fomites (e.g. broom handle, soil, clothing to develop example exposure profiles describing second-by-second estimates of fecal indicator bacteria (E. coli and enterococci concentrations on the caretaker's hands. The study demonstrates the application and utility of video activity data to quantify exposure factors for people in low-income countries and apply these factors to understand fecal contamination exposure pathways. This study provides both a methodological approach for the design and implementation of larger studies, and preliminary data suggesting contacts with dirt and sand may be important mechanisms of hand contamination. Increasing the scale of activity data collection and modeling to investigate individual-level exposure profiles within target populations for specific exposure scenarios would provide opportunities to identify the relative importance of fecal-oral disease transmission routes.

  12. A Pilot Study on Integrating Videography and Environmental Microbial Sampling to Model Fecal Bacterial Exposures in Peri-Urban Tanzania.

    Science.gov (United States)

    Julian, Timothy R; Pickering, Amy J

    2015-01-01

    Diarrheal diseases are a leading cause of under-five mortality and morbidity in sub-Saharan Africa. Quantitative exposure modeling provides opportunities to investigate the relative importance of fecal-oral transmission routes (e.g. hands, water, food) responsible for diarrheal disease. Modeling, however, requires accurate descriptions of individuals' interactions with the environment (i.e., activity data). Such activity data are largely lacking for people in low-income settings. In the present study, we collected activity data and microbiological sampling data to develop a quantitative microbial exposure model for two female caretakers in peri-urban Tanzania. Activity data were combined with microbiological data of contacted surfaces and fomites (e.g. broom handle, soil, clothing) to develop example exposure profiles describing second-by-second estimates of fecal indicator bacteria (E. coli and enterococci) concentrations on the caretaker's hands. The study demonstrates the application and utility of video activity data to quantify exposure factors for people in low-income countries and apply these factors to understand fecal contamination exposure pathways. This study provides both a methodological approach for the design and implementation of larger studies, and preliminary data suggesting contacts with dirt and sand may be important mechanisms of hand contamination. Increasing the scale of activity data collection and modeling to investigate individual-level exposure profiles within target populations for specific exposure scenarios would provide opportunities to identify the relative importance of fecal-oral disease transmission routes.

  13. Removal of pharmaceuticals and personal care products in aquatic plant-based systems: A review

    International Nuclear Information System (INIS)

    Zhang, Dongqing; Gersberg, Richard M.; Ng, Wun Jern; Tan, Soon Keat

    2014-01-01

    Pharmaceuticals and personal care products (PPCPs) in the aquatic environment are regarded as emerging contaminants and have attracted increasing concern. The use of aquatic plant-based systems such as constructed wetlands (CWs) for treatment of conventional pollutants has been well documented. However, available research studies on aquatic plant-based systems for PPCP removal are still limited. The removal of PPCPs in CWs often involves a diverse and complex set of physical, chemical and biological processes, which can be affected by the design and operational parameters selected for treatment. This review summarizes the PPCP removal performance in different aquatic plant-based systems. We also review the recent progress made towards a better understanding of the various mechanisms and pathways of PPCP attenuation during such phytoremediation. Additionally, the effect of key CW design characteristics and their interaction with the physico-chemical parameters that may influence the removal of PPCPs in functioning aquatic plant-based systems is discussed. -- Highlights: • Investigation of the removal performance of PPCPs in CW systems. • Investigation of the mechanisms and pathways contributing to PPCP removal in CWs. • Investigation of the effect of CW design parameters on PPCP removal. • Investigation of the correlation between physico-chemical parameters and PPCP removal. -- This review gives an overview of the present state of research on the removal of pharmaceutical and personal care products by means of constructed wetlands

  14. Herbivory and growth in terrestrial and aquatic populations of amphibious stream plants

    DEFF Research Database (Denmark)

    Sand-Jensen, Kaj; Jacobsen, Dean

    2002-01-01

    1. Many amphibious plant species grow in the transition between terrestrial and submerged vegetation in small lowland streams. We determined biomass development, leaf turnover rate and invertebrate herbivory during summer in terrestrial and aquatic populations of three amphibious species...... production (average 1.2-5.1%) than aquatic populations (2.9-17.3%), while the same plant dry mass was consumed per unit ground area. 3. Grazing loss increased linearly with leaf age apart from the youngest leaf stages. Grazing loss during the lifetime of leaves was therefore 2.4-3.1 times higher than mean...... apparent loss to standing leaves of all ages. The results imply that variation in density of grazers relative to plant production can account for differences in grazing impact between terrestrial and aquatic populations, and that fast leaf turnover keeps apparent grazing damage down. 4. We conclude...

  15. Supply chain analysis of peri-urban dairy chain around Addis Ababa, Ethiopia

    NARCIS (Netherlands)

    Valk, van der O.M.C.

    2009-01-01

    Despite this large number of animals in Ethiopia, the consumption of milk per capita is amongst the lowest in the continent. There is an unmet and growing demand for fresh milk in urban centres whilst processing plants still operate at under-capacity. To ease this problem, donors and NGO’s undertake

  16. Meta-Analysis of the Copper, Zinc, and Cadmium Absorption Capacities of Aquatic Plants in Heavy Metal-Polluted Water.

    Science.gov (United States)

    Li, Jing; Yu, Haixin; Luan, Yaning

    2015-11-26

    The use of aquatic plants for phytoremediation is an important method for restoring polluted ecosystems. We sought to analyze the capacity of different aquatic plant species to absorb heavy metals and to summarize available relevant scientific data on this topic. We present a meta-analysis of Cu, Zn, and Cd absorption capacities of aquatic plants to provide a scientific basis for the selection of aquatic plants suitable for remediation of heavy-metal pollution. Plants from the Gramineae, Pontederiaceae, Ceratophyllaceae, Typhaceae and Haloragaceae showed relatively strong abilities to absorb these metals. The ability of a particular plant species to absorb a given metal was strongly correlated with its ability to absorb the other metals. However, the absorption abilities varied with the plant organ, with the following trend: roots > stems > leaves. The pH of the water and the life habits of aquatic plants (submerged and emerged) also affect the plant's ability to absorb elements. Acidic water aids the uptake of heavy metals by plants. The correlation observed between element concentrations in plants with different aquatic life habits suggested that the enrichment mechanism is related to the surface area of the plant exposed to water. We argue that this meta-analysis would aid the selection of aquatic plants suitable for heavy-metal absorption from polluted waters.

  17. Aquatic Plant Control Research Program: The Habitat Value of Aquatic Macrophytes for Macroinvertebrates

    Science.gov (United States)

    1989-11-01

    seagrass ) and reported that it quickly colonized with algae and invertebrates that were on live plants. Rooke (1986) found considerable dif- ferences...al. (1982) observed that seagrass (Zostera marina) reduced current velocities inside the plant bed, but current velocities were actually higher over...hard-water lakes (Mickle and Wetzel 1978a, 1978b, 1979). Diurnal changes in photosynthesis rates within the boundary layer of macrophyte beds can cause a

  18. Evaluation of the Environmental DNA Method for Estimating Distribution and Biomass of Submerged Aquatic Plants.

    Science.gov (United States)

    Matsuhashi, Saeko; Doi, Hideyuki; Fujiwara, Ayaka; Watanabe, Sonoko; Minamoto, Toshifumi

    2016-01-01

    The environmental DNA (eDNA) method has increasingly been recognized as a powerful tool for monitoring aquatic animal species; however, its application for monitoring aquatic plants is limited. To evaluate eDNA analysis for estimating the distribution of aquatic plants, we compared its estimated distributions with eDNA analysis, visual observation, and past distribution records for the submerged species Hydrilla verticillata. Moreover, we conducted aquarium experiments using H. verticillata and Egeria densa and analyzed the relationships between eDNA concentrations and plant biomass to investigate the potential for biomass estimation. The occurrences estimated by eDNA analysis closely corresponded to past distribution records, and eDNA detections were more frequent than visual observations, indicating that the method is potentially more sensitive. The results of the aquarium experiments showed a positive relationship between plant biomass and eDNA concentration; however, the relationship was not always significant. The eDNA concentration peaked within three days of the start of the experiment in most cases, suggesting that plants do not release constant amounts of DNA. These results showed that eDNA analysis can be used for distribution surveys, and has the potential to estimate the biomass of aquatic plants.

  19. Uptake of inorganic phosphorus by the aquatic plant Isoetes australis inhabiting oligotrophic vernal rock pools

    DEFF Research Database (Denmark)

    Christiansen, Nina Høj; Pulido, Cristina; Pedersen, Ole

    2017-01-01

    The submerged aquatic freshwater macrophyte Isoetes australis S. Williams grows in rock pools situated in south-western Australia, an environment where dissolved inorganic phosphorus (Pi) availability possibly limits growth. In contrast to the two coexisting aquatic species, Glossostigma drummundii...... experiment revealed high amounts of Pi translocation internally in the plant which seemed to go from roots and oldest leaves to younger leaves. As a result of the high root to shoot ratio, high surface area, root uptake kinetics, and sediment Pi availability, roots accounted for 87% of plant Pi uptake...

  20. Occurrence of antibiotics in water, sediments, aquatic plants, and animals from Baiyangdian Lake in North China.

    Science.gov (United States)

    Li, Wenhui; Shi, Yali; Gao, Lihong; Liu, Jiemin; Cai, Yaqi

    2012-11-01

    This study investigated the presence and distribution of 22 antibiotics, including eight quinolones, nine sulfonamides and five macrolides, in the water, sediments, and biota samples from Baiyangdian Lake, China. A total of 132 samples were collected in 2008 and 2010, and laboratory analyses revealed that antibiotics were widely distributed in the lake. Sulfonamides were the dominant antibiotics in the water (0.86-1563 ng L(-1)), while quinolones were prominent in sediments (65.5-1166 μg kg(-1)) and aquatic plants (8.37-6532 μg kg(-1)). Quinolones (17.8-167 μg kg(-1)) and macrolides [from below detection limit (BDL) to 182 μg kg(-1)] were often found in aquatic animals and birds. Salvinia natans exhibited the highest bioaccumulation capability for quinolones among three species of aquatic plants. Geographical differences of antibiotic concentrations were greatly due to anthropogenic activities. Sewage discharged from Baoding City was likely the main source of antibiotics in the lake. Risk assessment of antibiotics on aquatic organisms suggested that algae and aquatic plants might be at risk in surface water, while animals were likely not at risk. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Can additional urban development have major impacts on streamflow of a peri-urban catchment? A case study from Portugal

    Science.gov (United States)

    Ferreira, Carla; Walsh, Rory; Nunes, João; Steenhuis, Tammo; de Lima, João; Coelho, Celeste; Ferreira, António

    2016-04-01

    It is well known that urban development brings about changes in hydrological response. Relatively little, however, is known about impacts on streamflow during urban development in the Mediterranean climate. This paper examines changes in streamflow resulting from the construction of an enterprise park, a major road and apartment blocks in a small partially urbanized peri-urban catchment (6.2 km2) in central Portugal. These developments led to an increase in urban area from 32% to 40% over a five-year period (hydrological years 2008/09-2012/13). In the initial two-year period minor land-use changes increased impervious surfaces from 12.8% to 13.2%. The subsequent three-year period led to a further 17.2% increase in impervious area. Streamflow was recorded by a V-notch weir at the catchment outlet. Rainfall was recorded at a weather station 0.5km north of the catchment, and by five tipping-bucket raingauges installed in January 2011 within the study catchment. Annual runoff and storm runoff coefficients ranged from 14% to 21% and 9% to 14%, respectively, recorded in 2011/12 and 2012/13. Although these differences in runoff were caused in part by variation in rainfall, the comparison between 2009/10 (pre-) and 2012/13 (post-additional urban development), with broadly similar rainfall (887mm vs 947mm, respectively) and evapotranspiration (740mm vs 746mm), showed a 43% increase in storm runoff (from 90mm to 129mm), resulting from additional overland flow generated largely by the 4.4% increase in impervious surfaces. The additional urban development also led to changes in hydrograph parameters. The increase in storm runoff was not progressive over the study period, but regression lines of storm runoff against rainstorm parameters exhibited higher vertical positions in 2012/13 than 2008/09. Increasing peak flows, however, were more progressive over the study period, with annual regression lines displaying higher vertical positions, but with a clear distance between pre

  2. Aquatic food production modules in bioregenerative life support systems based on higher plants

    Science.gov (United States)

    Bluem, V.; Paris, F.

    Most bioregenerative life support systems (BLSS) are based on gravitropic higher plants which exhibit growth and seed generation disturbances in microgravity. Even when used for a lunar or martian base the reduced gravity may induce a decreased productivity in comparison to Earth. Therefore, the implementation of aquatic biomass production modules in higher plant and/or hybrid BLSS may compensate for this and offer, in addition, the possibility to produce animal protein for human nutrition. It was shown on the SLS-89 and SLS-90 space shuttle missions with the C.E.B.A.S.-MINI MODULE that the edible non gravitropic rootless higher aquatic plant Ceratophyllum demeresum exhibits an undisturbed high biomass production rate in space and that the teleost fish species, Xiphophorus helleri, adapts rapidly to space conditions without loss of its normal reproductive functions. Based on these findings a series of ground-based aquatic food production systems were developed which are disposed for utilization in space. These are plant production bioreactors for the species mentioned above and another suitable candidate, the lemnacean (duckweed) species, Wolffia arrhiza. Moreover, combined intensive aquaculture systems with a closed food loop between herbivorous fishes and aquatic and land plants are being developed which may be suitable for integration into a BLSS of higher complexity.

  3. Helminth infections among people using wastewater and human excreta in peri-urban agriculture and aquaculture in Hanoi, Vietnam.

    Science.gov (United States)

    Do, Thuy Trang; Mølbak, Kåre; Phung, Dac Cam; Dalsgaard, Anders

    2007-12-01

    To assess the prevalence of helminth infections and their associated risks in a community using both wastewater and human excreta in agriculture and aquaculture. A cross-sectional study was conducted in a peri-urban area in Hanoi, Vietnam. Data on the demography, socioeconomics and sanitation were collected from a survey of 400 agricultural households. Parasitological examination for the eggs of Ascaris sp., Trichuris sp. and hookworm was performed on single stool specimens obtained from study household members' 15-70 years and 0-72 months of age. Of 807 stool samples collected from 620 adults and 187 children, 39% were infected with helminths. The prevalence of infections with Ascaris sp., Trichuris sp. and hookworm was 21.6%, 9.8% and 21.8%, respectively. Univariate and multivariate analyses showed that being an adult, female gender, living in a household without a latrine, excreta composted for less than 1 month and use of fresh human excreta were significantly associated with co-infection with all three helminths. Being an adult was an independent determinant for infections with individual helminths. The absence of a latrine and use of stored urine for irrigation were associated with an increased risk of Ascaris infection. Risk factors for Trichuris infection were inadequately composted excreta and year-round wastewater contact; risk factors for hookworm infection were female gender, household without a latrine and use of fresh human excreta. Wastewater exposure did not pose a major risk for helminth infection in this community. Instead, lack of sanitation facilities and use of fresh or inadequately composted human excreta in agriculture were important risk factors.

  4. Household willingness to pay for green electricity in urban and peri-urban Tigray, northern Ethiopia: Determinants and welfare effects

    International Nuclear Information System (INIS)

    Arega, Tiruwork; Tadesse, Tewodros

    2017-01-01

    This paper set out to estimate household willingness to pay for green electric services and welfare gains attributed to such schemes. For this purpose, contingent valuation survey was conducted on 300 urban and peri-urban households in northern Ethiopia. A bivariate probit model was used to elicit willingness to pay and analyze determinants of household willingness to pay. On the other hand, welfare gains were analyzed using consumer and producer surpluses. The mean willingness to pay was estimated to be Birr 12.5 (0.66 USD) per month per household for five years on top of monthly electricity bill. Among others, income played positive role on willingness to pay while difference in willingness to pay behavior was observed between male and female-headed households. In addition, distance to wood and charcoal (alternative energy) markets played encouraging role for willingness to pay. Results from the welfare analysis show that there is significant societal gain to be made both in terms of surplus for households and producers (government) if the previously ‘untapped’ green electricity service was implemented. The revenue (producer surplus) for the state would be instrumental in contributing to the state's endeavor to generate a much-needed capital for investment in and expansion of renewable energy. - Highlights: • Thin markets in alternative energy encourage WTP for green electricity services. • Households can significantly contribute to cost-sharing for green electricity. • Significant surpluses can be gained through improving green electricity services. • Welfare gains could be useful to support the state's effort to improve electricity.

  5. Geospatial Analysis of Land Use and Land Cover Transitions from 1986–2014 in a Peri-Urban Ghana

    Directory of Open Access Journals (Sweden)

    Divine Odame Appiah

    2017-12-01

    Full Text Available Recently, peri-urbanisation has led to the transformation of the rural landscape, changing rural land uses into peri-urban land uses, under varying driving factors. This paper analyzes the dynamic transitions among identified land use and land cover (LULC types in the Bosomtwe district of Ghana, from 1986 to 2014. An integrated approach of geo-information tools of satellite remote sensing in Earth Resource Data Analysis System (ERDAS Imagine 13 and ArcMap 10.2 Geographic Information System (GIS, with Markov chain analytical techniques were used to examine the combined forest land cover transitions, relative to build-up, recent fallows and grasslands and projected possible factors influencing the transitions under business as usual and unusual situations. Statistical analyses of the classified Landsat TM, ETM+ and Landsat 8 Operational Land Imager and Thermal Infrared Sensor (OLI/TIS indicated that over the period of 24 years, the Bosomtwe district has undergone a series of land use conversions with remarkable forest losses especially between 2002 and 2010. In 2010 dense forest cover was degraded to low forest by 4040 ha indicating 0.40% transition probability in the future. There was a remarkable increase of built-up/bare and concrete area with a 380% increment in the 1986–2002 transition periods. The application of the Markov futuristic land use dynamics by the years 2018 and 2028, projected from the 2014 LULC indicated a future steady decline in the area coverage of the dense forest to low forest category. This is currently being driven (as at the 2017 LULC trends, by the combined effects of increasing build up bare and concrete surface land uses as well as the expanding recent fallows and grassland. The paper concluded that the health of the ecosystem and biodiversity of the lake Bosomtwe need to be sustainably managed by the Bosomtwe district assembly.

  6. Operationalization of the Ghanaian Patients’ Charter in a Peri-urban Public Hospital: Voices of Healthcare Workers and Patients

    Science.gov (United States)

    Yarney, Lily; Buabeng, Thomas; Baidoo, Diana; Bawole, Justice Nyigmah

    2016-01-01

    Background: Health is a basic human right necessary for the exercise of other human rights. Every human being is, therefore, entitled to the highest possible standard of health necessary to living a life of dignity. Establishment of patients’ Charter is a step towards protecting the rights and responsibilities of patients, but violation of patients’ rights is common in healthcare institutions, especially in the developing world. This study which was conducted between May 2013 and May 2014, assessed the operationalization of Ghana’s Patients Charter in a peri-urban public hospital. Methods: Qualitative data collection methods were used to collect data from 25 healthcare workers and patients who were purposively selected. The interview data were analyzed manually, using the principles of systematic text condensation. Results: The findings indicate that the healthcare staff of the Polyclinic are aware of the existence of the patients’ Charter and also know some of its contents. Patients have no knowledge of the existence or the contents of the Charter. Availability of the Charter, community sensitization, monitoring and orientation of staff are factors that promote the operationalization of the Charter, while institutional implementation procedures such as lack of complaint procedures and low knowledge among patients militate against operationalization of the Charter. Conclusion: Public health facilities should ensure that their patients are well-informed about their rights and responsibilities to facilitate effective implementation of the Charter. Also, patients’ rights and responsibilities can be dramatized and broadcasted on television and radio in major Ghanaian languages to enhance awareness of Ghanaians on the Charter. PMID:27694679

  7. Operationalization of the Ghanaian Patients’ Charter in a Peri-urban Public Hospital: Voices of Healthcare Workers and Patients

    Directory of Open Access Journals (Sweden)

    Lily Yarney

    2016-09-01

    Full Text Available Background Health is a basic human right necessary for the exercise of other human rights. Every human being is, therefore, entitled to the highest possible standard of health necessary to living a life of dignity. Establishment of patients’ Charter is a step towards protecting the rights and responsibilities of patients, but violation of patients’ rights is common in healthcare institutions, especially in the developing world. This study which was conducted between May 2013 and May 2014, assessed the operationalization of Ghana’s Patients Charter in a peri-urban public hospital. Methods Qualitative data collection methods were used to collect data from 25 healthcare workers and patients who were purposively selected. The interview data were analyzed manually, using the principles of systematic text condensation. Results The findings indicate that the healthcare staff of the Polyclinic are aware of the existence of the patients’ Charter and also know some of its contents. Patients have no knowledge of the existence or the contents of the Charter. Availability of the Charter, community sensitization, monitoring and orientation of staff are factors that promote the operationalization of the Charter, while institutional implementation procedures such as lack of complaint procedures and low knowledge among patients militate against operationalization of the Charter. Conclusion Public health facilities should ensure that their patients are well-informed about their rights and responsibilities to facilitate effective implementation of the Charter. Also, patients’ rights and responsibilities can be dramatized and broadcasted on television and radio in major Ghanaian languages to enhance awareness of Ghanaians on the Charter.

  8. Operationalization of the Ghanaian Patients' Charter in a Peri-urban Public Hospital: Voices of Healthcare Workers and Patients.

    Science.gov (United States)

    Yarney, Lily; Buabeng, Thomas; Baidoo, Diana; Bawole, Justice Nyigmah

    2016-04-23

    Health is a basic human right necessary for the exercise of other human rights. Every human being is, therefore, entitled to the highest possible standard of health necessary to living a life of dignity. Establishment of patients' Charter is a step towards protecting the rights and responsibilities of patients, but violation of patients' rights is common in healthcare institutions, especially in the developing world. This study which was conducted between May 2013 and May 2014, assessed the operationalization of Ghana's Patients Charter in a peri-urban public hospital. Qualitative data collection methods were used to collect data from 25 healthcare workers and patients who were purposively selected. The interview data were analyzed manually, using the principles of systematic text condensation. The findings indicate that the healthcare staff of the Polyclinic are aware of the existence of the patients' Charter and also know some of its contents. Patients have no knowledge of the existence or the contents of the Charter. Availability of the Charter, community sensitization, monitoring and orientation of staff are factors that promote the operationalization of the Charter, while institutional implementation procedures such as lack of complaint procedures and low knowledge among patients militate against operationalization of the Charter. Public health facilities should ensure that their patients are well-informed about their rights and responsibilities to facilitate effective implementation of the Charter. Also, patients' rights and responsibilities can be dramatized and broadcasted on television and radio in major Ghanaian languages to enhance awareness of Ghanaians on the Charter. © 2016 by Kerman University of Medical Sciences

  9. Does consumption of leafy vegetables grown in peri-urban agriculture pose a risk to human health?

    International Nuclear Information System (INIS)

    Nabulo, G.; Black, C.R.; Craigon, J.; Young, S.D.

    2012-01-01

    Concentrations of potentially toxic elements were measured in soils and five contrasting tropical leafy vegetables grown in a replicated field trial at five contaminated urban agriculture sites in Kampala City, Uganda. Soil contamination at each site could be tentatively ascribed to known waste disposal practices. There was considerable variation in metal uptake between vegetable types. Washing leafy vegetables reduced chromium and lead concentrations but exogenous contamination of leaves also depended on vegetable type, with Gynandropsis gynandra L. showing a marked tendency to accumulate Pb and Cr. For the worst case scenario of children consuming unwashed vegetables, some metal ‘hazard quotient’ (HQ) limits (1.0) were violated at four of the five sites studied. For the 25 ‘site-vegetable’ combinations assessed, the HQ for Pb exceeded 1.0 in 36% of cases. A vegetable-specific site screening tool based on soil extraction with 0.01 M CaCl 2 and extrapolation to provide HQ values was assessed. - Highlights: ► Solubility of toxic metals in soils used for urban agriculture is highly variable. ► Washing leafy vegetables prior to cooking reduces consumption of Cr, Pb, As and Ni. ► Lead (Pb) presents the greatest hazard in produce from agriculture in Kampala City. ► Agriculture in East African cities can be practiced safely with the right choices. ► Soil screening to predict hazard to consumers may be useful in site surveys. - Peri-urban agriculture requires careful consideration of vegetable choice and site characteristics.

  10. Dietary intake and the dynamics of stress, hypertension and obesity in a peri-urban community in Accra.

    Science.gov (United States)

    Mohammed, Husein; Ghosh, Shibani; Vuvor, Fred; Mensah-Armah, Seth; Steiner-Asiedu, Matilda

    2016-03-01

    This study intends to investigate the association between dietary intake, stress and prevalence of chronic diseases. The study was a cross-sectional design conducted in two poor peri-urban communities in Accra. A total of 90 households each with a male and female between the ages of 18 and 45 years were sampled, and their socio-demographic status, anthropometric measurement and fasting blood sugar were assessed. Blood pressure was measured and chronic stress/anxiety was determined using the trait and state inventory (T-stai) questionnaire. Three days repeated 24-hour dietary recall was also done. Analysis of variance and linear regression analysis were used in data analysis. About 28% of the subjects were hypertensive and 55.5% had high chronic stress. Hypertension was higher in males (32.2%) than females (24.4%) (p=.023) whiles stress was higher in females (60.9%) than males (50.0%) (p=.017). Hypertensive subjects recorded higher stress (51.02%) and hypertension was more prevalent in subjects with high stress (32.89%) especially in females (57.14%, p=.036). Hypertension increased with mean age whiles stress decreased with mean age. Hypertensive subjects recorded a significantly higher BMI and sodium intake whiles high stress individuals recorded a lower animal protein but a higher cereal protein intake (pstress was associated with intake of low animal protein and high cereal protein. Increased dietary diversity score was associated with decreased obesity prevalence (pstress, and obesity were linked, and affected by dietary sodium, animal protein, and dietary diversity of subjects respectively.

  11. Aeromonas presence in drinking water from collective reservoirs and wells in peri-urban area in Brazil

    Directory of Open Access Journals (Sweden)

    Maria Tereza Pepe Razzolini

    2010-10-01

    Full Text Available Aeromonas genus is considered an emerging pathogen and its presence in drinking water supplies is a reason to public health concern. This study investigated the occurrence of Aeromonas in samples from collective reservoirs and wells used as drinking water sources in a peri-urban area. A total of 35 water samples were collected from collective reservoirs and 32 from wells bimonthly, from September 2007 to September 2008. Aeromonas spp determination was carried out using a Multiple-Tube Technique. Samples were inoculated into alkaline peptone water and the superficial film formed was transferred to blood agar plates amended with ampicillin. Typical Aeromonas colonies were submitted to a biochemical screening and then to biochemical tests for species differentiation. Aeromonas was detected in 13 (19% of the 69 samples examined (6 from collective reservoirs and 7 from wells. Concentrations of Aeromonas in collective reservoirs ranged from <0.3 to 1.2 x10²MPN/100mL and, in wells, from <0.3 to 2.4 x10²MPN/100mL. The most frequent specie in the collective reservoir samples was Aeromonas spp (68%, followed by A. encheleia (14% and A. allosaccharophila (8% and A. hydrophila (8%. Aeromonas spp (87% was the most frequent specie isolated from well samples, followed by A. allosacchariphila (8%, A. encheleia (2% and A. jandaei (5%. These data show the presence and diversity of Aeromonas genus in the samples analyzed and highlight that its presence in drinking water poses a significant public health concern.

  12. Household attitudes and knowledge on drinking water enhance water hazards in peri-urban communities in Western Kenya

    Directory of Open Access Journals (Sweden)

    Kimongu J. Kioko

    2012-12-01

    Full Text Available Ensuring safe drinking water remains a big challenge in developing countries where waterborne diseases cause havoc in many communities. A major challenge is limited knowledge, misinformation and attitudes that work against ensuring that drinking water is safe. This study investigated the knowledge, attitudes and practices of peri-urban households in Kakamega Town of Western Kenya, concerning the collection, treatment and storage of drinking water. Alongside this we examined the role of solid waste disposal in water safety. Three hundred and seventy eight households from four residential regions of varying economic levels were randomly sampled in Kakamega Town. Data was collected via questionnaire interviews that incorporated attitude questions based on a Likert scale of 1−5, and administered to the households and key informants. The results showed most respondents were knowledgeable about ideal methods of water collection, treatment and storage. However, they did not practise them appropriately. Some attitudes among the respondents worked against the ideals of achieving safe drinking water. For instance, many households perceived their drinking water source as safe and did not treat it, even when obtained from open sources like rivers. Further, they preferred to store drinking water in clay pots, because the pots kept the water cold, rather than use the narrow-necked containers that limit exposure to contaminants. Also, hand washing with soap was not practised enough in their daily lives to avoid contact with waterborne hazards. We recommend that the government undertake training programmes on drinking water safety that advocate appropriate water use, hygiene and sanitation strategies.

  13. Impact of rotavirus vaccination on rotavirus and all-cause gastroenteritis in peri-urban Kenyan children.

    Science.gov (United States)

    Wandera, Ernest Apondi; Mohammad, Shah; Bundi, Martin; Komoto, Satoshi; Nyangao, James; Kathiiko, Cyrus; Odoyo, Erick; Miring'u, Gabriel; Taniguchi, Koki; Ichinose, Yoshio

    2017-09-12

    A monovalent rotavirus vaccine (RV1) was introduced into the National Immunization Program in Kenya in July 2014. We examined the impact of the vaccine on hospitalization for all-cause acute gastroenteritis (AGE) and rotavirus-specific AGE and strain distribution at a large referral hospital which serves a predominantly peri-urban population in Central Kenya. Data on rotavirus AGE and strain distribution were derived from ongoing hospital-based AGE surveillance. Hospital administrative data were used to compare trends in all-cause AGE. Pre-vaccine (July 2009-June 2014) and post-vaccine (July 2014-June 2016) periods were compared for changes in hospitalization for all-cause AGE and rotavirus AGE and strain distribution. Following the vaccine introduction, the proportion of children aged rotavirus declined by 30% (95% CI: 19-45%) in the first year and 64% (95% CI: 49-77%) in the second year. Reductions in rotavirus positivity were most pronounced among the vaccine-eligible group (rotavirus and all-cause AGE were reduced substantially. There was an increased detection of G2P[4], G3P[6] and G3P[8], which coincided temporally with the timing of the vaccine introduction. Thus, introducing the rotavirus vaccine into the routine immunization program in Kenya has resulted in a notable decline in rotavirus and all-cause AGE hospitalizations in Central Kenya. This provides early evidence for public health policy makers in Kenya to support the sustained use of the rotavirus vaccine in routine immunizations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Accumulation of americium-241 in the biomass of aquatic plants of the Yenisei river: experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Zotina, T.A.; Bolsunovsky, A.Y.A.; Bondareva, L.G. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk (Russian Federation)

    2004-07-01

    Due to the operation of the Mining-and-Chemical Combine (Krasnoyarsk-26), which has been manufacturing weapons-grade plutonium for several decades, the Yenisei River is contaminated with transuranic elements (including {sup 241}Am). {sup 241}Am was found in the riverside soil, sediment and in the biomass of aquatic plants (Bolsunovsky et al., 1999, 2002). Aquatic plants are an important link in the migration of radionuclides in an aquatic ecosystem. In laboratory experiments, we investigated accumulation of {sup 241}Am by the submerged macrophyte from the Yenisei River: the pond weed (Elodea canadensis) and the aquatic moss (Fontinalis antipyretica), and release of {sup 241}Am from the biomass. The content of {sup 241}Am was measured on a Canberra (USA) gamma-spectrometer. The experiments showed that specific accumulation and concentration factors of {sup 241}Am in the plants were in inverse proportion to their biomass. We obtained new data on release of {sup 241}Am from the biomass of macrophyte. Americium-241 was more firmly fixed in the biomass of the aquatic moss. In 12 months, the biomass of the aquatic moss released about 30% of the initial americium activity into the water. To compare, the biomass of the pond weed released into the water medium up to 64% of the initial {sup 241}Am activity in 1.5 4 months. The release rate was dependent on the decomposition rate of the plant biomass. The experiments showed that submerged macrophyte of the Yenisei River can accumulate considerable activities of {sup 241}Am and retain americium for long periods of time in biomass. (author)

  15. Accumulation of americium-241 in the biomass of aquatic plants of the Yenisei river: experimental study

    International Nuclear Information System (INIS)

    Zotina, T.A.; Bolsunovsky, A.Y.A.; Bondareva, L.G.

    2004-01-01

    Due to the operation of the Mining-and-Chemical Combine (Krasnoyarsk-26), which has been manufacturing weapons-grade plutonium for several decades, the Yenisei River is contaminated with transuranic elements (including 241 Am). 241 Am was found in the riverside soil, sediment and in the biomass of aquatic plants (Bolsunovsky et al., 1999, 2002). Aquatic plants are an important link in the migration of radionuclides in an aquatic ecosystem. In laboratory experiments, we investigated accumulation of 241 Am by the submerged macrophyte from the Yenisei River: the pond weed (Elodea canadensis) and the aquatic moss (Fontinalis antipyretica), and release of 241 Am from the biomass. The content of 241 Am was measured on a Canberra (USA) gamma-spectrometer. The experiments showed that specific accumulation and concentration factors of 241 Am in the plants were in inverse proportion to their biomass. We obtained new data on release of 241 Am from the biomass of macrophyte. Americium-241 was more firmly fixed in the biomass of the aquatic moss. In 12 months, the biomass of the aquatic moss released about 30% of the initial americium activity into the water. To compare, the biomass of the pond weed released into the water medium up to 64% of the initial 241 Am activity in 1.5 4 months. The release rate was dependent on the decomposition rate of the plant biomass. The experiments showed that submerged macrophyte of the Yenisei River can accumulate considerable activities of 241 Am and retain americium for long periods of time in biomass. (author)

  16. Chemical fractionation of radionuclides and stable elements in aquatic plants of the Yenisei River.

    Science.gov (United States)

    Bolsunovsky, Alexander

    2011-09-01

    The Yenisei River is contaminated with artificial radionuclides released by one of the Russian nuclear plants. The aquatic plants growing in the radioactively contaminated parts of the river contain artificial radionuclides. The aim of the study was to investigate accumulation of artificial radionuclides and stable elements by submerged plants of the Yenisei River and estimate the strength of their binding to plant biomass by using a new sequential extraction scheme. The aquatic plants sampled were: Potamogeton lucens, Fontinalis antipyretica, and Batrachium kauffmanii. Gamma-spectrometric analysis of the samples of aquatic plants has revealed more than 20 radionuclides. We also investigated the chemical fractionation of radionuclides and stable elements in the biomass and rated radionuclides and stable elements based on their distribution in biomass. The greatest number of radionuclides strongly bound to biomass cell structures was found for Potamogeton lucens and the smallest for Batrachium kauffmanii. For Fontinalis antipyretica, the number of distribution patterns that were similar for both radioactive isotopes and their stable counterparts was greater than for the other studied species. The transuranic elements (239)Np and (241)Am were found in the intracellular fraction of the biomass, and this suggested their active accumulation by the plants.

  17. Proper survey methods for research of aquatic plant ecology and management

    Science.gov (United States)

    Proper survey methods are essential for objective, quantitative assessment of the distribution and abundance of aquatic plants as part of research and demonstration efforts. For research, the use of the appropriate method is an essential part of the scientific method, to ensure that the experimenta...

  18. Ecophysiological traits of terrestrial and aquatic carnivorous plants: are the costs and benefits the same?

    Czech Academy of Sciences Publication Activity Database

    Ellison, A. M.; Adamec, Lubomír

    2011-01-01

    Roč. 120, č. 11 (2011), 1721-1731 ISSN 0030-1299 Institutional research plan: CEZ:AV0Z60050516 Keywords : terrestrial and aquatic carnivorous plants * photosynthesis * mineral nutrition Subject RIV: EF - Botanics Impact factor: 3.061, year: 2011

  19. Potential for biotic resistance from herbivores to tropical and subtropical plant invasions in aquatic ecosystems

    NARCIS (Netherlands)

    Petruzella, A.; Grutters, B.M.C.; Thomaz, S.M.; Bakker, E.S.

    2017-01-01

    Invasions of tropical and subtropical aquatic plants threaten biodiversity and cause ecological and economic impacts worldwide. An urgent question is whether native herbivores are able to inhibit the spread of these alien species thus providing biotic resistance. The potential for biotic resistance

  20. Influence of nonylphenol on the fatty acids and hydrocarbon composition of aquatic plants

    Directory of Open Access Journals (Sweden)

    І. О. Osinna

    2009-11-01

    Full Text Available Composition of surface lipids of aquatic plants Acorus calamus L., Typha latifolia L. and Carex acuta L. was investigated under the influence of nonylphenol strong solution. Experimental plants showed some significant changes in the surface lipids composition in comparison with a control. Change in the fatty acids composition, decrease of hydrocarbons content and biosynthetical disorder in the elongation processes of some certain components were revealed.

  1. Effects of snails, submerged plants and their coexistence on eutrophication in aquatic ecosystems

    OpenAIRE

    Mo Shuqing; Zhang Xiufeng; Tang Yali; Liu Zhengwen; Kettridge Nicholas

    2017-01-01

    Eutrophication resulting from nutrient loading to freshwater habitats is a severe problem, leading to degradation of ecosystems, including deterioration of water quality, water clarity and loss of biodiversity. Measures enacted to restore degraded freshwater ecosystems often involve the reintroduction of submerged plants and aquatic animals with beneficial ecological functions. In a mesocosm experiment, three treatments (planting with Vallisneria natans, introduction of the snail Bellamya aer...

  2. Effect of Aquatic Plants on Phosphorus Removal and Electrical Conductivity Decrease in Municipal Effluent

    OpenAIRE

    Sara Samimi Loghmani; Ali Abbaspour

    2014-01-01

    Phosphorus (P) is one of essential elements for living organisms, though its critical concentration in surface and ground waters impose a serious problem such as eutrophication. So treatment of polluted waters is required before discharging to water resources. One of effective ways to decrease water pollution is using aquatic plants. An experiment was conducted in pilots with a closed flowing system on two plants, elodea (egria densa) and duck weed (lemna minor) with four treatments and three...

  3. By which mechanism does prey capture enhance plant growth in aquatic carnivorous plants: Stimulation of shoot apex?

    Czech Academy of Sciences Publication Activity Database

    Adamec, Lubomír

    2011-01-01

    Roč. 178, č. 2 (2011), s. 171-176 ISSN 1863-9135 Institutional research plan: CEZ:AV0Z60050516 Keywords : aquatic carnivorous plants * dark respiration * tissue N and P content Subject RIV: EF - Botanics Impact factor: 1.145, year: 2011

  4. Mineralization of Surfactants by Microbiota of Aquatic Plants

    OpenAIRE

    Federle, Thomas W.; Schwab, Burney S.

    1989-01-01

    The biodegradation of linear alkylbenzene sulfonate (LAS) and linear alcohol ethoxylate (LAE) by the microbiota associated with duckweed (Lemna minor) and the roots of cattail (Typha latifolia) was investigated. Plants were obtained from a pristine pond and a pond receiving wastewater from a rural laundromat. Cattail roots and duckweed plants were incubated in vessels containing sterile water amended with [14C]LAS, [14C]LAE, or 14C-labeled mixed amino acids (MAA). Evolution of 14CO2 was deter...

  5. Patterns and risk factors of helminthiasis and anemia in a rural and a peri-urban community in Zanzibar, in the context of helminth control programs.

    Directory of Open Access Journals (Sweden)

    Stefanie Knopp

    Full Text Available BACKGROUND: The control of helminth infections and prevention of anemia in developing countries are of considerable public health importance. The purpose of this study was to determine patterns and risk factors of helminth infections and anemia in a rural and a peri-urban community of Zanzibar, Tanzania, in the context of national helminth control programs. METHODOLOGY/PRINCIPAL FINDINGS: We carried out a community-based cross-sectional study in 454 individuals by examining at least two stool samples with different methods for soil-transmitted helminths (Ascaris lumbricoides, hookworm, Strongyloides stercoralis, and Trichuris trichiura and one urine sample for Schistosoma haematobium. Finger-prick blood was taken to estimate anemia levels and to detect antibody reactions against ascariasis, strongyloidiasis and schistosomiasis, using an enzyme-linked immunosorbent assay (ELISA approach. Parasitological methods determined a helminth prevalence of 73.7% in the rural, and 48.9% in the peri-urban setting. Most helminth infections were of light intensity with school-aged children showing the highest intensities. Multiple helminth species infections were pervasive in rural dwellers regardless of age. More than half of the participants were anemic, with a particularly high prevalence in the peri-urban setting (64.7%. Risk factors for helminth infections were age, sex, consumption of raw vegetables or salad, recent travel history, and socio-economic status. CONCLUSION/SIGNIFICANCE: After several years of chemotherapy-based morbidity control efforts in Zanzibar, helminth prevalences are still high and anemia is common, but helminth infection intensities are low. Hence, chemotherapy should be continued, and complemented with improved access to clean water, adequate sanitation, and health education, along with poverty alleviation measures for a more enduring impact.

  6. High prevalence of cardiovascular risk factors in Peruvian adolescents living in a peri-urban shantytown: a cross-sectional study.

    Science.gov (United States)

    Abbs, Elizabeth S; Viñoles, José; Alarcón, Jorge O; Johnson, Heather M; Zunt, Joseph R

    2017-05-22

    Adults of the peri-urban Peruvian shantytown of Lomas de Zapallal have a high prevalence of risk factors for developing cardiovascular disease (CVD)-likely due to behavioral choices established during childhood and adolescence. To guide the development of community-based risk reduction programs, we assessed the prevalence of risk factors for developing CVD among adolescents. We collected cross sectional data from adolescents of Peruvian peri-urban shantytown to evaluate four domains of CVD risk factors: (1) clinical (blood pressure, fasting blood glucose, and blood lipids), (2) anthropometric (height, weight, and waist circumference), (3) behavioral (physical activity, diet, and substance abuse), and (4) psychosocial (mental health and violence). We enrolled 275 adolescents (56.4% female, mean age 14 years). Prevalence of overweight or obese status was 27.8%. High blood pressure was more common in males (37.4%) than females (20.5%) (p = 0.002). Total cholesterol was elevated (>170 mg/dL) in nearly half (45.5%) of the adolescents, and 71% had impaired fasting blood glucose (>100 mg/dL). Females were less likely to exercise daily (95.4%) than males (84.2%) (p = 0.002) but reported higher rates of depression (66.4%), anhedonia (67.6%), and self-harm behavior (37.9%) (all p < 0.01). Adolescents living in the peri-urban population of Puente Piedra had high prevalence of risk factors for future development of CVD; preventative efforts focused on improving nutrition, increasing physical inactivity, and addressing mental health conditions could reduce such risk factors.

  7. Urbanization and Land Use Changes in Peri-Urban Area using Spatial Analysis Methods (Case Study: Ciawi Urban Areas, Bogor Regency)

    Science.gov (United States)

    Cahya, D. L.; Martini, E.; Kasikoen, K. M.

    2018-02-01

    Urbanization is shown by the increasing percentage of the population in urban areas. In Indonesia, the percentage of urban population increased dramatically form 17.42% (1971) to 42.15% (2010). This resulted in increased demand for housing. Limited land in the city area push residents looking for an alternative location of his residence to the peri-urban areas. It is accompanied by a process of land conversion from green area into built-up area. Continuous land conversion in peri-urban area is becoming increasingly widespread. Bogor Regency as part of the Jakarta Metropolitan Area is experiencing rapid development. This regency has been experienced land-use change very rapidly from agricultural areas into urban built up areas. Aim of this research is to analyze the effect of urbanization on land use changes in peri-urban areas using spatial analysis methods. This research used case study of Ciawi Urban Area that experiencing rapid development. Method of this research is using descriptive quantitative approach. Data used in this research is primary data (field survey) and secondary data (maps). To analyze land use change is using Geographic Information System (GIS) as spatial analysis methods. The effect of urbanization on land use changes in Ciawi Urban Area from year 2013 to 2015 is significant. The reduction of farm land is around -4.00% and wetland is around - 2.51%. The increasing area for hotel/villa/resort is around 3.10%. Based on this research, local government (Bogor Regency) should be alert to the land use changes that does not comply with the land use plan and also consistently apply the spatial planning.

  8. Patterns and risk factors of helminthiasis and anemia in a rural and a peri-urban community in Zanzibar, in the context of helminth control programs.

    Science.gov (United States)

    Knopp, Stefanie; Mohammed, Khalfan A; Stothard, J Russell; Khamis, I Simba; Rollinson, David; Marti, Hanspeter; Utzinger, Jürg

    2010-05-11

    The control of helminth infections and prevention of anemia in developing countries are of considerable public health importance. The purpose of this study was to determine patterns and risk factors of helminth infections and anemia in a rural and a peri-urban community of Zanzibar, Tanzania, in the context of national helminth control programs. We carried out a community-based cross-sectional study in 454 individuals by examining at least two stool samples with different methods for soil-transmitted helminths (Ascaris lumbricoides, hookworm, Strongyloides stercoralis, and Trichuris trichiura) and one urine sample for Schistosoma haematobium. Finger-prick blood was taken to estimate anemia levels and to detect antibody reactions against ascariasis, strongyloidiasis and schistosomiasis, using an enzyme-linked immunosorbent assay (ELISA) approach. Parasitological methods determined a helminth prevalence of 73.7% in the rural, and 48.9% in the peri-urban setting. Most helminth infections were of light intensity with school-aged children showing the highest intensities. Multiple helminth species infections were pervasive in rural dwellers regardless of age. More than half of the participants were anemic, with a particularly high prevalence in the peri-urban setting (64.7%). Risk factors for helminth infections were age, sex, consumption of raw vegetables or salad, recent travel history, and socio-economic status. After several years of chemotherapy-based morbidity control efforts in Zanzibar, helminth prevalences are still high and anemia is common, but helminth infection intensities are low. Hence, chemotherapy should be continued, and complemented with improved access to clean water, adequate sanitation, and health education, along with poverty alleviation measures for a more enduring impact.

  9. Differences in overland flow, hydrophobicity and soil moisture dynamics between Mediterranean woodland types in a peri-urban catchment in Portugal

    Science.gov (United States)

    Ferreira, C. S. S.; Walsh, R. P. D.; Shakesby, R. A.; Keizer, J. J.; Soares, D.; González-Pelayo, O.; Coelho, C. O. A.; Ferreira, A. J. D.

    2016-02-01

    Forest hydrology has been widely investigated, but the impacts of different woodland types on hydrological processes within a peri-urban catchment mosaic are poorly understood. This paper investigates overland flow generation processes in three different types of woodland in a small (6.2 km2) catchment in central Portugal that has undergone strong urban development over the past 50 years. A semi-natural oak stand and a sparse eucalyptus stand on partly abandoned peri-urban land and a dense eucalyptus plantation were each instrumented with three 16 m2 runoff plots and 15 throughfall gauges, which were monitored at c. 1- to 2-week intervals over two hydrological years. In addition, surface soil moisture content (0-5 cm) and hydrophobicity (0-2 cm, 2-5 cm and 5-7 cm) were measured at the same time as overland flow and throughfall. Although all three woodland types produced relatively little overland flow (woodland types. This contrast in overland flow can be attributed to infiltration-excess processes operating in storms following dry antecedent weather when severe hydrophobicity was widespread in the dense eucalypt plantation, whereas it was of moderate and low severity and less widespread in the sparse eucalypt and oak woodlands, respectively. In contrast, under wet conditions greater (albeit still small) percentages of overland flow were produced in oak woodland than in the two eucalypt plantations; this was probably linked to saturation-excess overland flow being generated more readily at the oak site as a result of its shallower soil. Differences in water retention in surface depressions affected overland flow generation and downslope flow transport. Implications of the seasonal differentials in overland flow generation between the three distinct woodland types for the hydrological response of peri-urban catchments are addressed.

  10. Physical activity level and its sociodemographic correlates in a peri-urban Nepalese population: a cross-sectional study from the Jhaukhel-Duwakot health demographic surveillance site.

    Science.gov (United States)

    Vaidya, Abhinav; Krettek, Alexandra

    2014-03-14

    Physical inactivity is a leading risk factor for cardiovascular and other noncommunicable diseases in high-, low- and middle-income countries. Nepal, a low-income country in South Asia, is undergoing an epidemiological transition. Although the reported national prevalence of physical inactivity is relatively low, studies in urban and peri-urban localities have always shown higher prevalence. Therefore, this study aimed to measure physical activity in three domains-work, travel and leisure-in a peri-urban community and assess its variations across different sociodemographic correlates. Adult participants (n=640) from six randomly selected wards of the Jhaukhel-Duwakot Health Demographic Surveillance Site (JD-HDSS) near Kathmandu responded to the Global Physical Activity Questionnaire. To determine total physical activity, we calculated the metabolic equivalent of task in minutes/week for each domain and combined the results. Respondents were categorized into high, moderate or low physical activity. We also calculated the odds ratio for low physical activity in various sociodemographic variables and self-reported cardiometabolic states. The urbanizing JD-HDSS community showed a high prevalence of low physical activity (43.3%; 95% CI 39.4-47.1). Work-related activity contributed most to total physical activity. Furthermore, women and housewives and older, more educated and self-or government-employed respondents showed a greater prevalence of physical inactivity. Respondents with hypertension, diabetes or overweight/obesity reported less physical activity than individuals without those conditions. Only 5% of respondents identified physical inactivity as a cardiovascular risk factor. Our findings reveal a high burden of physical inactivity in a peri-urban community of Nepal. Improving the level of physical activity involves sensitizing people to its importance through appropriate multi-sector strategies that provide encouragement across all sociodemographic groups.

  11. Benefits of flooding-induced aquatic adventitious roots depend on the duration of submergence: linking plant performance to root functioning.

    Science.gov (United States)

    Zhang, Qian; Huber, Heidrun; Beljaars, Simone J M; Birnbaum, Diana; de Best, Sander; de Kroon, Hans; Visser, Eric J W

    2017-07-01

    Temporal flooding is a common environmental stress for terrestrial plants. Aquatic adventitious roots (aquatic roots) are commonly formed in flooding-tolerant plant species and are generally assumed to be beneficial for plant growth by supporting water and nutrient uptake during partial flooding. However, the actual contribution of these roots to plant performance under flooding has hardly been quantified. As the investment into aquatic root development in terms of carbohydrates may be costly, these costs may - depending on the specific environmental conditions - offset the beneficial effects of aquatic roots. This study tested the hypothesis that the balance between potential costs and benefits depends on the duration of flooding, as the benefits are expected to outweigh the costs in long-term but not in short-term flooding. The contribution of aquatic roots to plant performance was tested in Solanum dulcamara during 1-4 weeks of partial submergence and by experimentally manipulating root production. Nutrient uptake by aquatic roots, transpiration and photosynthesis were measured in plants differing in aquatic root development to assess the specific function of these roots. As predicted, flooded plants benefited from the presence of aquatic roots. The results showed that this was probably due to the contribution of roots to resource uptake. However, these beneficial effects were only present in long-term but not in short-term flooding. This relationship could be explained by the correlation between nutrient uptake and the flooding duration-dependent size of the aquatic root system. The results indicate that aquatic root formation is likely to be selected for in habitats characterized by long-term flooding. This study also revealed only limited costs associated with adventitious root formation, which may explain the maintenance of the ability to produce aquatic roots in habitats characterized by very rare or short flooding events. © The Author 2017. Published by

  12. Impact of Climate Variability and Landscape Patterns on Water Budget and Nutrient Loads in a Peri-urban Watershed: A Coupled Analysis Using Process-based Hydrological Model and Landscape Indices.

    Science.gov (United States)

    Li, Chongwei; Zhang, Yajuan; Kharel, Gehendra; Zou, Chris B

    2018-06-01

    Nutrient discharge into peri-urban streams and reservoirs constitutes a significant pressure on environmental management, but quantitative assessment of non-point source pollution under climate variability in fast changing peri-urban watersheds is challenging. Soil and Water Assessment Tool (SWAT) was used to simulate water budget and nutrient loads for landscape patterns representing a 30-year progression of urbanization in a peri-urban watershed near Tianjin metropolis, China. A suite of landscape pattern indices was related to nitrogen (N) and phosphorous (P) loads under dry and wet climate using CANOCO redundancy analysis. The calibrated SWAT model was adequate to simulate runoff and nutrient loads for this peri-urban watershed, with Nash-Sutcliffe coefficient (NSE) and coefficient of determination (R 2 ) > 0.70 and percentage bias (PBIAS) between -7 and +18 for calibration and validation periods. With the progression of urbanization, forest remained the main "sink" landscape while cultivated and urban lands remained the main "source" landscapes with the role of orchard and grassland being uncertain and changing with time. Compared to 1984, the landscape use pattern in 2013 increased nutrient discharge by 10%. Nutrient loads modelled under wet climate were 3-4 times higher than that under dry climate for the same landscape pattern. Results indicate that climate change could impose a far greater impact on runoff and nutrient discharge in a peri-urban watershed than landscape pattern change.

  13. Impact of Climate Variability and Landscape Patterns on Water Budget and Nutrient Loads in a Peri-urban Watershed: A Coupled Analysis Using Process-based Hydrological Model and Landscape Indices

    Science.gov (United States)

    Li, Chongwei; Zhang, Yajuan; Kharel, Gehendra; Zou, Chris B.

    2018-06-01

    Nutrient discharge into peri-urban streams and reservoirs constitutes a significant pressure on environmental management, but quantitative assessment of non-point source pollution under climate variability in fast changing peri-urban watersheds is challenging. Soil and Water Assessment Tool (SWAT) was used to simulate water budget and nutrient loads for landscape patterns representing a 30-year progression of urbanization in a peri-urban watershed near Tianjin metropolis, China. A suite of landscape pattern indices was related to nitrogen (N) and phosphorous (P) loads under dry and wet climate using CANOCO redundancy analysis. The calibrated SWAT model was adequate to simulate runoff and nutrient loads for this peri-urban watershed, with Nash-Sutcliffe coefficient (NSE) and coefficient of determination ( R 2) > 0.70 and percentage bias (PBIAS) between -7 and +18 for calibration and validation periods. With the progression of urbanization, forest remained the main "sink" landscape while cultivated and urban lands remained the main "source" landscapes with the role of orchard and grassland being uncertain and changing with time. Compared to 1984, the landscape use pattern in 2013 increased nutrient discharge by 10%. Nutrient loads modelled under wet climate were 3-4 times higher than that under dry climate for the same landscape pattern. Results indicate that climate change could impose a far greater impact on runoff and nutrient discharge in a peri-urban watershed than landscape pattern change.

  14. Human resource for health reform in peri-urban areas: a cross-sectional study of the impact of policy interventions on healthcare workers in Epworth, Zimbabwe.

    Science.gov (United States)

    Taderera, Bernard Hope; Hendricks, Stephen James Heinrich; Pillay, Yogan

    2017-12-16

    The need to understand how healthcare worker reform policy interventions impact health personnel in peri-urban areas is important as it also contributes towards setting of priorities in pursuing the universal health coverage goal of health sector reform. This study explored the impact of post 2008 human resource for health reform policy interventions on healthcare workers in Epworth, a peri-urban community in Harare, Zimbabwe, and the implications towards health sector reform policy in peri-urban areas. The study design was exploratory and cross-sectional and involved the use of qualitative and quantitative methods in data collection, presentation, and analysis. A qualitative study in which data were collected through a documentary search, five key informant interviews, seven in-depth interviews, and five focus group discussions was carried out first. This was followed by a quantitative study in which data were collected through a documentary search and 87 semi-structured sample interviews with healthcare workers. Qualitative data were analyzed thematically whilst descriptive statistics were used to examine quantitative data. All data were integrated during analysis to ensure comprehensive, reliable, and valid analysis of the dataset. Three main factors were identified to help interpret findings. The first main factor consisted policy result areas that impacted most successfully on healthcare workers. These included the deployment of community health workers with the highest correlation of 0.83. Policy result areas in the second main factor included financial incentives with a correlation of 0.79, training and development (0.77), deployment (0.77), and non-financial incentives (0.75). The third factor consisted policy result areas that had the lowest satisfaction amongst healthcare workers in Epworth. These included safety (0.72), equipment and tools of trade (0.72), health welfare (0.65), and salaries (0.55). The deployment of community health volunteers impacted

  15. Effects of power plant cooling on aquatic biota

    International Nuclear Information System (INIS)

    Moeller, H.

    1978-01-01

    Several bibliographies and reviews on 'ecological consequences of power plant cooling' have been published. Other reports compile additional data, but are not available to the public. Altogether, more than 3,000 literature citations have been gathered until now, too many to be studied by an individual scientist. The bibliography becomes more comprehensible if only titles are accepted that deal with power plant cooling itself, neglecting the influence of temperature and other stress factors on organisms as examined under laboratory conditions. Among these 600 remaining titles, about 370 are published in journals and periodicals available to the public. They are presented in this bibliography. (orig./RW) [de

  16. Weed risk assessment for aquatic plants: modification of a New Zealand system for the United States.

    Directory of Open Access Journals (Sweden)

    Doria R Gordon

    Full Text Available We tested the accuracy of an invasive aquatic plant risk assessment system in the United States that we modified from a system originally developed by New Zealand's Biosecurity Program. The US system is comprised of 38 questions that address biological, historical, and environmental tolerance traits. Values associated with each response are summed to produce a total score for each species that indicates its risk of invasion. To calibrate and test this risk assessment, we identified 39 aquatic plant species that are major invaders in the continental US, 31 species that have naturalized but have no documented impacts (minor invaders, and 60 that have been introduced but have not established. These species represent 55 families and span all aquatic plant growth forms. We found sufficient information to assess all but three of these species. When the results are compared to the known invasiveness of the species, major invaders are distinguished from minor and non-invaders with 91% accuracy. Using this approach, the US aquatic weed risk assessment correctly identifies major invaders 85%, and non-invaders 98%, of the time. Model validation using an additional 10 non-invaders and 10 invaders resulted in 100% accuracy for the former, and 80% accuracy for the latter group. Accuracy was further improved to an average of 91% for all groups when the 17% of species with scores of 31-39 required further evaluation prior to risk classification. The high accuracy with which we can distinguish non-invaders from harmful invaders suggests that this tool provides a feasible, pro-active system for pre-import screening of aquatic plants in the US, and may have additional utility for prioritizing management efforts of established species.

  17. Control of parasitic infections among school children in the peri-urban area of Botucatu, São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Regina Coeli Cunha Dórea

    1996-10-01

    Full Text Available Tide prevalence of intestinal parasitosis ivas investigated in a primaiy school located in Rubiâo Júnior, a peri-urban district of Botucatu, São Paulo slate, Brazil, in order to assess the effect of treatment and practical measures of prophylaxis in the control of parasitic infections among 7-to- 18-year-old school children of a low socio-economic status. The first series of parasitological examinations included 219 school children, ef which 123 (56.1 % were found to be infected with one or more parasite species. Eighty- four children canying pathogenic parasites were submitted to various anti-parasitic treatment schedules. We re-evaluated 15 (89 % students after 4 to 6 months post- chemotherapy. The results indicate that the combination of treatment with prophylactic measures has been successful in the control of parasitic infections, since reinfection rates were generally low ( 73-1 % in children infected with most parasite species. The reasons for the apparent failure in the control of infections caused by Hymenolepis nana and Strongyloides stercoralis are discussed.Prôcedeu-se o estudo da prevalência de enteroparasitoses entre escolares de 7 a 18 anos, de condições sõcio-econômicas baixas e residentes no distritoperi-urbano de Rubião Júnior, município de Botucatu, São Paulo, com o objetivo de analisar o papel de medidas profiláticas e terapêuticas no controle das parasitoses diagnosticadas. Dos 219 alunos estudados na primeira avaliação parasitolõgica, 123 (56.1% mostraram-se positivos para unia ou mais parasitoses. O tratamento foi aplicado para 84 escolares, por serem estes portadores de parasitos patogênicos. A segunda avaliação parasitolõgica foi realizada 4 a 6 meses após o tratamento em 75 (89% escolares. Os resultados indicam que o uso combinado do tratamento e medidas profiláticas foi capaz de limitar a ocorrência de novas infecções para níveis 73-1% foram encontradas para a maioria das parasitoses, exceto

  18. Post partum anxiety and depression in peri-urban communities of Karachi, Pakistan: a quasi-experimental study

    Directory of Open Access Journals (Sweden)

    Azam Iqbal S

    2009-10-01

    Full Text Available Abstract Background Postpartum anxiety and depression is a major public health concern because of its adverse effects on the cognitive and social development of the infant. Globally postpartum depression has been widely investigated but as anxiety is a more prominent feature of postpartum depression we assessed the prevalence of anxiety and depression and their associated factors in post partum women. Methods A quasi-experimental study investigating the impact of postpartum anxiety and depression on child growth and development was conducted in two peri-urban, multiethnic, communities of Karachi, a mega city of Pakistan. A house to house questionnaire based survey was done by trained field workers; 420 consenting pregnant women were identified and data for socio-demographic, home environment and family relationship variables was collected between 36 weeks of pregnancy and within 10 days of childbirth. Mother's levels of anxiety and depression were assessed after one month, two months, six months and twelve months of childbirth; this was two step process: initially an indigenous, validated screening instrument Aga Khan University Anxiety and Depression Scale was used and diagnostic confirmation was done through a psychologist's interview based on DSM IV criteria. Women found to be anxious and depressed at least once out of four assessments were considered for the computation of overall prevalence of postpartum anxiety and depression as well as its risk factors. However, point prevalence's of postpartum anxiety and depression were also reported at each assessment time. Two sixty seven women could be followed for one year. Data was analyzed using SPSS. Chi-square test, simple and multiple logistic regression were used to see the association of different factors. Results The overall prevalence of postpartum anxiety and depression was found to be 28.8 percent. Domestic violence, difficulty in breast feeding at birth and unplanned current pregnancy

  19. Role of algae and higher aquatic plants in decontamination of cyanide-containing waters

    International Nuclear Information System (INIS)

    Timofeeva, S.S.; Kraeva, V.Z.; Men'shikova, O.A.

    1986-01-01

    Cyanide compounds and especially free cyanides stand out among components of wastewaters of hydrometallurgy, electroforming, and other such enterprises with respect to toxicity and danger for man and fauna of water bodies. In this article data on a study of the regularities of decontamination of cyanide-containing wastewaters by hydrophytes are given, the mechanisms of this process are examined, and the results of testing the hydrobotanical method of treating wastewaters of a goldrecovery plant are examined. The experiments were carried out with hydrophytes from the Angara River, Lake Baikal, and small lakes and ponds in the vicinity of Irkutsk and Tashkent. The series of experiments established that algae and higher aquatic plants are resistant to cyanides. A table shows the kinetic parameters of the removal of cyanide by algae and higher aquatic plants collected in Baikal. Of the multitude of species investigated for detoxifying ability, the most resistant were detected in the experimental basins and the most suitable were charophytes

  20. Avoidance and tolerance to avian herbivores in aquatic plants

    NARCIS (Netherlands)

    Hidding, A.

    2009-01-01

    Tolerance and avoidance are the two contrasting strategies that plants may adopt to cope with herbivores. Tolerance traits define the degree to which communities remain unaffected by herbivory. Trade-offs between herbivore avoidance and competitive strength and between avoidance and colonization

  1. Aquatic indicator organisms as a tool to monitor discharges from nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Outola, Iisa; Vartti, Vesa-Pekka; Klemola, Seppo [STUK - Radiation and Nuclear Safety Authority, P.O. Box 14, 00881 Helsinki (Finland)

    2014-07-01

    There are four operating nuclear power plant units in Finland at two separate locations. The units started operation during 1977-1980. The surveillance of radioactive substances in the vicinities of the nuclear power plant is carried out under the permanent monitoring programs. Some 1000 samples are taken annually from the surroundings of the power plants to confirm that the discharges from the power plants are within permissible release limits and to monitor the dispersion of discharges in the environment. Aquatic indicator organisms (macro-algae, periphyton, mussels, crustacean, submerged aquatic plants) are included in the monitoring program. The indicator organisms are valuable monitoring objects both in normal and emergency situations because they accumulate effectively and often very rapidly radioactive substances from the medium. Six different species (Periphyton, Fucus vesiculosus, Myriophyllum spicatum, Potamogeton pectinatus, Saduria entomon, Macoma Baltica/Mytilus edulis) are collected regularly. Number of sampling location for each species varies from 1 to 7. Some species are collected continuously, some 1-2 times in a year. In this study we have evaluated the monitoring results for the aquatic indicator organisms for the period of 2005-2010 concerning concentration of discharge nuclides. Our aim was to answer the following questions using the monitoring data from aquatic organisms: 1) Which radionuclides are released to the marine environment and how often do we detect them? 2) How far from the nuclear power plants discharge radionuclides are detected? 3) How concentration of discharge radionuclides has changed with time in aquatic organisms? The number of discharge nuclides detected in the aquatic indicator samples was 11. Most of them were only detected in few samples, but {sup 58}Co, {sup 60}Co, {sup 54}Mn and {sup 110m}Ag were detected more frequently. Most of the observations above detection limits were made within the 5 km distance from the

  2. Aquatic emergency response model at the Savannah River Plant

    International Nuclear Information System (INIS)

    Hayes, D.W.

    1987-01-01

    The Savannah River Plant emergency response plans include a stream/river emergency response model to predict travel times, maximum concentrations, and concentration distributions as a function of time at selected downstream/river locations from each of the major SRP installations. The menu driven model can be operated from any of the terminals that are linked to the real-time computer monitoring system for emergency response

  3. Nitrogen kinetics in aquatic plants in arctic Alaska

    International Nuclear Information System (INIS)

    McRoy, C.P.; Alexander, V.

    1975-01-01

    The kinetics of nitrogen in terms of ammonia uptake was measured for Carex aquatilis in arctic tundra ponds using 15 N tracer techniques. Nitrogen content of the leaves and primary productivity were measured throughout a growing season. The maximum uptake velocity for ammonia was 2.75 x 10 -2 % N/g dry weight per h with a Ksub(t) of 8.4-12.5 μgatoms/l. A second estimate of nitrogen uptake was made from the increase in nitrogen content throughout the season and from this a rate of 1.85 x 10 -2 % N/g dry weight per day was obtained for Carex aquatilis and 3.6 x 10 -2 % N/g dry weight per day for Arctophylla fulva. The total nitrogen concentration in the leaves was closely related to productivity, possible providing a new approach to productivity measurements for emergent vascular plants. Emergent vascular plants absorb ammonia across and translocate it to all portions of the plant. The ecological significance of this is considerable, since in many waters inorganic nitrogen content of sediment is much higher than that of the water surrounding the leaves and stems, and can provide a source of nitrogen

  4. Mineralization of Surfactants by Microbiota of Aquatic Plants.

    Science.gov (United States)

    Federle, Thomas W; Schwab, Burney S

    1989-08-01

    The biodegradation of linear alkylbenzene sulfonate (LAS) and linear alcohol ethoxylate (LAE) by the microbiota associated with duckweed (Lemna minor) and the roots of cattail (Typha latifolia) was investigated. Plants were obtained from a pristine pond and a pond receiving wastewater from a rural laundromat. Cattail roots and duckweed plants were incubated in vessels containing sterile water amended with [C]LAS, [C]LAE, or C-labeled mixed amino acids (MAA). Evolution of CO(2) was determined over time. The microbiota of cattail roots from both ponds mineralized LAS, LAE, and MAA without lag periods, and the rates and extents of mineralization were not significantly affected by the source of the plants. Mineralization of LAS and LAE was more rapid in the rhizosphere than in nearby root-free sediments, which exhibited differences as a function of pond. The microbiota of duckweed readily mineralized LAE and MAA but not LAS. The rate and extent of mineralization were not affected by the source of the duckweed.

  5. Mineralization of surfactants by microbiota of aquatic plants

    International Nuclear Information System (INIS)

    Federle, T.W.; Schwab, B.S.

    1989-01-01

    The biodegradation of linear alkylbenzene sulfonate (LAS) and linear alcohol ethoxylate (LAE) by the microbiota associated with duckweed (Lemna minor) and the roots of cattail (Typha latifolia) was investigated. Plants were obtained from a pristine pond and a pond receiving wastewater from a rural laundromat. Cattail roots and duckweed plants were incubated in vessels containing sterile water amended with [ 14 C]LAS, [ 14 C]LAE, or 14 C-labeled mixed amino acids (MAA). Evolution of 14 CO 2 was determined over time. The microbiota of cattail roots from both ponds mineralized LAS, LAE, and MAA without lag periods, and the rates and extents of mineralization were not significantly affected by the source of the plants. Mineralization of LAS and LAE was more rapid in the rhizosphere than in nearby root-free sediments, which exhibited differences as a function of pond. The microbiota of duckweed readily mineralized LAE and MAA but not LAS. The rate and extent of mineralization were not affected by the source of the duckweed

  6. The effect of radioactive contamination of the Yenisei river on cytogenetic characteristics of aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Bolsunovsky, A.; Medvedeva, M. [Institute of Biophysics SB Russian Academy of Sciences (Russian Federation); Muratova, E. [Institute of Forest SB Russian Academy of Sciences (Russian Federation)

    2014-07-01

    The Yenisei River, one of the world's largest rivers, is contaminated with artificial radionuclides released by one of the Russian facilities producing weapons-grade plutonium (the Mining-and-Chemical Combine, MCC), which has been in operation for many years. Aquatic plants are an important component of water ecosystems, which can accumulate high levels of radionuclides and, thus, can be used in bio-monitoring and bioremediation. The purpose of the study was to assess levels of radionuclides and to evaluate the frequency of chromosomal aberrations in samples of submerged plants collected in different parts of the Yenisei River. The following species were studied: Fontinalis antipyretica, Batrachium kauffmanii, Myriophyllum spicatum, Elodea canadensis, Ceratophyllum demersum and various Potamogeton species. Samples were collected at positions in the vicinity of the MCC discharge point, at a distance of 330 km downstream of Krasnoyarsk, and upstream of the MCC, during sampling campaigns in 2003-2012. Detailed analysis of radioactive contamination of aquatic plants of the Yenisei River revealed large-scale contamination of aquatic plants as far as 250 km downstream of the MCC. Before the last MCC reactor was shut down in 2010, about 30 radionuclides, including uranium and transuranium elements, were detected in the biomass of aquatic plants. The highest concentration factors of the major radionuclides were obtained for Fontinalis antipyretica and Potamogeton lucens. Samples of the plants collected after the shutdown of the reactor contained considerably lower activity levels of artificial radionuclides, and their diversity was significantly decreased. Results of cytogenetic investigations of aquatic plants collected when the reactor was still operating (2003-2009) suggest that at the MCC discharge site and downstream the occurrence of chromosomal aberrations in ana-telophase and metaphase cells of the plants was considerably higher (up to 30%) than in the control

  7. Ubiquitous water-soluble molecules in aquatic plant exudates determine specific insect attraction.

    Science.gov (United States)

    Sérandour, Julien; Reynaud, Stéphane; Willison, John; Patouraux, Joëlle; Gaude, Thierry; Ravanel, Patrick; Lempérière, Guy; Raveton, Muriel

    2008-10-08

    Plants produce semio-chemicals that directly influence insect attraction and/or repulsion. Generally, this attraction is closely associated with herbivory and has been studied mainly under atmospheric conditions. On the other hand, the relationship between aquatic plants and insects has been little studied. To determine whether the roots of aquatic macrophytes release attractive chemical mixtures into the water, we studied the behaviour of mosquito larvae using olfactory experiments with root exudates. After testing the attraction on Culex and Aedes mosquito larvae, we chose to work with Coquillettidia species, which have a complex behaviour in nature and need to be attached to plant roots in order to obtain oxygen. This relationship is non-destructive and can be described as commensal behaviour. Commonly found compounds seemed to be involved in insect attraction since root exudates from different plants were all attractive. Moreover, chemical analysis allowed us to identify a certain number of commonly found, highly water-soluble, low-molecular-weight compounds, several of which (glycerol, uracil, thymine, uridine, thymidine) were able to induce attraction when tested individually but at concentrations substantially higher than those found in nature. However, our principal findings demonstrated that these compounds appeared to act synergistically, since a mixture of these five compounds attracted larvae at natural concentrations (0.7 nM glycerol, insect relationships in aquatic eco-systems.

  8. Heavy metal pollution in aquatic ecosystems and its phytoremediation using wetland plants: An ecosustainable approach

    Energy Technology Data Exchange (ETDEWEB)

    Rai, P.K. [Mizoram Central University, Tanhril (India). School for Earth Science & Natural Resource Management

    2008-07-01

    This review addresses the global problem of heavy metal pollution originating from increased industrialization and urbanization and its amelioration by using wetland plants both in a microcosm as well as natural/field condition. This review mentions salient features of wetland ecosystems, their vegetation component, and the pros and cons involved in heavy metal removal. Wetland plants are preferred over other bio-agents due to their low cost, frequent abundance in aquatic ecosystems, and easy handling. Constructed wetlands proved to be effective for the abatement of heavy metal pollution from acid mine drainage; landfill leachate; thermal power; and municipal, agricultural, refinery, and chlor-alkali effluent. the physicochemical properties of wetlands provide many positive attributes for remediating heavy metals. Typha, Phragmites, Eichhornia, Azolla, Lemna, and other aquatic macrophytes are some of the potent wetland plants for heavy metal removal. Biomass disposal problem and seasonal growth of aquatic macrophytes are some limitations in the transfer of phytoremediation technology from the laboratory to the field. However, the disposed biomass of macrophytes may be used for various fruitful applications. An ecosustainable model has been developed through the author's various works, which may ameliorate some of the limitations. The creation of more areas for phytoremediation may also aid in wetlands conservation. Genetic engineering and biodiversity prospecting of endangered wetland plants are important future prospects in this regard.

  9. A pharm-ecological perspective of terrestrial and aquatic plant-herbivore interactions.

    Science.gov (United States)

    Forbey, Jennifer Sorensen; Dearing, M Denise; Gross, Elisabeth M; Orians, Colin M; Sotka, Erik E; Foley, William J

    2013-04-01

    We describe some recent themes in the nutritional and chemical ecology of herbivores and the importance of a broad pharmacological view of plant nutrients and chemical defenses that we integrate as "Pharm-ecology". The central role that dose, concentration, and response to plant components (nutrients and secondary metabolites) play in herbivore foraging behavior argues for broader application of approaches derived from pharmacology to both terrestrial and aquatic plant-herbivore systems. We describe how concepts of pharmacokinetics and pharmacodynamics are used to better understand the foraging phenotype of herbivores relative to nutrient and secondary metabolites in food. Implementing these concepts into the field remains a challenge, but new modeling approaches that emphasize tradeoffs and the properties of individual animals show promise. Throughout, we highlight similarities and differences between the historic and future applications of pharm-ecological concepts in understanding the ecology and evolution of terrestrial and aquatic interactions between herbivores and plants. We offer several pharm-ecology related questions and hypotheses that could strengthen our understanding of the nutritional and chemical factors that modulate foraging behavior of herbivores across terrestrial and aquatic systems.

  10. Topical report on sources and systems for aquatic plant biomass as an energy resource

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, J.C.; Ryther, J.H.; Waaland, R.; Wilson, E.H.

    1977-10-21

    Background information is documented on the mass cultivation of aquatic plants and systems design that is available from the literature and through consultation with active research scientists and engineers. The biology of microalgae, macroalgae, and aquatic angiosperms is discussed in terms of morphology, life history, mode of existence, and ecological significance, as they relate to cultivation. The requirements for growth of these plants, which are outlined in the test, suggest that productivity rates are dependent primarily on the availability of light and nutrients. It is concluded that the systems should be run with an excess of nutrients and with light as the limiting factor. A historical review of the mass cultivation of aquatic plants describes the techniques used in commercial large-scale operations throughout the world and recent small-scale research efforts. This review presents information on the biomass yields that have been attained to date in various geographical locations with different plant species and culture conditions, emphasizing the contrast between high yields in small-scale operations and lower yields in large-scale operations.

  11. Potential of some aquatic plants for removal of arsenic from wastewater by green technology

    Directory of Open Access Journals (Sweden)

    Mohammed Barznji Dana A.

    2015-03-01

    Full Text Available Phytoremediation or green technology is counted among the successful and effective biological contaminated water treatment techniques. Basically, the concept of this green, cost-effective, simple, environmentally nondisruptive method consists in using plants and microbiological processes to reduce contaminants in the ecosystem. Different species from aquatic plants (emerged, free-floating, and submerged have been studied to mitigate toxic contaminants such as arsenic, cadmium, chromium, copper, lead, mercury, zinc, etc. Arsenic is one of the most severe toxic elements; it is widely distributed in the environment, usually found in combination with chloride, oxygen, sulphur and metal ions as a result of mineral dissolution from sedimentary or volcanic rocks and the dilution of geothermal water. The effluents from both industrial and agricultural sectors are also regarded as sources to contaminate water. From the accumulation point of view, several aquatic plants have been mentioned as good arsenic accumulators and their performance is evaluated using the green technology method. These include Spirodela polyrhiza, Wolffia globosa, Lemna gibba, L. minor, Eichhornia crassipes, Azolla caroliniana, Azolla filiculoides, Azolla pinnata, Ceratophyllum demersum and Pistia stratiotes. The up-to-date information illustrated in this review paper generates knowledge about the ability of some common aquatic plants around the globe to remediate arsenic from contaminated water.

  12. A new mechanism of macrophyte mitigation: how submerged plants reduce malathion's acute toxicity to aquatic animals.

    Science.gov (United States)

    Brogan, William R; Relyea, Rick A

    2014-08-01

    A growing body of evidence suggests that aquatic plants can mitigate the toxicity of insecticides to sensitive aquatic animals. The current paradigm is that this ability is driven primarily by insecticide sorption to plant tissues, especially for hydrophobic compounds. However, recent work shows that submerged plants can strongly mitigate the toxicity of the relatively hydrophilic insecticide malathion, despite the fact that this compound exhibits a slow sorption rate to plants. To examine this disparity, we tested the hypothesis that the mitigating effect of submerged plants on malathion's toxicity is driven primarily by the increased water pH from plant photosynthesis causing the hydrolysis of malathion, rather than by sorption. To do this, we compared zooplankton (Daphnia magna) survival across five environmentally relevant malathion concentrations (0, 1, 4, 6, or 36 μg L(-1)) in test containers where we chemically manipulated water pH in the absence of plants or added the submerged plant (Elodea canadensis) but manipulated plant photosynthetic activity via shading or no shading. We discovered that malathion was equally lethal to Daphnia at all concentrations tested when photosynthetically inactive (i.e. shaded) plants were present (pH at time of dosing=7.8) or when pH was chemically decreased (pH=7.7). In contrast, when photosynthetically active (i.e. unshaded) plants were present (pH=9.8) or when pH was chemically increased (pH=9.5), the effects of 4 and 6 μg L(-1) of malathion on Daphnia were mitigated strongly and to an equal degree. These results demonstrate that the mitigating effect of submerged plants on malathion's toxicity can be explained entirely by a mechanism of photosynthesizing plants causing an increase in water pH, resulting in rapid malathion hydrolysis. Our findings suggest that current ecotoxicological models and phytoremediation strategies may be overlooking a critical mechanism for mitigating pesticides. Copyright © 2014 Elsevier Ltd

  13. A Geographical Information System Based Approach for Integrated Strategies of Tick Surveillance and Control in the Peri-Urban Natural Reserve of Monte Pellegrino (Palermo, Southern Italy).

    Science.gov (United States)

    Torina, Alessandra; Blanda, Valeria; Blanda, Marcellocalogero; Auteri, Michelangelo; La Russa, Francesco; Scimeca, Salvatore; D'Agostino, Rosalia; Disclafani, Rosaria; Villari, Sara; Currò, Vittoria; Caracappa, Santo

    2018-02-27

    Ticks (Acari: Ixodidae) are bloodsucking arthropods involved in pathogen transmission in animals and humans. Tick activity depends on various ecological factors such as vegetation, hosts, and temperature. The aim of this study was to analyse the spatial/temporal distribution of ticks in six sites within a peri-urban area of Palermo (Natural Reserve of Monte Pellegrino) and correlate it with field data using Geographical Information System (GIS) data. A total of 3092 ticks were gathered via dragging method from June 2012 to May 2014. The species collected were: Ixodes ventalloi (46.09%), Hyalomma lusitanicum (19.99%), Rhipicephalus sanguineus (17.34%), Rhipicephalus pusillus (16.11%), Haemaphisalis sulcata (0.36%), Dermacentor marginatus (0.10%), and Rhipicephalus turanicus (0.03%). GIS analysis revealed environmental characteristics of each site, and abundance of each tick species was analysed in relation to time (monthly trend) and space (site-specific abundance). A relevant presence of I. ventalloi in site 2 and H. lusitanicum in site 5 was observed, suggesting the possible exposure of animals and humans to tick-borne pathogens. Our study shows the importance of surveillance of ticks in peri-urban areas and the useful implementation of GIS analysis in vector ecology; studies on temporal and spatial distribution of ticks correlated to GIS-based ecological analysis represent an integrated strategy for decision support in public health.

  14. Lack of protection against rabies in neighbourhood dogs in some peri-urban and rural areas of Ogun and Oyo states, Nigeria.

    Science.gov (United States)

    Oluwayelu, D O; Adebiyi, A I; Ohore, O G; Cadmus, S I B

    2014-12-01

    Rabies is a highly fatal zoonosis that causes severe destruction to the central nervous system and remains underreported in developing countries like Nigeria. The increasing close contact between dogs and their owners or neighbours suggest a need for investigation of the protective level of rabies virus (RABV) antibodies in dogs. Sera from 150 apparently healthy neighbourhood dogs from some peri-urban and rural areas of Ogun and Oyo states, southwestern Nigeria were analyzed for the presence of RABV antibodies using the indirect ELISA technique. These dogs were kept as pets, used for hunting or sold for human consumption. The results showed that none of the dogs had optimal RABV antibody titres, 25 (16.7%) had sub-optimal antibody titres while 125 (83.3%) were negative. Detection of sub-optimal RABV antibody levels in these unvaccinated dogs suggests that they might have been exposed to rabies or rabies-related viruses. Data obtained from interviews conducted revealed that 21.3% of the dog owners were informed about rabies but neglected vaccination while 44.7% were uninformed. We conclude that these dogs lacked protective levels of RABV antibodies and thus constitute a public, health threat. This finding underscores the need for dog anti-rabies vaccination campaigns covering peri-urban and rural areas as well as the promotion of large scale public enlightenment programmes on rabies in Nigeria.

  15. Polar pesticide contamination of an urban and peri-urban tropical watershed affected by agricultural activities (Yaoundé, Center Region, Cameroon).

    Science.gov (United States)

    Branchet, Perrine; Cadot, Emmanuelle; Fenet, Hélène; Sebag, David; Ngatcha, Benjamin Ngounou; Borrell-Estupina, Valérie; Ngoupayou, Jules Remy Ndam; Kengne, Ives; Braun, Jean-Jacques; Gonzalez, Catherine

    2018-04-18

    Urban agriculture is crucial to local populations, but the risk of it contaminating water has rarely been documented. The aim of this study was to assess pesticide contamination of surface waters from the Méfou watershed (Yaoundé, Cameroon) by 32 selected herbicides, fungicides, and insecticides (mainly polar) according to their local application, using both grab sampling and polar organic compounds integrative samplers (POCIS). Three sampling campaigns were conducted in the March/April and October/November 2015 and June/July 2016 rainy seasons in urban and peri-urban areas. The majority of the targeted compounds were detected. The quantification frequencies of eight pesticides were more than 20% with both POCIS and grab sampling, and that of diuron and atrazine reached 100%. Spatial differences in contamination were evidenced with higher contamination in urban than peri-urban rivers. In particular, diuron was identified as an urban contaminant of concern because its concentrations frequently exceeded the European water quality guideline of 0.200 μg/L in freshwater and may thus represent an ecological risk due to a risk quotient > 1 for algae observed in 94% of grab samples. This study raises concerns about the impacts of urban agriculture on the quality of water resources and to a larger extent on the health of the inhabitants of cities in developing countries. Graphical abstract ᅟ.

  16. Sand flies naturally infected by Leishmania (L.) mexicana in the peri-urban area of Chetumal city, Quintana Roo, México.

    Science.gov (United States)

    Sánchez-García, Laura; Berzunza-Cruz, Miriam; Becker-Fauser, Ingeborg; Rebollar-Téllez, Eduardo A

    2010-06-01

    The surveillance of prevalent Leishmania sand fly vectors is an important issue for epidemiological studies in populated areas where leishmaniasis is endemic. In this study, we collected sand flies from a peri-urban area in the southeast of Mexico. Natural infection with Leishmania (L.) mexicana was studied by PCR using a Leishmania internal transcribed spacer of the ribosomal RNA gene for amplification. Infected Lutzomyia olmeca olmeca, Lu. shannoni and Lu. cruciata sand flies were collected mainly during the high transmission season (November to March), coinciding with the highest sand fly densities. Additionally, positive specimens of Lu. olmeca olmeca were also captured during July and August. The infected sand flies were from primary forest (subperennial forest) and secondary forest (18-25 years old and 10-15 years old respectively). Sand flies collected with Disney and Shannon traps were the ones found to be infected with L. (L.) mexicana. We conclude that the high-risk period in which L. (L.) mexicana is transmitted in the peri-urban area of Chetumal City is from July to March and that transmission is associated with both the subperennial forest and the secondary forest. 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  17. A Geographical Information System Based Approach for Integrated Strategies of Tick Surveillance and Control in the Peri-Urban Natural Reserve of Monte Pellegrino (Palermo, Southern Italy

    Directory of Open Access Journals (Sweden)

    Alessandra Torina

    2018-02-01

    Full Text Available Ticks (Acari: Ixodidae are bloodsucking arthropods involved in pathogen transmission in animals and humans. Tick activity depends on various ecological factors such as vegetation, hosts, and temperature. The aim of this study was to analyse the spatial/temporal distribution of ticks in six sites within a peri-urban area of Palermo (Natural Reserve of Monte Pellegrino and correlate it with field data using Geographical Information System (GIS data. A total of 3092 ticks were gathered via dragging method from June 2012 to May 2014. The species collected were: Ixodes ventalloi (46.09%, Hyalomma lusitanicum (19.99%, Rhipicephalus sanguineus (17.34%, Rhipicephalus pusillus (16.11%, Haemaphisalis sulcata (0.36%, Dermacentor marginatus (0.10%, and Rhipicephalus turanicus (0.03%. GIS analysis revealed environmental characteristics of each site, and abundance of each tick species was analysed in relation to time (monthly trend and space (site-specific abundance. A relevant presence of I. ventalloi in site 2 and H. lusitanicum in site 5 was observed, suggesting the possible exposure of animals and humans to tick-borne pathogens. Our study shows the importance of surveillance of ticks in peri-urban areas and the useful implementation of GIS analysis in vector ecology; studies on temporal and spatial distribution of ticks correlated to GIS-based ecological analysis represent an integrated strategy for decision support in public health.

  18. Importance of triggers and veto-barriers for the implementation of sanitation in informal peri-urban settlements – The case of Cochabamba, Bolivia

    Science.gov (United States)

    Rauch, Sebastien; Cossio, Claudia; Landaeta, Graciela; McConville, Jennifer

    2018-01-01

    An estimated 2.4 billion people lack access to improved sanitation which has devastating consequences for human health and the environment. Understanding what constitute sanitation demand is crucial for accelerating the spread of improved sanitation. This study aims to understand the adoption mechanisms for improved sanitation. An informal peri-urban settlement in Cochabamba, Bolivia was selected as a case study to understand adoption patterns. Various qualitative methods of data collection and analysis were employed. The findings showed that pour-flush toilets was the only preferred sanitation alternative at the study site. An adoption framework for waterborne toilets was developed based on diffusion of innovation theory. Factors that influence adoption were identified. Some functioned as triggers and initiated adoption, whereas some factors blocked adoption and constituted veto-barriers. Most factors were connected to the individual household situation and its members, but neighborhood development also affected pour-flush adoption. Based on adoption time the residents were divided into the following adoption groups: first adopters, early majority, late majority, laggards and non-adopters. Each adoption group followed its own adoption route with specific characteristics and respective triggers or veto-barriers. We argue that the strong demand for waterborne toilets in peri-urban areas need to be recognized and the developed framework could be used for customizing sanitation improvement programs for certain target groups. PMID:29617459

  19. Policy Needs for Social Security in the Process of Citizenization of the Peri-urban Farmers:A Case Study of Hefei City

    Institute of Scientific and Technical Information of China (English)

    TAN Jiang-lin; CHEN Rui; NI Wen-cong

    2012-01-01

    We conduct a survey of transformational towns and villages in High-tech Development District, Yaohai District and Shushan District, Hefei City. Using data, we analyze the "sideline effect" and inherent contradiction of transformational cities, research the policy needs for social security and its trend in the citizenization process of the peri-urban farmers. On this basis, we construct the social security policy system that can adapt to the accelerated process of urbanization. Finally, we put forth the following recommendations for the social security policy in the citizenization process of the peri-urban farmers: distinguishing different groups’ policy needs for social security; attaching importance to people’s dynamic policy needs for social security in urbanization; focusing on the adaptability of social security policy transformation in urbanization; attaching importance to the social psychosocial environment of social security policy transformation in urbanization; achieving the trinity of non-farm conversion, urbanization and citizenization in the process of urbanization; strengthening the government’s dominant position in the building of social security policy system.

  20. Geospatial analysis of land use and water interaction in the peri-urban area of Cuauhtémoc, Chihuahua. A socio-environmental study in northern Mexico

    Directory of Open Access Journals (Sweden)

    Rolando Enrique Díaz Caravantes

    2013-07-01

    Full Text Available For decades, city growth has been considered only in terms of land availability. In cities of northern Mexico, usually located in arid or semi-arid regions, there is a high dependence on groundwater. For this reason, comprehensive planning urban must consider the peri-urban area not only in terms of soil, but also groundwater. Water transfer for urban use produces severe alterations to the natural environment as aquifer depletion and drastic changes in land use/cover. This paper presents a spatial analysis of land use and water in the peri-urban area of Ciudad Cuauhtémoc. Using geographic modeling and remote sensing we assessed the dynamics of land use/cover. The results indicate that land change processes occur in a context of high competition for water between different users. This process is not usually considered in studies measuring urban spatial expansion, but should be considered to fully understand the effects of urban growth in the territory.

  1. Engaging with Peri-Urban Woodlands in England: The Contribution to People’s Health and Well-Being and Implications for Future Management

    Science.gov (United States)

    O’Brien, Liz; Morris, Jake; Stewart, Amy

    2014-01-01

    In this paper we engage with debates concerning people and their contact with the natural environment as part of everyday life drawing on Irwin’s ideas of co-construction and Gibson’s theory of affordances. We focus on peri-urban woodlands in England as important places where people can interact with nature for health and well-being. Qualitative data were collected in situ via walks in the woods, focus group discussions and photo elicitation, with a sample of 49 people. These methods provide rich data on the wide range of meanings associated with woodlands that can have a perceived impact on people’s health and well-being. The findings link to contemporary debates about health, well-being and ecosystem services. We explore the inter-play between attributes of the physical environment and the range of facilities provided to enable access, social interactions and the benefits people attribute to their woodland experiences. We conclude that peri-urban woodlands can clearly contribute to self-reported health and well-being in multiple ways, and that organized activities can be important for those who face barriers to accessing woodlands. A strong message emerging from the research is the opportunity afforded by woodlands for social connections with others, as well as the provision of a range of sensory benefits and opportunities to observe and enjoy seasonal change in woodlands. Mental restoration via connection with nature also emerged as important, confirming previous research. PMID:24927035

  2. Engaging with peri-urban woodlands in England: the contribution to people's health and well-being and implications for future management.

    Science.gov (United States)

    O'Brien, Liz; Morris, Jake; Stewart, Amy

    2014-06-12

    In this paper we engage with debates concerning people and their contact with the natural environment as part of everyday life drawing on Irwin's ideas of co-construction and Gibson's theory of affordances. We focus on peri-urban woodlands in England as important places where people can interact with nature for health and well-being. Qualitative data were collected in situ via walks in the woods, focus group discussions and photo elicitation, with a sample of 49 people. These methods provide rich data on the wide range of meanings associated with woodlands that can have a perceived impact on people's health and well-being. The findings link to contemporary debates about health, well-being and ecosystem services. We explore the inter-play between attributes of the physical environment and the range of facilities provided to enable access, social interactions and the benefits people attribute to their woodland experiences. We conclude that peri-urban woodlands can clearly contribute to self-reported health and well-being in multiple ways, and that organized activities can be important for those who face barriers to accessing woodlands. A strong message emerging from the research is the opportunity afforded by woodlands for social connections with others, as well as the provision of a range of sensory benefits and opportunities to observe and enjoy seasonal change in woodlands. Mental restoration via connection with nature also emerged as important, confirming previous research.

  3. Engaging with Peri-Urban Woodlands in England: The Contribution to People’s Health and Well-Being and Implications for Future Management

    Directory of Open Access Journals (Sweden)

    Liz O'Brien

    2014-06-01

    Full Text Available In this paper we engage with debates concerning people and their contact with the natural environment as part of everyday life drawing on Irwin’s ideas of co-construction and Gibson’s theory of affordances. We focus on peri-urban woodlands in England as important places where people can interact with nature for health and well-being. Qualitative data were collected in situ via walks in the woods, focus group discussions and photo elicitation, with a sample of 49 people. These methods provide rich data on the wide range of meanings associated with woodlands that can have a perceived impact on people’s health and well-being. The findings link to contemporary debates about health, well-being and ecosystem services. We explore the inter-play between attributes of the physical environment and the range of facilities provided to enable access, social interactions and the benefits people attribute to their woodland experiences. We conclude that peri-urban woodlands can clearly contribute to self-reported health and well-being in multiple ways, and that organized activities can be important for those who face barriers to accessing woodlands. A strong message emerging from the research is the opportunity afforded by woodlands for social connections with others, as well as the provision of a range of sensory benefits and opportunities to observe and enjoy seasonal change in woodlands. Mental restoration via connection with nature also emerged as important, confirming previous research.

  4. Utilization of emergent aquatic plants for biomass-energy-systems development

    Energy Technology Data Exchange (ETDEWEB)

    Kresovich, S.; Wagner, C.K.; Scantland, D.A.; Groet, S.S.; Lawhon, W.T.

    1982-02-01

    A review was conducted of the available literature pertaining to the following aspects of emergent aquatic biomass: identification of prospective emergent plant species for management; evaluation of prospects for genetic manipulation; evaluation of biological and environmental tolerances; examination of current production technologies; determination of availability of seeds and/or other propagules, and projections for probable end-uses and products. Species identified as potential candidates for production in biomass systems include Arundo donax, Cyperus papyrus, Phragmites communis, Saccharum spontaneum, Spartina alterniflora, and Typha latifolia. If these species are to be viable candidates in biomass systems, a number of research areas must be further investigated. Points such as development of baseline yield data for managed systems, harvesting conceptualization, genetic (crop) improvement, and identification of secondary plant products require refinement. However, the potential pay-off for developing emergent aquatic systems will be significant if development is successful.

  5. Estimation of potential biomass resource and biogas production from aquatic plants in Argentina

    Science.gov (United States)

    Fitzsimons, R. E.; Laurino, C. N.; Vallejos, R. H.

    1982-08-01

    The use of aquatic plants in artificial lakes as a biomass source for biogas and fertilizer production through anaerobic fermentation is evaluated, and the magnitude of this resource and the potential production of biogas and fertilizer are estimated. The specific case considered is the artificial lake that will be created by the construction of Parana Medio Hydroelectric Project on the middle Parana River in Argentina. The growth of the main aquatic plant, water hyacinth, on the middle Parana River has been measured, and its conversion to methane by anaerobic fermentation is determined. It is estimated that gross methane production may be between 1.0-4.1 x 10 to the 9th cu cm/year. The fermentation residue can be used as a soil conditioner, and it is estimated production of the residue may represent between 54,900-221,400 tons of nitrogen/year, a value which is 2-8 times the present nitrogen fertilizer demand in Argentina.

  6. Uptake of uranium by native aquatic plants: potential for bioindication and phytoremediation

    Directory of Open Access Journals (Sweden)

    Favas P. J. C.

    2013-04-01

    Full Text Available The work presented here is a part the on going study on the uraniferous geochemical province of Central Portugal in which, the use of aquatic plants as indicators of uranium contamination is being probed using aquatic plants emphasizing their potential use in the emerging phytotechnologies. Even though we have observed very low concentration of U in the fresh waters of the studied sites we found a set of vegetable species with the ability to accumulate U in concentrations which are orders of magnitude higher than the surrounding environment. We have observed that Apium nodiflorum, Callitriche stagnalis, Lemna minor and Fontinalis antipyretica accumulated significant amounts of uranium, whereas Oenanthe crocata excluded U. These results indicate substantial scope for proper radiophytoremediation and phytosociological investigation exploiting the native flora. These species show great potential for phytoremediation because they are endemic and easy to grow in their native conditions. A. nodiflorum and C. stagnalis have high bioproductivity and yield good biomass.

  7. Dinitrogen fixation associated with shoots of aquatic carnivorous plants: is it ecologically important?

    Czech Academy of Sciences Publication Activity Database

    Sirová, D.; Šantrůček, Jiří; Adamec, Lubomír; Bárta, J.; Borovec, Jakub; Pech, J.; Owens, S.M.; Šantrůčková, H.; Schaeufele, R.; Štorchová, Helena; Vrba, Jaroslav

    2014-01-01

    Roč. 114, č. 1 (2014), s. 125-133 ISSN 0305-7364 R&D Projects: GA ČR(CZ) GAP504/11/0783 Institutional support: RVO:60077344 ; RVO:67985939 ; RVO:61389030 Keywords : Aldrovanda vesiculosa * aquatic carnivorous plants * Utricularia vulgaris * nitrogen fixation Subject RIV: CE - Biochemistry; EF - Botanics (BU-J); EF - Botanics (UEB-Q) Impact factor: 3.654, year: 2014

  8. Aquatic plants: Test species sensitivity and minimum data requirement evaluations for chemical risk assessments and aquatic life criteria development for the USA

    Science.gov (United States)

    Phytotoxicity results from the publicly-available ECOTOX database were summarized for 20 chemicals and 188 aquatic plants to determine species sensitivities and the ability of a species-limited toxicity data set to serve as a surrogate for a larger data set. The lowest effect con...

  9. The mitochondrial genome of an aquatic plant, Spirodela polyrhiza.

    Directory of Open Access Journals (Sweden)

    Wenqin Wang

    Full Text Available BACKGROUND: Spirodela polyrhiza is a species of the order Alismatales, which represent the basal lineage of monocots with more ancestral features than the Poales. Its complete sequence of the mitochondrial (mt genome could provide clues for the understanding of the evolution of mt genomes in plant. METHODS: Spirodela polyrhiza mt genome was sequenced from total genomic DNA without physical separation of chloroplast and nuclear DNA using the SOLiD platform. Using a genome copy number sensitive assembly algorithm, the mt genome was successfully assembled. Gap closure and accuracy was determined with PCR products sequenced with the dideoxy method. CONCLUSIONS: This is the most compact monocot mitochondrial genome with 228,493 bp. A total of 57 genes encode 35 known proteins, 3 ribosomal RNAs, and 19 tRNAs that recognize 15 amino acids. There are about 600 RNA editing sites predicted and three lineage specific protein-coding-gene losses. The mitochondrial genes, pseudogenes, and other hypothetical genes (ORFs cover 71,783 bp (31.0% of the genome. Imported plastid DNA accounts for an additional 9,295 bp (4.1% of the mitochondrial DNA. Absence of transposable element sequences suggests that very few nuclear sequences have migrated into Spirodela mtDNA. Phylogenetic analysis of conserved protein-coding genes suggests that Spirodela shares the common ancestor with other monocots, but there is no obvious synteny between Spirodela and rice mtDNAs. After eliminating genes, introns, ORFs, and plastid-derived DNA, nearly four-fifths of the Spirodela mitochondrial genome is of unknown origin and function. Although it contains a similar chloroplast DNA content and range of RNA editing as other monocots, it is void of nuclear insertions, active gene loss, and comprises large regions of sequences of unknown origin in non-coding regions. Moreover, the lack of synteny with known mitochondrial genomic sequences shed new light on the early evolution of monocot

  10. Mapping tillage operations over peri-urban croplands using a synchronous SPOT4/ASAR ENVISAT pair and soil roughness measurements

    Science.gov (United States)

    Vaudour, Emmanuelle; Baghdadi, Nicolas; Gilliot, Jean-Marc

    2014-05-01

    Tillage operations (TOs) affect nutrient uptake, carbon sequestration, water and CO2 exchanges in soil, and therefore impact soil ecology together with biophysical processes such as soil erosion, leaching, run-off and infiltration. They are critical for parameterizing complex dynamic models of carbon and nitrogen. This study done in the framework of the Prostock-Gessol3 project presents an approach for mapping TOs of bare agricultural fields over a peri-urban area characterized by conventional tillage system in the western suburbs of Paris (France), combining synchronous SPOT4 and ENVISAT/ASAR images (HH and HV polarizations). Spatial modeling relied on 57 reference within-field areas named 'reference zones' (RZs) homogeneous for their soil properties, constructed in the vicinity of 57 roughness measurement locations and spread across 20 agricultural fields for which TOs were known. Soil roughness expressed as the standard deviation of surface height (Hrms) was estimated on the ground with a fully automatic photogrammetric method based on the processing of a set of overlapping pictures taken from different viewpoints from a simple digital camera all around a rectangular frame. The relationship was studied between the mean backscattering coefficient of the ASAR image and Hrms choosing a limited set of 28 RZs, on which successive random selections of training/validating RZs were then performed; the remaining 29 RZs were kept for validating the final map results. Six supervised per-pixel classifiers were used in order to map 2 TOs classes (seedbed&harrowed and late winter plough) in addition to 4 landuse classes (forest, urban,crops and grass, water bodies): support vector machine with polynomial kernel (pSVM), SVM with radial basis kernel (rSVM), artificial neural network (ANN), Maximum Likelihood (ML), regression tree (RT), and random forests (RF). All 6 classifiers were implemented in a bootstrapping approach in order to assess the uncertainty of map results. The

  11. Resting electrical network activity in traps of the aquatic carnivorous plants of the genera Aldrovanda and Utricularia

    Czech Academy of Sciences Publication Activity Database

    Masi, E.; Ciszak, M.; Colzi, I.; Adamec, Lubomír; Mancuso, S.

    2016-01-01

    Roč. 6, e24989 (2016), s. 1-11 ISSN 2045-2322 Institutional support: RVO:67985939 Keywords : electrophysiology * multielectrode array * aquatic carnivorous plants Subject RIV: ED - Physiology Impact factor: 4.259, year: 2016

  12. [Plant communities in the terrestrial-aquatic transition zone in the paramo of Chingaza, Colombia].

    Science.gov (United States)

    Schmidt-Mumm, Udo; Vargas Ríos, Orlando

    2012-03-01

    Plant communities in the terrestrial-aquatic transition zone in the paramo of Chingaza, Colombia. High Andean paramo ecosystems are an important water resource for many towns, and major cities in this region. The aquatic and wetland vegetation of different paramo lakes, pond, swamps and bogs was studied according to the classical phytosociological approach, which is based on homogenous stands, but excludes any border phenomena or transitional zone. The present research aimed at determining the aquatic and wetland vegetation along different moisture gradients. A total of 89 species in 30 transects were reported, of which Crassula venezuelensis, Carex honplandii, Callitriche nubigena, Eleocharis macrostachya, Ranunculus flagelliformis, R. nubigenus, Eleocharis stenocarpa, Galium ascendens y Alopecurus aequalis were present in more than one third of the transects. Numerical classification and indicator species analysis resulted in the definition of the next 18 communities: 1) Calamagrostis effusa, 2) Sphagnum cuspidatum, 3) Cyperus rufus, 4) Eleocharis stenocarpa, 5) Carex acutata, 6) Poa annua,7) Valeriana sp., 8) Ranunculus flagelliformis, 9) Carex bonplandii, 10) Festuca andicola. 11) Muhlenbergia fustigiata, 12) Elatine paramoana, 13) Isoëtes palmeri, 14) Crassula venezuelensis, 15) Lilaeopsis macloviana, 16) Callitriche nubigena, 17) Potamogeton paramoanus and 18) Potamogeton illinoensis. The ordination of communities reveals the presence of three different aquatic-terrestrial gradients which are related to the life form structure of species that characterized the various communities. We concluded that patchiness and heterogeneity of the vegetation is mainly the result of alterations caused by human activities (burning, cattle raise and material extraction for road and dam construction).

  13. Invasion strategies in clonal aquatic plants: are phenotypic differences caused by phenotypic plasticity or local adaptation?

    Science.gov (United States)

    Riis, Tenna; Lambertini, Carla; Olesen, Birgit; Clayton, John S.; Brix, Hans; Sorrell, Brian K.

    2010-01-01

    Background and Aims The successful spread of invasive plants in new environments is often linked to multiple introductions and a diverse gene pool that facilitates local adaptation to variable environmental conditions. For clonal plants, however, phenotypic plasticity may be equally important. Here the primary adaptive strategy in three non-native, clonally reproducing macrophytes (Egeria densa, Elodea canadensis and Lagarosiphon major) in New Zealand freshwaters were examined and an attempt was made to link observed differences in plant morphology to local variation in habitat conditions. Methods Field populations with a large phenotypic variety were sampled in a range of lakes and streams with different chemical and physical properties. The phenotypic plasticity of the species before and after cultivation was studied in a common garden growth experiment, and the genetic diversity of these same populations was also quantified. Key Results For all three species, greater variation in plant characteristics was found before they were grown in standardized conditions. Moreover, field populations displayed remarkably little genetic variation and there was little interaction between habitat conditions and plant morphological characteristics. Conclusions The results indicate that at the current stage of spread into New Zealand, the primary adaptive strategy of these three invasive macrophytes is phenotypic plasticity. However, while limited, the possibility that genetic diversity between populations may facilitate ecotypic differentiation in the future cannot be excluded. These results thus indicate that invasive clonal aquatic plants adapt to new introduced areas by phenotypic plasticity. Inorganic carbon, nitrogen and phosphorous were important in controlling plant size of E. canadensis and L. major, but no other relationships between plant characteristics and habitat conditions were apparent. This implies that within-species differences in plant size can be explained

  14. on the use of selected aquatic plants in tracing of some heavy metal pollutants

    International Nuclear Information System (INIS)

    Hammad, D.M.; Tawfik, T.A.

    2004-01-01

    three aquatic macrophyte plants namely; Cyperus Rotundus (emergent plant), Phragmits Australis (emergent plant) and Echhornia crassipes (floating plant) were selected to measure their ability for uptake of heavy metal pollutants from their ambient environments and to decide the possibility of using such plants in practical applications of water and sediment purity monitoring and decontamination . these plants with the corresponding water and sediment samples were collected from El-rayah El-menoufy (comparable site), near El- kanater El- khayria which receives its water directly from the River Nile (Dommietta branch) and from two drains namely. El remal drain (sewage drain), which receives its water from Abu-rawash waste water treatment plant and El-tibeen drain (mixed agricultural and industrial drain), located at the right bank of the River Nile and surrounded by huge industrial factories and receives its water from El-khashab canal. the water, sediment and plant samples collected from the selected areas were analyzed for anions, cations and heavy metal contents. studying and comparing the accumulative capacity of the emergent and floating plants to measure their ability in phytoremediatic applications and heavy metal pollution studies were performed . the correlations between the heavy metal concentrations in plants and in their ambient environments were calculated and the potential of the examined plants for pollution monitoring was estimated . in addition, the natural radioactivity of the environmental sediments was evaluated for K-40, Th -232 and Ra-226. the results obtained were compared with the international reference values

  15. Application of vascular aquatic plants for pollution removal, energy and food production in a biological system

    Science.gov (United States)

    Wolverton, B. C.; Barlow, R. M.; Mcdonald, R. C.

    1975-01-01

    Vascular aquatic plants such as water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxeroides) (Mart.) Griesb., when utilized in a controlled biological system (including a regular program of harvesting to achieve maximum growth and pollution removal efficiency), may represent a remarkably efficient and inexpensive filtration and disposal system for toxic materials and sewage released into waters near urban and industrial areas. The harvested and processed plant materials are sources of energy, fertilizer, animal feed, and human food. Such a system has industrial, municipal, and agricultural applications.

  16. Ecotoxicological assessments show sucralose and fluoxetine affect the aquatic plant, Lemna minor.

    Science.gov (United States)

    Amy-Sagers, Cherisse; Reinhardt, Keith; Larson, Danelle M

    2017-04-01

    Pharmaceuticals and personal care products (PPCP) are prevalent in aquatic systems, yet the fate and impacts on aquatic plants needs quantification for many compounds. We measured and detected sucralose (an artificial sweetener), fluoxetine (an antidepressant), and other PPCP in the Portneuf River in Idaho, USA, where Lemna minor (an aquatic plant in the environment and used in ecotoxicology studies) naturally occurs. Sucralose was hypothesized to negatively affect photosynthesis and growth of L. minor because sucralose is a chlorinated molecule that may be toxic or unusable for plant metabolism. A priori hypotheses were not created for fluoxetine due to lack of previous studies examining its impacts on plants. We conducted laboratory ecotoxicological assessments for a large range of concentrations of sucralose and fluoxetine on L. minor physiology and photosynthetic function. Frond green leaf area, root length, growth rate, photosynthetic capacity, and plant carbon isotopic composition (discrimination relative to a standard; δ 13 C) were measured among treatments ranging from 0 to 15000nmol/L-sucralose and 0-323nmol/L-fluoxetine. Contrary to our predictions, sucralose significantly increased green leaf area, photosynthetic capacity, and δ 13 C of L. minor at environmentally relevant concentrations. The increase of δ 13 C from sucralose amendments and an isotope-mixing model indicated substantial sucralose uptake and assimilation within the plant. Unlike humans who cannot break down and utilize sucralose, we documented that L. minor-a mixotrophic plant-can use sucralose as a sugar substitute to increase its green leaf area and photosynthetic capacity. Fluoxetine significantly decreased L. minor root growth, daily growth rate, and asexual reproduction at 323nmol/L-fluoxetine; however, ambiguity remains regarding the mechanisms responsible and the applicability of these extreme concentrations unprecedented in the natural environment. To our knowledge, this was the

  17. Proceedings, Annual Meeting (27th), Aquatic Plant Control Research Program Held in Bellevue, Washington on 16-19 November 1992

    Science.gov (United States)

    1993-09-01

    both site conditions and Overview of HERBICIDE the properties of the aquatic herbicide formu- lation (Reinert and Rodgers 1987; Westerdahl Structure... Westerdahl , H. E., and Getsinger, K. D., ed. ment Station, Vicksburg, MS, 279-282. (1988). "Aquatic plant identification and herbicide use guide; Volume 1...plants remain exposed to given concentrations of the Materials and Methods herbicide (Green and Westerdahl 1990; Van and Conant 1988; Netherland, Green

  18. Effects of snails, submerged plants and their coexistence on eutrophication in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Mo Shuqing

    2017-01-01

    Full Text Available Eutrophication resulting from nutrient loading to freshwater habitats is a severe problem, leading to degradation of ecosystems, including deterioration of water quality, water clarity and loss of biodiversity. Measures enacted to restore degraded freshwater ecosystems often involve the reintroduction of submerged plants and aquatic animals with beneficial ecological functions. In a mesocosm experiment, three treatments (planting with Vallisneria natans, introduction of the snail Bellamya aeruginosa and a combined treatment with both plants and snails were compared with controls to evaluate their effects on trophic state. The total nitrogen (TN, total phosphorus (TP and chlorophyll a (Chl a concentrations of planktonic and benthic algal samples were determined every two weeks, along with light intensity at the sediment surface. The plant-only treatment significantly reduced the TN levels and planktonic and benthic algal biomass and increased the light intensity at the sediment surface. The snail-only treatment reduced the concentrations of TN and reduced planktonic and benthic algal biomass. The combined treatment decreased the concentrations of TN and TP, reduced planktonic algal biomass and increased the light intensity on the sediment surface. The results indicate that while submerged plants and snails can both improve water quality, the most pronounced effect in aquatic ecosystems is achieved by their presence in combination. A combined reintroduction approach may provide enhanced benefits in restoring the eutrophic ecosystems, following the reduction of external nutrient loading.

  19. Recognition of pyrrolizidine alkaloid esters in the invasive aquatic plant Gymnocoronis spilanthoides (Asteraceae).

    Science.gov (United States)

    Boppré, Michael; Colegate, Steven M

    2015-01-01

    The freshwater aquatic plant Gymnocoronis spilanthoides (Senegal tea plant, jazmín del bañado, Falscher Wasserfreund) is an invasive plant in many countries. Behavioural observations of pyrrolizidine alkaloid-pharmacophagous butterflies suggested the presence of pyrrolizidine alkaloids in the plant. To determine whether the attraction of the butterflies to the plant is an accurate indicator of pyrrolizidine alkaloids in G. spilanthoides. The alkaloid fraction of a methanolic extract of G. spilanthoides was analysed using HPLC with electrospray ionisation MS and MS/MS. Two HPLC approaches were used, that is, a C18 reversed-phase column with an acidic mobile phase, and a porous graphitic carbon column with a basic mobile phase. Pyrrolizidine alkaloids were confirmed, with the free base forms more prevalent than the N-oxides. The major alkaloids detected were lycopsamine and intermedine. The porous graphitic carbon HPLC column, with basic mobile phase conditions, resulted in better resolution of more pyrrolizidine alkaloids including rinderine, the heliotridine-based epimer of intermedine. Based on the MS/MS and high-resolution MS data, gymnocoronine was tentatively identified as an unusual C9 retronecine ester with 2,3-dihydroxy-2-propenylbutanoic acid. Among several minor-abundance monoester pyrrolizidines recognised, spilanthine was tentatively identified as an ester of isoretronecanol with the unusual 2-acetoxymethylbutanoic acid. The butterflies proved to be reliable indicators for the presence of pro-toxic 1,2-dehydropyrrolizidine alkaloids in G. spilanthoides, the first aquatic plant shown to produce these alkaloids. The presence of the anti-herbivory alkaloids may contribute to the plant's invasive capabilities and would certainly be a consideration in any risk assessment of deliberate utilisation of the plant. The prolific growth of the plant and the structural diversity of its pyrrolizidine alkaloids may make it ideal for investigating biosynthetic

  20. Accumulation of uranium by aquatic plants in field conditions: Prospects for phytoremediation

    International Nuclear Information System (INIS)

    Favas, Paulo J.C.; Pratas, João; Varun, Mayank; D'Souza, Rohan; Paul, Manoj S.

    2014-01-01

    A study was undertaken to determine Uranium concentrations in water and aquatic plants in the uraniferous region of Beiras, Central Portugal. Samples were collected from running water (n = 200) at places where aquatic species were observed. Plant samples were collected from 28 species of submerged, free-floating and rooted emergent plants including 2 bryophytes and 1 pteridophyte. Uranium concentrations in surface waters ranged from 0.23 to 1217 μg L −1 . The aquatic plant species studied, including several previously untested species, exhibited the ability to accumulate U in concentrations many times that of the ambient water. In general submerged plants exhibited higher U content followed by rooted emergent and free floating species. The highest U concentrations were observed in the bryophyte Fontinalis antipyretica (up to 4979 mg kg −1 ) followed by Callitriche stagnalis (1963 mg kg −1 ), Callitriche hamulata (379 mg kg −1 ), Ranunculus peltatus subsp. saniculifolius (243 mg kg −1 ), Callitriche lusitanica (218 mg kg −1 ), and Ranunculus trichophyllus (65.8 mg kg −1 ). In two out of three rooted emergent species U seemed to be preferentially partitioned in rhizome/roots with highest rhizome U content recorded in Typha latifolia (380 mg kg −1 ). Among the free-floating species, the highest U content (42.5 mg kg −1 ) was seen in Lemna minor. The bryophyte F. antipyretica and Callitrichaceae members seem to be promising candidates for the development of phytofiltration methodologies based on U accumulation, abundance and biomass production. - Highlights: • Exploration of U contamination extent in uraniferous province of Central Portugal • A group of previously untested species with the ability to accumulate U was assessed • U accumulation patterns in the species indicate their potential in bioindication and phytoremediation of U-contaminated water

  1. Ubiquitous water-soluble molecules in aquatic plant exudates determine specific insect attraction.

    Directory of Open Access Journals (Sweden)

    Julien Sérandour

    Full Text Available Plants produce semio-chemicals that directly influence insect attraction and/or repulsion. Generally, this attraction is closely associated with herbivory and has been studied mainly under atmospheric conditions. On the other hand, the relationship between aquatic plants and insects has been little studied. To determine whether the roots of aquatic macrophytes release attractive chemical mixtures into the water, we studied the behaviour of mosquito larvae using olfactory experiments with root exudates. After testing the attraction on Culex and Aedes mosquito larvae, we chose to work with Coquillettidia species, which have a complex behaviour in nature and need to be attached to plant roots in order to obtain oxygen. This relationship is non-destructive and can be described as commensal behaviour. Commonly found compounds seemed to be involved in insect attraction since root exudates from different plants were all attractive. Moreover, chemical analysis allowed us to identify a certain number of commonly found, highly water-soluble, low-molecular-weight compounds, several of which (glycerol, uracil, thymine, uridine, thymidine were able to induce attraction when tested individually but at concentrations substantially higher than those found in nature. However, our principal findings demonstrated that these compounds appeared to act synergistically, since a mixture of these five compounds attracted larvae at natural concentrations (0.7 nM glycerol, <0.5 nM uracil, 0.6 nM thymine, 2.8 nM uridine, 86 nM thymidine, much lower than those found for each compound tested individually. These results provide strong evidence that a mixture of polyols (glycerol, pyrimidines (uracil, thymine, and nucleosides (uridine, thymidine functions as an efficient attractive signal in nature for Coquillettidia larvae. We therefore show for the first time, that such commonly found compounds may play an important role in plant-insect relationships in aquatic eco-systems.

  2. Accumulation of uranium by aquatic plants in field conditions: Prospects for phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Favas, Paulo J.C., E-mail: pjcf@utad.pt [School of Life Sciences and the Environment, University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real (Portugal); IMAR-CMA Marine and Environmental Research Centre, Faculty of Sciences and Technology, University of Coimbra, 3001-401 Coimbra (Portugal); Pratas, João [Department of Earth Sciences, Faculty of Sciences and Technology, University of Coimbra, 3001-401 Coimbra (Portugal); IMAR-CMA Marine and Environmental Research Centre, Faculty of Sciences and Technology, University of Coimbra, 3001-401 Coimbra (Portugal); Varun, Mayank; D' Souza, Rohan; Paul, Manoj S. [Department of Botany, St. John' s College, Agra 282 002 (India)

    2014-02-01

    A study was undertaken to determine Uranium concentrations in water and aquatic plants in the uraniferous region of Beiras, Central Portugal. Samples were collected from running water (n = 200) at places where aquatic species were observed. Plant samples were collected from 28 species of submerged, free-floating and rooted emergent plants including 2 bryophytes and 1 pteridophyte. Uranium concentrations in surface waters ranged from 0.23 to 1217 μg L{sup −1}. The aquatic plant species studied, including several previously untested species, exhibited the ability to accumulate U in concentrations many times that of the ambient water. In general submerged plants exhibited higher U content followed by rooted emergent and free floating species. The highest U concentrations were observed in the bryophyte Fontinalis antipyretica (up to 4979 mg kg{sup −1}) followed by Callitriche stagnalis (1963 mg kg{sup −1}), Callitriche hamulata (379 mg kg{sup −1}), Ranunculus peltatus subsp. saniculifolius (243 mg kg{sup −1}), Callitriche lusitanica (218 mg kg{sup −1}), and Ranunculus trichophyllus (65.8 mg kg{sup −1}). In two out of three rooted emergent species U seemed to be preferentially partitioned in rhizome/roots with highest rhizome U content recorded in Typha latifolia (380 mg kg{sup −1}). Among the free-floating species, the highest U content (42.5 mg kg{sup −1}) was seen in Lemna minor. The bryophyte F. antipyretica and Callitrichaceae members seem to be promising candidates for the development of phytofiltration methodologies based on U accumulation, abundance and biomass production. - Highlights: • Exploration of U contamination extent in uraniferous province of Central Portugal • A group of previously untested species with the ability to accumulate U was assessed • U accumulation patterns in the species indicate their potential in bioindication and phytoremediation of U-contaminated water.

  3. Ecotoxicological assessments show sucralose and fluoxetine affect the aquatic plant, Lemna minor

    Energy Technology Data Exchange (ETDEWEB)

    Amy-Sagers, Cherisse; Reinhardt, Keith; Larson, Danelle M., E-mail: danellelarson77@gmail.com

    2017-04-15

    Highlights: • Sucralose increased leaf area and photosynthetic capacity of Lemna minor. • Sucralose increased δ {sup 13}C of Lemna, indicating substantial uptake and assimilation. • 100 μg/L-fluoxetine decreased Lemna minor growth and asexual reproduction. - Abstract: Pharmaceuticals and personal care products (PPCP) are prevalent in aquatic systems, yet the fate and impacts on aquatic plants needs quantification for many compounds. We measured and detected sucralose (an artificial sweetener), fluoxetine (an antidepressant), and other PPCP in the Portneuf River in Idaho, USA, where Lemna minor (an aquatic plant in the environment and used in ecotoxicology studies) naturally occurs. Sucralose was hypothesized to negatively affect photosynthesis and growth of L. minor because sucralose is a chlorinated molecule that may be toxic or unusable for plant metabolism. A priori hypotheses were not created for fluoxetine due to lack of previous studies examining its impacts on plants. We conducted laboratory ecotoxicological assessments for a large range of concentrations of sucralose and fluoxetine on L. minor physiology and photosynthetic function. Frond green leaf area, root length, growth rate, photosynthetic capacity, and plant carbon isotopic composition (discrimination relative to a standard; δ{sup 13}C) were measured among treatments ranging from 0 to 15000 nmol/L-sucralose and 0–323 nmol/L-fluoxetine. Contrary to our predictions, sucralose significantly increased green leaf area, photosynthetic capacity, and δ {sup 13}C of L. minor at environmentally relevant concentrations. The increase of δ {sup 13}C from sucralose amendments and an isotope-mixing model indicated substantial sucralose uptake and assimilation within the plant. Unlike humans who cannot break down and utilize sucralose, we documented that L. minor—a mixotrophic plant—can use sucralose as a sugar substitute to increase its green leaf area and photosynthetic capacity. Fluoxetine

  4. Ecotoxicological assessments show sucralose and fluoxetine affect the aquatic plant, Lemna minor

    International Nuclear Information System (INIS)

    Amy-Sagers, Cherisse; Reinhardt, Keith; Larson, Danelle M.

    2017-01-01

    Highlights: • Sucralose increased leaf area and photosynthetic capacity of Lemna minor. • Sucralose increased δ "1"3C of Lemna, indicating substantial uptake and assimilation. • 100 μg/L-fluoxetine decreased Lemna minor growth and asexual reproduction. - Abstract: Pharmaceuticals and personal care products (PPCP) are prevalent in aquatic systems, yet the fate and impacts on aquatic plants needs quantification for many compounds. We measured and detected sucralose (an artificial sweetener), fluoxetine (an antidepressant), and other PPCP in the Portneuf River in Idaho, USA, where Lemna minor (an aquatic plant in the environment and used in ecotoxicology studies) naturally occurs. Sucralose was hypothesized to negatively affect photosynthesis and growth of L. minor because sucralose is a chlorinated molecule that may be toxic or unusable for plant metabolism. A priori hypotheses were not created for fluoxetine due to lack of previous studies examining its impacts on plants. We conducted laboratory ecotoxicological assessments for a large range of concentrations of sucralose and fluoxetine on L. minor physiology and photosynthetic function. Frond green leaf area, root length, growth rate, photosynthetic capacity, and plant carbon isotopic composition (discrimination relative to a standard; δ"1"3C) were measured among treatments ranging from 0 to 15000 nmol/L-sucralose and 0–323 nmol/L-fluoxetine. Contrary to our predictions, sucralose significantly increased green leaf area, photosynthetic capacity, and δ "1"3C of L. minor at environmentally relevant concentrations. The increase of δ "1"3C from sucralose amendments and an isotope-mixing model indicated substantial sucralose uptake and assimilation within the plant. Unlike humans who cannot break down and utilize sucralose, we documented that L. minor—a mixotrophic plant—can use sucralose as a sugar substitute to increase its green leaf area and photosynthetic capacity. Fluoxetine significantly

  5. Replacement of cowdung by fermentation of aquatic and terrestrial plants for use as fuel, fertilizer and biogas plant feed

    Energy Technology Data Exchange (ETDEWEB)

    Das, C. R.; Ghatnekar, S. D.

    1979-01-01

    With 85% of the entire Indian population living in villages and 98% of the household energy requirement of the rural population demanded for cooking, research was undertaken on the supply of biomass for those Indians who do not have cattle. This research was carried out on the fermentation of aquatic and terrestrial plants for use in biogas generation. The plants utilized for biogas generation are: water hyacinth, water lettuce, African payal, duck weed, water spinach, cattail ramban, ipil-ipil, morning glory, paragrass, purple nutsedge, and durva grass.

  6. Uptake of cesium and cobalt radionuclides from simulated radioactive wastewater by Ludwigia stolonifera aquatic plant

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, H.M., E-mail: hosamsaleh70@yahoo.com [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Bayoumi, T.A. [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Mahmoud, H.H. [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Central Laboratory for Elemental and Isotopic Analysis, Nuclear Research Center, Atomic Energy Authority (Egypt); Aglan, R.F. [Department of Analytical Chemistry, Hot Laboratories Center, Atomic Energy Authority, 13759 (Egypt)

    2017-04-15

    Highlights: • Radioactive contamination is a serious environmental problem. • Phytoremediation is a proper technique for soil and water decontamination. • Aquatic plant, Ludwigia stolonifera, for bioaccumulation of radionuclides. • Factors affecting uptake efficiency of {sup 137}Cs and {sup 60}Co radionuclides. - Abstract: The article reported herein was conducted as part of comprehensive study considered to evaluate the efficiency of Ludwigia stolonifera as a local aquatic plant located in the Egyptian environment for phytoremediation of hazardous toxic and radioactive elements dissolved in aqueous wastes dispersed from industrial and urban applications through the human activities. Ludwigia stolonifera was immersed in single and binary solution of {sup 60}Co and {sup 137}Cs. The specific uptake rate of plant was determined at various activity contents of radionuclides, multiplied masses of plant, lighting exposure and different pH values. Accumulation of {sup 60}Co and {sup 137}Cs in mixture was more than 95% and 65% respectively. pH was less effective than the other evaluated parameters.

  7. The aquatic toxicity and chemical forms of coke plant effluent cyanide -- Implications for discharge limits

    International Nuclear Information System (INIS)

    Garibay, R.; Rupnow, M.; Godwin-Saad, E.; Hall, S.

    1995-01-01

    Cyanide is present in treated cokemaking process waters at concentrations as high as 8.0 mg/L. In assessing options for managing the discharge of a treated effluent, the development and implementation of discharge limits for cyanide became a critical issue. A study was initiated to evaluate possible alternatives to cyanide permit limits at the US Steel Gary Works Facility. The objectives of the study were to: (1) evaluation the forms of cyanide present in coke plant effluent; (2) determine whether these forms of cyanide are toxic to selected aquatic organisms; (3) compare the aquatic toxicity of various chemical forms of cyanide; (4) identify if the receiving water modifies cyanide bioavailability; and (5) confirm, with respect to water quality-based effluent limits, an appropriate analytical method for monitoring cyanide in a coke plant effluent. The results of aquatic toxicity tests and corresponding analytical data are presented. Toxicity tests were conducted with various pure chemical forms of cyanide as well as whole coke plant effluent (generated from a pilot-scale treatment system). Test species included the fathead minnow (Pimephales promelas), rainbow trout (Oncorhynchus mykiss), Ceriodaphnia dubia (C. dubia) and Daphnia magna (D. magna). Analytical measurements for cyanide included total, weak acid dissociable, diffusible cyanide and selected metal species of cyanide. The findings presented by the paper are relevant with respect to the application of cyanide water quality criteria for a coke plant effluent discharge, the translation of these water quality-based effluent limits to permit limits, and methods for compliance monitoring for cyanide

  8. Participatory Livestock Farmer Training for improvement of animal health in rural and peri-urban smallholder dairy herds in Jinja, Uganda

    DEFF Research Database (Denmark)

    Vaarst, Mette; Byarugaba, D.K.; Nakavuma, J.

    2007-01-01

    in smallholder dairy farms in the Jinja district of Uganda. Two peri-urban groups and one rural group met for common learning and training two hours per fortnight during a 12-month period, facilitated by two local extension agents together with one or two scientists from Makerere University. Farmers rotated each...... knowledge and experience from training in systematic clinical examination of animals, evaluation of the farm environments, and identification of improvements. Much of the acquired new knowledge was about basic dairy cow management and husbandry practices. In addition, they gave examples of how they were now...... time between farms owned by group participants, which demanded mutual trust, openness and respect. From their own assessment the farmers felt they had improved their milk production and reduced mastitis incidence on their farms. In an evaluation workshop, they articulated how they had built up common...

  9. Couple Relationship Functioning as a Source or Mitigator of HIV Risk: Associations Between Relationship Quality and Sexual Risk Behavior in Peri-urban Uganda.

    Science.gov (United States)

    Ruark, Allison; Kajubi, Phoebe; Ruteikara, Sam; Green, Edward C; Hearst, Norman

    2018-04-01

    Despite evidence that a greater focus on couples could strengthen HIV prevention efforts, little health-related research has explored relationship functioning and relationship quality among couples in Africa. Using data from 162 couples (324 individuals) resident in a peri-urban Ugandan community, we assessed actor and partner effects of sexual risk behaviors on relationship quality, using psychometric measures of dyadic adjustment, sexual satisfaction, commitment, intimacy, and communication. For women and men, poor relationship quality was associated with having concurrent sexual partners and suspecting that one's partner had concurrent sexual partners (actor effects). Women's poor relationship quality was also associated with men's sexual risk behaviors (partner effects), although the inverse partner effect was not observed. These findings suggest that relationship quality is linked to HIV risk, particularly through the pathway of concurrent sexual partnerships, and that positive relationship attributes such as sexual satisfaction, intimacy, and constructive communication can help couples to avoid risk.

  10. Plant-microbe interaction in aquatic system and their role in the management of water quality: a review

    Science.gov (United States)

    Srivastava, Jatin K.; Chandra, Harish; Kalra, Swinder J. S.; Mishra, Pratibha; Khan, Hena; Yadav, Poonam

    2017-06-01

    Microbial assemblage as biofilm around the aquatic plant forms a firm association that largely depends upon the mutual supplies of nutrients, e.g., microbes interact with plants in an aquatic system most likely for organic carbon and oxygen, whereas plants receive defensive immunity and mineral exchange. Apart from the mutual benefits, plant-microbe interactions also influence the water quality especially at rhizosphere providing inherent ability to the aquatic system for the mitigation of pollution from the water column. The review presents and in-depth information along with certain research advancements made in the field of ecological and bio/chemical aspects of plant-microbe interactions and the underlying potential to improve water quality.

  11. Environmental Behavior and Fate of Explosives in Groundwater from the Milan Army Ammunition Plant in Aquatic and Wetland Plants. Fate of TNT and RDX

    National Research Council Canada - National Science Library

    Best, Elly

    1998-01-01

    The present study was performed to elucidate the environmental behavior and fate of TNT and RDX in aquatic and wetland plants collected from a field-scale wetland demonstration deployed at Milan Army...

  12. Functional trait composition of aquatic plants can serve to disentangle multiple interacting stressors in lowland streams

    Energy Technology Data Exchange (ETDEWEB)

    Baattrup-Pedersen, Annette, E-mail: abp@bios.au.dk [Department of Bioscience, Aarhus University, Vejlsøvej 25, P.O. Box 314, DK-8600 Silkeborg (Denmark); Göthe, Emma [Department of Bioscience, Aarhus University, Vejlsøvej 25, P.O. Box 314, DK-8600 Silkeborg (Denmark); Riis, Tenna [Department of Bioscience, Aarhus University, Ole Worms Allé 1, Building 1135, Room 217, DK-8000 Aarhus C (Denmark); O' Hare, Matthew T. [Centre for Ecology and Hydrology, Bush Estate, Penicuik EH26 0QB (United Kingdom)

    2016-02-01

    Historically, close attention has been paid to negative impacts associated with nutrient loads to streams and rivers, but today hydromorphological alterations are considered increasingly implicated when lowland streams do not achieve good ecological status. Here, we explore if trait-abundance patterns of aquatic plants change along gradients in hydromorphological degradation and eutrophication in lowland stream sites located in Denmark. Specifically, we hypothesised that: i) changes in trait-abundance patterns occur along gradients in hydromorphological degradation and ii) trait-abundance patterns can serve to disentangle effects of eutrophication and hydromorphological degradation in lowland streams reflecting that the mechanisms behind changes differ. We used monitoring data from a total of 147 stream reaches with combined data on aquatic plant species abundance, catchment land use, hydromorphological alterations (i.e. planform, cross section, weed cutting) and water chemistry parameters. Traits related to life form, dispersal, reproduction and survival together with ecological preference values for nutrients and light (Ellenberg N and L) were allocated to 41 species representing 79% of the total species pool. We found clear evidence that habitat degradation (hydromorphological alterations and eutrophication) mediated selective changes in the trait-abundance patterns of the plant community. Specific traits could distinguish hydromorphological degradation (free-floating, surface; anchored floating leaves; anchored heterophylly) from eutrophication (free-floating, submerged; leaf area). We provide a conceptual framework for interpretation of how eutrophication and hydromorphological degradation interact and how this is reflected in trait-abundance patterns in aquatic plant communities in lowland streams. Our findings support the merit of trait-based approaches in biomonitoring as they shed light on mechanisms controlling structural changes under environmental

  13. Functional trait composition of aquatic plants can serve to disentangle multiple interacting stressors in lowland streams

    International Nuclear Information System (INIS)

    Baattrup-Pedersen, Annette; Göthe, Emma; Riis, Tenna; O'Hare, Matthew T.

    2016-01-01

    Historically, close attention has been paid to negative impacts associated with nutrient loads to streams and rivers, but today hydromorphological alterations are considered increasingly implicated when lowland streams do not achieve good ecological status. Here, we explore if trait-abundance patterns of aquatic plants change along gradients in hydromorphological degradation and eutrophication in lowland stream sites located in Denmark. Specifically, we hypothesised that: i) changes in trait-abundance patterns occur along gradients in hydromorphological degradation and ii) trait-abundance patterns can serve to disentangle effects of eutrophication and hydromorphological degradation in lowland streams reflecting that the mechanisms behind changes differ. We used monitoring data from a total of 147 stream reaches with combined data on aquatic plant species abundance, catchment land use, hydromorphological alterations (i.e. planform, cross section, weed cutting) and water chemistry parameters. Traits related to life form, dispersal, reproduction and survival together with ecological preference values for nutrients and light (Ellenberg N and L) were allocated to 41 species representing 79% of the total species pool. We found clear evidence that habitat degradation (hydromorphological alterations and eutrophication) mediated selective changes in the trait-abundance patterns of the plant community. Specific traits could distinguish hydromorphological degradation (free-floating, surface; anchored floating leaves; anchored heterophylly) from eutrophication (free-floating, submerged; leaf area). We provide a conceptual framework for interpretation of how eutrophication and hydromorphological degradation interact and how this is reflected in trait-abundance patterns in aquatic plant communities in lowland streams. Our findings support the merit of trait-based approaches in biomonitoring as they shed light on mechanisms controlling structural changes under environmental

  14. Global searches for microalgae and aquatic plants that can eliminate radioactive cesium, iodine and strontium from the radio-polluted aquatic environment: a bioremediation strategy.

    Science.gov (United States)

    Fukuda, Shin-Ya; Iwamoto, Koji; Atsumi, Mika; Yokoyama, Akiko; Nakayama, Takeshi; Ishida, Ken-Ichiro; Inouye, Isao; Shiraiwa, Yoshihiro

    2014-01-01

    The Fukushima 1 Nuclear Power Plant accident in March 2011 released an enormously high level of radionuclides into the environment, a total estimation of 6.3 × 10¹⁷ Bq represented by mainly radioactive Cs, Sr, and I. Because these radionuclides are biophilic, an urgent risk has arisen due to biological intake and subsequent food web contamination in the ecosystem. Thus, urgent elimination of radionuclides from the environment is necessary to prevent substantial radiopollution of organisms. In this study, we selected microalgae and aquatic plants that can efficiently eliminate these radionuclides from the environment. The ability of aquatic plants and algae was assessed by determining the elimination rate of radioactive Cs, Sr and I from culture medium and the accumulation capacity of radionuclides into single cells or whole bodies. Among 188 strains examined from microalgae, aquatic plants and unidentified algal species, we identified six, three and eight strains that can accumulate high levels of radioactive Cs, Sr and I from the medium, respectively. Notably, a novel eustigmatophycean unicellular algal strain, nak 9, showed the highest ability to eliminate radioactive Cs from the medium by cellular accumulation. Our results provide an important strategy for decreasing radiopollution in Fukushima area.

  15. Availability of, access to and consumption of fruits and vegetables in a peri-urban area in KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Faber, Mieke; Laubscher, Ria; Laurie, Sunette

    2013-07-01

    Availability and consumption of fruits and vegetables were assessed in peri-urban households in KwaZulu-Natal Province, South Africa. Caregivers of 400 randomly selected grade 6 and 7 learners were interviewed using a questionnaire that included unquantified food frequency questions. Using a repeated 24-h dietary recall, dietary intake was quantified for learners, caregivers and 2- to 5-year-old children in the household. Usual household fruit and vegetable consumption was expressed over three Living Standard Measure (LSM) categories. Average per capita intake of fruit and/or vegetables was 99 g for 2- to 5-year-old children and 124 g for caregivers. For consumers, fruits and/or vegetables contributed towards total dietary intake of fibre (16-21%), calcium (13-21%), vitamin A (27-31%) and vitamin C (47-62%). For households not consuming fruits (n = 297) and vegetables (n = 178) daily, cost was the major constraint (≥75%). Of all households, 52% had fruit trees and 25% had a vegetable garden. Animals destroying vegetables was the major constraint to 59% of vegetable growers. Household consumption of fruits and vegetables increased over the LSM categories. Caregivers in the higher LSM group more likely used printed material for information on healthy eating, had fruit trees, were confident about vegetable gardening and sold some of their produce. To enable peri-urban populations of low socio-economic status to consume more frequently a bigger variety of fruits and vegetables, the cost of purchasing these food items needs to be addressed by government and business sector. Households should further receive support to overcome constraints which hamper the success of home gardens. © 2011 John Wiley & Sons Ltd.

  16. Source contributions to carbonaceous species in PM2.5 and their uncertainty analysis at typical urban, peri-urban and background sites in southeast China

    International Nuclear Information System (INIS)

    Niu, Zhenchuan; Wang, Sen; Chen, Jinsheng; Zhang, Fuwang; Chen, Xiaoqiu; He, Chi; Lin, Lifeng; Yin, Liqian; Xu, Lingling

    2013-01-01

    Determination of 14 C and levoglucosan can provide insights into the quantification of source contributions to carbonaceous aerosols, yet there is still uncertainty on the partitioning of organic carbon (OC) into biomass burning OC (OC bb ) and biogenic emission OC (OC bio ). Carbonaceous species, levoglucosan and 14 C in PM 2.5 were measured at three types of site in southeast China combined with Latin hypercube sampling, with the objectives to study source contributions to total carbon (TC) and their uncertainties, and to evaluate the influence of levoglucosan/OC bb ratios on OC bb and OC bio partitioning. It was found reliably that fossil fuel combustion is the main contributor (62.90–72.23%) to TC at urban and peri-urban sites. Biogenic emissions have important contribution (winter, 52.98%; summer, 45.71%) to TC at background site. With the increase in levoglucosan/OC bb ratios, the contribution of OC bio is increased while OC bb is decreased in a pattern of approximate natural logarithm at a given range. -- Highlights: •Source contributions to OC and EC were quantified by levoglucosan and 14 C. •Fossil fuel combustion is the main contributor to TC for urban and peri-urban sites. •Biogenic emissions have important contribution to TC for the background site. •Biomass burning is a minor contributor to TC and has high contribution in winter. •Ratios of OC bio and OC bb to TC have a natural logarithmic relation with lev/OC bb . -- The contributions of OC bio and OC bb to TC have a natural logarithmic relationship with the levoglucosan/OC bb ratios

  17. Application of eco-friendly tools and eco-bio-social strategies to control dengue vectors in urban and peri-urban settings in Thailand.

    Science.gov (United States)

    Kittayapong, Pattamaporn; Thongyuan, Suporn; Olanratmanee, Phanthip; Aumchareoun, Worawit; Koyadun, Surachart; Kittayapong, Rungrith; Butraporn, Piyarat

    2012-12-01

    Dengue is considered one of the most important vector-borne diseases in Thailand. Its incidence is increasing despite routine implementation of national dengue control programmes. This study, conducted during 2010, aimed to demonstrate an application of integrated, community-based, eco-bio-social strategies in combination with locally-produced eco-friendly vector control tools in the dengue control programme, emphasizing urban and peri-urban settings in eastern Thailand. Three different community settings were selected and were randomly assigned to intervention and control clusters. Key community leaders and relevant governmental authorities were approached to participate in this intervention programme. Ecohealth volunteers were identified and trained in each study community. They were selected among active community health volunteers and were trained by public health experts to conduct vector control activities in their own communities using environmental management in combination with eco-friendly vector control tools. These trained ecohealth volunteers carried out outreach health education and vector control during household visits. Management of public spaces and public properties, especially solid waste management, was efficiently carried out by local municipalities. Significant reduction in the pupae per person index in the intervention clusters when compared to the control ones was used as a proxy to determine the impact of this programme. Our community-based dengue vector control programme demonstrated a significant reduction in the pupae per person index during entomological surveys which were conducted at two-month intervals from May 2010 for the total of six months in the intervention and control clusters. The programme also raised awareness in applying eco-friendly vector control approaches and increased intersectoral and household participation in dengue control activities. An eco-friendly dengue vector control programme was successfully implemented in

  18. Detection and characterization of Brucella spp. in bovine milk in small-scale urban and peri-urban farming in Tajikistan

    Science.gov (United States)

    Lindahl-Rajala, Elisabeth; Hoffman, Tove; Fretin, David; Godfroid, Jacques; Sattorov, Nosirjon; Boqvist, Sofia; Lundkvist, Åke; Magnusson, Ulf

    2017-01-01

    Brucellosis is one of the most common zoonoses globally, and Central Asia remains a Brucella hotspot. The World Health Organization classifies brucellosis as a neglected zoonotic disease that is rarely in the spotlight for research and mainly affects poor, marginalized people. Urban and peri-urban farming is a common practice in many low-income countries, and it increases the incomes of families that are often restrained by limited economic resources. However, there is a concern that the growing number of people and livestock living close together in these areas will increase the transmission of zoonotic pathogens such as Brucella. This study investigates the presence of Brucella DNA in bovine milk in the urban and peri-urban area of Dushanbe, Tajikistan. Brucella DNA was detected in 10.3% of 564 cow milk samples by IS711-based real-time PCR. This finding is concerning because consumption of unpasteurized dairy products is common in the region. Furthermore, Brucella DNA was detected in the milk of all seropositive cows, but 8.3% of the seronegative cows also showed the presence of Brucella DNA. In addition, sequence analysis of the rpoB gene suggests that one cow was infected with B. abortus and another cow was most likely infected with B. melitensis. The discrepancies between the serology and real-time PCR results highlight the need to further investigate whether there is a need for implementing complementary diagnostic strategies to detect false serological negative individuals in Brucella surveillance, control, and eradication programmes. Furthermore, vaccination of cattle with S19 in addition to vaccination of small ruminants with Rev 1 might be needed in order to control Brucella infections in the livestock population but further research focusing on the isolation of Brucella is required to obtain a comprehensive understanding of the Brucella spp. circulating among the livestock in this region. PMID:28296882

  19. Detection and characterization of Brucella spp. in bovine milk in small-scale urban and peri-urban farming in Tajikistan.

    Science.gov (United States)

    Lindahl-Rajala, Elisabeth; Hoffman, Tove; Fretin, David; Godfroid, Jacques; Sattorov, Nosirjon; Boqvist, Sofia; Lundkvist, Åke; Magnusson, Ulf

    2017-03-01

    Brucellosis is one of the most common zoonoses globally, and Central Asia remains a Brucella hotspot. The World Health Organization classifies brucellosis as a neglected zoonotic disease that is rarely in the spotlight for research and mainly affects poor, marginalized people. Urban and peri-urban farming is a common practice in many low-income countries, and it increases the incomes of families that are often restrained by limited economic resources. However, there is a concern that the growing number of people and livestock living close together in these areas will increase the transmission of zoonotic pathogens such as Brucella. This study investigates the presence of Brucella DNA in bovine milk in the urban and peri-urban area of Dushanbe, Tajikistan. Brucella DNA was detected in 10.3% of 564 cow milk samples by IS711-based real-time PCR. This finding is concerning because consumption of unpasteurized dairy products is common in the region. Furthermore, Brucella DNA was detected in the milk of all seropositive cows, but 8.3% of the seronegative cows also showed the presence of Brucella DNA. In addition, sequence analysis of the rpoB gene suggests that one cow was infected with B. abortus and another cow was most likely infected with B. melitensis. The discrepancies between the serology and real-time PCR results highlight the need to further investigate whether there is a need for implementing complementary diagnostic strategies to detect false serological negative individuals in Brucella surveillance, control, and eradication programmes. Furthermore, vaccination of cattle with S19 in addition to vaccination of small ruminants with Rev 1 might be needed in order to control Brucella infections in the livestock population but further research focusing on the isolation of Brucella is required to obtain a comprehensive understanding of the Brucella spp. circulating among the livestock in this region.

  20. Application of eco-friendly tools and eco-bio-social strategies to control dengue vectors in urban and peri-urban settings in Thailand

    Science.gov (United States)

    Kittayapong, Pattamaporn; Thongyuan, Suporn; Olanratmanee, Phanthip; Aumchareoun, Worawit; Koyadun, Surachart; Kittayapong, Rungrith; Butraporn, Piyarat

    2012-01-01

    Background Dengue is considered one of the most important vector-borne diseases in Thailand. Its incidence is increasing despite routine implementation of national dengue control programmes. This study, conducted during 2010, aimed to demonstrate an application of integrated, community-based, eco-bio-social strategies in combination with locally-produced eco-friendly vector control tools in the dengue control programme, emphasizing urban and peri-urban settings in eastern Thailand. Methodology Three different community settings were selected and were randomly assigned to intervention and control clusters. Key community leaders and relevant governmental authorities were approached to participate in this intervention programme. Ecohealth volunteers were identified and trained in each study community. They were selected among active community health volunteers and were trained by public health experts to conduct vector control activities in their own communities using environmental management in combination with eco-friendly vector control tools. These trained ecohealth volunteers carried out outreach health education and vector control during household visits. Management of public spaces and public properties, especially solid waste management, was efficiently carried out by local municipalities. Significant reduction in the pupae per person index in the intervention clusters when compared to the control ones was used as a proxy to determine the impact of this programme. Results Our community-based dengue vector control programme demonstrated a significant reduction in the pupae per person index during entomological surveys which were conducted at two-month intervals from May 2010 for the total of six months in the intervention and control clusters. The programme also raised awareness in applying eco-friendly vector control approaches and increased intersectoral and household participation in dengue control activities. Conclusion An eco-friendly dengue vector control

  1. Comparison of two approaches for measuring household wealth via an asset-based index in rural and peri-urban settings of Hunan province, China

    Directory of Open Access Journals (Sweden)

    Balen Julie

    2010-09-01

    Full Text Available Abstract Background There are growing concerns regarding inequities in health, with poverty being an important determinant of health as well as a product of health status. Within the People's Republic of China (P.R. China, disparities in socio-economic position are apparent, with the rural-urban gap of particular concern. Our aim was to compare direct and proxy methods of estimating household wealth in a rural and a peri-urban setting of Hunan province, P.R. China. Methods We collected data on ownership of household durable assets, housing characteristics, and utility and sanitation variables in two village-wide surveys in Hunan province. We employed principal components analysis (PCA and principal axis factoring (PAF to generate household asset-based proxy wealth indices. Households were grouped into quartiles, from 'most wealthy' to 'most poor'. We compared the estimated household wealth for each approach. Asset-based proxy wealth indices were compared to those based on self-reported average annual income and savings at the household level. Results Spearman's rank correlation analysis revealed that PCA and PAF yielded similar results, indicating that either approach may be used for estimating household wealth. In both settings investigated, the two indices were significantly associated with self-reported average annual income and combined income and savings, but not with savings alone. However, low correlation coefficients between the proxy and direct measures of wealth indicated that they are not complementary. We found wide disparities in ownership of household durable assets, and utility and sanitation variables, within and between settings. Conclusion PCA and PAF yielded almost identical results and generated robust proxy wealth indices and categories. Pooled data from the rural and peri-urban settings highlighted structural differences in wealth, most likely a result of localized urbanization and modernization. Further research is needed

  2. Detection and characterization of Brucella spp. in bovine milk in small-scale urban and peri-urban farming in Tajikistan.

    Directory of Open Access Journals (Sweden)

    Elisabeth Lindahl-Rajala

    2017-03-01

    Full Text Available Brucellosis is one of the most common zoonoses globally, and Central Asia remains a Brucella hotspot. The World Health Organization classifies brucellosis as a neglected zoonotic disease that is rarely in the spotlight for research and mainly affects poor, marginalized people. Urban and peri-urban farming is a common practice in many low-income countries, and it increases the incomes of families that are often restrained by limited economic resources. However, there is a concern that the growing number of people and livestock living close together in these areas will increase the transmission of zoonotic pathogens such as Brucella. This study investigates the presence of Brucella DNA in bovine milk in the urban and peri-urban area of Dushanbe, Tajikistan. Brucella DNA was detected in 10.3% of 564 cow milk samples by IS711-based real-time PCR. This finding is concerning because consumption of unpasteurized dairy products is common in the region. Furthermore, Brucella DNA was detected in the milk of all seropositive cows, but 8.3% of the seronegative cows also showed the presence of Brucella DNA. In addition, sequence analysis of the rpoB gene suggests that one cow was infected with B. abortus and another cow was most likely infected with B. melitensis. The discrepancies between the serology and real-time PCR results highlight the need to further investigate whether there is a need for implementing complementary diagnostic strategies to detect false serological negative individuals in Brucella surveillance, control, and eradication programmes. Furthermore, vaccination of cattle with S19 in addition to vaccination of small ruminants with Rev 1 might be needed in order to control Brucella infections in the livestock population but further research focusing on the isolation of Brucella is required to obtain a comprehensive understanding of the Brucella spp. circulating among the livestock in this region.

  3. African swine fever control and market integration in Ugandan peri-urban smallholder pig value chains: An ex-ante impact assessment of interventions and their interaction.

    Science.gov (United States)

    Ouma, Emily; Dione, Michel; Birungi, Rosemirta; Lule, Peter; Mayega, Lawrence; Dizyee, Kanar

    2018-03-01

    Pig production in peri-urban smallholder value chains in Uganda is severely constrained by impact of disease, particularly African swine fever (ASF), and the economic consequences of an inefficient pig value chain. Interventions in the form of biosecurity to control ASF disease outbreaks and pig business hub models to better link smallholder farmers to pig markets have the potential to address the constraints. However, there is a dearth of evidence of the effects of the interventions on performance and distribution of outcomes along the pig value chain. An ex-ante impact assessment utilising System Dynamics model was used to assess the impact of the interventions in peri-urban pig value chains in Masaka district. The results showed that although implementation of biosecurity interventions results in reduction of ASF outbreaks, it also leads to a 6.3% reduction in farmer profit margins per year but more than 7% increase in other value chain actors' margins. The pig business hub intervention alone results in positive margins for all value chain actors but minimal reduction in ASF outbreaks. When biosecurity and the pig business hub interventions are implemented together, the interaction effects of the interventions result in positive outcomes for both the control of ASF and improvement in farmers' margins. Farmers may therefore be unwilling to adopt biosecurity practices if implemented alone to control ASF outbreaks unless there is a corresponding financial incentive to compensate for the high costs. This has implications for policy or developing institutions to facilitate cost sharing arrangement among chain actors and/or third party subsidy to provide incentives for producers to adopt biosecurity measures. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Nested PCR detection and phylogenetic analysis of Babesia bovis and Babesia bigemina in cattle from Peri-urban localities in Gauteng Province, South Africa.

    Science.gov (United States)

    Mtshali, Phillip Senzo; Tsotetsi, Ana Mbokeleng; Thekisoe, Matlhahane Molifi Oriel; Mtshali, Moses Sibusiso

    2014-01-01

    Babesia bovis and Babesia bigemina are tick-borne hemoparasites causing babesiosis in cattle worldwide. This study was aimed at providing information about the occurrence and geographical distribution of B. bovis and B. bigemina species in cattle from Gauteng province, South Africa. A total of 268 blood samples collected from apparently healthy animals in 14 different peri-urban localities were tested using previously established nested PCR assays for the detection of B. bovis and B. bigemina species-specific genes encoding rhoptry-associated protein 1 (RAP-1) and SpeI-AvaI restriction fragment, respectively. Nested PCR assays revealed that the overall prevalence was 35.5% (95% confidence interval [CI]=± 5.73) and 76.1% (95% CI=± 5.11) for B. bovis and B. bigemina, respectively. PCR results were corroborated by sequencing amplicons of randomly selected samples. The neighbor-joining trees were constructed to study the phylogenetic relationship between B. bovis and B. bigemina sequences of randomly selected isolates. Analysis of phylogram inferred with B. bovis RAP-1 sequences indicated a close relationship between our isolates and GenBank strains. On the other hand, a tree constructed with B. bigemina gp45 sequences revealed a high degree of polymorphism among the B. bigemina isolates investigated in this study. Taken together, the results presented in this work indicate the high incidence of Babesia parasites in cattle from previously uncharacterised peri-urban areas of the Gauteng province. These findings suggest that effective preventative and control measures are essential to curtail the spread of Babesia infections among cattle populations in Gauteng.

  5. Effect of Aquatic Plants on Phosphorus Removal and Electrical Conductivity Decrease in Municipal Effluent

    Directory of Open Access Journals (Sweden)

    Sara Samimi Loghmani

    2014-05-01

    Full Text Available Phosphorus (P is one of essential elements for living organisms, though its critical concentration in surface and ground waters impose a serious problem such as eutrophication. So treatment of polluted waters is required before discharging to water resources. One of effective ways to decrease water pollution is using aquatic plants. An experiment was conducted in pilots with a closed flowing system on two plants, elodea (egria densa and duck weed (lemna minor with four treatments and three replications. Data were analyzed in a factorial completely randomized design. Treatments included effluent with and without the plants, and effluent diluted (dilution grade 1/2 with and without the plants. Total dissolved P, electrical conductivity (EC and pH value were measured after 8, 16 and 24 days in effluent samples. The results showed that pH value decreased up to 0.2 units during of 24 days of the experiment, but there was found no significant difference (p≤0.05 in pH values among the treatments. Both plants decreased EC about 7 % relative to the control (without plant after 24 days. The plants were also effective in reducing total dissolved phosphorus, so that duck weed and elodea decreased total dissolved P in the effluent about 49 and 7%, respectively. It is concluded that duck weed is more effective in the P removal from the effluent than the other plant.

  6. Using high-performance mathematical modelling tools to predict erosion and sediment fluxes in peri-urban catchments

    Science.gov (United States)

    Pereira, André; Conde, Daniel; Ferreira, Carla S. S.; Walsh, Rory; Ferreira, Rui M. L.

    2017-04-01

    the standard observed in available models. The assembled parallel model is expected to achieve faster than real-time simulations for high resolutions (from meters to sub-meter) in large scaled problems (from cities to watersheds), effectively bridging the gap between detailed and timely simulation results. The model was validated in Ribeira dos Covões watershed, a peri-urban catchment (6 km2) in the outskirts of the Coimbra city, in central Portugal. Urban land-use has increased from 6% in 1958 to 40% in 2012. The watershed geology comprises a limestone sandstone areas. The soils are generally deep and hydrophobic for part of the year, particularly in the forested areas. Previous research used a sediment fingerprinting approach to establish the relative importance of sediment inputs from different urban areas (Ferreira et al., submitted). The study showed that most of the current catchment erosion is derived from construction sites in the sandstone areas. This was supported by the higher measured discharges and suspended sediment concentrations in storm events from downslope tributaries. The results of the model are well correlated with field surveys. However, the sever disruption of the channel network by human usage, namely land partition, poses specific modelling challenges, causing the quantitative agreement to be poor. To tackle this problem, it is necessary to introduce as much detail as possible in the specification of the elevation model. Acknowledgements This research was partially supported by Portuguese and European funds, within programs COMPETE2020 and PORL-FEDER, through project PTDC/ECM-HID/6387/2014 granted by the National Foundation for Science and Technology (FCT). References Canelas, R.; Murillo, J. & Ferreira, R.M.L. (2013), Two-dimensional depth-averaged modelling of dam-break flows over mobile beds. Journal of Hydraulic Research, 51(4), 392-407. Conde, D.A.S.; Telhado, M.J.; Viana Baptista, M.A. & Ferreira, R. M. L. (2015) Severity and exposure

  7. Cold shock to aquatic organisms: guidance for power-plant siting, design, and operation

    International Nuclear Information System (INIS)

    Coutant, C.C.

    1977-01-01

    Problems of cold-shock damages to aquatic organisms have arisen at some condenser cooling-water discharges of thermal power stations when the warm-water releases have suddenly terminated. The basis for such damage lies in the exposure of resident organisms to a rapid decrease in temperature and a sustained exposure to low temperature that induces abnormal behavioral or physiological performance and often leads to death. Although some spectacular fish kills from cold shock have occurred, the present knowledge of the hydraulic and biological processes involved can provide guidance for the siting, design, and operation of power-plant cooling systems to minimize the likelihood of significant cold-shock effects. Preventing cold-shock damages is one consideration in minimizing overall environmental impacts of power-plant cooling and in balancing plant costs with environmental benefits

  8. Extraction of 14C-labeled photosynthate from aquatic plants with dimethyl sulfoxide (DMSO)

    International Nuclear Information System (INIS)

    Filbin, G.J.; Hough, R.A.

    1984-01-01

    DMSO was tested as a solvent to extract 14 C-labeled photosynthate from three species of aquatic plants in photosynthesis measurements and compared with the dry oxidation method for plant radioassay. Extraction of ca. 300 mg of fresh or rehydrated dry plant tissue samples in 10 ml of reagent-grade DMSO for 8h at 65 0 C resulted in a stable, nonviscous solution with excellent liquid scintillation counting characteristics. Extraction efficiency was in the range of 96-99% of fixed 14 C, and precision was comparable to, or better than, that obtained with dry oxidation. The method is simple and inexpensive, and for fresh tissue the same sample extracts can be used for chlorophyll analyses

  9. Ecological life histories of the three aquatic nuisance plants, Myriophyllum spicatum, Potamogeton crispus and Elodea canadensis

    Science.gov (United States)

    Nichols, S.A.; Shaw, B.H.

    1986-01-01

    The life histories of Myriophyllum spicatum L., Elodea canadensis Michx., and Potamogeton crispus L., serious aquatic nuisances in many regions of the world, are reviewed to provide insights into the life style of successful aquatic nuisance plants. Specifically, their distribution and spread in North America; their life cycle, productive and reproductive potential; and their ecosystem relationships are reviewed. Hopefully this review will improve a manager's ability to deal with aquatic nuisance problems. It also provides suggestions for basic research needed to develop more effective management practices. It was found that all three species possess a number of adaptations, including an ability to rapidly propagate vegetatively, an opportunistic nature for obtaining nutrients, a life cycle that favors cool weather, and a number of mechanisms which enhance photosynthetic efficiency, which allow them to proliferate. These three species do provide benefits to the ecosystem through their roles in materials cycling and energy flow. Therefore, management of these species should take an integrated approach which recognizes these benefits. The life history information available about the three species varies tremendously; however, a better understanding of resource gain and allocation is needed to manage all three species. Specifically, more research is needed to provide a better understanding of: 1) the role bicarbonate plays in photosynthesis, 2) the role roots play in supplying CO2 to the plabts, 3) resource accumulation and allocation under different temperature and light regimes, 4) resource allocation on a seasonal basis, and 5) nutrient cycling under different management regimes. ?? 1986 Dr W. Junk Publishers.

  10. AQUATIC PLANT SPECIATION AFFECTED BY DIVERSIFYING SELECTION OF ORGANELLE DNA REGIONS(1).

    Science.gov (United States)

    Kato, Syou; Misawa, Kazuharu; Takahashi, Fumio; Sakayama, Hidetoshi; Sano, Satomi; Kosuge, Keiko; Kasai, Fumie; Watanabe, Makoto M; Tanaka, Jiro; Nozaki, Hisayoshi

    2011-10-01

    Many of the genes that control photosynthesis are carried in the chloroplast. These genes differ among species. However, evidence has yet to be reported revealing the involvement of organelle genes in the initial stages of plant speciation. To elucidate the molecular basis of aquatic plant speciation, we focused on the unique plant species Chara braunii C. C. Gmel. that inhabits both shallow and deep freshwater habitats and exhibits habitat-based dimorphism of chloroplast DNA (cpDNA). Here, we examined the "shallow" and "deep" subpopulations of C. braunii using two nuclear DNA (nDNA) markers and cpDNA. Genetic differentiation between the two subpopulations was measured in both nDNA and cpDNA regions, although phylogenetic analyses suggested nuclear gene flow between subpopulations. Neutrality tests based on Tajima's D demonstrated diversifying selection acting on organelle DNA regions. Furthermore, both "shallow" and "deep" haplotypes of cpDNA detected in cultures originating from bottom soils of three deep environments suggested that migration of oospores (dormant zygotes) between the two habitats occurs irrespective of the complete habitat-based dimorphism of cpDNA from field-collected vegetative thalli. Therefore, the two subpopulations are highly selected by their different aquatic habitats and show prezygotic isolation, which represents an initial process of speciation affected by ecologically based divergent selection of organelle genes. © 2011 Phycological Society of America.

  11. Toxic Effects of Nickel Oxide Bulk and Nanoparticles on the Aquatic Plant Lemna gibba L.

    Directory of Open Access Journals (Sweden)

    Abdallah Oukarroum

    2015-01-01

    Full Text Available The aquatic plant Lemna gibba L. was used to investigate and compare the toxicity induced by 30 nm nickel oxide nanoparticles (NiO-NPs and nickel(II oxide as bulk (NiO-Bulk. Plants were exposed during 24 h to 0–1000 mg/L of NiO-NPs or NiO-Bulk. Analysis of physicochemical characteristics of nanoparticles in solution indicated agglomerations of NiO-NPs in culture medium and a wide size distribution was observed. Both NiO-NPs and NiO-Bulk caused a strong increase in reactive oxygen species (ROS formation, especially at high concentration (1000 mg/L. These results showed a strong evidence of a cellular oxidative stress induction caused by the exposure to NiO. Under this condition, NiO-NPs and NiO-Bulk induced a strong inhibitory effect on the PSII quantum yield, indicating an alteration of the photosynthetic electron transport performance. Under the experimental conditions used, it is clear that the observed toxicity impact was mainly due to NiO particles effect. Therefore, results of this study permitted determining the use of ROS production as an early biomarker of NiO exposure on the aquatic plant model L. gibba used in toxicity testing.

  12. The avoidance strategy of environmental constraints by an aquatic plant Potamogeton alpinus in running waters.

    Science.gov (United States)

    Robionek, Alicja; Banaś, Krzysztof; Chmara, Rafał; Szmeja, Józef

    2015-08-01

    Aquatic plants anchored in streams are under pressure from various constraints linked to the water flow and display strategies to prevent their damage or destruction. We assume that the responses of aquatic plants to fast-water flow are a manifestation of a trade-off consisting in either maximizing the resistance to damage (tolerance strategy) in minimizing the hydrodynamic forces (avoidance strategy), or both. Our main hypothesis was that Potamogeton alpinus demonstrate the avoidance strategy. We analyzed architecture traits of the modules of this clonal plant from slow- and fast-flowing streams. In fast-flowing waters, the avoidance strategy of P. alpinus is reflected by the following: (1) the presence of floating leaves that stabilize the vertical position of the stem and protect the inflorescence against immersion; (2) elongation of submerged leaves (weakens the pressure of water); and (3) shoot diameter reduction and increase in shoot density (weakens the pressure of water, increases shoot elasticity), and by contrast in slow-water flow include the following: (4) the absence of floating leaves in high intensity of light (avoiding unnecessary outlays on a redundant organ); (5) the presence of floating leaves in low intensity of light (avoidance of stress caused by an insufficient assimilation area of submerged leaves).

  13. Compiled data on the vascular aquatic plant program, 1975 - 1977. [for sewage lagoon

    Science.gov (United States)

    Wolverton, B. C.; Mcdonald, R.

    1977-01-01

    The performance of a single cell, facultative sewage lagoon was significantly improved with the introduction of vascular aquatic plants. Water hyacinth (Eichhornia crassipes) was the dominant plant from April to November; duckweed (Lemna spp.) and (Spirodela spp.) flourished from December to March. This 2 ha lagoon received approximately 475 cu m/day of untreated sewage and has a variable COD sub 5 loading rate of 22-30 kg/ha/day. During the first 14 months of operation with aquatic plants, the average influent BOD sub 5 was reduced by 95% from 110 mg/l to an average of 5 mg/l in the effluent. The average influent suspended solids were reduced by 90% from 97 mg/l to 10 mg/l in the effluent. Significant reductions in nitrogen and phosphorus were effected. The monthly kjeldahl nitrogen for influent and effluent averaged 12.0 and 3.4 mg/l, respectively, a reduction of 72%. The total phosphorus was reduced on an average of 56% from 3.7 mg/l influent to 1.6 mg/l effluent.

  14. Activated carbon derived from harmful aquatic plant for high stable supercapacitors

    Science.gov (United States)

    Li, Jiangfeng; Wu, Qingsheng

    2018-01-01

    Considering cost and environmental protection, the harmful aquatic plant altemanthera philoxeroides derived carbon material with super high specific surface area (2895 m2 g-1) is an ideal electrode material for supercapacitor. The structure and composition of these carbon materials were characterized by SEM, EDS, XPS and BET measurements. The obtained material exhibits a maximum specific capacitance of 275 F g-1 at 0.5 A g-1 and retains a capacitance of 210 F g-1 even at 50 A g-1. In addition, it also shows excellent capacity retention of 5000 cycles at 10 A g-1.

  15. Fate of psychoactive compounds in wastewater treatment plant and the possibility of their degradation using aquatic plants.

    Science.gov (United States)

    Mackuľak, Tomáš; Mosný, Michal; Škubák, Jaroslav; Grabic, Roman; Birošová, Lucia

    2015-03-01

    In this study we analyzed and characterized 29 psychoactive remedies, illicit drugs and their metabolites in single stages of wastewater treatment plants in the capital city of Slovakia. Psychoactive compounds were present within all stages, and tramadol was detected at a very high concentration (706 ng/L). Significant decreases of codeine, THC-COOH, cocaine and buprenorphine concentration were observed in the biological stage. Consequently, we were interested in the possibility of alternative tertiary post-treatment of effluent water with the following aquatic plants: Cabomba caroliniana, Limnophila sessiliflora, Egeria najas and Iris pseudacorus. The most effective plant for tertiary cleansing was I. pseudacorus which demonstrated the best pharmaceutical removal capacity. After 48 h codeine and citalopram was removed with 87% efficiency. After 96 h were all analyzed compounds were eliminated with efficiencies above 58%. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Trade-off between drag reduction and light interception of macrophytes: comparing five aquatic plants with contrasting morphology

    NARCIS (Netherlands)

    Bal, K.D.; Bouma, T.J.; Buis, K.; Struyf, E.; Jonas, S.; Backx, H.; Meire, P.

    2011-01-01

    1. Macrophytes in running waters experience an often dynamic and harsh environment. To avoid breakage, plants have to reduce the experienced drag force. However, by reducing leaf area, photosynthetic production is less. Aquatic plants therefore have to find a balance between reducing drag and

  17. Concentration of heavy metals in brook trout in comparison to aquatic plants and sediments

    Energy Technology Data Exchange (ETDEWEB)

    Abo-Rady, M.D.

    1983-01-01

    From 1974 to 1977 the heavy metal content of river water, fishes (Salmo trutta fario), three aquatic plants (Cladophora glomerata, Potamogeton pectinatus, Zannichellia palustris), one river-bank plant (Phalaris arundinacea), and sediments (clay fraction) taken from the River Leine, up and downstream of Goettingen, were determined. Galvanic-bath sewage containing heavy metals caused an increase (11-60%) in the concentration of nine elements in the water. The average level of heavy metals in the river water corresponded to that of the Ems, Elbe and Weser, but was lower than that of the Neckar, Rhine and Danube. It was also below the European Community Guidelines (1975) on the quality of water used for the artificial recharging of ground water. River water upstream of the city has been used for this recharging for many years. There is a good correlation between the metal content in the investigated samples and in the water. In the muscles, only Cd, Co and Mn, in the liver Cd, Co, Cr. Hg, Mn and Zn, and in the total fish Cd, Co, Cr, Cu and Zn had increased significantly. In contrast to all other elements, Cr shows the highest concentration in the muscles. A previous accumulation of Cr in the liver is not a prerequisite for the accumulation in the muscles. Mercury shows the highest accumulation in the muscles, apparently because of the high retention rate of this element. Muscles also are a good monitor for this element. The impact of heavy metals on the Leine water was reflected in aquatic plants, which showed an increase in concentration up to 95-fold (according to metal or plant) - but not in river-bank plants. C. glomerata has the remarkable capability of accumulating all ten elements. Since P. arundinacea cannot reflect the different load of heavy metals it is therefore less suitable as a biological monitor for these metals.

  18. Bibliographical survey of radiostrontium uptake capacity and processes in aquatic plants

    International Nuclear Information System (INIS)

    Pally, M.; Foulquier, L.

    1983-09-01

    This report covers 302 articles published between 1949 and 1980 on the contamination of freshwater and marine aquatic plants by radioactive strontium. For the marine and continental environments, the results of laboratory experiments on the dynamics of radiostrontium buildup and localization, concentration factors, elimination processes, the effects of biological factors and of the environment, the activity levels and concentration factors measured in areas directly and indirectly affected by waste discharges, discrimination factors and the role of plants as radiation indicators, are examined. The radioactive strontium uptake potentials are higher for freshwater plants -especially mosses and characeae- than for marine plants. In zones not directly affected by waste discharges, the maximum activity measured is 82 pCi/kg wet weight, compared with 750 pCi/kg for freshwater plants. The peak values were observed in 1964-1965. In zones directly affected by waste discharges, the activity levels range from 15 to 1700 pCi of 90 Sr per kilogram of wet weight in the marine environment, and from 20 to 207000 pCi/kg in fresh water. This work underlines the need for greater accuracy in allowing for the ecological characteristics of each site when assessing the impact of nuclear facilities, and for thoroughly correlating field observations with laboratory experiments in order to obtain a prospective view of the potentials for radioactive strontium uptake by plants according to the activity levels present in the liquid effluents [fr

  19. Microbial plant litter decomposition in aquatic and terrestrial boreal systems along a natural fertility gradient

    Science.gov (United States)

    Soares, A. Margarida P. M.; Kritzberg, Emma S.; Rousk, Johannes

    2017-04-01

    Plant litter decomposition is a global ecosystem process, with a crucial role in carbon and nutrient cycling. The majority of litter processing occurs in terrestrial systems, but an important fraction also takes place in inland waters. Among environmental factors, pH impacts the litter decomposition through its selective influence on microbial decomposers. Fungal communities are less affected by pH than bacteria, possibly owing to a wider pH tolerance by this group. On the other hand, bacterial pH optima are constrained to a narrower range of pH values. The microbial decomposition of litter is universally nutrient limited; but few comparisons exist between terrestrial and aquatic systems. We investigated the microbial colonisation and decomposition of plant litter along a fertility gradient, which varied in both pH and N availability in both soil and adjacent water. To do this we installed litterbags with birch (Betula pendula) in streams and corresponding soils in adjacent riparian areas in a boreal system, in Krycklan, Sweden. During the four months covering the ice-free growth season we monitored the successional dynamics of fungal (acetate incorporation into ergosterol) and bacterial growth (thymidine incorporation), microbial respiration in leaf litter, and quantitative and qualitative changes in litter over time. We observed that bacterial growth rates were initially higher in litter decomposing in streams than those in soils, but differences between terrestrial and aquatic bacterial production converged towards the end of the experiment. In litter bags installed in soils, bacterial growth was lower at sites with more acidic pH and lower N availability, while aquatic bacteria were relatively unaffected by the fertility level. Fungal growth rates were two-fold higher for litter decomposing in streams than in soils. In aquatic systems, fungal growth was initially lower in low fertility sites, but differences gradually disappeared over the time course. Fungal

  20. Screening potential genotoxic effect of aquatic plant extracts using the mussel micronucleus test

    Directory of Open Access Journals (Sweden)

    Bettina Eck-Varanka

    2016-01-01

    Full Text Available Objective: To assess the genotoxic potential of selected aquatic macrophytes: Ceratophyllum demersum L. (hornwort, family Ceratophyllaceae, Typha angustifolia L. (narrowleaf cattail, family Typhaceae, Stratiotes aloides L. (water soldier, family Butomaceae, and Oenanthe aquatica (L. Poir. (water dropwort, family Umbelliferae. Methods: For genotoxicity assessment, the mussel micronucleus test was applied. Micronucleus frequency was determined from the haemolymph of Unio pictorum L. (painter’s mussel. In parallel, total and hydrolisable tannin contents were determined. Results: All plant extracts elucidated significant mutagenic effect. Significant correlation was determined between tannin content and mutagenic capacity. Conclusions: The significant correlation between genotoxicity as expressed by micronucleus frequency and tannin content (both total and hydrolisable tannins indicate that tannin is amongst the main compounds being responsible for the genotoxic potential. It might be suggested that genotoxic capacity of these plants elucidate a real ecological effect in the ecosystem.

  1. Groundwater interactions with Lobelia lakes- effects on the aquatic plant, Littorella uniflora

    DEFF Research Database (Denmark)

    Ommen, Daniela Oliveira; Vinther, Hanne Fogh; Krüger, Laila

    Lake Hampen is representative of a group of lakes called Lobelia lakes. These are oligotrophic, clear water lakes which tend to have a low alkalinity. These lakes are termed “Lobelia lakes” due to the characteristic isoetid species which thrive in these conditions. Isoetids are small, evergreen...... aquatic plants whose leaves grow in a rosette form and have a large root base. The large root system enables the plants to better assimilate nutrients from the sediments, and the uptake of CO2 which is used for photosynthesis, and to release O2 into otherwise anoxic sediments. Lake Hampen is situated high...... up in the Jylland ridge and lies close to the groundwater boundary. This means that the groundwater flow between the aquifer and the lake is not constant, sometimes the groundwater flows from the aquifer into the lake (discharge) and other times it flows from the lake into the aquifer (recharge...

  2. Phytochelatin synthesis in response to Hg uptake in aquatic plants near a chlor-alkali factory.

    Science.gov (United States)

    Turull, Marta; Grmanova, Gabriela; Dago, Àngela; Ariño, Cristina; Díez, Sergi; Díaz-Cruz, José Manuel; Esteban, Miquel

    2017-06-01

    The effects of mercury (Hg) released from a chlor-alkali factory in aquatic plants along the Ebro River basin (NE Spain) were analysed considering the phytochelatins (PC n ) and their isoforms content in these plants. These compounds were analyzed using HPLC with amperometric detection, and the macrophytes species Ceratophyllum demersum and Myriopyllum spicatum were collected in two sampling campaigns, autumn and spring, respectively. To correlate the PC n content in macrophytes with the Hg contamination, analysis of total Hg (THg) content in plants and suspended particulate matter, as well as the dissolved-bioavailable fraction of Hg in water measured by the diffusive gradient in thin film (DGT) technique were done. The results confirm the presence of PC 2 -Ala in extracts of C. demersum and PC 2 -desGly in M. spicatum, and the concentration of these thiol compounds depends clearly on the distance between the hot spot and the downstream sites: the higher the levels are, the closer the hot spot is. Since most of the Hg is hypothesized to be associated with SPM and transported downstream, our results of the DGT suggest that trace amounts of Hg in water can be released as free metal ions yielding a certain accumulation in plants (reaching the ppb level) that are enough for activation of induction of PCs. A few PCs species have been determined, at different seasons, indicating that they can be used as good indicators of the presence of bioavailable Hg in aquatic media throughout the year. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding.

    Science.gov (United States)

    Ghahramanzadeh, R; Esselink, G; Kodde, L P; Duistermaat, H; van Valkenburg, J L C H; Marashi, S H; Smulders, M J M; van de Wiel, C C M

    2013-01-01

    Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to prevent them from entering a country. However, many related species are commercially traded, and distinguishing invasive from non-invasive species based on morphology alone is often difficult for plants in a vegetative stage. In this regard, DNA barcoding could become a good alternative. In this study, 242 samples belonging to 26 species from 10 genera of aquatic plants were assessed using the chloroplast loci trnH-psbA, matK and rbcL. Despite testing a large number of primer sets and several PCR protocols, the matK locus could not be amplified or sequenced reliably and therefore was left out of the analysis. Using the other two loci, eight invasive species could be distinguished from their respective related species, a ninth one failed to produce sequences of sufficient quality. Based on the criteria of universal application, high sequence divergence and level of species discrimination, the trnH-psbA noncoding spacer was the best performing barcode in the aquatic plant species studied. Thus, DNA barcoding may be helpful with enforcing a ban on trade of such invasive species, such as is already in place in the Netherlands. This will become even more so once DNA barcoding would be turned into machinery routinely operable by a nonspecialist in botany and molecular genetics. © 2012 Blackwell Publishing Ltd.

  4. Investigating the molecular basis for heterophylly in the aquatic plant Potamogeton octandrus (Potamogetonaceae with comparative transcriptomics

    Directory of Open Access Journals (Sweden)

    Dingxuan He

    2018-02-01

    Full Text Available Many plant species exhibit different leaf morphologies within a single plant, or heterophylly. The molecular mechanisms regulating this phenomenon, however, have remained elusive. In this study, the transcriptomes of submerged and floating leaves of an aquatic heterophyllous plant, Potamogeton octandrus Poir, at different stages of development, were sequenced using high-throughput sequencing (RNA-Seq, in order to aid gene discovery and functional studies of genes involved in heterophylly. A total of 81,103 unigenes were identified in submerged and floating leaves and 6,822 differentially expressed genes (DEGs were identified by comparing samples at differing time points of development. KEGG pathway enrichment analysis categorized these unigenes into 128 pathways. A total of 24,025 differentially expressed genes were involved in carbon metabolic pathways, biosynthesis of amino acids, ribosomal processes, and plant-pathogen interactions. In particular, KEGG pathway enrichment analysis categorized a total of 70 DEGs into plant hormone signal transduction pathways. The high-throughput transcriptomic results presented here highlight the potential for understanding the molecular mechanisms underlying heterophylly, which is still poorly understood. Further, these data provide a framework to better understand heterophyllous leaf development in P. octandrus via targeted studies utilizing gene cloning and functional analyses.

  5. Design and analysis of aquatic monitoring programs at nuclear power plants

    International Nuclear Information System (INIS)

    McKenzie, D.H.; Kannberg, L.D.; Gore, K.L.; Arnold, E.M.; Watson, D.G.

    1977-11-01

    This report addresses some of the problems of designing, conducting, and analyzing aquatic environmental monitoring programs for impact assessment of nuclear power plants. The concepts discussed are applicable to monitoring the effects of chemical, radioactive, or thermal effluents. The concept of control and treatment station pairs is the fundamental basis for the experimental method proposed. This concept is based on the hypothesis that the relationship between the two stations forming the pair can be estimated from the preoperational period and that this relationship holds during the operational period. Any changes observed in this relationship during the operational period are assumed to be the result of the power plant impacts. Thus, it is important that station pairs are selected so it can be assumed that they respond to natural environmental changes in a manner that maintains that relationship. The major problem in establishing the station pairs will be the location of the control station. The universal heterogeneity in the environment will prevent the establishment of identical station pairs. The requirement that the control station remain unaffected by the operation of the power plant dictates a spacial separation with its associated differences in habitat. Thus, selection of the control station will be based upon balancing the following two criteria: (1) far enough away from the plant site to be beyond the plant influence, and (2) close enough to the treatment station that the biological communities will respond to natural environmental changes consistently in the same manner

  6. Evaluation of sensitivity to desertification by a modified ESAs method in two sub-Saharan peri-urban areas: Ouagadougou (Burkina Faso) and Saint Louis (Senegal)

    Science.gov (United States)

    Topa, Maria Elena; Iavazzo, Pietro; Terracciano, Stefano; Adamo, Paola; Coly, Adrien; De Paola, Francesco; Giordano, Simonetta; Giugni, Maurizio; Traoré, Seydou Eric

    2013-04-01

    Desertification is regarded as one of the major global environmental problems of the 21st century. The African sub-Sahara is often quoted as the most seriously affected region with a significant loss of biological and economic productivity of the land due to climate characteristics and fluctuations, unsustainable land uses, overgrazing and inappropriate agricultural practices. Due to its complexity, dynamism and extent, desertification is complicated to check and assess. The absence of an agreed methodology for the identification of affected areas is a critical point in desertification monitoring and assessment. An integrated approach which uses both qualitative and quantitative measures is crucial to reach the aim of sustainable resource use and has to be reflected in application of sets of indicators. The selection of appropriate indicators and their integration and interpretation should be conducted by the objectives to be achieved and the questions to be answered. This study, carried out within the FP7-ENV-2010 CLUVA project (Climate change and Urban Vulnerability in Africa), aimed to assess the sensitivity to desertification in peri-urban areas of both Ouagadougou (Burkina Faso) and Saint Louis (Senegal) cities. The approach was based on the implementation and adaptation to the local conditions of the modeling methodology developed within the MEDALUS project (Mediterranean Desertification And Land Use). The model is characterized by a multi-factor approach based on the assessment of both environmental quality indicators (vegetation, soil, climate) and anthropogenic factors (land management). All local data, arranged in a GIS environment, allowed the generation of maps identifying Environmentally Sensitive Areas (ESAs) and an Index of Environmentally Sensitive Areas (ESAI). Changes and integrations to the original methodology have been set taking into account the environmental and social features of the whole sub-Saharan west Africa in order to allow the use of

  7. The toxicity of sulfolane and DIPA from sour gas plants to aquatic species

    International Nuclear Information System (INIS)

    Lintott, D.R.; Goudey, J.S.; Wilson, J.; Swanson, S.; Drury, C.

    1997-01-01

    The ecological effects of sulfolane and diisopropanolamine (DIPA), which are used to remove sulfur compounds from natural gas, were studied to establish risk-based cleanup criteria and to evaluate effective remedial measures. Toxicity tests were conducted on both the parent compounds and the thermal and biological degradation products. Toxicity testing focused on aquatic species because surface outlets, such as creeks, were found to be the major pathways for the water soluble DIPA and sulfolane chemicals. Sulfolane proved to be relatively non-toxic to aquatic species, with the exception of bacteria. DIPA was relatively toxic to algae at pH found in ground and surface waters. Aqueous and methanol reclaimer bottom extracts from five different gas plant sites were also tested using modified acute toxicity screening tests with different species. The reclaimer bottoms were found to be highly toxic to all species tested. DIPA and sulfolane did not entirely account for the toxicity of the reclaimer bottoms. Inorganic salts and metals present in reclaimer bottoms were found not to contribute to toxicity directly. The same was true for DIPA and sulfolane degradation products. 3 refs., 7 tabs., 8 figs

  8. The toxicity of sulfolane and DIPA from sour gas plants to aquatic species

    Energy Technology Data Exchange (ETDEWEB)

    Lintott, D.R.; Goudey, J.S. [HydroQual Consultants, Inc., Calgary, AB (Canada); Wilson, J.; Swanson, S. [Golder Associates, Calgary, AB (Canada); Drury, C. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre

    1997-12-31

    The ecological effects of sulfolane and diisopropanolamine (DIPA), which are used to remove sulfur compounds from natural gas, were studied to establish risk-based cleanup criteria and to evaluate effective remedial measures. Toxicity tests were conducted on both the parent compounds and the thermal and biological degradation products. Toxicity testing focused on aquatic species because surface outlets, such as creeks, were found to be the major pathways for the water soluble DIPA and sulfolane chemicals. Sulfolane proved to be relatively non-toxic to aquatic species, with the exception of bacteria. DIPA was relatively toxic to algae at pH found in ground and surface waters. Aqueous and methanol reclaimer bottom extracts from five different gas plant sites were also tested using modified acute toxicity screening tests with different species. The reclaimer bottoms were found to be highly toxic to all species tested. DIPA and sulfolane did not entirely account for the toxicity of the reclaimer bottoms. Inorganic salts and metals present in reclaimer bottoms were found not to contribute to toxicity directly. The same was true for DIPA and sulfolane degradation products. 3 refs., 7 tabs., 8 figs.

  9. Internal nitrogen removal from sediments by the hybrid system of microbial fuel cells and submerged aquatic plants.

    Directory of Open Access Journals (Sweden)

    Peng Xu

    Full Text Available Sediment internal nitrogen release is a significant pollution source in the overlying water of aquatic ecosystems. This study aims to remove internal nitrogen in sediment-water microcosms by coupling sediment microbial fuel cells (SMFCs with submerged aquatic plants. Twelve tanks including four treatments in triplicates were designed: open-circuit (SMFC-o, closed-circuit (SMFC-c, aquatic plants with open-circuit (P-SMFC-o and aquatic plants with closed-circuit (P-SMFC-c. The changes in the bio-electrochemical characteristics of the nitrogen levels in overlying water, pore water, sediments, and aquatic plants were documented to explain the migration and transformation pathways of internal nitrogen. The results showed that both electrogenesis and aquatic plants could facilitate the mineralization of organic nitrogen in sediments. In SMFC, electrogenesis promoted the release of ammonium from the pore water, followed by the accumulation of ammonium and nitrate in the overlying water. The increased redox potential of sediments due to electrogenesis also contributed to higher levels of nitrate in overlying water when nitrification in pore water was facilitated and denitrification at the sediment-water interface was inhibited. When the aquatic plants were introduced into the closed-circuit SMFC, the internal ammonium assimilation by aquatic plants was advanced by electrogenesis; nitrification in pore water and denitrification in sediments were also promoted. These processes might result in the maximum decrease of internal nitrogen with low nitrogen levels in the overlying water despite the lower power production. The P-SMFC-c reduced 8.1%, 16.2%, 24.7%, and 25.3% of internal total nitrogen compared to SMFC-o on the 55th, 82th, 136th, and 190th days, respectively. The smaller number of Nitrospira and the larger number of Bacillus and Pseudomonas on the anodes via high throughput sequencing may account for strong mineralization and denitrification in the

  10. Interactions of metal-based engineered nanoparticles with aquatic higher plants: A review of the state of current knowledge.

    Science.gov (United States)

    Thwala, Melusi; Klaine, Stephen J; Musee, Ndeke

    2016-07-01

    The rising potential for the release of engineered nanoparticles (ENPs) into aquatic environments requires evaluation of risks to protect ecological health. The present review examines knowledge pertaining to the interactions of metal-based ENPs with aquatic higher plants, identifies information gaps, and raises considerations for future research to advance knowledge on the subject. The discussion focuses on ENPs' bioaccessibility; uptake, adsorption, translocation, and bioaccumulation; and toxicity effects on aquatic higher plants. An information deficit surrounds the uptake of ENPs and associated dynamics, because the influence of ENP characteristics and water quality conditions has not been well documented. Dissolution appears to be a key mechanism driving bioaccumulation of ENPs, whereas nanoparticulates often adsorb to plant surfaces with minimal internalization. However, few reports document the internalization of ENPs by plants; thus, the role of nanoparticulates' internalization in bioaccumulation and toxicity remains unclear, requiring further investigation. The toxicities of metal-based ENPs mainly have been associated with dissolution as a predominant mechanism, although nano toxicity has also been reported. To advance knowledge in this domain, future investigations need to integrate the influence of ENP characteristics and water physicochemical parameters, as their interplay determines ENP bioaccessibility and influences their risk to health of aquatic higher plants. Furthermore, harmonization of test protocols is recommended for fast tracking the generation of comparable data. Environ Toxicol Chem 2016;35:1677-1694. © 2016 SETAC. © 2016 SETAC.

  11. Effects of acidification on metal accumulation by aquatic plants and invertebrates. 1. Constructed wetlands

    Science.gov (United States)

    Albers, P.H.; Camardese, M.B.

    1993-01-01

    The pH of lake water is often inversely correlated with concentrations of trace metals in the water column. Concentrations of Al, Cd, Ca, Cu, Fe, Hg, Pb, Mg, Mn, Ni, P, and Zn were compared in water, plants, and aquatic insects from three acidified (pH 5.0) and three nonacidified (pH 6.5) constructed wetlands. Concentrations of Zn in water and bur-reed (Sparganium americanum) were higher in acidified wetlands than in nonacidified wetlands. Floating nonrooted plants contained mean concentrations of Fe, Mg, and Mn that were higher than recommended maximum levels for poultry feed. The mean concentrations of all metals in insects were below recommended maximum levels for poultry feed and below levels that cause toxic effects in wild birds. Smaller than expected increases of metal concentrations in the water of acidified wetlands were probably due to limited mobilization of metals from the sediments and insignificant changes in sedimentation of aqueous metals. Calcium was lower in acidified than in nonacidified wetland water, but the Ca content of insects and bur-reed was not lower. Low concentrations of Ca in aquatic insects from both groups of wetlands indicate that calcium-rich crustaceans and mollusks are probably important to female waterfowl and their young during the spring, when invertebrates make up the majority of the diet. Although toxic effects from metal ingestion seem to be unlikely consequences of wetland acidification, the adverse effect of low pH on the occurrence of crustaceans and mollusks could threaten egg production and development of young.

  12. Larval development of Aedes aegypti and Aedes albopictus in peri-urban brackish water and its implications for transmission of arboviral diseases.

    Directory of Open Access Journals (Sweden)

    Ranjan Ramasamy

    2011-11-01

    Full Text Available Aedes aegypti (Linnaeus and Aedes albopictus Skuse mosquitoes transmit serious human arboviral diseases including yellow fever, dengue and chikungunya in many tropical and sub-tropical countries. Females of the two species have adapted to undergo preimaginal development in natural or artificial collections of freshwater near human habitations and feed on human blood. While there is an effective vaccine against yellow fever, the control of dengue and chikungunya is mainly dependent on reducing freshwater preimaginal development habitats of the two vectors. We show here that Ae. aegypti and Ae. albopictus lay eggs and their larvae survive to emerge as adults in brackish water (water with 30 ppt salt are termed fresh, brackish and saline respectively. Brackish water with salinity of 2 to 15 ppt in discarded plastic and glass containers, abandoned fishing boats and unused wells in coastal peri-urban environment were found to contain Ae. aegypti and Ae. albopictus larvae. Relatively high incidence of dengue in Jaffna city, Sri Lanka was observed in the vicinity of brackish water habitats containing Ae. aegypti larvae. These observations raise the possibility that brackish water-adapted Ae. aegypti and Ae. albopictus may play a hitherto unrecognized role in transmitting dengue, chikungunya and yellow fever in coastal urban areas. National and international health authorities therefore need to take the findings into consideration and extend their vector control efforts, which are presently focused on urban freshwater habitats, to include brackish water larval development habitats.

  13. A community-based cluster randomized survey of noncommunicable disease and risk factors in a peri-urban shantytown in Lima, Peru.

    Science.gov (United States)

    Heitzinger, Kristen; Montano, Silvia M; Hawes, Stephen E; Alarcón, Jorge O; Zunt, Joseph R

    2014-05-21

    An estimated 863 million people-a third of the world's urban population-live in slums, yet there is little information on the disease burden in these settings, particularly regarding chronic preventable diseases. From March to May 2012, we conducted a cluster randomized survey to estimate the prevalence of noncommunicable diseases (NCDs) and associated risk factors in a peri-urban shantytown north of Lima, Peru. Field workers administered a questionnaire that included items from the WHO World Health Survey and the WHO STEPS survey of chronic disease risk factors. We used logistic regression to assess the associations of NCDs and related risk factors with age and gender. We accounted for sampling weights and the clustered sampling design using statistical survey methods. A total of 142 adults were surveyed and had a weighted mean age of 36 years (range 18-81). The most prevalent diseases were depression (12%) and chronic respiratory disease (8%), while lifetime prevalence of cancer, arthritis, myocardial infarction, and diabetes were all less than 5%. Fifteen percent of respondents were hypertensive and the majority (67%) was unaware of their condition. Being overweight or obese was common for both genders (53%), but abdominal obesity was more prevalent in women (54% vs. 10% in men, p Peru and suggests that prevention and treatment interventions could be optimized according to age and gender.

  14. Assessment of imidacloprid and acetamiprid residues in okra and eggplant grown in peri-urban areas and their dietary intake in humans

    International Nuclear Information System (INIS)

    Amjad, A.; Akhtar, S.; Randhawa, M.; Binyameen, M.

    2018-01-01

    This research work was designed to estimate the gradually increasing use of insecticides on vegetables to create awareness among the consumers regarding their insecticide residues. The main aim of this study is to highlight the harmful effects of insecticides in comparison with dietary intake assessment of vegetables. In this regard, total 180 (n = 60×3) samples of okra (Abelmoschus esculentus) and eggplant (Solanum melongena) comprising of 30 samples vegetable were collected from the peri-urban farming system of Multan, Faisalabad and Gujranwala to assess insecticide residues along with their dietary intake assessment. The selected samples were quantified for the insecticide residues by using High Performance Liquid Chromatography (HPLC) technique equipped with UV/Visible detector. Results revealed that imidacloprid residues found in eggplant (0.226 mg Kg-1) and okra (0.176 mg Kg-1) from Multan region were greater than the residues reported from Gujranwala and Faisalabad. Out of all analyzed samples for imidacloprid and acetamaprid residues, 58% and 65% samples contained detectable residues respectively. Whereas 10% and 15% samples exceeded their maximum residue limits (MRLs) established by European Commission. Dietary intake assessment for imidacloprid and acetamiprid was calculated as per their maximum permissible intake (MPI) values i.e. 3.84 and 4.48 mg person-1day-1, respectively, which revealed that although a reasonable proportion of samples exceeded MRLs but their consumption was found within safe limit. (author)

  15. Abundance of Pathogenic Escherichia coli Virulence-Associated Genes in Well and Borehole Water Used for Domestic Purposes in a Peri-Urban Community of South Africa.

    Science.gov (United States)

    Abia, Akebe Luther King; Schaefer, Lisa; Ubomba-Jaswa, Eunice; Le Roux, Wouter

    2017-03-20

    In the absence of pipe-borne water, many people in Africa, especially in rural communities, depend on alternative water sources such as wells, boreholes and rivers for household and personal hygiene. Poor maintenance and nearby pit latrines, however, lead to microbial pollution of these sources. We evaluated the abundance of Escherichia coli and the prevalence of pathogenic E. coli virulence genes in water from wells, boreholes and a river in a South African peri-urban community. Monthly samples were collected between August 2015 and November 2016. In all, 144 water samples were analysed for E. coli using the Colilert 18 system. Virulence genes ( eagg , eaeA , stx1 , stx2 , flichH7 , ST , ipaH , ibeA ) were investigated using real-time polymerase chain reaction. Mean E. coli counts ranged between 0 and 443.1 Most Probable Number (MPN)/100 mL of water sample. Overall, 99.3% of samples were positive for at least one virulence gene studied, with flicH7 being the most detected gene (81/140; 57.6%) and the stx2 gene the least detected gene (8/140; 5.7%). Both intestinal and extraintestinal pathogenic E. coli genes were detected. The detection of virulence genes in these water sources suggests the presence of potentially pathogenic E. coli strains and is a public health concern.

  16. Abundance of Pathogenic Escherichia coli Virulence-Associated Genes in Well and Borehole Water Used for Domestic Purposes in a Peri-Urban Community of South Africa

    Directory of Open Access Journals (Sweden)

    Akebe Luther King Abia

    2017-03-01

    Full Text Available In the absence of pipe-borne water, many people in Africa, especially in rural communities, depend on alternative water sources such as wells, boreholes and rivers for household and personal hygiene. Poor maintenance and nearby pit latrines, however, lead to microbial pollution of these sources. We evaluated the abundance of Escherichia coli and the prevalence of pathogenic E. coli virulence genes in water from wells, boreholes and a river in a South African peri-urban community. Monthly samples were collected between August 2015 and November 2016. In all, 144 water samples were analysed for E. coli using the Colilert 18 system. Virulence genes (eagg, eaeA, stx1, stx2, flichH7, ST, ipaH, ibeA were investigated using real-time polymerase chain reaction. Mean E. coli counts ranged between 0 and 443.1 Most Probable Number (MPN/100 mL of water sample. Overall, 99.3% of samples were positive for at least one virulence gene studied, with flicH7 being the most detected gene (81/140; 57.6% and the stx2 gene the least detected gene (8/140; 5.7%. Both intestinal and extraintestinal pathogenic E. coli genes were detected. The detection of virulence genes in these water sources suggests the presence of potentially pathogenic E. coli strains and is a public health concern.

  17. A Feasibility Study of Biogas Technology to Solving Peri-urban Sanitation Problems in Developing Countries. A Case for Harare, Zimbabwe

    Directory of Open Access Journals (Sweden)

    G Sibanda

    2013-06-01

    Full Text Available This study investigated the feasibility of converting organic waste into energy using biogas technology to address sanitation problems in peri-urban suburbs of Harare, Zimbabwe.These suburbs with an estimated population of 156.975 are unique in that they are not connected to the Harare main water sewer system. A baseline survey was conducted to determine the quantity of biodegradable human and kitchen waste (N=60. Biodigester sizing and costing was done for various scenarios mainly household standalone, single centralised suburb and combined suburbs centralised biogas models. In addition potential biogas conversion to electricity was done for single centralised suburb and combined suburbs centralised biogas models. This was followed by a cost benefit analysis of employing combined suburbs biogas technology. A combined suburbs centralised biogas model was found to be the most feasible scenario producing 7378 m3 of biogas per day with electricity production capacity of 384 kW .There was a potential of wood savings of 6129 tonnes/year, paraffin savings of 2.556 tonnes/year and greenhouse benefits of 980 tonnes of CO2 equivalent emissions/ year and which would attract U$2940 from carbon credits sales per year. The study recommended the adoption of the biogas technology because of its potential toaddress both economic and sanitation challenges being faced by local authorities in developing countries particularly, improved hygienic conditions, energy supply chronic epidemics and sewerreticulation.

  18. Herd prevalence of bovine brucellosis and analysis of risk factors in cattle in urban and peri-urban areas of the Kampala economic zone, Uganda

    Directory of Open Access Journals (Sweden)

    Eisler Mark C

    2011-10-01

    Full Text Available Abstract Background Human brucellosis has been found to be prevalent in the urban areas of Kampala, the capital city of Uganda. A cross-sectional study was designed to generate precise information on the prevalence of brucellosis in cattle and risk factors for the disease in its urban and peri-urban dairy farming systems. Results The adjusted herd prevalence of brucellosis was 6.5% (11/177, 95% CI: 3.6%-10.0% and the adjusted individual animal prevalence was 5.0% (21/423, 95% CI: 2.7% - 9.3% based on diagnosis using commercial kits of the competitive enzyme-linked immunosorbent assay (CELISA for Brucella abortus antibodies. Mean within-herd prevalence was found to be 25.9% (95% CI: 9.7% - 53.1% and brucellosis prevalence in an infected herd ranged from 9.1% to 50%. A risk factor could not be identified at the animal level but two risk factors were identified at the herd level: large herd size and history of abortion. The mean number of milking cows in a free-grazing herd (5.0 was significantly larger than a herd with a movement restricted (1.7, p Conclusions Vaccination should be targeted at commercial large-scale farms with free-grazing farming to control brucellosis in cattle in and around Kampala city.

  19. Using Formative Research to Design a Behavior Change Strategy to Increase the Use of Improved Cookstoves in Peri-Urban Kampala, Uganda

    Directory of Open Access Journals (Sweden)

    Stephanie L. Martin

    2013-12-01

    Full Text Available Household air pollution from cooking with biomass fuels negatively impacts maternal and child health and the environment, and contributes to the global burden of disease. In Uganda, nearly 20,000 young children die of household air pollution-related pneumonia every year. Qualitative research was used to identify behavioral determinants related to the acquisition and use of improved cookstoves in peri-urban Uganda. Results were used to design a behavior change strategy for the introduction of a locally-fabricated top-lit updraft gasifier (TLUD stove in Wakiso district. A theoretical framework—opportunity, ability, and motivation—was used to guide the research and behavior change strategy development. Participants consistently cited financial considerations as the most influential factor related to improved cookstove acquisition and use. In contrast, participants did not prioritize the potential health benefits of improved cookstoves. The theoretical framework, research methodology, and behavior change strategy design process can be useful for program planners and researchers interested in identifying behavioral determinants and designing and evaluating improved cookstove interventions.

  20. Provision of private, piped water and sewerage connections and directly observed handwashing of mothers in a peri-urban community of Lima, Peru.

    Science.gov (United States)

    Oswald, William E; Hunter, Gabrielle C; Kramer, Michael R; Leontsini, Elli; Cabrera, Lilia; Lescano, Andres G; Gilman, Robert H

    2014-04-01

    To estimate the association between improved water and sanitation access and handwashing of mothers living in a peri-urban community of Lima, Peru. We observed 27 mothers directly, before and after installation of private, piped water and sewerage connections in the street just outside their housing plots, and measured changes in the proportion of faecal-hand contamination and hand-to-mouth transmission events with handwashing. After provision of water and sewerage connections, mothers were approximately two times more likely to be observed washing their hands within a minute of defecation, compared with when they relied on shared, external water sources and non-piped excreta disposal (RR = 2.14, 95% CI = 0.99-4.62). With piped water and sewerage available at housing plots, handwashing with or without soap occurred within a minute after 48% (10/21) of defecation events and within 15 min prior to 8% (11/136) of handling food events. Handwashing increased following installation of private, piped water and sewerage connections, but its practice remained infrequent, particularly before food-related events. Infrastructural interventions should be coupled with efforts to promote hygiene and ensure access to water and soap at multiple on-plot locations convenient to mothers. © 2014 John Wiley & Sons Ltd.

  1. Determinants of Caregivers' Use and Adoption of Household Water Chlorination: A Qualitative Study with Peri-urban Communities in the Peruvian Amazon

    Science.gov (United States)

    Rothstein, Jessica D.; Leontsini, Elli; Olortegui, Maribel Paredes; Yori, Pablo Peñataro; Surkan, Pamela J.; Kosek, Margaret

    2015-01-01

    The gap between the efficacy and the effectiveness of household water treatment in reducing diarrhea-related morbidity indicates the need for a better understanding of the determinants of long-term behavior change. To explore the barriers to drinking water chlorination in the Peruvian Amazon, where diarrhea is endemic among under-5 children, we conducted qualitative research with 23 caregivers from peri-urban communities of Iquitos, Peru. Our inquiry drew on the Transtheoretical Model of behavior change and the Integrated Behavioral Model for Water, Sanitation, and Hygiene to identify the most relevant contextual, psychosocial, and technological determinants of initial action and long-term adoption of chlorination. Our findings suggest that the decision to try out this practice resulted from the combined effect of knowledge of chlorination benefits and product availability and affordability. Progress from action to adoption was influenced by caretakers' understanding of dosage, the packaging of chlorine products, knowledge and skills for multipurpose laundry bleach, the taste of treated water, and reinforcement. This analysis suggests that a focus on these determinants and the household domain may help to improve the sustainability of future intervention efforts. PMID:26175028

  2. Plant pigment types, distributions, and influences on shallow water submerged aquatic vegetation mapping

    Science.gov (United States)

    Hall, Carlton R.; Bostater, Charles R., Jr.; Virnstein, Robert

    2004-11-01

    Development of robust protocols for use in mapping shallow water habitats using hyperspectral imagery requires knowledge of absorbing and scattering features present in the environment. These include, but are not limited to, water quality parameters, phytoplankton concentrations and species, submerged aquatic vegetation (SAV) species and densities, epiphytic growth on SAV, benthic microalgae and substrate reflectance characteristics. In the Indian River Lagoon, Fl. USA we conceptualize the system as having three possible basic layers, water column and SAV bed above the bottom. Each layer is occupied by plants with their associated light absorbing pigments that occur in varying proportions and concentrations. Phytoplankton communities are composed primarily of diatoms, dinoflagellates, and picoplanktonic cyanobacteria. SAV beds, including flowering plants and green, red, and brown macro-algae exist along density gradients ranging in coverage from 0-100%. SAV beds may be monotypic, or more typically, mixtures of the several species that may or may not be covered in epiphytes. Shallow water benthic substrates are colonized by periphyton communities that include diatoms, dinoflagellates, chlorophytes and cyanobacteria. Inflection spectra created form ASIA hyperspectral data display a combination of features related to water and select plant pigment absorption peaks.

  3. Effects of long-term radiation exposure on the higher aquatic plants in the Chernobyl exclusion zone

    Energy Technology Data Exchange (ETDEWEB)

    Shevtsova, N.; Gudkov, D. [Institute of Hydrobiology (Russian Federation)

    2014-07-01

    From the earliest years after the Chernobyl accident in 1986 the radioecological study on freshwater plant communities in the water-bodies within the Chernobyl exclusion zone (ChEZ) has been held. At first stages it was the research on plant species collection and radionuclide contamination of aquatic ecosystems. Now, it is the seasonal monitoring with several groups of data deals with different areas of plant communities investigation: (1) the data characterized the level of radionuclides contamination of the abiotic and biotic components of phyto-coenosis and connected absorbed dose rates for various species of aquatic plants; (2) indexes of plant reproduction, including productivity, sterility, seed germination indexes and different abnormalities of ontogenesis; (3) indexes of morphological deviations (radiomorphoses) of aquatic plant's reproduction organs such as panicle and seeds; (4) cytogenetic indexes including the rate and spectrum of chromosome aberrations in cells of apical root meristem of air-aquatic plants; (5) the group of indexes, connected with plant's immunity. The calculated absorbed dose rate for littoral emergent plants in sampling water bodies was varied from 0.7 to 1.4 Gy/year in dependence of radioactive contamination of bottom sediments, plant tissues and level of gamma-background. There were registered rather low rate of plant productivity (hundred times lower than normal), high percentage of sterility (20-80%), low germinating ability (14-48 %) and germinating power (40-50%) of seeds from all sampling water bodies within the ChEZ. Against the general suppressed background the effect of relative stimulation of more affected seeds was observed. With increase of internal absorbed dose in range of 0.2-5.3 mGy/year the number of germinated seeds was increased. At the same time the number of different abnormalities of seeds was increased as well. The highest rate of the morphological damages (up to 25 % of the total number of

  4. Aquatic Plant Control Research Program. Biological Control of Pistia stratiotes L. (Waterlettuce) Using Neohydronomus affinis Hustache (Coleoptera: Curculionidae).

    Science.gov (United States)

    1992-07-01

    plant must also be examined for herbivores attacking the weed. This ensures that time and money are not wasted by importing insects already present in...Agricultural Research Service Aquatic Weed Research Laboratory in Fort Lauder - dale, FL, from quarantine tacilities in Gainesville, FL, on 11 February

  5. Field growth analysis of Utricularia stygia and U. intermedia-two aquatic carnivorous plants with dimorphic shoots

    Czech Academy of Sciences Publication Activity Database

    Adamec, Lubomír

    2010-01-01

    Roč. 49, č. 2 (2010), s. 241-251 ISSN 0079-2047 Institutional research plan: CEZ:AV0Z60050516 Keywords : aquatic carnivorous plant s * Lentibulariaceae * dystrophic water Subject RIV: EF - Botanics Impact factor: 0.462, year: 2010

  6. Finding the harvesting frequency to maximize nutrient removal in a constructed wetland dominated by submerged aquatic plants

    NARCIS (Netherlands)

    Verhofstad, M.J.J.M.; Poelen, M.D.M.; Van Kempen, M.M.L.; Bakker, E.S.; Smolders, A.J.P.

    2017-01-01

    Water quality is still poor in many freshwater ecosystems around the world as a result of anthropogenic nutrient loading. Constructed wetlands can be used to remove excess nutrients. In these wetlands, helophytes or free floating aquatic plants are traditionally used to absorb the nutrients. The

  7. UPTAKE AND PHYTOTRANSFORMATION OF O,P'-DDT AND P,P'-DDT BY AXENICALLY CULTIVATED AQUATIC PLANTS

    Science.gov (United States)

    The uptake and phytotransformation of o,p'-DDT and p,p'-DDT were investigated in vitro using three axenically cultivated aquatic plants: parrot feather (Mariophyllum aquaticum), duckweed (Spirodela oligorrhiza), and elodea (Elodea canadensis). The decay profile of DDT from the aq...

  8. 33 CFR Appendix C to Part 273 - Information Requirements for Aquatic Plant Control Program Environmental Impact Statements

    Science.gov (United States)

    2010-07-01

    ... Aquatic Plant Control Program Environmental Impact Statements C Appendix C to Part 273 Navigation and... Environmental Impact Statements 1. Description of the problem. a. Pests. Identify the pest to be controlled by.... Relationship to environmental situation. Non-target organisms and integrated pest management programs. 2...

  9. Why are most aquatic plants widely distributed? Dispersal, clonal growth and small-scale heterogeneity in a stressful environment

    NARCIS (Netherlands)

    Santamaria, L.

    2002-01-01

    Non-marine aquatic vascular plants generally show broad distributional ranges. Climatic factors seem to have limited effects on their distributions, besides the determination of major disjunctions (tropical-temperate-subarctic). Dispersal should have been frequent enough to assure the quick

  10. Applying the seedling-emergence method under waterlogged conditions to detect the seed bank of aquatic plants in submerged sediments

    NARCIS (Netherlands)

    Boedeltje, G; ter Heerdt, GNJ; Bakker, JP

    Seed bank studies focused on submerged aquatic plants are generally performed under submerged conditions, using the seedling-emergence method. However, if a study targets at both submerged species and helophytes, submerged conditions are generally not suitable. We tested the emergence of seedlings

  11. Utilizing next generation sequencing to characterize microsatellite loci in a tropical aquatic plant species Cryptocoryne cordata var. cordata (Araceae)

    DEFF Research Database (Denmark)

    Rosazlina, Rusly; Jacobsen, Niels; Ørgaard, Marian

    2015-01-01

    Abstract Cryptocoryne cordata var. cordata (2n = 34) is an aquatic plant species distributed from the southern part of Peninsular Thailand through the Malay Peninsula. It propagates both sexually and asexually via stolons. The current study is aimed at developing nuclear microsatellite markers...

  12. Potential accumulation of estrogenic substances in biofilms and aquatic plants collected in sewage treatment plant (STP) and receiving water

    Energy Technology Data Exchange (ETDEWEB)

    Schultis, T.; Kuch, B.; Kern, A.; Metzger, J.W. [Inst. for Sanitary Engineering, Water Quality and Solid Waste Management ISWA, Stuttgart Univ. (Germany)

    2004-09-15

    During the past years the estrogenic potency of natural (e.g. estrone and 17{beta}-estradiol E2) and synthetic hormones (e.g. ethinylestradiol EE2) and xenoestrogens (e.g. pesticides, polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), dioxins (PCDDs) and furans (PCDFs), alkylphenolic compounds or bisphenol A (BPA)) has attracted increasing scientific attention. Especially the occurrence and behaviour of these substances in waste water of sewage treatment plants (STPs) were often investigated. Andersen et al. found steroid estrogen concentrations in the effluent of a municipal STP always below the limit of quantification of 1 ng/l. However, Aerni et al. detected E2 and EE2 concentrations up to 6 ng/l and 2 ng/l, and alkylphenols, alkylphenolmonoand diethoxylates even at {mu}g/l concentrations in the effluent of a wastewater treatment plant with a significant industrial impact3. In activated and digested sewage sludge concentrations of estrone and E2 up to 37 ng/g and 49 ng/g, of the synthetic EE2 up to 17 ng/g were observed4. In river sediments the concentrations detected were lower with up to 2 ng/g estrone and 0,9 ng/g EE24. In the meantime many studies exist about raw and treated water in STPs, but there is little knowledge about the influence of estrogenic active substances on aquatic plants so far. In this study we investigated therefore the potency of estrogenic substances to accumulate in the duckweed Lemna minor from STP in comparison to the estrogenicity of duckweed from a natural pond, biofilms in drain and microsieve of the STP by the in vitro E-Screen- and LYES-assay (yeast estrogen screen-assay assisted by enzymatic digestion with lyticase). In addition, we tested the estrogenic activity of moss-like aquatic plants collected at different sites of the receiving water and analyzed the concentrations of four phenolic xenoestrogens in the effluent by GC/MS.

  13. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India

    Energy Technology Data Exchange (ETDEWEB)

    Jha, V.N., E-mail: jhavn1971@gmail.com; Tripathi, R.M., E-mail: tripathirm@yahoo.com; Sethy, N.K., E-mail: sethybarc@rediffmail.com; Sahoo, S.K., E-mail: sksbarc@gmail.com

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r = 0.86, p < 0.003). For sediment rooted plants significant correlation was found between uranium concentration in plant and the substrate (r = 0.88, p < 0.001). Both for other free floating species and sediment rooted plants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p < 0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. - Highlights: • Uranium mill tailings pond. • Jaduguda, India. • Fresh water plants. • Uranium uptake. • Relationship of uranium with stable elements.

  14. Multiple mitigation mechanisms: Effects of submerged plants on the toxicity of nine insecticides to aquatic animals.

    Science.gov (United States)

    Brogan, William R; Relyea, Rick A

    2017-01-01

    Understanding the processes that regulate contaminant impacts in nature is an increasingly important challenge. For insecticides in surface waters, the ability of aquatic plants to sorb, or bind, hydrophobic compounds has been identified as a primary mechanism by which toxicity can be mitigated (i.e. the sorption-based model). However, recent research shows that submerged plants can also rapidly mitigate the toxicity of the less hydrophobic insecticide malathion via alkaline hydrolysis (i.e. the hydrolysis-based model) driven by increased water pH resulting from photosynthesis. However, it is still unknown how generalizable these mitigation mechanisms are across the wide variety of insecticides applied today, and whether any general rules can be ascertained about which types of chemicals may be mitigated by each mechanism. We quantified the degree to which the submerged plant Elodea canadensis mitigated acute (48-h) toxicity to Daphnia magna using nine commonly applied insecticides spanning three chemical classes (carbamates: aldicarb, carbaryl, carbofuran; organophosphates: malathion, diazinon, chlorpyrifos; pyrethroids: permethrin, bifenthrin, lambda-cyhalothrin). We found that insecticides possessing either high octanol-water partition coefficients (log K ow ) values (i.e. pyrethroids) or high susceptibility to alkaline hydrolysis (i.e. carbamates and malathion) were all mitigated to some degree by E. canadensis, while the plant had no effect on insecticides possessing intermediate log K ow values and low susceptibility to hydrolysis (i.e. chlorpyrifos and diazinon). Our results provide the first general insights into which types of insecticides are likely to be mitigated by different mechanisms based on known chemical properties. We suggest that current models and mitigation strategies would be improved by the consideration of both mitigation models. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The biology and in vitro propagation of the ornamental aquatic plant, Aponogeton ulvaceus.

    Science.gov (United States)

    Kam, Melissa Yit Yee; Chai, Li Chin; Chin, Chiew Foan

    2016-01-01

    Aponogeton ulvaceus Baker (Aponogetonaceae) is a commercially important ornamental aquatic plant species with traditional medicinal uses. Due to the low survival rate of seedlings, propagation by conventional means has been met with many difficulties. In this study, botanical aspects of A. ulvaceus were examined with regards to the morphology, anatomy and physiology of the plant and an efficient protocol for its in vitro propagation using immature tuber explants has been established. The existence of glandular trichomes on the leaves was discovered and the occurrence of circumnutation in A. ulvaceus has been demonstrated. Immature tuber segments with meristems were cultured on MS medium supplemented with various combinations (0, 1, 2, and 3 mg/L) of BAP and NAA for callus induction. The highest percentage of callus production (100 %) was obtained in two different treatments: 1 mg/L BAP and 3 mg/L NAA, and 2 mg/L BAP and 3 mg/L NAA. For shoot and root organogenesis, the combination of 1 mg/L BAP and 1 mg/L NAA was shown to be significant for A. ulvaceus regeneration when compared to control, which yields a mean shoot and root number of 22.50 and 29.50 respectively. The current protocol is the first reported successful establishment of in vitro clonal propagation of A. ulvaceus .

  16. Hydrologic alteration affects aquatic plant assemblages in an arid-land river

    Science.gov (United States)

    Vinson, Mark; Hestmark, Bennett; Barkworth, Mary E.

    2014-01-01

    We evaluated the effects of long-term flow alteration on primary-producer assemblages. In 1962, Flaming Gorge Dam was constructed on the Green River. The Yampa River has remained an unregulated hydrologically variable river that joins the Green River 100 km downstream from Flaming Gorge Dam. In the 1960s before dam construction only sparse occurrences of two macroalgae, Cladophora and Chara, and no submerged vascular plants were recorded in the Green and Yampa rivers. In 2009–2010, aquatic plants were abundant and widespread in the Green River from the dam downstream to the confluence with the Yampa River. The assemblage consisted of six vascular species, Elodea canadensis, Myriophyllum sibiricum, Nasturtium officinale,Potamogeton crispus, Potamogeton pectinatus, and Ranunculus aquatilis, the macroalgae Chara and Cladophora, and the bryophyte, Amblystegium riparium. In the Green River downstream from the Yampa River, and in the Yampa River, only sparse patches of Chara and Cladophora growing in the splash zone on boulders were collected. We attribute the observed changes in the Green River to an increase in water transparency and a reduction in suspended and bed-load sediment and high flow disturbances. The lack of hydrophyte colonization downstream from the confluence with the Yampa River has implications for understanding tributary amelioration of dam effects and for designing more natural flow-regime schedules downstream from large dams.

  17. Laboratory tests for the phytoextraction of heavy metals from polluted harbor sediments using aquatic plants.

    Science.gov (United States)

    Mânzatu, Carmen; Nagy, Boldizsár; Ceccarini, Alessio; Iannelli, Renato; Giannarelli, Stefania; Majdik, Cornelia

    2015-12-30

    The aim of this study was to investigate the concentrations and pollution levels of heavy metals, organochlorine pesticides, and polycyclic aromatic hydrocarbons in marine sediments from the Leghorn Harbor (Italy) on the Mediterranean Sea. The phytoextraction capacity of three aquatic plants Salvinia natans, Vallisneria spiralis, and Cabomba aquatica was also tested in the removal of lead and copper, present in high concentration in these sediments. The average detectable concentrations of metals accumulated by the plants in the studied area were as follows: >3.328 ± 0.032 mg/kg dry weight (DW) of Pb and 2.641 ± 0.014 mg/kg DW of Cu for S. natans, >3.107 ± 0.034 g/kg DW for V. spiralis, and >2.400 ± 0.029 mg/kg DW for C. aquatica. The occurrence of pesticides was also analyzed in the sediment sample by gas chromatography coupled with mass spectrometry (GC/MS). Due to its metal and organic compound accumulation patterns, S. natans is a potential candidate in phytoextraction strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Assessment of macro and microelement accumulation capability of two aquatic plants

    International Nuclear Information System (INIS)

    Baldantoni, Daniela; Alfani, Anna; Di Tommasi, Paul; Bartoli, Giovanni; De Santo, Amalia Virzo

    2004-01-01

    The concentrations of four macroelements (C, N, P, S) and eight trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) were measured in the leaves and roots of the emergent plant, Phragmites communis Trin., and in the shoots and roots of the submersed Najas marina L., taken from Lake Averno (Naples, Italy). Phragmites communis leaves showed higher concentrations of carbon, nitrogen and phosphorus than roots, while the roots exhibited significantly higher concentrations of sulphur and trace metals. Najas marina roots also showed higher concentrations of sulphur and trace metals than shoots, but these differences were less marked than in Phragmites communis except for sulphur. Sulphur was the only macronutrient to show the highest concentrations in the roots. Phragmites communis roots had higher values of Cr, Cu, Fe, Mn and Ni than Najas marina roots. By contrast, Cd, Cr, Fe, Ni, Pb and Zn concentrations were higher in Najas marina shoots than in Phragmites communis leaves. Phragmites communis, available through the year, showing high capability to accumulate trace metals in the roots, appears a good monitor of lake contamination, better than Najas marina. - Element accumulation in roots and shoots of aquatic plants was used as a criteria for selecting useful biomonitors

  19. Ants swimming in pitcher plants: kinematics of aquatic and terrestrial locomotion in Camponotus schmitzi.

    Science.gov (United States)

    Bohn, Holger Florian; Thornham, Daniel George; Federle, Walter

    2012-06-01

    Camponotus schmitzi ants live in symbiosis with the Bornean pitcher plant Nepenthes bicalcarata. Unique among ants, the workers regularly dive and swim in the pitcher's digestive fluid to forage for food. High-speed motion analysis revealed that C. schmitzi ants swim at the surface with all legs submerged, with an alternating tripod pattern. Compared to running, swimming involves lower stepping frequencies and larger phase delays within the legs of each tripod. Swimming ants move front and middle legs faster and keep them more extended during the power stroke than during the return stroke. Thrust estimates calculated from three-dimensional leg kinematics using a blade-element approach confirmed that forward propulsion is mainly achieved by the front and middle legs. The hind legs move much less, suggesting that they mainly serve for steering. Experiments with tethered C. schmitzi ants showed that characteristic swimming movements can be triggered by submersion in water. This reaction was absent in another Camponotus species investigated. Our study demonstrates how insects can use the same locomotory system and similar gait patterns for moving on land and in water. We discuss insect adaptations for aquatic/amphibious lifestyles and the special adaptations of C. schmitzi to living on an insect-trapping pitcher plant.

  20. Crassulacean acid metabolism enhances underwater photosynthesis and diminishes photorespiration in the aquatic plant Isoetes australis

    DEFF Research Database (Denmark)

    Pedersen, Ole; Rich, S.M.; Pulido Pérez, Cristina

    2011-01-01

    Underwater photosynthesis by aquatic plants is often limited by low availability of CO2, and photorespiration can be high. Some aquatic plants utilize crassulacean acid metabolism (CAM) photosynthesis. The benefits of CAM for increased underwater photosynthesis and suppression of photorespiration...... photorespiration was evident at a range of O2 concentrations, including values below air equilibrium. At a high O2 concentration of 2.2-fold the atmospheric equilibrium concentration, net photosynthesis was reduced substantially and, although it remained positive in leaves containing high malate concentrations...... were evaluated for Isoetes australis, a submerged plant that inhabits shallow temporary rock pools. • Leaves high or low in malate were evaluated for underwater net photosynthesis and apparent photorespiration at a range of CO2 and O2 concentrations. • CAM activity was indicated by 9.7-fold higher leaf...

  1. Biogas production from Eichhornia crassipes aquatic plant; Producao de biogas a partir da planta aquatica Eichhornia crassipes

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Roberto Guimaraes; Silva, Jose Goncalves da; Fernandes Filho, Jorge; Pereira, Maria Cristina Duarte Eiras [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica. Programa de Pos-Graduacao em Engenharia Mecanica]. E-mail: temrobe@vm.uff.br; Melo, Ricardo Bichara de [Light Servicos de Eletricidade S.A., Rio de Janeiro, RJ (Brazil)]. E-mail: rbmelo@light.com.br

    2004-07-01

    Virtually all plants and waste plants and animals may in some way be used as an energy source. The anaerobic digestion of these materials is an option, resulting in the biogas. Besides the gas obtained in the process, is produced, inside the biodigester, an excellent fertilizer. The aquatic plant Eichhornia crassipes is found in large quantities in various water bodies, such as reservoirs, lakes and ponds, becoming mostly often a big problem and it is necessary its systematic removal of water. The bench biodigester used in the experiment of biodigestion of aquatic plants is composed of a reactor containing the biomass, where the biogas is produced, and a reservoir to monitor the production of biogas. The reactor is located within a receptacle containing water that can be heated by an electrical resistance, with the purpose of maintaining the temperature inside the reactor around 35 deg C. The results of analysis of gas of the reactor made in a gas chromatograph to CG MASTER of double ionization detector with a flame and thermal conductivity, show a percentage of 50% of methane in the biogas. The process of biodigestion of aquatic plant Eichhornia crassipes shows potential to obtain biogas, with considerable levels of methane in order to make its exploitation. Also, were analyzed the biomass in the biodigester for determination of humid, total organic matter, mineral and organic carbon residue.

  2. Comparative radiocarbon dating of terrestrial plant macrofossils and aquatic moss from the ice-free corridor of western Canada

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, G.M.; Beukens, R.P.; Kieser, W.E.; Vitt, D.H.

    1987-09-01

    In order to assess the reliability of aquatic moss for radiocarbon dating, /sup 14/C analyses were performed on a stratigraphic series of terrestrial plant macrofossils and samples of Drepanocladus crassicostatus from a small, hard-water lake (pH = 8.2) in the ice-free corridor of Alberta. All /sup 14/C dating was done by using accelerator mass spectrometry. Mazama Ash provided an independent chronological control. The aquatic bryophyte samples consistently produced /sup 14/C ages significantly older than the terrestrial macrofossils. The relation between the radiocarbon dates from the macrofossils and the moss was not linear, and age differences ranged from approximately 1400 to 6400 yr. The /sup 14/C content of D. crassicostatus growing in the lake at present was less than 85% modern. Despite the apparent inability to take up /sup 14/C-deficient carbon by the direct incorporation of bicarbonate, the bryophytes clearly do not provide reliable material /sup 14/C dating. The /sup 14/C deficiency of aquatic mosses may be explained by the generation of /sup 14/C-deficient CO/sub 2/ through isotopic exchange, the formation of CO/sub 2/ from bicarbonate by chemical processes, and metabolic CO/sub 2/ production. These results demonstrate the potential unreliability of /sup 14/C dates from aquatic mosses and raise serious concerns about the deglaciation dates from the ice-free corridor that were obtained from aquatic Drepanocladus.

  3. Nuclear microprobe study of heavy metal uptake and transport in aquatic plant species

    International Nuclear Information System (INIS)

    Kertesz, Zs.; Kocsar, I.; Szikszai, Z.; Lakatos, Gy.

    2005-01-01

    Complete text of publication follows. In aquatic ecosystems water contamination by trace metals is one of the main types of pollution that may stress the biotic community. Although some metals are needed as micronutrients for autotrophic organisms, they can have toxic effects at higher concentration. Aquatic plants can take up large quantities of nutrients and metals from the environment, they can live under extreme environmental conditions therefore they are being increasingly used in remediation processes to reduce contamination. Besides the usually applied bulk analytical techniques quantitative micro-PIXE investigation of the macro, micro and trace element distribution within the root can lead to a better understanding of the heavy metal up-take, transport and detoxification mechanisms of the plants and thus helps to select the proper species for the remedial activity, or possibly to increase the efficiency of the remediation. In this work we determined the elemental distributions in root cross sections and along the roots of reed (Phragmaties australis), bulrush (Typha angustifolia) and sea club-rush (Bolboschoemus maritimus) using the Debrecen nuclear microprobe. The plants originate from the dried units of the wastewater sedimentation pond system of the tannery of Kunszentmarton. 1500 m 3 waste water containing lime, sodium-salts, ammonium-salts, chromium-salts, sodium, chlorine and magnesium ions, sulphur and organic material was released to the pond system every day till 1988. The chosen species are the dominant species of the area, composing 85-90% of the green plant covering. This heavily contaminated area has been regularly monitored by the colleagues of the Dept. of Applied Ecology of the Univ. of Debrecen since 1998. They focused their work the potentially toxic heavy metal chromium. In order to conserve the samples in the living state, the roots were frozen in liquid nitrogen. 16-20 μm thick cross sections were made with cryo-microtome, and all the

  4. Is the tier-1 effect assessment for herbicides protective for aquatic algae and vascular plant communities?

    Science.gov (United States)

    van Wijngaarden, René P A; Arts, Gertie H P

    2018-01-01

    In the aquatic tier-1 effect assessment for plant protection products with an herbicidal mode of action in Europe, it is usually algae and/or vascular plants that determine the environmental risks. This tier includes tests with at least 2 algae and 1 macrophyte (Lemna). Although such tests are considered to be of a chronic nature (based on the duration of the test in relation to the life cycle of the organism), the measurement endpoints derived from the laboratory tests with plants (including algae) and used in the first-tier effect assessment for herbicides are acute effect concentrations affecting 50% of the test organisms (EC50 values) and not no-observed-effect concentrations (NOECs) or effect concentrations affecting 10% of the test organisms (EC10) values. Other European legislative frameworks (e.g., the Water Framework Directive) use EC10 values. The present study contributes to a validation of the tiered herbicide risk assessment approach by comparing the standard first-tier effect assessment with results of microcosm and mesocosm studies. We evaluated EC50 and EC10 values for standard test algae and macrophytes based on either the growth rate endpoint (E r C50) or the lowest available endpoint for growth rate or biomass/yield (E r /E y C50). These values were compared with the regulatory acceptable concentrations for the threshold option as derived from microcosm and mesocosm studies. For these studies, protection is maintained if growth rate is taken as the regulatory endpoint instead of the lowest value of either growth rate or biomass/yield in conjunction with the standard assessment factor of 10. Based on a limited data set of 14 herbicides, we did not identify a need to change the current practice. Environ Toxicol Chem 2018;37:175-183. © 2017 SETAC. © 2017 SETAC.

  5. Actual versus predicted impacts of three ethanol plants on aquatic and terrestrial resources

    International Nuclear Information System (INIS)

    Eddlemon, G.K.; Webb, J.W.; Hunsaker, D.B. Jr.; Miller, R.L.

    1993-01-01

    To help reduce US dependence on imported petroleum, Congress passed the Energy Security Act of 1980 (public Law 96-294). This legislation authorized the US Department of Energy (DOE) to promote expansion of the fuel alcohol industry through, among other measures, its Alcohol Fuels Loan Guarantee Program. Under this program, selected proposals for the conversion of plant biomass into fuel-grade ethanol would be granted loan guarantees. of 57 applications submitted for loan guarantees to build and operate ethanol fuel projects under this program, 11 were considered by DOE to have the greatest potential for satisfying DOE's requirements and goals. In accordance with the National Environmental Policy Act (NEPA), DOE evaluated the potential impacts of proceeding with the Loan Guarantee Program in a programmatic environmental assessment (DOE 1981) that resulted in a finding of no significant impact (FANCY) (47 Federal Register 34, p. 7483). The following year, DOE conducted site-specific environmental assessments (EAs) for 10 of the proposed projects. These F-As predicted no significant environmental impacts from these projects. Eventually, three ethanol fuel projects received loan guarantees and were actually built: the Tennol Energy Company (Tennol; DOE 1982a) facility near Jasper in southeastern Tennessee; the Agrifuels Refining Corporation (Agrifuels; DOE 1985) facility near New Liberia in southern Louisiana; and the New Energy Company of Indiana (NECI; DOE 1982b) facility in South Bend, Indiana. As part of a larger retrospective examination of a wide range of environmental effects of ethanol fuel plants, we compared the actual effects of the three completed plants on aquatic and terrestrial resources with the effects predicted in the NEPA EAs several years earlier. A secondary purpose was to determine: Why were there differences, if any, between actual effects and predictions? How can assessments be improved and impacts reduced?

  6. Assessment of pit latrines in a peri-urban community in KwaZulu-Natal (South Africa) as a source of antibiotic resistant E. coli strains.

    Science.gov (United States)

    Beukes, Lorika S; King, Tracy L B; Schmidt, Stefan

    2017-11-01

    Due to the frequent use of antibiotics and recurring illnesses related to multidrug-resistant (MDR) bacteria in South Africa, we determined if MDR Escherichia coli were present in pit latrine fecal sludge samples obtained from a peri-urban community in KwaZulu-Natal, South Africa. The abundance of E. coli in pit latrine samples was established using a most probable number (MPN) method with species confirmation done using biochemical tests and polymerase chain reaction (PCR). Forty-four randomly selected E. coli pit latrine isolates were further characterized, using the European committee on antimicrobial susceptibility testing (EUCAST) disk diffusion method to establish antibiotic resistance profiles for these E. coli isolates. The resulting MPN values for E. coli ranged from one to 6.2 log 10 MPN per gram of fresh pit latrine fecal sludge. While only 3 out of 44 E. coli pit latrine isolates showed no resistance to any of the 12 tested antibiotics, most isolates were resistant to two or more antibiotics. The majority of isolates showed resistance to at least one of the two tested aminoglycosides, one isolate showed resistance to the carbapenem ertapenem, and although resistance was not detected for tigecycline four pit latrine E. coli isolates showed intermediate resistance to this antibiotic. However, about 14% of the E. coli pit latrine isolates were categorized as MDR, all of which showed resistance to four or more antibiotics. The presence of MDR E. coli strains in pit latrine samples demonstrates that these facilities are potential sources for MDR bacteria. Copyright © 2017 Elsevier GmbH. All rights reserved.

  7. Socio-cultural acceptability of urine diverted composting toilets: A review of literature for possible adoption in peri-urban areas as a sustainable sanitation solution

    Science.gov (United States)

    Ahmed, Sk. Kabir; Ahmed, Sarder Shakil

    2017-12-01

    The improvements of strategies and treatment options adapted to conditions prevailing in developing countries have long been neglected as regards faecal sludge (FS) - the by-products of on-site sanitation installations. In recent years, an encouraging number of initiatives towards improved FS management, including appropriate FS treatment schemes, have been developed, particularly in Nepal, Thailand, Vietnam and Bangladesh. These initiatives assist urban and peri-urban dwellers and authorities to overcome the challenges of undifferentiating and uncontrolled disposal of faecal sludge into drains, canals and onto open spaces, thus producing a "faecal film" in urban areas that impair public health and cause pollution. Though people around the world are buying, or being offered with, pit latrines, shared toilets, or other enhanced sanitation solutions, this is vital to reduce transmission of diseases; questions arise about how to deal with the fecal sludge management. Sanitation is the hygienic way of upholding health through avoidance of human contact with the hazards of wastes as well as the treatment and proper disposal of sewage or wastewater. Waterborne diseases are the single most vital cause of death and illness in developing countries. The understanding of social issues is paramount introducing an alternative sanitation system. Although treating excreta is a universal aspect of human existence, the topic has not been rigorously investigated by social scientists identifying three cultural influences that affect the acceptance (or rejection) of an alternative sanitation system: psychology, religion and gender. Composting literature review focuses on increasing awareness and developing good understanding of composting toilets as an alternative urban sanitation technology.

  8. Intestinal parasitosis and socio-environmental factor sof a population from peri-urban area of Manaus - AM - doi: 10.5020/18061230.2010.p30

    Directory of Open Access Journals (Sweden)

    Cecília Leite Motta de Oliveira

    2012-01-01

    Full Text Available Objectives: To describe the prevalence of intestinal parasitosis in patients who sought a Basic Health Unit and get to know the conditions and socio-environmental characteristics of a population of peri-urban area of Manaus - AM, Brazil. Methods: A study conducted by spontaneous demand of patients in a Basic Health Unit, Northern Zone of Manaus, Amazonas, between April and July 2007, conducting parasitological examination in 400 stool samples by Hoffmann-Pons-Janer’s method, and interviews. Results: From the total, 271/400 (67,8% contained parasites; 181/268 (45,25% samples were of females; 147/224 (36,7% aged between 19 and 85 years; 119/170 (29,75% with incomplete elementary school; 207/299 (51.75% with a family income between one and three minimum wages; 220/316 (55% were natural from Amazonas; 192/284 (48% worked at home; 199/298 (49,7% consumed water from artesian public well; 106/152 (26.5% treated the water; 165/248 (66% did not treat the consumed water. The most frequent helminthes found: Ascaris lumbricoides 48 (12%, Enterobius vermicularis 44 (11%, Ancilostomídeos 38 (9,5%. Protozoa: Entamoeba histolytica 83 (20,8%, Entamoeba coli and Endolimax nana, 79 (19,8% e 79 (19,8% respectively, Giardia lamblia 41 (10,3% and Iodamoeba butschlii 17 (4,3%. It was observed monoparasitism for E. histolytica 83 (20,8%, biparasitism 104/271 (26% E. histolytica and A. lumbricóides, E. histolytica and E. vermicularis, E. histolytica and G. lamblia. Conclusions:   We recorded a high prevalence of parasites in young people with low income, low cultural level, predominantly women of the household. Among the environmental factors associated with these indexes are a deficiency in water services and sanitary sewer.

  9. Suicidal ideation and behaviour among persons seeking HIV testing in peri-urban areas of Cape Town, South Africa: a lost opportunity for suicide prevention.

    Science.gov (United States)

    Bantjes, Jason; Kagee, Ashraf; Saal, Wylene

    2017-07-01

    Suicidal ideation and behaviour (SIB) are among the psychiatric sequela of HIV/AIDS. Few studies have however examined the prevalence and correlates of SIB among persons seeking HIV testing. We set out to document the prevalence and correlates of SIB among people seeking HIV testing in peri-urban areas of Cape Town, South Africa (SA). A cross-sectional research design was used to recruit a sample (n = 500) of individuals seeking HIV testing. Self-report measures were used to assess two-week prevalence of SIB as well as life-time prevalence of suicide attempt. A structured clinical interview was used to assess common mental disorders (CMDs). Regression analysis was used to determine if CMD and socio-demographic variables predicted suicidal ideation. The mean age of the sample was 36 years, 51.6% were female and 46.6% were unemployed. The two-week prevalence of suicidal ideation was 24.27% while the two-week prevalence of suicide attempt and suicide plans was 2.8%. Suicidal ideation was not associated with age, gender, employment status, family income or household food insecurity. CMDs were significantly associated with suicidal ideation; individuals with depressive disorders were approximately 5.5 times more likely to report suicidal ideation, while those with generalised anxiety disorder, trauma-related disorders and alcohol use disorder were approximately 7, 4.7 and 2.8 times more likely to report suicidal ideation, respectively. Results suggest that persons seeking HIV testing may be a well-delineated group of persons at risk of suicide in this region of SA. Contact with the health care system during HIV testing provides an opportunity for targeted suicide prevention interventions in what appears to be a high risk group.

  10. Correlates of male involvement in maternal and newborn health: a cross-sectional study of men in a peri-urban region of Myanmar.

    Science.gov (United States)

    Ampt, Frances; Mon, Myo Myo; Than, Kyu Kyu; Khin, May May; Agius, Paul A; Morgan, Christopher; Davis, Jessica; Luchters, Stanley

    2015-05-27

    Evidence suggests that increasing male involvement in maternal and newborn health (MNH) may improve MNH outcomes. However, male involvement is difficult to measure, and further research is necessary to understand the barriers and enablers for men to engage in MNH, and to define target groups for interventions. Using data from a peri-urban township in Myanmar, this study aimed to construct appropriate indicators of male involvement in MNH, and assess sociodemographic, knowledge and attitude correlates of involvement. A cross-sectional study of married men with one or more children aged up to one year was conducted in 2012. Structured questionnaires measured participants' involvement in MNH, and their sociodemographic characteristics, knowledge and attitudes. An ordinal measure of male involvement was constructed describing the subject's participation across five areas of MNH, giving a score of 1-4. Proportional-odds regression models were developed to determine correlates of male involvement. A total of 210 men participated in the survey, of which 203 provided complete data. Most men reported involvement level scores of either 2 or 3 (64 %), with 13 % reporting the highest level (score of 4). Involvement in MNH was positively associated with wives' level of education (AOR = 3.4; 95 % CI: 1.9-6.2; p MNH (AOR = 1.2; 95 % CI: 1.1-1.3; p MNH. The composite index proved a useful summary measure of involvement; however, it may have masked differential determinants of the summed indicators. There is a need for greater understanding of the influence of gender attitudes on male involvement in Myanmar and more robust indicators that capture these gender dynamics for use both in Myanmar and globally.

  11. Infant Development at the Age of 6 Months in Relation to Feeding Practices, Iron Status, and Growth in a Peri-Urban Community of South Africa.

    Science.gov (United States)

    Rothman, Marinel; Faber, Mieke; Covic, Namukolo; Matsungo, Tonderayi M; Cockeran, Marike; Kvalsvig, Jane D; Smuts, Cornelius M

    2018-01-12

    Evidence on the association between feeding practices, iron deficiency, anaemia, stunting, and impaired psychomotor development during infancy is limited. This study assessed the association between psychomotor development with early feeding practices, growth, iron status, and anaemia. This was cross-sectional baseline data of a randomised controlled trial which included 6-month-old infants and their mothers or primary caregivers ( n = 750) in a peri-urban community in the North West province of South Africa. The Kilifi Developmental Inventory and a parent rating scale were used to assess psychomotor development. Feeding practices and anthropometric measurements were based on the World Health Organisation (WHO) guidelines. Anaemia and iron status were determined by blood sample analysis. Prevalence of anaemia and stunting for the infants were 36.4% and 28.5%, respectively. Multiple regression analysis showed that birth weight was related to combined psychomotor scores ( β = -3.427 (-4.603, 1.891), p psychomotor scores ( β = -1.419 (-2.466, 0.373), p = 0.008), as well as parent rating scores ( β = -0.747 (-1.483, -0.010), p = 0.047). In this setting, with high prevalence of anaemia and stunting, important associations between lower psychomotor development scores and birthweight as well as length-for-age z -scores in 6-month-old infants were found. These findings warrant further investigation to develop a greater understanding of factors influencing the association between child growth and psychomotor development within the first 1000 days of life.

  12. Identification of human intestinal parasites affecting an asymptomatic peri-urban Argentinian population using multi-parallel quantitative real-time polymerase chain reaction.

    Science.gov (United States)

    Cimino, Rubén O; Jeun, Rebecca; Juarez, Marisa; Cajal, Pamela S; Vargas, Paola; Echazú, Adriana; Bryan, Patricia E; Nasser, Julio; Krolewiecki, Alejandro; Mejia, Rojelio

    2015-07-17

    In resource-limited countries, stool microscopy is the diagnostic test of choice for intestinal parasites (soil-transmitted helminths and/or intestinal protozoa). However, sensitivity and specificity is low. Improved diagnosis of intestinal parasites is especially important for accurate measurements of prevalence and intensity of infections in endemic areas. The study was carried out in Orán, Argentina. A total of 99 stool samples from a local surveillance campaign were analyzed by concentration microscopy and McMaster egg counting technique compared to the analysis by multi-parallel quantitative real-time polymerase chain reaction (qPCR). This study compared the performance of qPCR assay and stool microscopy for 8 common intestinal parasites that infect humans including the helminths Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Trichuris trichiura, and the protozoa Giardia lamblia, Cryptosporidium parvum/hominis, and Entamoeba histolytica, and investigated the prevalence of polyparasitism in an endemic area. qPCR showed higher detection rates for all parasites as compared to stool microscopy except T. trichiura. Species-specific primers and probes were able to distinguish between A. duodenale (19.1%) and N. americanus (36.4%) infections. There were 48.6% of subjects co-infected with both hookworms, and a significant increase in hookworm DNA for A. duodenale versus N. americanus (119.6 fg/μL: 0.63 fg/μL, P parasites in an endemic area that has improved diagnostic accuracy compared to stool microscopy. This first time use of multi-parallel qPCR in Argentina has demonstrated the high prevalence of intestinal parasites in a peri-urban area. These results will contribute to more accurate epidemiological survey, refined treatment strategies on a public scale, and better health outcomes in endemic settings.

  13. The association between domestic animal presence and ownership and household drinking water contamination among peri-urban communities of Kisumu, Kenya.

    Science.gov (United States)

    Barnes, Amber N; Anderson, John D; Mumma, Jane; Mahmud, Zahid Hayat; Cumming, Oliver

    2018-01-01

    Household drinking water can be contaminated by diarrheagenic enteropathogens at numerous points between the source and actual consumption. Interventions to prevent this contamination have focused on preventing exposure to human waste through interventions to improve drinking water, sanitation and hygiene (WASH). In many cases though, the infectious agent may be of zoonotic rather than human origin suggesting that unsafely managed animal waste may contribute to the contamination of household drinking water and the associated diarrheal disease burden. A cross-sectional household survey of 800 households was conducted across three informal peri-urban neighborhoods of Kisumu, Kenya, collecting stored drinking water samples, administering a household survey including water, sanitation and hygiene infrastructure and behaviors, and recording domestic animal presence and ownership. We used multivariate logistic regression to assess the association of traditional WASH factors and domestic animal presence and ownership on microbial contamination of household drinking water. The majority of households sampled had fecally contaminated drinking water (67%), defined by the presence of any colony forming units of the fecal indicator bacteria enterococci. After adjustment for potential confounders, including socio-economic status and water and sanitation access, both household animal ownership (aOR 1.31; CI 1.00-1.73, p = 0.05) and the presence of animal waste in the household compound (aOR 1.38; CI 1.01, 1.89, p = 0.04) were found to be significantly associated with household drinking water contamination. None of the conventional WASH variables were found to be significantly associated with household drinking water contamination in the study population. Water, sanitation, and hygiene strategies to reduce diarrheal disease should consider the promotion of safe animal contact alongside more traditional interventions focusing on the management of human waste. Future research on

  14. Socio-economic and ecological transformations of the peri-urban region of Gurgaon: an analysis of the trickle-down effect in the post globalization era

    Science.gov (United States)

    Yadav, A.; Punia, M.

    2014-11-01

    Economic processes are a manifestation of dynamic complex interdependent array of factors which involves resources, technology and an acting innovative human mind. Production, growth and development are the processes which has vast number of complex drivers, determinants and factors. Innovation, research, diffusion and dissemination are vital instrument of the economic processes of production, which are part of education. Whereas ecological transformations can be corroborated and analyzed by integrating remote sensing based information related to expansion of built-up area beyond city boundaries, extending to peripheries. City reflect economic, environmental, technological and social processes in their change, yet all are in turn profoundly driven by the urban spatial expansion. Metropolitan cities reflects expansion of existing urban and peri-urban areas with a significant socio-ecological transformation in terms of employment, education, and work force participation and land use changes. From the point of view of New Economic Geography (NEG) Theory 2009, the growth dynamic of metros is influenced by their proximity and dependence to a metropolis and the probable spillover effect. Entry point of discussion is the change in production of space in the post globalization era. It attempts to understand city morphology by using remote sensing datasets of LISS IV, IRS-P6 of 5.8 m spatial resolution for 2008 and 2013 and used Gurgaon Municipal Corporation's (GMC) ward boundary to represent socio-political meaning of this expansion and ways of life within the suburb. To understand how city works, detailed analysis related occupational structure, education and informality of ward 31 of Gurgaon and two villages namely Behlpa, Fazalwas and ward 11 of Nuh ( Mewat) along with the village Gabsanpur is attempted as the spatial units of study.

  15. Predictors of inconsistent condom use among a hard to reach population of young women with multiple sexual partners in peri-urban South Africa.

    Directory of Open Access Journals (Sweden)

    Yanga Z Zembe

    Full Text Available Evidence suggests that multiple concurrent sexual partnering may be a key driver of the high HIV prevalence among young women in South Africa. However, little is known about whether and to what extent women who have multiple sexual partners also engage in other high risk sexual behaviors such as inconsistent condom use. And yet, multiple concurrent sexual partnering is of little epidemiological relevance if all partners in these sexual networks use condoms consistently. This study assesses the prevalence of sexual risk behaviors and HIV, and predictors of inconsistent condom use among women aged 16-24 with multiple sexual partners in a peri-urban setting in South Africa.We used Respondent Driven Sampling, a sampling strategy for hard-to-reach populations to recruit 259 women aged 16-24 in a bio-behavioral cross-sectional survey in the Western Cape province. Estimates of population proportions and 95% confidence intervals (CIs were calculated using the Respondent-Driven Sampling Analysis Tool 5.6 (RDSAT. The primary outcome was inconsistent condom use in the past three months.Young women reported an average of 7 partners in the past 3 months and a high prevalence of sexual risk behaviors: concurrency (87%, transactional sex (91% and age mixing (59%. Having >5 sexual partners in the last 3 months doubled the risk of unprotected sex (OR 2.43, CI 1.39-4.25. HIV prevalence was 4% among 16-19 year olds, increasing threefold (12% at age 20-24.Multiple sexual partnering, where a high number of partners are acquired in a short space of time, is a fertile context for unprotected and risky sexual behavior. The young women featured in this survey present with a constellation of high-risk sexual behaviors that cluster to form a risk syndrome. Carefully tailored repeat bio-behavioral surveillance surveys are recommended for this sub-population.

  16. Spatiotemporal variability of hydrologic soil properties and the implications for overland flow and land management in a peri-urban Mediterranean catchment

    Science.gov (United States)

    Ferreira, C. S. S.; Walsh, R. P. D.; Steenhuis, T. S.; Shakesby, R. A.; Nunes, J. P. N.; Coelho, C. O. A.; Ferreira, A. J. D.

    2015-06-01

    Planning of semi-urban developments is often hindered by a lack of knowledge on how changes in land-use affect catchment hydrological response. The temporal and spatial patterns of overland flow source areas and their connectivity in the landscape, particularly in a seasonal climate, remain comparatively poorly understood. This study investigates seasonal variations in factors influencing runoff response to rainfall in a peri-urban catchment in Portugal characterized by a mosaic of landscape units and a humid Mediterranean climate. Variations in surface soil moisture, hydrophobicity and infiltration capacity were measured in six different landscape units (defined by land-use on either sandstone or limestone) in nine monitoring campaigns at key times over a one-year period. Spatiotemporal patterns in overland flow mechanisms were found. Infiltration-excess overland flow was generated in rainfalls during the dry summer season in woodland on both sandstone and limestone and on agricultural soils on limestone due probably in large part to soil hydrophobicity. In wet periods, saturation overland flow occurred on urban and agricultural soils located in valley bottoms and on shallow soils upslope. Topography, water table rise and soil depth determined the location and extent of saturated areas. Overland flow generated in upslope source areas potentially can infiltrate in other landscape units downslope where infiltration capacity exceeds rainfall intensity. Hydrophilic urban and agricultural-sandstone soils were characterized by increased infiltration capacity during dry periods, while forest soils provided potential sinks for overland flow when hydrophilic in the winter wet season. Identifying the spatial and temporal variability of overland flow sources and sinks is an important step in understanding and modeling flow connectivity and catchment hydrologic response. Such information is important for land managers in order to improve urban planning to minimize flood risk.

  17. Influence of cooling water discharges from Kaiga Nuclear Power Plant on aquatic ecology of the Kadra reservoir

    International Nuclear Information System (INIS)

    Ghosh, T.K.; Zargar, S.; Kulkarni, A.V.

    2007-01-01

    The alterations induced in the ambient temperature can lead to wide manifestations in species distribution and community structure. In general, elevated water temperature causes changes in species composition, species dominance, standing crop and productivity of biota including phytoplankton communities in any aquatic ecosystem. Thus warm water discharges from power plants into the receiving water bodies may adversely affect aquatic ecology. In the absence of exhaustive data on the response of aquatic organisms and ecosystems in the tropics to elevated temperatures, the only option is to draw inferences, from the experiences in the subtropical and temperature areas. Since, sufficient data on similar line are not available in tropical environment, present paper delineates certain aspects of aquatic ecology of the Kadra reservoir where cooling water is discharged. The study suggests the heated effluents from Kaiga Nuclear Power plant caused changes in dissolved oxygen and pH of water, heterotrophic bacterial population, sediment biogeochemical cycles related biochemical processes, species composition, species dominance, standing crop and productivity of biota including phytoplankton communities within 500 m from End of Discharge Canal point of Kadra reservoir when two units are running in full capacity. (author)

  18. On the Relationship between Aquatic Plant Stem Characteristics and Drag Force: Is a Modeling Application Possible?

    Directory of Open Access Journals (Sweden)

    Anna Maria Łoboda

    2018-04-01

    Full Text Available This paper presents a basic model that shows the relationship between the diameter of a stem and its flexural rigidity. The model was developed from experimental measurements of biomechanical traits (i.e., tensile and bending traits like maximum forces, stresses, moduli of elasticity, flexural rigidity, strain of three freshwater macrophyte species (Elodea canadensis Michx., Potamogeton pectinatus L., and P. crispus L., reflecting the seasonal changes in plant biomechanics throughout the vegetative season. These were obtained with the use of a bench-top testing machine in 2016 and 2017. The presented calculations are based on the ratio of drag-to-bending forces, in which the flexural rigidity plays a key role. The proposed model has the form EI = adb, and two approaches based on a regression analysis were applied to determine the parameters of the model—a and b. In the first method, the parameters were identified separately for each day of measurement, while in the second method, the coefficient b was calculated for all data from all days as a unified number for individual plants. The results suggest that coefficient b may provide information about the proportion of changes in drag forces depending on plant stiffness. The values of this coefficient were associated with the shape of the stem cross-section. The more circular the cross-section, the closer the value of the parameter was to 1. The parameter values were 1.60 for E. canadensis, 1.98 for P. pectinatus, and 2.46 for P. crispus. Moreover, this value also depended on the density of the cross-section structure. Most of the results showed that with an increase in stem diameter, the ratio between the drag and bending forces decreased, which led to fewer differences between these two forces. The model application may be introduced in many laboratory measurements of flow–biota interactions as well as in aquatic plant management applications. The implementation of these results in control

  19. Physiological Integration Affects Expansion of an Amphibious Clonal Plant from Terrestrial to Cu-Polluted Aquatic Environments

    Science.gov (United States)

    Xu, Liang; Zhou, Zhen-Feng

    2017-03-01

    The effects of physiological integration on clonal plants growing in aquatic and terrestrial habitats have been extensively studied, but little is known about the role in the extension of amphibious clonal plants in the heterogeneous aquatic-terrestrial ecotones, especially when the water environments are polluted by heavy metals. Ramets of the amphibious clonal herb Alternanthera philoxeroides were rooted in unpolluted soil and polluted water at three concentrations of Cu. The extension of populations from unpolluted terrestrial to polluted aqueous environments mainly relied on stem elongation rather than production of new ramets. The absorbed Cu in the ramets growing in polluted water could be spread horizontally to other ramets in unpolluted soil via physiological integration and redistributed in different organs. The performances of ramets in both terrestrial and aquatic habitats were negatively correlated with Cu intensities in different organs of plants. It is concluded that physiological integration might lessen the fitness of connected ramets in heterogeneously polluted environments. The mechanical strength of the stems decreased with increasing Cu levels, especially in polluted water. We suggest that, except for direct toxicity to growth and expansion, heavy metal pollution might also increase the mechanical risk in breaking failure of plants.

  20. Impact of Temperature and Nutrients on Carbon: Nutrient Tissue Stoichiometry of Submerged Aquatic Plants: An Experiment and Meta-Analysis

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    Mandy Velthuis

    2017-05-01

    Full Text Available Human activity is currently changing our environment rapidly, with predicted temperature increases of 1–5°C over the coming century and increased nitrogen and phosphorus inputs in aquatic ecosystems. In the shallow parts of these ecosystems, submerged aquatic plants enhance water clarity by resource competition with phytoplankton, provide habitat, and serve as a food source for other organisms. The carbon:nutrient stoichiometry of submerged aquatic plants can be affected by changes in both temperature and nutrient availability. We hypothesized that elevated temperature leads to higher carbon:nutrient ratios through enhanced nutrient-use efficiency, while nutrient addition leads to lower carbon:nutrient ratios by the luxurious uptake of nutrients. We addressed these hypotheses with an experimental and a meta-analytical approach. We performed a full-factorial microcosm experiment with the freshwater plant Elodea nuttallii grown at 10, 15, 20, and 25°C on sediment consisting of pond soil/sand mixtures with 100, 50, 25, and 12.5% pond soil. To address the effect of climatic warming and nutrient addition on the carbon:nutrient stoichiometry of submerged freshwater and marine plants we performed a meta-analysis on experimental studies that elevated temperature and/or added nutrients (nitrogen and phosphorus. In the microcosm experiment, C:N ratios of Elodea nuttallii decreased with increasing temperature, and this effect was most pronounced at intermediate nutrient availability. Furthermore, higher nutrient availability led to decreased aboveground C:P ratios. In the meta-analysis, nutrient addition led to a 25, 22, and 16% reduction in aboveground C:N and C:P ratios and belowground C:N ratios, accompanied with increased N content. No consistent effect of elevated temperature on plant stoichiometry could be observed, as very few studies were found on this topic and contrasting results were reported. We conclude that while nutrient addition

  1. Aquatic vascular plants as handicraft: a case study in southern Brazil

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    Mabel R. Báez-Lizarazo

    2017-11-01

    Full Text Available ABSTRACT This study aimed to evaluate knowledge about and the usage and importance of aquatic vascular plants (AVPs in the production of handicrafts by communities on the north coast of the state of Rio Grande do Sul in southern Brazil. The snowball technique was employed to locate people who use and have knowledge regarding the use of AVPs for handicrafts. Data were collected through semi-structured interviews and guided tours with 35 interviewees who were involved in artisanal activity at the time of the study. The data were analyzed using the importance value (IV index and the consensus value for the forms of use (CMU. The Spearman correlation test (rs was employed to determine the correlations of each social variable with the knowledge variables, and Mann-Whitney U tests to verify whether men and women exhibited differences in knowledge. The interviewees cited 16 AVPs that were employed in 17 types of handicrafts, among which the four main species were Schoenoplectus californicus, Typha domingensis, T. latifolia and Androtrichum giganteum. Interviewee age, residence time on site and time working with handicrafts were the main social parameters that described the level of knowledge and use of AVPs. These AVPs reflect cultural knowledge and complement family incomes.

  2. Use of the aquatic plant Elodea canadensis to assess toxicity and genotoxicity of Yenisei River sediments.

    Science.gov (United States)

    Zotina, Tatiana A; Trofimova, Elena A; Medvedeva, Marina Yu; Dementyev, Dmitry V; Bolsunovsky, Alexander Ya

    2015-10-01

    The toxicity, cytotoxicity, and genotoxicity of bulk sediments from the Yenisei River (Siberia, Russia) were estimated in laboratory bioassays based on several endpoints in the aquatic plant Elodea canadensis. The bottom sediment samples were collected in the Yenisei River upstream and downstream of the sources of chemical and radioactive contamination. The testing revealed different sensitivities of Elodea endpoints to the quality of the bottom sediment: weight of shoots Elodea) was the highest in sediments with chemical pollution, whereas the highest inhibition of toxicity endpoints (shoot and root length) occurred in sediments with the highest level of radioactive pollution. The extreme response of Elodea endpoints to the quality of certain sediment samples may be regarded as related to the possible presence of unknown toxicants. The results show that E. canadensis can be used as an indicator species in laboratory contact testing of bottom sediment. The responses of shoot and root length growth endpoints of Elodea can be recommended as basic sensitivity indicators of bottom sediment toxicity. Analysis of cells carrying abnormal chromosomes in the apical root meristem of Elodea can be performed optionally in the same test to assess the genotoxicity of sediments. © 2015 SETAC.

  3. Mitigating arsenic contamination in rice plants with an aquatic fern, Marsilea minuta.

    Science.gov (United States)

    Hassi, Ummehani; Hossain, Md Tawhid; Huq, S M Imamul

    2017-10-10

    Dangers of arsenic contamination are well known in human civilization. The threat increases when arsenic is accumulated in food and livestock through irrigated crops or animal food. Hence, it is important to mitigate the effects of arsenic as much as possible. This paper discusses a process for reducing the level of arsenic in different parts of rice plants with an aquatic fern, Marsilea minuta L. A pot experiment was done to study the possibility of using Marsilea minuta as a phytoremediator of arsenic. Rice and Marsilea minuta were allowed to grow together in soils. As a control, Marsilea minuta was also cultured alone in the presence and absence of arsenic (applied at 1 mg/L as irrigation water). We did not find any significant change in the growth of rice due to the association of Marsilea minuta, though it showed a reduction of approximately 58.64% arsenic accumulation in the roots of rice grown with the association of fern compared to that grown without fern. We measured a bioaccumulation factor (BF) of > 5.34, indicating that Marsilea minuta could be a good phytoremediator of arsenic in rice fields.

  4. Performance of aquatic plant species for phytoremediation of arsenic-contaminated water

    Science.gov (United States)

    Jasrotia, Shivakshi; Kansal, Arun; Mehra, Aradhana

    2017-05-01

    This study investigates the effectiveness of aquatic macrophyte and microphyte for phytoremediation of water bodies contaminated with high arsenic concentration. Water hyacinth ( Eichhornia crassipes) and two algae ( Chlorodesmis sp. and Cladophora sp.) found near arsenic-enriched water bodies were used to determine their tolerance toward arsenic and their effectiveness to uptake arsenic thereby reducing organic pollution in arsenic-enriched wastewater of different concentrations. Parameters like pH, chemical oxygen demand (COD), and arsenic concentration were monitored. The pH of wastewater during the course of phytoremediation remained constant in the range of 7.3-8.4, whereas COD reduced by 50-65 % in a period of 15 days. Cladophora sp. was found to survive up to an arsenic concentration of 6 mg/L, whereas water hyacinth and Chlorodesmis sp. could survive up to arsenic concentrations of 2 and 4 mg/L, respectively. It was also found that during a retention period of 10 days under ambient temperature conditions, Cladophora sp. could bring down arsenic concentration from 6 to arsenic by 40-50 %; whereas, water hyacinth could reduce arsenic by only 20 %. Cladophora sp. is thus suitable for co-treatment of sewage and arsenic-enriched brine in an algal pond having a retention time of 10 days. The identified plant species provides a simple and cost-effective method for application in rural areas affected with arsenic problem. The treated water can be used for irrigation.

  5. Concentration and distribution of 14C in aquatic environment around Qinshan nuclear power plant

    International Nuclear Information System (INIS)

    Wang Zhongtang; Guo Qiuju; Hu Dan; Xu Hong

    2015-01-01

    In order to study the concentration and distribution of 14 C in aquatic environment in the vicinity of Qinshan Nuclear Power Plant (NPP) after twenty years' operation, an apparatus extracting dissolved inorganic carbon from water was set up and applied to pretreat the water samples collected around Qinshan NPP. The 14 C concentration was measured by accelerator mass spectrometer (AMS). The results show that the 14 C specific activities in surface seawater samples range from 196.8 to 206.5 Bq/kg 203.4 ± 5.6) Bq/kg in average), which are close to the background. The 14 C concentrations in cooling water discharged from Qinshan NPP are close to the 14 C values in near shore seawater samples out of liquid radioactive effluent discharge period. It can be further concluded that the 14 C discharged previously is diluted and diffused well, and no 14 C enrichment in seawater is found. Also, no obvious increment in the 14 C specific activities of surface water and underground water samples are found between Qinshan NPP region and the reference region. (authors)

  6. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India.

    Science.gov (United States)

    Jha, V N; Tripathi, R M; Sethy, N K; Sahoo, S K

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r=0.86, puranium concentration in plant and the substrate (r=0.88, puranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (puranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. [Spatial and seasonal characterization of the drinking water from various sources in a peri-urban town of Salta].

    Science.gov (United States)

    Rodriguez-Alvarez, María S; Moraña, Liliana B; Salusso, María M; Seghezzo, Lucas

    Drinking water monitoring plans are important to characterize both treated and untreated water used for drinking purposes. Access to drinking water increased in recent years as a response to the Millennium Development Goals set for 2015. The new Sustainable Development Goals aim to ensure universal access to safe drinking water by 2030. Within the framework of these global goals, it is crucial to monitor local drinking water systems. In this paper, treated and untreated water from different sources currently consumed in a specific town in Salta, northern Argentina, was thoroughly assessed. Monitoring extended along several seasons and included the physical, chemical and microbiological variables recommended by the Argentine Food Code. On the one hand, treated water mostly complies with these standards, with some non-compliances detected during the rainy season. Untreated water, on the other hand, never meets microbiological standards and is unfit for human consumption. Monitoring seems essential to detect anomalies and help guarantee a constant provision of safe drinking water. New treatment plants are urgently needed to expand the water grid to the entire population. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  8. Impact on the aquatic environment of hydro-peaking in hydroelectric plants

    International Nuclear Information System (INIS)

    Sabaton, C.; Lauters, F.; Valentin, S.

    1996-01-01

    There are a number of types of hydroelectric installations on French rivers. Some of these intermittently turbine water stored in dammed reservoirs, in order to use available reserves at the most opportune moment for power generation. These plants, run under 'hydro-peaking' management procedures, cause variations in discharge in river sections downstream of the restitution, on a daily or weekly scale. To answer questions concerning the impact of such variations in discharge on the aquatic environment, EDF launched a research program aimed at describing and better understanding the physical and biological phenomena related to hydro-peaking and assessing the possible impact of this type of plant management on French streams. Seven sites subjects to hydro-peaking were studied on rivers with mean flow rates lower than 20 m 3 /s (which corresponds to over 65 % of EDF hydro-peaking sites). Four themes in particular were examined: hydraulic characterization of hydro-peaking, modifications in thermal regime and water quality, response of benthic invertebrates and response of fish populations to hydro-peaking. For fish as well as for invertebrates, the role of the base discharge - in the absence of peaking flow - and that of the morphology of the river bed (and, in particular, the presence of shelter for fish) during periods of strong discharge were clearly highlighted. Impact assessment requires a precise diagnosis of the state of biocenoses. To carry out such a diagnosis, one must reason in terms of species, life phase (particularly the most sensitive phases) and population structure as well as the type of stream and the faunizone involved. A risk assessment is possible by means of simultaneous study of the morphology of the river bed and the response of the signal generated by hydro-peaking in terms of hydrology and physical characteristics downstream of the restitution. (authors)

  9. Investigation on concentration of elements in wetland sediments and aquatic plants

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    H. Janadeleh

    2016-01-01

    Full Text Available The major aim of the present study was to investigate element (Fe, Ni, Pb, V, Zn concentrations in sediment and different tissues of Phragmities australis and Typha latifolia in Hor al-Azim Wetland Southwest Iran. Sampling of sediments and aquatic plants was carried out during spring and summer 2014. Results showed that the mean  concentrations of elements in Phragmities australis  in root and stem-leaf were as follows: Iron:4448 mg/kg, Nickel: 28 mg/kg, Lead:8 mg/kg, Vanadium:10 mg/kg  and Zinc 15.5 mg/kg in root and: Fe:645 mg/kg, Ni:15 mg/kg, Pb:4 mg/kg, V:4 mg/kg and Zinc 16 mg/kg respectively. Also, the mean concentrations of Fe, Ni, Pb, V and Zn in roots of Typha latifolia were 8696 mg/kg, 34 mg/kg, 5 mg/kg, 19 mg/kg and 27 mg/kg respectively. The mean concentrations of Fe, Ni, V, Pb, Zn in stem-leaves of Typha latifolia were as follows: 321 mg/kg, 3 mg/kg, 7 mg/kg, 2 mg/kg and 14 mg/kg respectively. The mean concentrations of Fe, Ni, V, Pb and zinc were as: 40991 mg/kg, 65 mg/kg, 60 mg/kg, 31 mg/kg, 60 mg/kg respectively in surface sediment of study area. Concentration pattern of elements in sediment were as: Fe>Ni>Zn>V>Pb. The highest concentration of elements in the plant was seen in the roots. Also, Typha latifolia can uptake more concentration of elements than Phragmities australis. Based on the enrichment factor, Ni in summer had the highest EF values among the elements studied and it has a moderate enrichment.

  10. Algal and aquatic plant carbon concentrating mechanisms in relation to environmental change.

    Science.gov (United States)

    Raven, John A; Giordano, Mario; Beardall, John; Maberly, Stephen C

    2011-09-01

    species with or without CCMs. The information available permits less predictive power as to the effect of the forcing factors on CCM expression than for their overall effects on growth. CCMs are currently not part of models as to how global environmental change has altered, and is likely to further alter, algal and aquatic plant primary productivity.

  11. Monitoring and assessment of mercury pollution in the vicinity of a chloralkali plant. IV. Bioconcentration of mercury in in situ aquatic and terrestrial plants at Ganjam, India.

    Science.gov (United States)

    Lenka, M; Panda, K K; Panda, B B

    1992-02-01

    In situ aquatic and terrestrial plants including a few vegetable and crop plants growing in and around a chloralkali plant at Ganjam, India were analyzed for concentrations of root and shoot mercury. The aquatic plants found to bioconcentrate mercury to different degrees included Marsilea spp., Spirodela polyrhiza, Jussiea repens, Paspalum scrobiculatam, Pistia stratiotes, Eichhornia crassipes, Hygrophila schulli, Monochoria hastata and Bacopa monniera. Among wild terrestrial plants Chloris barbata, Cynodon dactylon, Cyperus rotundus and Croton bonplandianum were found growing on heavily contaminated soil containing mercury as high as 557 mg/kg. Analysis of mercury in root and shoot of these plants in relation to the mercury levels in soil indicated a significant correlation between soil and plant mercury with the exception of C. bonplandianum. Furthermore, the tolerance to mercury toxicity was highest with C. barbata followed by C. dactylon and C. rotundus, in that order. The rice plants analyzed from the surrounding agricultural fields did not show any significant levels of bioconcentrated mercury. Of the different vegetables grown in a contaminated kitchen garden with mercury level at 8.91 mg/kg, the two leafy vegetables, namely cabbage (Brassica oleracea) and amaranthus (Amaranthus oleraceous), were found to bioconcentrate mercury at statistically significant levels. The overall study indicates that the mercury pollution is very much localized to the specific sites in the vicinity of the chloralkali plant.

  12. Biodigestion of the aquatics plants mixtures and biogas production; Biodigestao de misturas de plantas aquaticas e producao de biogas

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Roberto Guimaraes; Abreu, Fernando Luiz Barbuda de; Fernandes Filho, Jorge; Pereira, Maria Cristina Duarte Eiras [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica. Programa de Pos-Graduacao em Engenharia Mecanica]. E-mail: temrobe@vm.uff.br; Melo, Ricardo Bichara de [Light Servicos de Eletricidade S.A., Rio de Janeiro, RJ (Brazil). Gerencia de Estudos e Gestao de Geracao]. E-mail: rbmelo@light.com.br

    2004-07-01

    Several systems of generating electricity using water storage reservoirs. One problem that occurs constantly in these reservoirs is the accumulation of aquatic plants, such as Eichhornia crassipes, Eichhornia azurea, Pistia stratiotes and Salvinia that may cause serious problems for the system. Periodically, the biomass must be removed and disposed of appropriate form, so that does not cause contamination of soil, groundwater or allowing the proliferation of vectors. One possible destination is the use of biomass in a process of biodigestion, resulting in biogas. The bench of biodigester used in the experiment of biodigestion of aquatic plants is composed of a reactor containing the biomass, where the biogas is produced and a reservoir for the monitoring the production of biogas. The reactor is located inside a container containing water that can be heated by an electrical resistance, with the aim of maintaining the temperature inside the reactor around 35 deg C. The results of analysis of gas of the reactor was obtained using a gas chromatograph to CG MASTER of double ionization detector with a flame and thermal conductivity. These results show a percentage of 50% of methane in the biogas. Also, were analyzed the biomass in the biodigester for determination of humidity, total organic matter, waste mineral and organic carbon. The process of biodigestion of the mixture of aquatic plants: Eichhornia crassipes, Eichhornia azurea and Pistia stratiotes and Salvinia shows potential for obtaining biogas, with considerable levels of methane, in order to facilitate its recovery.

  13. Roles for root iron plaque in sequestration and uptake of heavy metals and metalloids in aquatic and wetland plants.

    Science.gov (United States)

    Tripathi, Rudra D; Tripathi, Preeti; Dwivedi, Sanjay; Kumar, Amit; Mishra, Aradhana; Chauhan, Puneet S; Norton, Gareth J; Nautiyal, Chandra S

    2014-10-01

    Toxic metal(loid) contamination of soil and sediment poses long term risk to soil and human health through plant-human or plant-animal-human food chain pathways. Iron plaque (IP) formation is frequent in aquatic and wetland plant species and is responsible for the sequestration of various metal(loids). The presence of IP may act as a buffer or barrier and may thus enhance or reduce the uptake of potentially phytotoxic metals and metalloids by plants. If IP acts as a barrier, then low IP producing macrophytes/aquatic plants may be better accumulators of toxic metals and may find use in constructed wetlands for remediation of pollutants, while high IP forming edible plant species could be safer for human consumption. Conversely, if IP acts as a buffer for mineral nutrients and toxic elements then those cultivars may be rich in nutrients, but may also cause toxicity. However, an ecotoxicological risk is also inevitable if IP rich macrophyte roots containing heavy metals are consumed by herbivores. In this review, we summarize the current understanding about the role of IP in metal and metalloid sequestration, uptake, and transport. Furthermore, we will address the role of root IP in Oryza sativa for arsenic (As) sequestration leading to lower grain As translocation, reducing the risk of human exposure.

  14. Density-dependent reproductive and vegetative allocation in the aquatic plant Pistia stratiotes (Araceae

    Directory of Open Access Journals (Sweden)

    Flávia Freitas Coelho

    2005-09-01

    Full Text Available Pistia stratiotes is an aquatic macrophyte that grows in temporary-ponds in the southern Pantanal, Brazil. It reproduces both sexually and asexually and is usually observed forming dense mats on the water surface, a condition favored by the plant’s vegetative reproduction coupled with an ability for rapid growth. In this study we examined the effect of densely crowded conditions on the production of reproductive and vegetative structures. In addition, we verified whether there is a trade-off between clonal growth and investment in sexual reproductive structures, and whether there is an allocation pattern with plant size. Individual plant biomass and the number of the rosettes producing sexual reproductive structures and vegetative growth structures both increased with density. Increase in plant size resulted in increased proportional allocation to sexual reproductive structures and vegetative growth structures. Allocation of biomass to reproduction did not occur at the expense of clonal growth. Thus, the density response appears as a increase of rosettes producing sexual reproductive structures and vegetative growth structures. Therefore, long leaves and stolons may be adaptive under densely crowded conditions where competition for light is intense. An important aspect in the study of trade-offs is the size-dependency of the allocation patterns .Usually, larger plants produce more biomass. Therefore, larger plants can allocate more biomass to both vegetative and sexual reproduction than smaller plants and thus show a positive correlation between both traits rather than the expected negative one. Rev. Biol. Trop. 53(3-4: 369-376. Epub 2005 Oct 3.Pistias strariotes es una macrófita acuática que crece en charcas estacionales en el Pantanal sureño de Brasil. Se reproduce tanto sexual como asexualmente y se obsrva generalmente que forma densas parches sobre la superficie del agua, una condicion que favorecida por la reproduccion vegetativa de la

  15. THE ABILITY OF LEAVES AND RHIZOMES OF AQUATIC PLANTS TO ACCUMULATE MACRO- AND MICRONUTRIENTS

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    Agnieszka Edyta Parzych

    2015-06-01

    Full Text Available The samples of macrophytes and bottom sediments originated from the littoral zone of the Słupia River were collected in summer 2013. The aim of this study was to compare the properties of the accumulation of leaves and rhizomes of Glyceria maxima, Phragmites australis, Typha latifolia and Phalaris arundinacea for macro- and micronutrients. The largest quantities of macroelements were found in the leaves of the examined species, and microelements dominated the rhizomes of most examined macrophytes except for Mn in P.australis and T.latifolia. The obtained results show that N and K dominated in the leaves of P.arundinacea, P and Mg in the leaves of P.australis, and Ca in the leaves of G.maxima. The largest quantities of N, P and K were cumulated in the rhizomes of P.arundinacea, while Mg and Ca in the rhizome of T.latifolia. The leaves of aquatic plants accumulated from 1354.9 mmolc·kg-1 (T.latifolia to 1844.0 mmolc·kg-1 (P.arundinacea, and rhizomes from 985.8 mmolc·kg-1 (G.maxima to 1335.2 mmolc·kg-1 (P.arundinacea of all the analyzed components. In these species of macrophytes lower accumulated value of the sum of macro- and microelements were found in the rhizomes. The share of nitrogen was 42.4–59.8% of this amount, phosphorus 4.3–8.6%, potassium 22.8–35.1%, calcium from 2,6% to 12.4%, magnesium 3.0–7.5%, and heavy metals were from 0.6% (G.maxima to 1.2% (T.latifolia in leaves and from 2.2% (T.latifolia to 8.7% (G.maxima in rhizomes.

  16. Genome size as a key to evolutionary complex aquatic plants: polyploidy and hybridization in Callitriche (Plantaginaceae.

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    Jan Prančl

    Full Text Available Despite their complex evolutionary histories, aquatic plants are highly underrepresented in contemporary biosystematic studies. Of them, the genus Callitriche is particularly interesting because of such evolutionary features as wide variation in chromosome numbers and pollination systems. However, taxonomic difficulties have prevented broader investigation of this genus. In this study we applied flow cytometry to Callitriche for the first time in order to gain an insight into evolutionary processes and genome size differentiation in the genus. Flow cytometry complemented by confirmation of chromosome counts was applied to an extensive dataset of 1077 Callitriche individuals from 495 localities in 11 European countries and the USA. Genome size was determined for 12 taxa. The results suggest that many important processes have interacted in the evolution of the genus, including polyploidization and hybridization. Incongruence between genome size and ploidy level, intraspecific variation in genome size, formation of autotriploid and hybridization between species with different pollination systems were also detected. Hybridization takes place particularly in the diploid-tetraploid complex C. cophocarpa-C. platycarpa, for which the triploid hybrids were frequently recorded in the area of co-occurrence of its parents. A hitherto unknown hybrid (probably C. hamulata × C. cophocarpa with a unique chromosome number was discovered in the Czech Republic. However, hybridization occurs very rarely among most of the studied species. The main ecological preferences were also compared among the taxa collected. Although Callitriche taxa often grow in mixed populations, the ecological preferences of individual species are distinctly different in some cases. Anyway, flow cytometry is a very efficient method for taxonomic delimitation, determination and investigation of Callitriche species, and is even able to distinguish homoploid taxa and identify introduced

  17. Inelastic hyperspectral lidar for aquatic ecosystems monitoring and landscape plant scanning test

    Science.gov (United States)

    Zhao, Guangyu; Malmqvist, Elin; Rydhmer, Klas; Strand, Alfred; Bianco, Giuseppe; Hansson, Lars-Anders; Svanberg, Sune; Brydegaard, Mikkel

    2018-04-01

    We have developed an aquatic inelastic hyperspectral lidar with unrestricted focal-depth and enough sensitivity and spatio-temporal resolution to detect and resolve position and behavior of individual sub-millimeter aquatic organisms. We demonstrate ranging with monitoring of elastic echoes, water Raman signals and fluorescence from chlorophyllbearing phytoplankton and dye tagged organisms. The system is based on a blue CW diode laser and a Scheimpflug optical arrangement.

  18. Inelastic hyperspectral lidar for aquatic ecosystems monitoring and landscape plant scanning test

    Directory of Open Access Journals (Sweden)

    Zhao Guangyu

    2018-01-01

    Full Text Available We have developed an aquatic inelastic hyperspectral lidar with unrestricted focal-depth and enough sensitivity and spatio-temporal resolution to detect and resolve position and behavior of individual sub-millimeter aquatic organisms. We demonstrate ranging with monitoring of elastic echoes, water Raman signals and fluorescence from chlorophyllbearing phytoplankton and dye tagged organisms. The system is based on a blue CW diode laser and a Scheimpflug optical arrangement.

  19. The association between domestic animal presence and ownership and household drinking water contamination among peri-urban communities of Kisumu, Kenya

    Science.gov (United States)

    Mumma, Jane; Mahmud, Zahid Hayat

    2018-01-01

    Introduction Household drinking water can be contaminated by diarrheagenic enteropathogens at numerous points between the source and actual consumption. Interventions to prevent this contamination have focused on preventing exposure to human waste through interventions to improve drinking water, sanitation and hygiene (WASH). In many cases though, the infectious agent may be of zoonotic rather than human origin suggesting that unsafely managed animal waste may contribute to the contamination of household drinking water and the associated diarrheal disease burden. Methods A cross-sectional household survey of 800 households was conducted across three informal peri-urban neighborhoods of Kisumu, Kenya, collecting stored drinking water samples, administering a household survey including water, sanitation and hygiene infrastructure and behaviors, and recording domestic animal presence and ownership. We used multivariate logistic regression to assess the association of traditional WASH factors and domestic animal presence and ownership on microbial contamination of household drinking water. Results The majority of households sampled had fecally contaminated drinking water (67%), defined by the presence of any colony forming units of the fecal indicator bacteria enterococci. After adjustment for potential confounders, including socio-economic status and water and sanitation access, both household animal ownership (aOR 1.31; CI 1.00–1.73, p = 0.05) and the presence of animal waste in the household compound (aOR 1.38; CI 1.01, 1.89, p = 0.04) were found to be significantly associated with household drinking water contamination. None of the conventional WASH variables were found to be significantly associated with household drinking water contamination in the study population. Conclusions Water, sanitation, and hygiene strategies to reduce diarrheal disease should consider the promotion of safe animal contact alongside more traditional interventions focusing on the

  20. Longitudinal analysis of antibody responses in symptomatic malaria cases do not mirror parasite transmission in peri-urban area of Cote d'Ivoire between 2010 and 2013.

    Directory of Open Access Journals (Sweden)

    David Koffi

    Full Text Available In the agenda towards malaria eradication, assessment of both malaria exposure and efficacy of anti-vectorial and therapeutic strategies is a key component of management and the follow-up of field interventions. The simultaneous use of several antigens (Ags as serological markers has the potential for accurate evaluation of malaria exposure. Here we aimed to measure the longitudinal evolution of the background levels of immunity in an urban setting in confirmed clinical cases of malaria.A retrospective serological cross-sectional study on was carried out using 234 samples taken from 2010 to 2013 in peri-urban sentinel facility of Cote d'Ivoire. Antibody responses to recombinant proteins or BSA-peptides, 8 Plasmodium falciparum (PfAMA1, PfMSP4, PfMSP1, PfEMP1-DBL1α1-PF13, PfLSA1-41, PfLSA3-NR2, PfGLURP and PfCSP, one P. malariae (PmCSP and one Anopheles gambiae salivary (gSG6-P1 antigens were measured using magnetic bead-based multiplex immunoassay (MBA. Total anti- P. falciparum IgG responses against schizont lysate from african 07/03 strain (adapted to culture and 3D7 strain was measured by ELISA.High prevalence (7-93% and levels of antibody responses to most of the antigens were evidenced. However, analysis showed only marginal decreasing trend of Ab responses from 2010 to 2013 that did not parallel the reduction of clinical malaria prevalence following the implementation of intervention in this area. There was a significant inverse correlation between Ab responses and parasitaemia (P<10-3, rho = 0.3. The particular recruitment of asymptomatic individuals in 2011 underlined a high background level of immunity almost equivalent to symptomatic patients, possibly obscuring observable yearly variations.The use of cross-sectional clinical malaria surveys and MBA can help to identify endemic sites where control measures have unequal impact providing relevant information about population immunity and possible decrease of transmission. However, when

  1. Effects of different thinning systems on the economic value of ecosystem services: A case-study in a black pine peri-urban forest in Central Italy

    Directory of Open Access Journals (Sweden)

    Alessandro Paletto

    2017-12-01

    Full Text Available Sustainable Forest Management (SFM should be able to produce an optimal level of bundle of Ecosystem Services (ES, thus ensuring more resilient forest ecosystems also creating benefits for local population and human well-being. Yet, choosing between alternative forest management practices is not straightforward as it necessarily involves ES trade-offs. Forest management decisions have to reconcile the socio-economic and ecological contributions of forest ecosystems by fostering a synergistic relation between multiple ES while lowering ES trade-offs. The aim of the study is to analyze different forest management practices (selective and traditional thinning in black pine peri-urban forest in Central Italy, by investigating their contribution in terms of provisioning (wood production, cultural (recreational benefits, regulating (climate change mitigation ES. For each management option was performed: (1 the biophysical assessment of selected ES by using primary data and calculating indicators for wood production with special regard to biomass for energy use (living trees and deadwood volume harvested, recreational benefits (tourists’ preferences for each forest management practice, climate change mitigation (carbon sequestration in above-ground and below-ground biomass, and (2 the economic valuation of wood production, recreational benefits and climate change mitigation ES using direct and indirect methods (environmental evaluation techniques. The results show that the effects of the selective thinning on ES is higher that the effects of the traditional thinning. The economic value of the three ES provided by traditional and selective thinning are respectively: bioenergy production 154.2 € ha-1 yr-1 and 223.3 € ha-1 yr-1; recreational benefits 193.2 € ha-1 yr-1 and 231.9 € ha-1 yr-1; carbon sequestration 29.0 € ha-1 yr-1and 36.2 € ha-1 yr-1. The integrated (biophysical and economic assessment of ES in addition to the trade

  2. Influence of aquatic plants on the predation of Piaractus mesopotamicus larvae by Pantala flavescens - doi: 10.4025/actascibiolsci.v32i2.5167 Influence of aquatic plants on the predation of Piaractus mesopotamicus larvae by Pantala flavescens - doi: 10.4025/actascibiolsci.v32i2.5167

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Bento Fernandes

    2010-05-01

    Full Text Available The experiment aimed to study the influence of the aquatic plants E. najas, P. stratiotes and S. auriculata on the predation of P. mesopotamicus larvae by P. flavescens. One hundred and twenty larvae of P. mesopotamicus and 24 larvae of P. flavescens were placed in 24 aquariums with capacity of 12 L, with one Odonate per aquarium. Treatments were different regarding the species of aquatic plants E. najas, S. auriculata and P. stratiotes, with one control treatment without aquatic plants. One aquarium (12 L containing one Odonate and 30 P. mesopotamicus larvae was considered one experimental unit. After 18 hours, the Odonates were removed from the aquariums and fish larvae left (alive were counted in each experimental unit. The survival rate of P. mesopotamicus larvae in the treatment without aquatic plants (control was significantly lower than in the treatment with E. najas. However, the survival rates in the aquariums with floating aquatic plants did not differ from the control. The morphological characteristics of E. najas promoted higher structural complexity in the environment, offering more protection to the fish larvae, and increasing their survival. We concluded that the presence of the submerged aquatic plant E. najas promoted the reduction of predation of P. mesopotamicus larvae by Pantala flavescens. Larvae; Piaractus mesopotamicus; Pantala flavescens; predation; aquatic plantsThe experiment aimed to study the influence of the aquatic plants E. najas, P. stratiotes and S. auriculata on the predation of P. mesopotamicus larvae by P. flavescens. One hundred and twenty larvae of P. mesopotamicus and 24 larvae of P. flavescens were placed in 24 aquariums with capacity of 12 L, with one Odonate per aquarium. Treatments were different regarding the species of aquatic plants E. najas, S. auriculata and P. stratiotes, with one control treatment without aquatic plants. One aquarium (12 L containing one Odonate and 30 P. mesopotamicus larvae was

  3. Preliminary assessment of the aquatic impacts of a proposed defense waste processing facility at the Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Mackey, H.E. Jr.

    1979-01-01

    A review of the literature indicates that a significant body of descriptive information exists concerning the aquatic ecology of Upper Three Runs Creek and Four Mile Creek of the Savannah River Plant south of Aiken, South Carolina. This information is adequate for preparation of an environmental document evaluating these streams. These streams will be impacted by construction and operation of a proposed Defense Waste Processing Facility for solidification of high level defense waste. Potential impacts include (1) construction runoff, erosion, and siltation, (2) effluents from a chemical and industrial waste treatment facility, and (3) radionuclide releases. In order to better evaluate potential impacts, recommend mitigation methods, and comply with NEPA requirements, additional quantitative biological information should be obtained through implementation of an aquatic baseline program.

  4. Preliminary assessment of the aquatic impacts of a proposed defense waste processing facility at the Savannah River Plant

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.

    1979-01-01

    A review of the literature indicates that a significant body of descriptive information exists concerning the aquatic ecology of Upper Three Runs Creek and Four Mile Creek of the Savannah River Plant south of Aiken, South Carolina. This information is adequate for preparation of an environmental document evaluating these streams. These streams will be impacted by construction and operation of a proposed Defense Waste Processing Facility for solidification of high level defense waste. Potential impacts include (1) construction runoff, erosion, and siltation, (2) effluents from a chemical and industrial waste treatment facility, and (3) radionuclide releases. In order to better evaluate potential impacts, recommend mitigation methods, and comply with NEPA requirements, additional quantitative biological information should be obtained through implementation of an aquatic baseline program

  5. Distribution of C, N, P in aquatic plants of some lakes in the middle of Yangtze river

    International Nuclear Information System (INIS)

    Huang Liang; Wu Ying; Zhou Juzhen; Zhang Jing; Li Wei

    2003-01-01

    By analyzing three elements (C, N, P, 13 C) in the ten aquatic plants of nine lakes in the middle of Yangtze River, the concentrations of C, N and δ 13 C in leaves of aquatic macrophytes depend on the environment where they live in. The concentration of C and N in leaves of submerged macrophytes is significantly lower than that of leaves of floating and emergent macrophytes because of limitation of inorganic carbon; And at the same time, because δ 13 C of inorganic carbon in water is higher than that of CO 2 in air, δ 13 C of leaves of submerged macrophytes is higher than that of leaves of floating and emergent macrophytes. (authors)

  6. An Assessment of the Food and Nutrition Security Status of Weaned 7-12 Months Old Children in Rural and Peri-Urban Communities of Gauteng and Limpopo Provinces, South Africa.

    Science.gov (United States)

    Ntila, Sithandiwe; Siwela, Muthulisi; Kolanisi, Unathi; Abdelgadir, Hafiz; Ndhlala, Ashwell

    2017-09-01

    This study assessed the food and nutrition security status of children receiving complementary food in rural and peri-urban communities. A group of 106 mothers from Lebowakgomo village and Hammanskraal Township, respectively, participated in the survey. Additionally, six focus group discussions were conducted per study area to assess the mothers' perceptions about children's food access. The Children's Food Insecurity Access Scale (CFIAS) was used to assess the food security status (access) of the children. The Individual Dietary Diversity Score (IDDS) together with the unquantified food consumption frequency survey were used as a proxy measure of the nutritional quality of the children's diets. The age and weight of the children obtained from the children's clinic health cards were used to calculate Weight-for-Age Z scores (WAZ) in order to determine the prevalence of underweight children. The findings showed that a large percentage of children were severely food-insecure, 87% and 78%, in rural and peri-urban areas, respectively. Additionally, Lebowakgomo children (23.6%) and Hammanskraal children (17.9%) were severely underweight. Overall, children's diets in both study areas was characterized by nutrient-deficient complementary foods. Cheaper foods with a longer stomach-filling effect such as white maize meal and sugar were the most commonly purchased and used. Hence, the children consumed very limited amounts of foods rich in proteins, minerals, and vitamins, which significantly increased the risk of their being malnourished.

  7. Evaluating bio environmental effects of Bushehr Nuclear Power Plant on water and aquatic organism of Persian Gulf

    International Nuclear Information System (INIS)

    Ayatti, F.

    2000-01-01

    The operation of nuclear power plants is always subjected to emission of some radioactive materials in the form of gaseous, liquids and solids in the environment. The heat from condenser coolant discharged to the sea can have some adverse effects on biological systems as thermal pollution. In this project, the radiation and thermal effects on Bushehr Nuclear Power Plants on aquatic animals in Persian Gulf were studied. The mathematical models for atmospheric dispersion of pollutant and pathways of radioactive materials from air to sea water and from sea to animals and human bodies were considered. some environmental samples from Persian Gulf were measured for radioactivity using high-purity Ge/Li detectors and Gamma-spectroscopy. The results indicates that the erection of B usher Nuclear Power Plants and its operation in the normal operation can have no adverse effects on environment, and also its thermal pollution is of no importance due to low area for coolant discharges

  8. Can sacrificial feeding areas protect aquatic plants from herbivore grazing? Using behavioural ecology to inform wildlife management.

    Directory of Open Access Journals (Sweden)

    Kevin A Wood

    Full Text Available Effective wildlife management is needed for conservation, economic and human well-being objectives. However, traditional population control methods are frequently ineffective, unpopular with stakeholders, may affect non-target species, and can be both expensive and impractical to implement. New methods which address these issues and offer effective wildlife management are required. We used an individual-based model to predict the efficacy of a sacrificial feeding area in preventing grazing damage by mute swans (Cygnus olor to adjacent river vegetation of high conservation and economic value. The accuracy of model predictions was assessed by a comparison with observed field data, whilst prediction robustness was evaluated using a sensitivity analysis. We used repeated simulations to evaluate how the efficacy of the sacrificial feeding area was regulated by (i food quantity, (ii food quality, and (iii the functional response of the forager. Our model gave accurate predictions of aquatic plant biomass, carrying capacity, swan mortality, swan foraging effort, and river use. Our model predicted that increased sacrificial feeding area food quantity and quality would prevent the depletion of aquatic plant biomass by swans. When the functional response for vegetation in the sacrificial feeding area was increased, the food quantity and quality in the sacrificial feeding area required to protect adjacent aquatic plants were reduced. Our study demonstrates how the insights of behavioural ecology can be used to inform wildlife management. The principles that underpin our model predictions are likely to be valid across a range of different resource-consumer interactions, emphasising the generality of our approach to the evaluation of strategies for resolving wildlife management problems.

  9. Behavior of sartans (antihypertensive drugs) in wastewater treatment plants, their occurrence and risk for the aquatic environment.

    Science.gov (United States)

    Bayer, Anne; Asner, Robert; Schüssler, Walter; Kopf, Willi; Weiß, Klaus; Sengl, Manfred; Letzel, Marion

    2014-09-01

    Pharmaceuticals and other anthropogenic trace contaminants reach wastewaters and are often not satisfactorily eliminated in sewage treatment plants. These contaminants and/or their degradation products may reach surface waters, thus influencing aquatic life. In this study, the behavior of five different antihypertonic pharmaceuticals from the sartan group (candesartan, eprosartan, irbesartan, olmesartan and valsartan) is investigated in lab-scale sewage plants. The elimination of the substances with related structures varied broadly from 17 % for olmesartan up to 96 % for valsartan. Monitoring data for these drugs in wastewater effluents of six different sewage treatment plants (STPs) in Bavaria, and at eight rivers, showed median concentrations for, e.g. valsartan of 1.1 and 0.13 μg L(-1), respectively. Predicted environmental concentrations (PEC) were calculated and are mostly consistent with the measured environmental concentrations (MEC). The selected sartans and the mixture of the five sartans showed no ecotoxic effects on aquatic organisms in relevant concentrations. Nevertheless, the occurrence of pharmaceuticals in the environment should be reduced to minimize the risk of their distribution in surface waters, ground waters and bank filtrates used for drinking water.

  10. Preliminary comparison of the uptake of chromium-51 and zinc-65 by three species of aquatic plants from Louisiana

    International Nuclear Information System (INIS)

    Sklar, F.H.

    1980-01-01

    Accumulation of radionuclides was much greater for duckweed (Spirodela punctata) than for larger aquatic plants of slower growth (Bacopa caroliniana and Elodea canadensis). Higher specific activity (dpm/gm) was recorded in leaves than in stems. Chromium-51 accumulation factors ranged from a low of 66 for stems of E. canadensis to a high of 436 for S. punctata fronds. Zinc-65 accumulation factors were much higher: 142 for stems of B. caroliniana and 18,118 for fronds of S. punctata. Significant reductions in zinc-65 activity in the water surrounding growing S. punctata was detected within 10 minutes

  11. Physical model of a floating trash boom to control aquatic weeds at the TVA Widows Creek Fossil Plant

    International Nuclear Information System (INIS)

    Hopping, P.N.

    1991-01-01

    This paper reports that the Tennessee Valley Authority (TVA) Widows Creek Fossil plant seasonally encounters adverse accumulations of aquatic weeds at the intakes of the condenser cooling water pumps. To reduce the accumulations, a floating trash boom has been proposed for the intakes. To evaluate the hydraulic feasibility of a boom, a physical model of the intakes has been built at the TVA Engineering Laboratory. The model was used to determine the boom alignment and depth of skimming needed to successfully deflect weeds away from the intakes and provide self-cleaning

  12. 77 FR 49601 - Endangered and Threatened Wildlife and Plants; Endangered Status for Six West Texas Aquatic...

    Science.gov (United States)

    2012-08-16

    ... critical habitat for six west Texas aquatic invertebrate species under the Endangered Species Act. These... their habitat under the Endangered Species Act. DATES: We will accept comments received or postmarked on... Pecos County, Texas. Why we need to publish a rule. Under the Endangered Species Act, a species may...

  13. Vegetation development following stream/river restoration: more natural fluvial dynamics and morphology, return of aquatic and riparian plant species?

    Science.gov (United States)

    Soons, M. B.

    2012-04-01

    After centuries of human interventions in stream/river dynamics and morphology aimed at optimizing landscapes for agricultural and industrial purposes, new insights have inspired water managers to try and combine stream and river ecosystem functions with the conservation of biodiversity. Around the world, aquatic and riparian species have declined strongly due to pollution, destruction and fragmentation of their habitat, so that biodiversity conservation initiatives primarily focus on habitat restoration. In the past decades many stream and river restoration projects have been carried out and often hydrological dynamics and morphology have been restored to a more natural state. However, the successful restoration of aquatic and riparian habitats very often failed to result in restoration of their biodiversity. This lack of success from a biodiversity conservation perspective is usually attributed to 'dispersal limitation', meaning that the habitat may be restored, but species fail to reach the site and re-colonize it. Especially re-colonization by aquatic and riparian plant species is important, as such species function as ecosystem engineers: their presence alters fluvial dynamics and morphology, generates additional habitat heterogeneity and provides habitat and food for animal species. Following minor disturbances, re-colonization is often possible through locally remaining populations, by seeds in the seed bank or by surviving plant fragments. However, following major disturbances, colonization and establishment from other source populations are necessary. This usually occurs through dispersal of seeds (and in more aquatic species also by dispersal of vegetative fragments) into the restored wetland area. As dispersal occurs predominantly over short distances and source populations of aquatic and riparian species may be lacking in the surroundings, dispersal may be a limiting factor in the development of aquatic and riparian vegetation at a restored site. But

  14. Enhancing the performance of cut-and-carry based dairy production in selected peri-urban areas of the United Republic of Tanzania through strategic feed supplementation

    International Nuclear Information System (INIS)

    Nkya, R.; Kessy, B.M.; Shem, M.N.; Mwanga, I.E.

    2002-01-01

    A survey was conducted in 81 smallholder farms in the peri-urban areas of Morogoro (Site I: n=52) and Dar es Salaam (Site II: n=29). The results showed that food supply was insufficient and of poor quality resulting in the poor performance of cows. In order to investigate the effect of farm-formulated concentrate (FC) or urea-molasses multinutrient-blocks (UMMB) in improving the productive and reproductive performance of dairy cattle, two feeding trials were carried out in 56 farms, 48 at Site I and 8 at Site II. The cost:benefit analysis determined their suitability for incorporation in dry season feeding. The FC was given to 14 farms at Site I (n=37 cows) to be incorporated in the diet of cows at the rate of 0.8 kg per litre of milk produced. The UMMB was tested in 18 farms (14 at Site I and 4 at Site II), fed to 27 cows (18 in Site I and 9 in Site II) at approximately 0.7 - 1.0 kg per cow per day. The Control group comprised of 14 farms (10 at Site I and 4 at Site II) with 28 cows (20 at Site I and 8 at Site II). The supplements were introduced to the farms after successful on-station trials for acceptability by dairy cows. Chemical composition and in sacco rumen degradability of the major feeds showed low CP content and degradability. Supplementation of forage with FC and UMMB was associated with increased milk production of 1.26 and 1.5 litres per cow/day and BCS and body weight changes of 0.2 and 4 kg and 0.25 and 8 kg, respectively. The improvement in milk yield, BCS and body weight change were significantly different in the UMMB supplemented cows (P 0.05), and the control groups. Both supplementation strategies had no significant effect on reproductive performance. However, there was a slight reduction in the number of days postpartum (DPP) to first progesterone rise (65.3 vs 77.6), DPP to conception oestrus (120.2 vs 128.7), and calving interval (400 vs 414.5 days) in the UMMB supplemented cows compared to non-supplemented control animals. Conception rate

  15. INTERGROWTH-21st Gestational Dating and Fetal and Newborn Growth Standards in Peri-Urban Nairobi, Kenya: Quasi-Experimental Implementation Study Protocol.

    Science.gov (United States)

    Millar, Kathryn; Patel, Suha; Munson, Meghan; Vesel, Linda; Subbiah, Shalini; Jones, Rachel M; Little, Sarah; Papageorghiou, Aris T; Villar, Jose; Wegner, Mary Nell; Pearson, Nick; Muigai, Faith; Ongeti, Catherine; Langer, Ana

    2018-06-22

    The burden of preterm birth, fetal growth impairment, and associated neonatal deaths disproportionately falls on low- and middle-income countries where modern obstetric tools are not available to date pregnancies and monitor fetal growth accurately. The INTERGROWTH-21 st gestational dating, fetal growth monitoring, and newborn size at birth standards make this possible. To scale up the INTERGROWTH-21 st standards, it is essential to assess the feasibility and acceptability of their implementation and their effect on clinical decision-making in a low-resource clinical setting. This study protocol describes a pre-post, quasi-experimental implementation study of the standards at Jacaranda Health, a maternity hospital in peri-urban Nairobi, Kenya. All women with viable fetuses receiving antenatal and delivery services, their resulting newborns, and the clinicians caring for them from March 2016 to March 2018 are included. The study comprises a 12-month preimplementation phase, a 12-month implementation phase, and a 5-month post-implementation phase to be completed in August 2018. Quantitative clinical and qualitative data collected during the preimplementation and implementation phases will be assessed. A clinician survey was administered eight months into the implementation phase, month 20 of the study. Implementation outcomes include quantitative and qualitative analyses of feasibility, acceptability, adoption, appropriateness, fidelity, and penetration of the standards. Clinical outcomes include appropriateness of referral and effect of the standards on clinical care and decision-making. Descriptive analyses will be conducted, and comparisons will be made between pre- and postimplementation outcomes. Qualitative data will be analyzed using thematic coding and compared across time. The study was approved by the Amref Ethics and Scientific Review Committee (Kenya) and the Harvard University Institutional Review Board. Study results will be shared with stakeholders

  16. A Survey of the Invasive Aquatic and Riparian Plants of the Low Rio Grande

    Science.gov (United States)

    2005-04-01

    many areas. In 2001 and 2003, surveys were conducted starting below Amistad Reservoir to immediately below Falcon Reservoir to assess the...River were surveyed from Amistad Reservoir to Anzulduas Dam for the presence of hydrilla and other invasive aquatic weed species (Grodowitz et al...to difficulties in accessing the river. During the 2001 survey, hydrilla was found in Amistad Reservoir and below Falcon Reservoir. In August 2002

  17. Does extensive agriculture influence the concentration of trace elements in the